This is the generic class for:
1. Inorganic Compounds
2. Nonmetallic Elements
3. Processes. .. (a) Processes of producing or separating by a chemical reaction a product a product of 1. or 2. supra, (b) chemical reaction processes not elsewhere provided for, (c) processes of separating or purifying a gaseous mixture including a chemical reaction and (d) processes which are directed to extracting, leaching or dissolving a product or 1. or 2. supra from a mixture either, per se, or in combination with steps not otherwise provided for and for dissolving of such a product to make a water solution thereof.
AMPLIFICATION OF CLASS SUBJECT MATTER
This class provides for what is generally termed the field of inorganic chemistry. It includes inorganic compounds, nonmetallic elements and processes of producing the same involving a chemical reaction. The products are generally in a relatively pure state but may be a mixture with no other utility than as a source material for an inorganic compound or element. This includes metal compound products useful in metallurgical processes of obtaining free metals (see Subclass References to the Current Class, below).
A mixture of an inorganic compound or nonmetallic element with a preserving agent whose sole function is to prevent physical or chemical change of such compound or element is provided for in this class, unless the mixture is disclosed or claimed as having a function or utility provided for in the composition classification (see Subclass References to the Current Class, below). Also, processes of merely incorporating a preservative are included in this class.
The rules for determining class placement of the original
reference (OR) for claimed chemical compositions are set forth in the class definition for compositions. See the (17) Note under LINES WITH OTHER CLASSES AND WITHIN THIS CLASS for additional information.
This class also provides for processes of separating or purifying a normally gaseous mixture by a chemical reaction, unless the resulting mixture has a disclosed utility provided for in the composition classification.
This class is also the residual class for all chemical reactions not provided for elsewhere, e.g., a reactive process where no specific product compound is disclosed.
For this class, the nonmetallic elements are: the halogens including astatine, the inert gases, hydrogen, boron, carbon, silicon, nitrogen, phosphorus, oxygen, sulfur, selenium and tellurium.
This class is also the class for extracting, leaching or dissolving processes not provided for elsewhere (see Subclass References to the Current Class, below).

LINES WITH OTHER CLASSES AND WITHIN THIS CLASS
(1) Note. An inorganic compound for this class must contain a nonmetallic element; intermetallic compounds, or union of metallic elements only are excluded and will be found in Class 420.
(2) Note. Subclasses which recite nitrogen or hydrogen in their titles do not include the ammonium radical (NH[subscrpt]4[end subscrpt][supscrpt]+[end supscrpt]) within their definitions; the NH[subscrpt]4[end subscrpt][supscrpt]+ [end supscrpt]radical is considered to be, and is treated as, an entity or element, equivalent to Na, Ca, N, etc.
(3) Note. When a radical is indicated in a subclass title, (e.g., sulfide, carbonate, phosphate, etc.), all forms thereof (i.e., the acid forms, such as HSO[subscrpt]3[end subscrpt][supscrpt]- [end supscrpt], HCO[subscrpt]3[end subscrpt][supscrpt]-[end supscrpt], HPO[subscrpt]4[end subscrpt][supscrpt]2-[end supscrpt], H[subscrpt]2[end subscrpt]PO[subscrpt]4[end subscrpt][supscrpt]-[end supscrpt]) are also included within the definition, unless specifically stated otherwise. Generally, however, in the metal recovery area, subclasses 1+, only the radicals listed in the titles are involved and no other. For example, in subclass 36, "sulfating" means that only the sulfate (SO[subscrpt]4[end subscrpt][supscrpt]2-[end supscrpt]) radical is intended. In the remaining areas of the schedule all forms of the radical are generally intended.
(4) Note. Use of a chemically reactive material, e.g., acid or base is considered to involve a chemical treatment for this class, unless there is evidence to the contrary or where otherwise stated, (see subclass 210, reference to Class 95,
for example).
(6) Note. Processes of purification which involve oxidation or chemical conversions of impurities, as well as those processes wherein the compound sought to be purified is first converted into some other form or derivative from which it is reverted to the original compound are also considered to be chemical treatment.
(7) Note. Processes of preparation of an inorganic compound or a nonmetallic element which include chemical treatment or preparation are classified in the appropriate compound or element subclass, unless a process subclass is specifically provided therefor under the compound or element subclass, even though combined with a purely physical operation precedent, subsequent, or both. However, a patent containing a claim to the product and a claim to the process of manufacture thereof, which process is indented under the product subclass, should be placed in the outdent (product subclass) and cross-referenced to the other. A claim to the product of making it is considered to be a product claim and should be classified in the appropriate product subclass and cross referenced to the process, if any.
(8) Note. Processes of preparation or treatment of inorganic compounds and nonmetallic elements which involve only physical treatment except for extracting, leaching or dissolving, per se, are classified in 23, Chemistry: Physical Processes, subclasses 293+ unless specifically provided for in some other main class. When extracting, leaching or dissolving processes are combined with significant crystallization steps, see Class 23, Chemistry: Physical Processes, subclasses 295+. Also see Class 23, Chemistry: Physical Processes, subclasses 293, 294 and 306 thru 308 for extracting, leaching or dissolving which may be combined with physical steps therein provided for. When patents include claims to a physical process and also claims to the compound or element treated, the original patent is classified in Class 423 in the appropriate subclass providing for the compound or element and cross-referenced to the appropriate process subclass in Class 23.
(9) Note. Varying the amount of water of crystallization or hydration is considered to involve a chemical reaction; merely changing from one crystalline form to another or from or to a non crystalline form is not considered to be a chemical reaction.
(10) Note. The combination of a nominal molding step and a chemical reaction is properly classified in Class 423. See definition of Class 264 for examples of "nominal" molding steps.
(11) Note. The combinations of a chemical reaction and magnetic separation is in Class 423.
(12) Note. A compound having water of hydration or
crystallization attached thereto is classified with the basic compound unless there is a specific subclass provided for the hydrated compound. In this respect, the water (H[subscrpt]2[end subscrpt]O) is treated as a unit and the hydrogen and oxygen therein of themselves do not cause classification in the oxygen area (579+) or the hydrogen area (644+).
(13) Note. A material or substance containing a metal or other element in a range of absolute values or mole ratios compared to another metal or other element, (e.g., 1.7-3.5 parts, mole ratio of M to X in the range of 1.1-3.7, etc.), will be considered proper for a composition class; if the metal or other element is present in specifically defined whole integer values, (e.g., 1, 2 or 3 parts, etc.), it will be considered a compound properly classified in Class 423. Similarly if atoms or molecules in a chemical formula are not present as whole small integer values or cannot be multiplied by a factor to yield integer values, then the substance represented by the formula will be considered to be a mixture or composition classifiable in a locus other than Class 423. However, see (1) Note in subclass 328 for exception to general rule stated above.
(14) Note. A water solution (whether preserved or not) of a Class 423 compound or element is classified in Class 423 unless its use is claimed or a single use is disclosed, in which case classification in the use class is indicated.
(15) Note. When a patent includes (1) a single claim directed to the formation of 2 or more desired products, or (2) plural, equally comprehensive claims defining processes or products wherein the individual claims would be classified in separate classes, the following rules apply: (1) As between Class 423 and other classes providing for compounds the patent is placed in Class 423. (2) As between Class 423 and Class 75 the patent is placed in Class 75. (3) As between Class 423 and classes providing for compositions, the patent is placed in the composition class.
(16) Note. Where a process includes a step of recovery of the energy in a fluid (e.g., expansion in a motor to produce mechanical or electrical power, use in a heat exchanger for utilization outside of the process, etc.) the intent of the patentee must be considered for proper classification. If the intent is to conduct the chemical reaction, make the product or purify a gas or separate a mixture as provided for in Class 423 and recovery of the energy in the fluid is simply for economic reasons the classification is proper for Class 423. If the intent of the chemical reaction, is to increase the energy level in the fluid for the purpose of producing the mechanical or electrical power, then classification in another main class is indicated. If the power produced is used in the process, e.g., pumping, refrigeration, heat exchange, etc. classification in Class 423 in proper.
(17) Note. The rules for determining Class placement of the
Original Reference (OR) for claimed chemical compositions are set forth in the Class Definition of Class 252 in the section LINES WITH OTHER CLASSES AND WITHIN THIS CLASS, subsection COMPOSITION CLASS SUPERIORITY, which includes a hierarchical ORDER OF SUPERIORITY FOR COMPOSITION CLASSES.

