US 7,484,679 B2
Method of milling cerium compound by means of