SEE OR SEARCH THIS CLASS, SUBCLASS:
1 for treating mixture to obtain metal containing compound (see the Class Definition, above).
265 .for products or processes comprising a compound or a nonmetallic element physically interrelated with another substance which serves to improve, protect or modify the product, which substance does not take part in the reaction, which makes the product, but is added to the reaction or to the product or is made by a separate and distinct reaction.
658.5 for extracting, leaching or dissolving processes.

REFERENCES TO OTHER CLASSES

SEE OR SEARCH CLASS:
23, Chemistry: Physical Processes, for processes of preparing or treating inorganic compounds or nonmetallic elements which involve only physical treatments except for extracting, leaching, or dissolving, per se, and not specifically provided for in some other class; for processes for analysis which involve a chemical reaction.
48, Gas: Heating and Illuminating, for processes for making heating and illuminating gas in general and processes and apparatus for purifying a heating and illuminating gas; processes involving a chemical reaction for making or purifying heating or illuminating gas consisting of a single element or organic compound, per se, are classified in Class 423.
53, Package Making, appropriate subclasses especially 428 for methods of manufacturing chemical compounds followed by a subsequent packaging step.
65, Glass Manufacturing, for a process or apparatus for chemically manufacturing silicon or silicon dioxide (arbitrarily considered to be glass for Class 65) combined with significant shaping or heat treating.
71, Chemistry: Fertilizers, appropriate subclasses for compositions, and processes of making such compositions, having a nutrient action on plant growth. See (1) Note in the definition of Class 71 and (13) Note and (15) Note in the definition of Class 423 for lines between these two classes.
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, the line with the Class 75,
Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, is generally as follows: Class 75 provides for metals and processes for their manufacture. Class 423 provides for chemically modifying metal bearing compositions to form intermederiary products which comprise inorganic compounds even if intended for subsequent reduction to free metals. When it is not clear from the claimed disclosure whether the product produced is an intermediary of a free metal, it is assumed to be intermediary. A smelting process is assumed to produce a free metal unless otherwise stated. Class 75 provides for ore beneficiating processes which claim a sintering or agglomerating step, even though the production of a free metal is not claimed, and compounding of ingredient to make a composition which is in better form for pyrometallurgy, even though some chemical reaction is involved. Patents including claims classifiable in Class 423 and equally comprehensive claims classifiable in Class 75 are classified in Class 75 and cross-referenced to Class 423. Processes resulting in the production or separation of undesired metallic material, e.g, impurities, during the manufacture of Class 423 compounds are classified in Class 423. If the metal is a desired material, however, the patent is classified in Class 75. See also the note to Class 420, Alloy or Metallic Composition below. As between Class 75 and Class 423, intermetallic compounds are in Class 75. Processes resulting in the production or separation of undesired metallic material, e.g., impurities, during the manufacture of Class 423 compounds are classified in Class 423. If the metal is a desired material, however, the patent is classified in Class 75.
95, Gas Separation: Processes, for processes of a purely physical nature involving steps resulting in separation of a gas from a fluid mixture comprising (a) a gas and solid or liquid particles entrained therein, (b) a liquid and gas entrained therein, or (c) a plurality of gases. For patents to be placed in Class 423, a particular chemical must be claimed and the chemical reaction must be inherent or disclosed. Broadly reciting the separating material as a "chemical" or as "gas purifying material" does not exclude the patent from Class 95. Absorption and adsorption are not considered chemical reactions in this respect. Processes for separating a gaseous fluid mixture having therein ammonia (NH[subscrpt]3[end subscrpt]) or acid anhydrides (e.g., CO[subscrpt]2[end subscrpt], SO[subscrpt]2[end subscrpt], etc.) by contacting the gaseous fluid mixture with water and thus dissolving these gases out of the gaseous fluid mixture are in Class 95, notwithstanding the fact that a chemical reaction occurs in the solution and that ammonium hydroxide or the acids are formed. See also, search class note to Class 95 in Class 423, subclass 210.
106, Compositions: Coating or Plastic, appropriate subclasses for coating or plastic compositions not otherwise provided for. For the line between Classes 106 and 423. In regard to materials and ingredients, e.g., pigments, see the
note to the definition of Class 106 under the heading "Materials or Ingredients". See also (13) Note and (15) Note in the definition of Class 423 and (4) Note in subclass 265 of that class.
117, Single-Crystal, Oriented-Crystal, and Epitaxy Growth Processes; Non-Coating Apparatus Therefor, for processes and non-coating apparatus for growing therein-defined single-crystal of all types of materials, including inorganic or organic.
134, Cleaning and Liquid Contact With Solids, appropriate subclasses, especially 2 for the process of treating a mixture to remove foreign matter from the surface. The line between this Class 134 and Class 423 is as follows: in Class 423 the intent is to recover a metal compound from a mixture thereof, while in Class 134, the intent is merely to clean the mixture, whether or not the removed foreign matter is later treated to recover valuable by-products.
148, Metal Treatment, for processes for making case hardened metals and the corresponding products (e.g., carbided or nitrided metals) in which a metal is treated so as to form the nitride or carbide of the metal in more or less as a layer thereon, but which layer varies in composition towards the inside, the intention being to form case hardened metal, not to form a definite compound for recovery thereof.
162, Paper Making and Fiber Liberation, appropriate subclasses for process of chemically preparing or recovering inorganic compound with a fiber liberation step, and especially 29 for processes of regenerating, for purposes of reusing, a fiber treating liquor, even though a compound or nonmetallic element for Class 423 is recovered. For the line between this Class 162 and Class 423 in regard to regeneration, the intent of the disclosure must be considered. If there is an intent to regenerate, reconstitute, reclaim or recycle the waste or used liquor being treated, whether or not a Class 423 product is recovered, classification is in Class 162.
201, Distillation: Processes, Thermolytic, appropriate subclasses for a process of carbonizing solid carbonaceous material, or for calcining coke to produce a coke or other impure carbon containing material, not otherwise provided for. A document having claims to both the process of coking and the additional steps of producing carbon black will be classified in Class 423 and cross referenced to Class 201.
203, Distillation: Processes, Separatory, for a process of separating a liquid mixture by vaporizing and condensing a portion thereof to isolate in the distillate or in the residue a relatively pure compound which was present as such in the original mixture, and for a process including a chemical reaction and a separatory distillation operation when the chemical reaction merely facilitates the isolation by the distillation process of a pre-existing substance in
the original mixture. Class 423, Inorganic Chemistry, takes a process of preparing a compound and isolating it by a separatory distillation process or vaporizing a mixture and contacting the vaporous mixture with a substance which purified the mixture and prepares a compound for that class.
204, Chemistry: Electrical and Wave Energy, for processes of producing an inorganic compound or nonmetallic element by directly employing electrical or wave energy. The general line between this Class 423, and Class 204 is as follows: Class 423 provides for (1) process steps falling within the definition of Class 204 wherein a simultaneous or subsequent chemical reaction takes place which modified the product of the Class 204 to produce a different compound or element, and (2) branching processes wherein one of the branches comprises a process falling within the definition of Class 204 and at least one branch falls within the definition of Class 423. Class 204 takes processes wherein an initial or preparatory reaction of the type provided for in Class 423 is followed by process step of the type provided for in Class 204 which modifies the product of the initial reaction. In processes where a useful by-product is formed, the patent is classified accordingly.
(1) Note. If electrolysis takes place in a reagent which immediately reacts with a product of the electrolysis to yield a Class 423 product, classification is proper for Class 423.
209, Classifying, Separating, and Assorting Solids, appropriate subclasses, for processes of separating a mixture of compounds by magnetic action. However, processes which include both a chemical reaction and a magnetic separation are classified in the appropriate chemical class, e.g., Class 423, etc.
210, Liquid Purification or Separation, for chemical processes where the main intent is to purify a liquid, not to purify or recover a compound or nonmetallic element for Class 423, in regard to treatment of an effluent or waste liquor, the intent of the disclosure must be considered. If it be the main intent to purify the effluent liquor for disposal, classification is in Class 210 even though a product for Class 423 is recovered as an incident to the purification. If the main intent is to treat the effluent to recover a Class 423 product then classification in Class 423 is indicated. If the disclosure contains both intentions and it cannot be determined which is the primary intention, then classification is in Class 423 with cross reference to Class 210 where necessary.
252, Compositions, appropriate subclasses, for compositions of matter not otherwise provided for. See the definitions of Class 252 for its scope and the notes thereto for classification of other compositions. See also (13) Note and (15) Note in the definition of Class 423.
260, Chemistry of Carbon Compounds, appropriate subclasses, for claimed chemical processes in which an organic compound is the end result, even though the intent is to make an inorganic compound from this organic intermediate. However, a process which results in several different chemical compounds, one of which is classifiable in Class 423 and another is classifiable in Class 260, is classified in Class 423 and cross referenced into Class 260, except where the compound classifiable in Class 423 is only incidentally produced by the reaction, such as, for example, HC1 and is not an objective of the process.
376, Induced Nuclear Reactions: Processes, Systems, and Elements for appropriate subclasses for changes in the chemical nature of materials brought about by nuclear reactions; and 156 and 323+ for production of materials, other than or in addition to the conversion of nuclear fuel, by means of nuclear reactions.
420, Alloys or Metallic Compositions, appropriate subclasses for alloys, intermetallic compounds or compounds or composition containing a continuous phase of metal and methods of making them. See the class definition of Class 420 for the line between Class 420 and Class 75 for processes fo making alloys.
422, Chemical Apparatus and Process Disinfecting, Deodorizing, Preserving, or Sterilizing, subclasses 1-44 for processes for disinfecting, deodorizing, preserving, or sterilizing. Inorganic compounds or nonmetallic elements claimed with an additive which only serves to preserve the product are in Class 423. See also the notes in Class 423, subclasses 265+ and subclasses 45+ for chemical reactors and apparatus for carrying out chemical physical processes.
424, Drug, Bio-Affecting and Body Treating Compositions, appropriate subclasses for a Class 423 product combined with an additive which is claimed or solely disclosed as having a Class 424 utility. A Class 423 product having combined therewith an additive which protects the product, itself against biological attack is proper for Class 423, see 265.
426, Food or Edible Material: Processes, Compositions, and Products, 160, for baking powder compositions, which in some cases are made to deliberately contain impurities to stabilize the same and to cause proper reaction rates. In many instances, the compound is calcium acid pyrophoshate and the impurity is a calcium or aluminum compound.
428, Stock Material or Miscellaneous Articles, appropriate subclasses, for metallic compounds having specific outer structure, especially 379 for a structurally defined or coated rod, strand, fiber or particle which may include a metal compound; subclasses 432 and 469+ for a non structural composite web or sheet including a layer of a metal compound.
429, Chemistry: Electrical Current Producing Apparatus, Product, and Process, 188 for electrolyte compositions; subclass 247 for materials used to make a battery separator; and other appropriate subclasses having compositions combined with structure.
432, Heating, 1, for a residual process of heating. The line between Classes 423 and 432 is generally as follows: Class 423 takes heating processes which involve a chemical reaction to produce an inorganic compound or nonmetallic element. Materials identified by, terms such as "lime", "limestone" and "gypsum", are considered to be compounds for Class 423, but terms such as "cement" and "clay" are not. Residual processes which do not include a chemical reaction or do not result in a compound are in Class 432. The terms "calcining", "burning", "removing water of hydration", etc. are considered to involve a chemical reaction.
435, Chemistry: Molecular Biology and Microbiology, for processes of making separating or purifying compounds or elements by operations that include fermentation, and compositions and apparatus that are specialized for use therein and processes of making such compositions for such use.
504, Plant Protecting and Regulating Compositions, appropriate subclasses for compositions, and processes of making such compositions, having a stimulating or regulating action on plant growth. See (13) Note and (15) Note in the definition of Class 423 for lines between these two classes.
505, Superconductor Technology: Apparatus, Material, Process, 100 for high temperature (T[subscrpt]c[end subscrpt] 30 K) superconducting materials, per se, or subclasses 300+ for processes of producing same.
585, Chemistry of Hydrocarbon Compounds, appropriate subclasses for a claimed chemical process to synthesize a hydrocarbon. When a process produces an inorganic compound for Class 423 and a hydrocarbon compound for Class 585, both of which are intended to be recovered, the patent is classified as an original in Class 423 and cross-referenced to Class 585.
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the process of destruction of hazardous or toxic waste by way of incineration heating or other chemical reactions when the destruction of the waste is the intended purpose, Class 423 takes all intended production or recovery of marketable products in the form of inorganic compounds or elements.

GLOSSARY:
Terms used throughout the schedule and definitions are to have the meanings ascribed below. In some instances all the limitations found below may not have been included in the
subclass definitions; all discrepancies should be resolved in favor of the following definitions.
ABSORPTION
The ability of a substance to retain or concentrate gases, liquids or dissolved substance (absorbate) within its bodies.
ADSORPTION
The ability of a substance (usually a solid) to retain or concentrate gases, liquids or dissolved substances (adsorbate) upon its surface.
ALKALI METALS
The metal elements of the first group of the periodic system, consisting of Li, Na, K, Rb, Cs.
ALKALINE EARTH METALS
The metal elements in Group II A of the periodic system, consisting of Mg, Ca, Sr, Ba.
BINARY COMPOUND
A chemical compound consisting of 2 elements only with 2 or more atoms; e.g., NaC1, FeC1[subscrpt]3[end subscrpt], Fe[subscrpt]3[end subscrpt]0[subscrpt]4[end subscrpt], etc.
CHALCOGEN
Also known as chalcogenide(s), the elements oxygen, sulfur, selenium, tellurium and polonium.
CATALYST
A substance which either increases or decreases the speed of a chemical reaction without itself undergoing a permanent change.
COMPLEX COMPOUND
A chemical combination of two or more compounds or ions; e.g., 4 KCN and Fe (Cn)[subscrpt]2[end subscrpt] give the complex compound K[subscrpt]4[end subscrpt]Fe (Cn)[subscrpt]6[end subscrpt]; 2 HF and Si F[subscrpt]4[end subscrpt]give the complex acid H[subscrpt]2[end subscrpt] Si F[subscrpt]6[end subscrpt]. An electrically charged radical or group of atoms, e.g., Cu (NH[subscrpt]3[end subscrpt]) [subscrpt]2[end subscrpt][supscrpt]+[end supscrpt], is a complex ion.
COMPOUND
The elements or compounds comprising a material or produced
from it by analysis.
COMPOUND
A substance whose molecules consist of unlike atoms, whose constituents cannot be separated by physical means, whose properties are entirely different from those of its constituent elements and which contains definite proportions of its constituent elements, depending on their atomic weights.
FLOTATION
A process for the concentration of selective separation of components of ores by grinding the ores with a frothing agent, floating them on water and agitating the mixture with compressed air, causing the wet gangue (earthy portion of the ore) to settle and permitting the concentrated ore to be skimmed off.
FLUIDIZED BED
A mass of solid particles maintained in a state of constant turbulent motion in a gas stream, resulting in a suspension of finely divided particles in a stream of gas thus increasing the surface area and therefor surface activity of the particles.
HALOGENS
Also known as halogenides, the nonmetallic elements of the seventh group of the periodic system and consisting of F, C1, Br, I, At.
INERT GASES
The noble gases of the zero group of the periodic system, consisting of He, Ne, Ar, Kr, Xe, Rn, which have no valency and combine only with great difficulty, if at all, with other elements.
ION EXCHANGE
A process in which ions are chemically transferred from a material to a liquid or solid separatory substance or exchanger which, because of its chemical structure of loosely bound ions, has an affinity for certain ions and gives up some of its own ions to the material. The exchange occurs between ions of like charge; the exchanger substance can usually be regenerated by passing another material through it to elute the previously sorbed ions and replace them with the original kind of loosely bound ions. These ion exchange substances are usually resins or zeolites or chelates.
IRON GROUP METALS
Those metals in the central part of the third period of the
periodic system consisting of Fe, Co and Ni, all of which form colored salts and 2 or more series of compounds.
LEACHING
The process of extracting or dissolving a soluble component from a mixture by contacting the mixture with a solvent, resulting in dissolution or solution of the solubles and leaving an insoluble material.
(Note. Solution of a substance in a normally solid, molten material is not considered to be "leaching" as defined above.)
LIQUID-LIQUID EXTRACTION
The process of transferring a substance (fluid or solid) from one liquid phase in which it is dispersed or dissolved to a second liquid phase which is immiscible with the first liquid.
NONMETALLIC ELEMENTS
The electronegative elements on the right of the periodic system, which generally exist in several stages of oxidation and whose oxides form acids. See main class definition for list of nonmetals for this class.
ORGANIC COMPOUND
A compound as defined in the definition of Class 260, Chemistry of Carbon Compounds as qualified by (34) Note.
PLATINUM METALS
A group of noble metals that occur together in nature and form 2 groups in the periodic system, i.e., Ru, Rh, Pd, Os, Ir and Pt.
PROMOTER
A substance which stimulates or aids the effect of a catalyst.
RADIOACTIVE
Able to give off rays by spontaneous disintegration. The radioactive elements are usually those having an atomic number of 84 or greater and the phenomenon of radioactivity is not affected by chemical or physical influences.
RARE EARTHS
The oxides of the rare earth metals consisting of the elements having atomic numbers 21, 39, 57-71, inclusive.
RECOVERY
The extraction or removal of a valuable constituent from a raw material, by-product or waste product.
REFRACTORY METALS
Those metals in Group IV B, V B and VIB of the periodic system, consisting of Ti, Zr, Hf, V, Nb, Ta, Cr, Mo and W, some of which are used in making bricks or cement which resist heat and are slow to soften.
TERNARY COMPOUND
A chemical compound consisting of 3 elements only, such as NaOH, H[subscrpt]2[end subscrpt]SO[subscrpt]4[end subscrpt], KCN, etc.
VOLATIZING
Converting a normally solid or liquid material into a gas or vapor state; mere volatization of water or a solvent is excluded under this definition.

This subclass is indented under the class definition. Processes wherein a mixture is chemically treated to obtain or recover a compound of a metal contained in the original mixture as an element, a compound or a precursor transmutable to the metal.
(1) Note. The chemical reaction need not involve the desired metal, it may be with another constituent of the mixture for easier separation of the desired compound.
(2) Note. The following are assumed to be mixtures unless otherwise specifically disclosed or stated: the slightly impure compound, ores, metalliferous materials, minerals, alloys, amalgams, scrap metal, clay, metals coated, plated or jacketed on other metals, or on other material, spent or waste liquors (regenerating, purifying or recovering from) limestone, flue dust, gypsum.
(3) Note. It must be the inventor's intent that a metal in compound form be obtained, but it is not necessary that this compound be separated from the mixture. For example, the process of changing Fe[subscrpt]2 [end subscrpt]O[subscrpt]3[end subscrpt]in ore to Fe[subscrpt]3 [end subscrpt]O[subscrpt]4[end subscrpt]by magnetic roasting in order to obtain a better form for smelting is properly classified in this group of subclasses (151+). Further the
initial or starting material must be considered in order to determine whether or not the claimed process is for isolating a metallic compound from a mixture. Where two compounds are first mixed together, as disclosed, and subsequent to a chemical reaction, a separation is made, classification of such a process is not in this group of subclasses even though the initial step of mixing is not claimed; such a patent may be classified in other areas of this class on other features. Also, where a mixture results from an intermediate step in a process for making a product and the mixture is separated, that is not considered as treating a mixture to obtain metal compounds for this group of subclasses.
(4) Note. Changing the form of a compound to render it less effective as an impurity or to make it nondetrimental is not considered to be recovery under this definition. Further, converting part of a mixture which is considered an impurity to the desired part is not considered to be recovery under this definition. For example converting the Na[subscrpt]2[end subscrpt]CO[subscrpt]3 [end subscrpt]in a mixture with Na[subscrpt]2[end subscrpt]S to Na[subscrpt]2[end subscrpt]S, therefore resulting in all Ma[subscrpt]2[end subscrpt]S, is not recovery.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, appropriate subclasses, for a process of (1) purifying mixtures and obtaining the free metal, (2) making agglomerates for metallurgical purposes, (3) smelting (which is assumed to result in the free metal unless otherwise specifically disclosed), (4) cementation of one metal on another, (5) deposition of a metal on another material (6) making an impure metal but in the elemental form. As between Classes 423 and 75, the claimed process which goes to the metallic compound indicates classification in Class 423, whether the purpose is to commercially use the compound or to later dissociate the compound to obtain the free metal, while the additional claimed step of yielding the free metal brings the claim to Class 75; in the situation where some of the claims recite the metal and others recite the metallic compound, the most comprehensive or combination claim controls (free metal) and the document is classified in Class 75; similarly if the intent is to obtain both the metal and the compound and both processes are claimed the patent goes to Class 75, as an original. If a metal which is definitely only an impurity is removed as an element and the desired metal is in compound form, classification of the original is in Class 423.
134, Cleaning and Liquid Contact With Solids, 2, for a process of removing foreign matter from a metallic substance, where the intent is merely for cleaning purposes, not to recover a metal containing compound.
209, Classifying, Separating, and Assorting Solids,
appropriate subclasses, for separating parts of a solid mixture where no chemical reaction is involved.
216, Etching a Substrate: Processes, for etching of any material not otherwise provided for, and including composite substrates or mixtures.
241, Solid Material Comminution or Disintegration, for ore crushing and physical separation.
299, Mining or In Situ Disintegration of Hard Material, for in situ chemical separation.
420, Alloy or Metallic Compositions, appropriate subclasses for alloys, intermetallic compounds or composition containing a continuous phase of metal and methods of making them.
432, Heating, 1, for a residual process of applying heat to a material.

This subclass is indented under subclass 1. Processes in which the compound comprises a metal which exhibits spontaneous nuclear disintegration with emission of radioactive particles, either as (1) the naturally unstable metal which has an atomic number of at least 84, or (2) a metal which has been treated to render an isotope thereof radioactive; see Glossary.
(1) Note. Compounds of the trans-actinide elements, i.e., those having atomic numbers greater than 103 will be found in this group of subclasses.
(2) Note. Patents wherein the claims are directed to making an element radioactive or to forming a different isotope of a radioactive element are classified in Class 376, Induced Nuclear Reactions: Processes, Systems, and Elements, subclasses 156+ even when the element is in compound form.

SEE OR SEARCH THIS CLASS, SUBCLASS:
249 for a radioactive compound, element or isotope, per se.

This subclass is indented under subclass 2. Processes in which the radio-active compound comprises a metal of the actinide series, i.e., one having an atomic number of 89 or
greater.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, for processes in general of obtaining pure metal values in a metallurgical process and particularly subclass 84.1 for pyrometallurgical processes for obtaining actinide and trans-actinide series metals. Production of the metal, e.g., uranium, plutonium, etc., compounds or concentrates as products even if disclosed for metallurgical purposes are classified in this and indented subclasses.
204, Chemistry: Electrical and Wave Energy, appropriate subclasses for electrical or wave energy preparation, separation, or recovery of actinide series products. Also see the References to Other Classes section of the Class 204 definition for the general class line between Class 204 and Class 423.
205, Electrolysis: Processes, Compositions Used Therein, and Methods of Preparing the Compositions, 43 for electrolytic processes involving an actinide series element or compound, including preparation, separation, or recovery of actinide series products.
376, Induced Nuclear Reactions: Processes, Systems, and Elements, for processes of producing a reaction product by an impact or bombardment of a nucleus and in subclass 189, 195, 198, and 201 for such processes followed by product treatment for recovery or separation.
420, Alloys or Metallic Compositions, 1 for alloys, metallic compositions or intermetallic compounds containing an actinide or transactinide series metal.

This subclass is indented under subclass 3. Processes in which the actinide metal comprises a nuclear fuel element and is obtained by treating the fuel element to remove the covering or casing material therefrom.

SEE OR SEARCH CLASS:
252, Compositions, 625, for processes producing a useful composition containing actinide series elements and such compositions.
376, Induced Nuclear Reactions: Processes, Systems, and Elements, 409 for the structure of the fuel element, per
se.
534, Organic Compounds, for organic actinide compounds and methods of making the same, in particular 11 for carbocyclic or acyclic actinide compounds. See also main class definition of Class 260.

This subclass is indented under subclass 3. Processes in which the treatment includes the step of melting material or using molten material.

This subclass is indented under subclass 2. Processes which include (1) attracting and retaining a component of the mixture by contact with an ion exchange substance or (2) using a substance which has an affinity for and retains a selected component or portion of the mixture being treated; see Glossary.

SEE OR SEARCH CLASS:
95, Gas Separation: Processes, 90 for processes of gas separation using solid sorbents, per se.
210, Liquid Purification or Separation, 24, for processes of separation in general by ion exchange or sorption.

This subclass is indented under subclass 6. Processes in which the substance is an organic synthetic resin.
(1) Note. For the definition of "synthetic resin", see Class 520, subclass 1.

This subclass is indented under subclass 3. Processes which
include the step of selectively dissolving a compound in one of two contacting immiscible liquids for separation; see Glossary.

SEE OR SEARCH THIS CLASS, SUBCLASS:
24 54, 63, 70, 112, 139, 157, and 181, for processes of treating mixtures including a desired metal to form a compound of the metal, in which the step of liquid-liquid extraction if utilized.

This subclass is indented under subclass 8. Processes in which one of the immiscible liquids is an organic solvent containing nitrogen, e.g., amines, etc.

SEE OR SEARCH CLASS:
260, Chemistry of Organic Compounds, appropriate subclasses for nitrogen containing organic solvents.

This subclass is indented under subclass 8. Processes in which one of the liquids is an organic solvent which contains phosphorus.

SEE OR SEARCH CLASS:
260, Chemistry of Organic Compounds, appropriate subclasses for phosphorus containing organic solvents.

This subclass is indented under subclass 3. Processes wherein a liquid or slurry is treated to form a substance which is insoluble therein and comes out of solution, or wherein the composition of the liquid is changed so that one part of the mixture becomes insoluble therein, so the insoluble substance can be separated from the liquid and the materials which remain soluble in the liquid.
(1) Note. Crystallization of a substance is included under this definition of insolubilization.

This subclass is indented under subclass 11. Processes in which another substance is caused to become insoluble and acts to carry out ions of the actinide series metal while coming out of solution.
(1) Note. In some instances, the carrier compound acts to sorb the additional ions.

This subclass is indented under subclass 12. Processes in which the other compound comprises bismuth.

This subclass is indented under subclass 12. Processes in which the other compound comprises lanthanum.

This subclass is indented under subclass 11. Processes in which a compound formed contains the ammonium (NH[subscrpt]4[end subscrpt]+) radical or another metal in addition to an actinide series metal.
(1) Note. In this subclass will be found, for example, double salts of uranium compounds, i.e., those containing at least two cations and which crystallize as a single substance but ionize as two substances, and compounds of uranic acid (U[subscrpt]2[end subscrpt]O[subscrpt]7[end subscrpt]2-).

This subclass is indented under subclass 11. Processes which
include forming a peroxide such as UO[subscrpt]4[end subscrpt], etc.

This subclass is indented under subclass 11. Processes which include making a separation by using a carbonate as an active ingredient to leach, wash, or dissolve; see Glossary.

This subclass is indented under subclass 11. Processes which include making a separation by using an acid as an active ingredient to leach, wash, or dissolve; see Glossary.

This subclass is indented under subclass 3. Processes including the step of causing a normally liquid or solid substance in element or compound form to be changed into a gas or a vapor; see Glossary.
(1) Note. Mere volatization of water or a solvent to concentrate a solution is not included under this definition; classification of such a process is based on other features.

This subclass is indented under subclass 3. Processes which include making a separation by using an acid as an active ingredient to leach, wash, or dissolve; see Glossary.

SEE OR SEARCH THIS CLASS, SUBCLASS:
18 for similar processes which include acid leaching in combination with forming an insoluble substance in a liquid.

Rare earth metal (At. No. 21, 39, or 57-71):
This subclass is indented under subclass 1. Processes in which the compound comprises one of the metals known as the "rare earth metals" and which has an atomic number of 21, 39, or 57-71, inclusive.

SEE OR SEARCH CLASS:
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the treatment of hazardous or toxic waste containing rare earth metals (atomic numbers 21, 39, or 57-71).

Ion exchanging or liquid-liquid extracting:
This subclass is indented under subclass 21.1. Processes which include the step of (a) attracting and retaining a compound of the mixture by contact with an ion exchange substance or (b) selectively dissolving a compound in one of two immiscible liquids to effect a separation; see Glossary.

This subclass is indented under subclass 1. Processes in which the compound comprises one of the metals known as the platinum group metals, i.e., ruthenium rhodium, palladium, osmium, iridium or platinum.

SEE OR SEARCH CLASS:
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the destruction or containment of hazardous or toxic waste containing platinum group elements (ruthenium, rhodium, palladium, osmium, iridium, or platinum).

This subclass is indented under subclass 1. Processes wherein the compound comprises copper, silver or gold.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use
Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, subclass 100, 117 and 118, for hydrometallurgical processes wherein the metal values recovered consist of copper, silver or gold in elemental form.
556, Organic Compounds, 110 for organo-metallo compounds containing copper, silver or gold or the processes for preparing such compounds.
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the destruction or containment of hazardous or toxic waste being volatilized or containing (Cu, Ag, or Au) halogens, oxygen sulfur, or nitrogen.

This subclass is indented under subclass 23. Processes, which include the step of (1) attracting and retaining a component of the mixture by contact with an ion exchange substance or (2) selectively dissolving a component in one of two immiscible liquids to effect a separation; see Glossary.

This subclass is indented under subclass 23. Processes which include the step of attracting or retaining a component or portion of the mixture by means of magnetic lines of force or by selective adherence to the surface of a solid; see Glossary.

This subclass is indented under subclass 23. Processes which include the step of floating or causing concentrated metal values of the mixture to rise to the top and to be skimmed off while the earthy portions of the ore are permitted to settle; see Glossary.

This subclass is indented under subclass 23. Processes, including a step of causing separation by leaching, washing or dissolving out; see Glossary.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, 101, for a process of obtaining a pure elemental metal and including the step of leaching with a chemical.

This subclass is indented under subclass 27. Processes which specify a particular particle size or range for the starting mixture, the intermediate or the final product.

This subclass is indented under subclass 27. Processes in which one of the active leaching ingredients is a cyanide.

SEE OR SEARCH THIS CLASS, SUBCLASS:
371 for a cyanide compound, per se, or the process of preparing such a compound where the starting material is substantially a pure substance.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, subclass 105 for the process of obtaining a pure elemental metal and which includes the step of leaching with a cyanide compound.

This subclass is indented under subclass 29. Processes in which a pressure above atmospheric is employed while the leaching is being effected.
(1) Note. Included under this definition is the use of gas under pressure contacting the mixture either above the
surface thereof or as a submerged blast.

This subclass is indented under subclass 29. Processes, wherein the reaction mixture is subjected to stirring, vibration or mixing while being leached.
(1) Note. The agitation of the mixture may be effected by any means, e.g., fluid, mechanical or sonic, etc.

This subclass is indented under subclass 27. Processes in which one of the active leaching ingredients is ammonia or an ammonium compound.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, subclass 103, for a process of obtaining a pure elemental metal and which includes the step of leaching with ammonia or an ammonium compound.

This subclass is indented under subclass 32. Processes wherein a specified temperature or range thereof is recited.
(1) Note. This subclass includes patents which specify a temperature preceding, during or following the leaching step.

This subclass is indented under subclass 27. Processes wherein a liquid or slurry is treated to form a substance which is insoluble therein, and comes out of solution or wherein the composition of the liquid is changed so that one part of the mixture becomes insoluble therein, so the
insoluble substance can be separated from the liquid and the materials which remain soluble in the liquid.
(1) Note. Included under this definition of insolubilization is that wherein a substance crystallizes out of solution due to temperature or concentration change.
(2) Note. The compounds formed by the titles specifically set out in the indented subclasses need not be those which come out of the solution; they may remain soluble while others formed by the process precipitate out.

SEE OR SEARCH THIS CLASS, SUBCLASS:
42 for a process of forming an insoluble substance in a liquid which process does not involve a leaching step.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, 101 for a process of obtaining a pure elemental metal, which includes the step of chemical leaching and which may involve precipitating a substance or causing it to come out of solution; and subclasses 106+ for a process of obtaining a pure elemental element by causing it or a compound thereof to come out of solution and which involves leaching with a cyanide compound.

This subclass is indented under subclass 34. Processes in which an oxide or carbonate is formed.

This subclass is indented under subclass 34. Processes which includes chemically forming a compound having the sulfate (SO[subscrpt]4[end subscrpt][supscrpt]2-[end supscrpt]) radical.
(1) Note. In this subclass may be found disclosures to double sulfates of a monovalent metal and a tri-valent metal.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose
Metal Particulate Mixtures, subclass 110 and 115+ for a process of obtaining a pure elemental metal and which involves the formation of a sulfate compound.

This subclass is indented under subclass 34. Processes which includes chemically forming a compound having the sulfide (S[supscrpt]2-[end supscrpt]) ion.

This subclass is indented under subclass 27. Processes which include chemically forming a halogen containing compound.
(1) Note. Included in this and the indented subclasses are methods of wet or dry chloridizing precedent to or subsequent to leaching.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, 111 for a process of forming a pure elemental metal which includes the step of chloridizing.

This subclass is indented under subclass 38. Processes in which a specific temperature or a range of temperatures is recited during at least part of the process either for the mixture or for a substance involved in the process.

This subclass is indented under subclass 38. Processes in which the halogen in the compound formed is chlorine and is provided by using as a reactant either chlorine gas or chlorinated water.

This subclass is indented under subclass 27. Processes which include chemically forming a compound having the sulfate (SO[supscrpt]4[end supscrpt][subscrpt]2[end subscrpt][supscrpt]-[end supscrpt]) radical.

SEE OR SEARCH THIS CLASS, SUBCLASS:
36 for a process of forming a similar metal compound which includes the step of forming a sulfate as well as the steps of leaching or dissolution and causing a substance to become insoluble in, or precipitate out of a liquid or slurry.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, subclass 110 and 115+ for a process of obtaining a pure elemental metal which includes the step of sulfating.

This subclass is indented under subclass 23. Processes wherein a liquid or slurry is treated to form a substance which is insoluble therein and comes out of solution or wherein the composition of the liquid is changed so that one part of the mixture becomes insoluble therein, so the insoluble substance can be separated from the liquid and other materials which remain soluble in the liquid.
(1) Note. Crystallization of a substance is included under this definition of insolubilization.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, 108 for a process of obtaining a pure elemental metal and which includes step of precipitation.

This subclass is indented under subclass 42. Processes in which specific alkalinity or acidity is employed during the process.

This subclass is indented under subclass 23. Processes including the step of causing copper, silver or gold in either the elemental or compound form to pass into the form of a gas or a vapor; see Glossary.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, 111 for a process of obtaining a pure elemental metal which may include a step of volatizing a substance.

This subclass is indented under subclass 23. Processes which include chemically forming a compound containing the (SO[subscrpt]4[end subscrpt][supscrpt]2-[end supscrpt]) sulfate radical.

SEE OR SEARCH THIS CLASS, SUBCLASS:
36 for a process in which a similar sulfate compound is formed, but in which also a substance is caused to come out of solution in a liquid or slurry and in which leaching is effected.
41 in which a similar sulfate compound is formed and in which leaching effected.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, subclass 110 and 115+ for a process of obtaining a pure elemental metal and which involves the formation of a sulfate compound.

This subclass is indented under subclass 23. Processes which include chemically forming a halogen containing compound.

SEE OR SEARCH THIS CLASS, SUBCLASS:
38 for a process of obtaining a similar metal compound in which a halogen containing compound is formed and in which the step of leaching or dissolution is included.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidatedr Metal Powder Compositions, and Loose Metal Particulate Mixtures, subclass 110 and 111+ for a process of obtaining a pure elemental metal and which involves the formation of a chlorine containing compound.

This subclass is indented under subclass 23. Processes including the removal of sulfur or of arsenic from the mixture.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, subclass for a process of removing at least a portion of the sulfur or of the arsenic from an ore for the purpose of concentrating the metal values of the ores.

This subclass is indented under subclass 23. Processes which include forming a sulfide compound or a mixture of sulfides known as a matte.

This subclass is indented under subclass 1. Processes wherein the compound comprises manganese, technetium or rhenium.
(1) Note. Technetium does not occur naturally; it is a fission product of uranium. Compounds of technetium are known, however, e.g., Tc[subscrpt]2[end subscrpt] deg.7, NH[subscrpt]4[end subscrpt]Tc deg.4, etc.

SEE OR SEARCH THIS CLASS, SUBCLASS:
2 for processes of treating mixtures to obtain radioactive group VIIB metal compounds and subclasses 249+ for the radioactive metal compound, per se.

SEE OR SEARCH CLASS:
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the destruction or containment of hazardous or toxic waste containing (Mn, Tc, or Re) halogen, oxygen, or sulfur.

This subclass is indented under subclass 49. Processes wherein a liquid or slurry is treated to form a substance which is insoluble therein and comes out of solution, or wherein the composition of the liquid is changed so that one part of the mixture becomes insoluble substance can be separated from the liquid and the materials which remain soluble in the liquid.
(1) Note. Crystallization of a substance is included under this definition of insolubilization.

This subclass is indented under subclass 50. Processes including the step of chemically forming a compound containing a halogen.

This subclass is indented under subclass 50. Process including the step of forming a compound containing the sulfate (SO[subscrpt]4[end subscrpt][supscrpt]2-[end supscrpt]) radical.

This subclass is indented under subclass 1. Processes wherein the compound comprises chromium, molybdenum, or wolfram (tungsten).

SEE OR SEARCH CLASS:
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the destruction or containment of hazardous or toxic waste being volatilized or containing Cr, Mo, or W.

This subclass is indented under subclass 53. Processes which include the step of (1) attracting and retaining a component of the mixture by contact with an ion exchange substance or (2) selectively dissolving a component in one of two immiscible liquids to effect a separation; see Glossary.

This subclass is indented under subclass 53. Processes wherein a liquid or slurry is treated to form a substance which is insoluble therein and comes out of solution, or wherein the composition of the liquid is changed so that one part of the mixture becomes insoluble therein, so the insoluble substance can be separated from the liquid and the materials which remain soluble in the liquid.
(1) Note. Crystallization of a substance is included under this definition of insolubilization.

This subclass is indented under subclass 55. Processes including the step of chemically forming a compound which contains the ammonium (NH[subscrpt]4[end subscrpt]+) or nitrate (NO[subscrpt]3[end subscrpt]-) radical.

This subclass is indented under subclass 55. Processes including the step of chemically forming a compound having the sulfate (SO[subscrpt]4[end subscrpt][supscrpt]2-[end supscrpt]) radical.

This subclass is indented under subclass 55. Processes including the step of chemically forming a compound which contains at least two metals.

This subclass is indented under subclass 53. Processes including the step of causing a normally solid or liquid substance in either elemental or compound form to be changed into a gas or a vapor; see Glossary.

This subclass is indented under subclass 59. Processes wherein the substance is a compound which contains chlorine.

This subclass is indented under subclass 53. Processes including the step of chemically forming a compound which contains at least two metals.

SEE OR SEARCH THIS CLASS, SUBCLASS:
58 for process of forming a plural metal containing compound containing a Group VIB metal from a mixture, which process also includes forming an insoluble substance in a liquid.

This subclass is indented under subclass 1. Processes wherein the compound comprises vanadium, niobium, or tantalum.

SEE OR SEARCH CLASS:
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the destruction or containment of hazardous or toxic waste containing V, Nb, or Ta.

This subclass is indented under subclass 62. Processes which include the step of (1) attracting and retaining a component of the mixture by contact with an ion exchange substance, or (2) selectively dissolving a component in one of two immiscible liquids to effect a separation; see Glossary.

This subclass is indented under subclass 62. Processes wherein the compound is separated from liquids which are organic compounds, i.e., those nonpolar compounds consisting of carbon and hydrogen with or without other elements (except for those compounds in which carbon plays an unimportant part, as carbonates) e.g., petroleum oils, etc.

This subclass is indented under subclass 62. Processes wherein a liquid or slurry is treated to form a substance which is insoluble therein and comes out of solution, or wherein the composition of the liquid is changed so that one part of the mixture becomes insoluble therein, so the insoluble substance can be separated from the liquid and the materials which remain soluble in the liquid.
(1) Note. Crystallization of a substance is included under this definition of insolubilization.

This subclass is indented under subclass 65. Processes including the step of chemically forming a hydroxide or a hydrate.

This subclass is indented under subclass 65. Processes including the step of chemically forming a compound which contains the ammonium (NH[subscrpt]4[end subscrpt][supscrpt]+[end supscrpt]) radical or the sulfate (SO[subscrpt]4[end subscrpt][supscrpt]2-[end supscrpt]) radical.

This subclass is indented under subclass 62. Processes which include leaching, washing, or dissolving out a portion of the mixture; see Glossary.

This subclass is indented under subclass 1. Processes wherein the compound comprises titanium, zirconium, or hafnium.

SEE OR SEARCH CLASS:
75, Specialized Metallurgical Processes, Compositions for Use Therein, Consolidated Metal Powder Compositions, and Loose Metal Particulate Mixtures, especially 84 for a process in which Ti, Zr, or Hf is reduced to metallic state from a compound thereof after a treatment to separate such compounds from mixtures.
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the treatment of hazardous or toxic containing Ti, Zr, or Hf.

This subclass is indented under subclass 69. Processes which include the step of (1) attracting and retaining a component of the mixture by contact with an ion exchange substance, or (2) selectively dissolving a component in one of two immiscible liquids to effect a separation; see Glossary.

This subclass is indented under subclass 69. Processes including chemically forming a compound which contains at least two metals.

This subclass is indented under subclass 71. Processes in which the compound also contains a halogen.

This subclass is indented under subclass 69. Processes in which the mixture contains at least two members from the group comprising Ti, Zr, and Hf, and in which one of these members is recovered separately from any other.

This subclass is indented under subclass 69. Processes in which solids are suspended in upward flowing gas or vapor, the upward force of the fluid on the solids being countered by gravity, resulting in the formation of a zone in which the particles are compacted into a dense phase; see Glossary.
(1) Note. The particles are in a state of hindered settling and the dense bed resembles a boiling liquid and above this dense bed some solids may be suspended in a dilute or dispersed phase.

This subclass is indented under subclass 69. Processes which include the step of causing a normally solid or liquid substance in either elemental or compound form to be changed into a gas or vapor; see Glossary.

SEE OR SEARCH CLASS:
203, Distillation: Processes, Separatory, appropriate subclasses, especially 28 for a process which includes a chemical reaction solely for the purpose of facilitating the isolation by distillation of a component of the original mixture. A process which includes vaporizing an impure mixture and then chemically treating the impure vapor to recover or separate therefrom a desired metal compound is classified in Class 423; see also reference to Class 203 in section III, Line and Search Notes.

This subclass is indented under subclass 75. Processes in which titanium, zirconium or hafnium is volatized in elemental or compound form.
(1) Note. This subclass includes processes where an impure chloride is purified by distillation of the Group IVB metal chloride.

This subclass is indented under subclass 76. Processes in which the vapor stream is treated to remove undesired materials, the Group IVB metal values remaining in vapor form during the separation.

SEE OR SEARCH THIS CLASS, SUBCLASS:
75 and 76, for a process in which either the undesirable material or the Ti, Zr, or Hf is volatilized, there being no separation of one from the other in the vapor stream.

This subclass is indented under subclass 76. Processes in which volatilization takes place using solids which have been given a claimed physical shape; e.g., briquettes, pellets, etc.

SEE OR SEARCH CLASS:
264, Plastic and Nonmetallic Article Shaping or Treating: Processes, appropriate subclasses, for briquetting or otherwise shaping solid mixtures.

This subclass is indented under subclass 76. Processes in which the vaporization of the Ti, Zr, or Hf is effected during contact of a solid feed material with gaseous chlorine.

This subclass is indented under subclass 69. Processes in which a chemical reaction is performed upon the mixture to enable two solid components of the mixture, usually of different compositions, to be more readily separated from each other by nonchemical methods and while the components are still in a solid-state.
(1) Note. Examples of solid-solid separation are: magnetic, gravity, centrifugal, etc. Solution (leaching) of one of the solids is not considered to be solid-solid separation for this subclass.

SEE OR SEARCH CLASS:
209, Classifying, Separating, and Assorting Solids, for methods and apparatus for solid-solid separation, per se, especially 3 for treatments, preliminary to a solid-solid separation, which do not involve a chemical reaction.

This subclass is indented under subclass 69. Processes which include the step of reacting or contacting the mixture with a compound which contains nitrogen, e.g., nitric acid, ammonia, etc.

This subclass is indented under subclass 69. Processes which include the step of reacting or contacting the mixture with an acid which contains sulfur or a halogen, e.g., H[subscrpt]2[end subscrpt]S, H[subscrpt]2[end subscrpt]SO[subscrpt]4[end subscrpt], HC1, etc.

This subclass is indented under subclass 82. Processes which include the formation of iron in elemental form or of an insoluble iron containing compound.

This subclass is indented under subclass 69. Processes which include the step of reacting or contacting the mixture with a compound which contains an alkali metal or an alkaline earth metal.

This subclass is indented under subclass 69. Processes in which a liquid or slurry is treated to form a substance containing a Group IVB metal and which substance is insoluble in, and comes out of solution from, the liquid or slurry, or the composition of the liquid is changed so that the part of the mixture containing the Group IVB metal becomes insoluble therein, so the insoluble substance can be separated from the liquid and the materials which remain soluble in the liquid or slurry.

This subclass is indented under subclass 69. Processes which include the step of dissolving or leaching iron and thereby separating it from part of the original mixture; see Glossary.

SEE OR SEARCH THIS CLASS, SUBCLASS:
150.3 for general processes for chemically leaching iron values from iron-bearing ores.

This subclass is indented under subclass 1. Processes in which the compound comprises antimony, bismuth or arsenic.
(1) Note. For purposes of this Class 423, arsenic is considered to be a metal.

SEE OR SEARCH CLASS:
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the destruction or containment of hazardous or toxic waste containing Sb, Bi, or As.

This subclass is indented under subclass 87. Processes which include the step of causing a normally solid or liquid substance in either elemental or compound form to be changed into a gas or a vapor; see Glossary.

This subclass is indented under subclass 1. Processes in which the compound comprises germanium, tin, or lead.

SEE OR SEARCH CLASS:
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the destruction or containment of hazardous or toxic waste containing Ge, Sn, or Pb.

This subclass is indented under subclass 89. Processes in which the compound comprises tin and is obtained by treating an article or waste material of a mixture of metals which includes tin (e.g., terne plate, tin plate, cans, etc.).

SEE OR SEARCH CLASS:
134, Cleaning and Liquid Contact With Solids, 2 for a process of treating articles or material for the purpose of cleaning or removing foreign matter therefrom, not to remove or strip a metal coating to recover the metal.

This subclass is indented under subclass 90. Processes in which the article or waste material is treated with a halogen which is either in the free state or combined with hydrogen as a halogen containing acid.

This subclass is indented under subclass 89. Processes in which a liquid or slurry is treated to form a substance which is insoluble in and comes out of solution, or wherein the composition of the liquid is changed so that one part of the mixture becomes insoluble therein, so the insoluble substance can be separated from the liquid and the materials which remain soluble in the liquid.
(1) Note. Crystallization of a substance is included under this definition of insolubilization.

This subclass is indented under subclass 92. Processes in which a chemical reaction takes place while the pressure on the mixture is higher than atmospheric or while the mixture is agitated or vibrated.
(1) Note. Agitation or vibration can be effected by any means, e.g., mechanical, sonic, fluid, etc. Pressure increase can be effected by any means, e.g., submerged blast of a gas into a liquid or slurry mixture, pumping of the liquid or slurry mixture, increase in pressure of the gas space above a liquid surface, etc.

This subclass is indented under subclass 92. Processes which includes the step of chemically forming a compound containing a halogen.

This subclass is indented under subclass 92. Processes which include the step of chemically forming a compound which contains the nitrate (NO[subscrpt]3-[end subscrpt]) radical or the sulfate (SO[subscrpt]4[end subscrpt][supscrpt]2-[end supscrpt]) radical.

This subclass is indented under subclass 89. Processes including the step of causing germanium or tin in elemental or compound form to be changed into a gas or vapor; see Glossary.

This subclass is indented under subclass 89. Processes including the step of causing lead in elemental or compound form to be changed into a gas or vapor; see Glossary.

This subclass is indented under subclass 89. Processes which
include leaching, washing or dissolving out a portion of the mixture; see Glossary.

SEE OR SEARCH THIS CLASS, SUBCLASS:
90 for a process of destining scrap metal by forming and dissolving a tin compound.

This subclass is indented under subclass 1. Processes wherein the compound comprises zinc, cadmium or mercury.

SEE OR SEARCH CLASS:
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the destruction or containment of hazardous or toxic waste containing Zn, Cd, or Hg.

This subclass is indented under subclass 99. Processes which include the step of (1) attracting and retaining a component of the mixture by contact with an ion exchange substance or (2) attracting and separating a component of the mixture from another component by means of magnetic lines of force; see Glossary.

This subclass is indented under subclass 99. Processes wherein a liquid or a slurry is treated to form a substance which is insoluble therein and comes out of solution, or wherein the composition of the liquid is changed so that one part of the mixture becomes insoluble therein, so the insoluble substance can be separated from the liquid and the materials which remain soluble in the liquid.
(1) Note. Crystallization of a substance is included under this definition of insolubilization.

This subclass is indented under subclass 101. Processes in which a chemical reaction takes place while the mixture is agitated or vibrated.
(1) Note. Agitation or vibration can be effected by any means, e.g., mechanical, sonic, fluid, etc.

This subclass is indented under subclass 101. Processes including the step of chemically forming a compound which contains a halogen.

This subclass is indented under subclass 101. Processes including the step of chemically forming a hydroxide or a hydrate.

This subclass is indented under subclass 101. Processes including the step of chemically forming a compound having the carbonate (CO[subscrpt]3[end subscrpt][supscrpt]2-[end supscrpt]) radical.

This subclass is indented under subclass 101. Processes including the step of chemically forming a compound having the sulfate (SO[subscrpt]4[end subscrpt][supscrpt]2-[end supscrpt]) radical.

This subclass is indented under subclass 99. Processes including the step of causing zinc, cadmium or mercury in elemental or compound form to be changed into a gas or a vapor; see Glossary.

This subclass is indented under subclass 107. Processes wherein the mixture contains lead.

This subclass is indented under subclass 99. Processes which include leaching, washing, or dissolving out a portion of the mixture; see Glossary.

This subclass is indented under subclass 99. Processes including the step of removing at least some sulfur from the mixture.

This subclass is indented under subclass 1. Processes wherein the compound comprises beryllium, aluminum, gallium, indium or thallium.

SEE OR SEARCH CLASS:
588, Hazardous or Toxic Waste Destruction or Containment, appropriate subclasses for the destruction or containment of hazardous or toxic waste containing, Al, Ga, In, Tl, or Be.

This subclass is indented under subclass 111. Processes
which include the step of (1) attracting and retaining a component of the mixture by contact with an ion exchange substance or (2) selectively dissolving a component in one of two immiscible liquids to effect a separation; see Glossary.

This subclass is indented under subclass 111. Processes wherein a separation is made by attracting and separating a component of the mixture from another component by means of magnetic lines of force; see Glossary.

This subclass is indented under subclass 111. Processes including the step of chemically forming a compound which contains the ammonium radical and a metal.

This subclass is indented under subclass 111. Processes including the step of chemically forming a compound which contains a plurality of metals.

This subclass is indented under subclass 115. Processes wherein the compound also contains a halogen.

This subclass is indented under subclass 115. Processes wherein the compound also contains sulfur.

Aluminosilicate other than zeolite:
This subclass is indented under subclass 115. Processes wherein the compound is an aluminosilicate, other than a zeolite, containing silicon, oxygen, aluminum, and another metal; e.g., sodium aluminosilicate.

SEE OR SEARCH THIS CLASS, SUBCLASS:
700 for products and processes for producing zeolites.

This subclass is indented under subclass 115. Processes wherein the compound is an alkali metal aluminate, e.g., sodium aluminate (Na[subscrpt]2[end subscrpt]Al[subscrpt]2[end subscrpt]0[subscrpt]4[end subscrpt] or Na Al O[subscrpt]2[end subscrpt]).

This subclass is indented under subclass 119. Processes wherein the mixture or source material includes the mineral alunite, which is naturally occurring K[subscrpt]2[end subscrpt]SO[subscrpt]4[end subscrpt].Al[subscrpt]2[end subscrpt](SO[subscrpt]4[end subscrpt])[subscrpt]3[end subscrpt] 4Al(OH)[subscrpt]3[end subscrpt] or KAl[subscrpt]3[end subscrpt](OH) [subscrpt]6[end subscrpt](SO[subscrpt]4[end subscrpt])[subscrpt]3[end subscrpt].

This subclass is indented under subclass 119. Processes wherein the mixture or source material is the mineral bauxite, which is naturally occurring Al[subscrpt]2[end subscrpt]O(OH)[subscrpt]4[end subscrpt].

This subclass is indented under subclass 111. Processes wherein a liquid or slurry is treated to form a substance which is insoluble therein and comes out of solution, or wherein the composition of the liquid is changed so that one part of the mixture becomes insoluble therein, so the insoluble substance can be separated from the liquid and the materials which remain soluble in the liquid.
(1) Note. Crystallization of a substance is included under this definition of insolubilization.

This subclass is indented under subclass 122. Processes wherein a chemical reaction takes place while the pressure on the mixture is either higher or lower than atmospheric; or while steam or water vapor is brought into contact with the mixture.
(1) Note. Pressure increase, or decrease can be effected by any means, e.g., submerged blast of a gas into a slurry or liquid, pumping of the liquid or slurry, increase or decrease in pressure of the gas space above a liquid surface, etc.

This subclass is indented under subclass 122. Processes wherein a chemical reaction takes place while the mixture is agitated or vibrated.
(1) Note. Agitation or vibration can be effected by any means, e.g., mechanical, sonic, fluid, etc.

This subclass is indented under subclass 122. Processes including the step of chemically forming a compound having the nitrate (NO[subscrpt]3[end subscrpt][supscrpt]-[end supscrpt]) radical.

This subclass is indented under subclass 122. Processes which include the step of chemically forming a compound having a halogen as part thereof.

This subclass is indented under subclass 122. Processes including the step of chemically forming a hydroxide or a hydrate.

This subclass is indented under subclass 122. Processes including the step of chemically forming a compound containing the sulfate (SO[subscrpt]4[end subscrpt][supscrpt]2-[end supscrpt])radical.

This subclass is indented under subclass 122. Processes including the step of chemically forming a compound having the carbonate (CO[subscrpt]3[end subscrpt][supscrpt]2-[end supscrpt]) radical.

This subclass is indented under subclass 111. Processes in which the mixture contains an impurity which meets the definitions of an organic compound and the process includes a step of (1) removing the impurity from the mixture or (2) doing away with or breaking up completely the impurity.
(1) Note. The organic impurity may be done away with or broken up completely by any means, as for example, chemical or flame oxidation, or combustion, etc.

This subclass is indented under subclass 111. Processes which include leaching, washing, or dissolving out a portion of the mixture; see Glossary.

This subclass is indented under subclass 131. Processes in which an acid is used as the leaching, washing or the solvent medium.

This subclass is indented under subclass 111. Processes including the step of causing a normally solid or liquid substance in either element or compound form to be changed into a gas or a vapor; see Glossary.

This subclass is indented under subclass 133. Processes in which the substance is beryllium.

This subclass is indented under subclass 133. Processes in which the substance is aluminum, gallium, indium or thallium.

This subclass is indented under subclass 135. Processes which include the step of reacting an uncombined halogen.

This subclass is indented under subclass 111. Processes in which include the step of using elemental carbon as a reducing agent.

This subclass is indented under subclass 1. Processes wherein the compound c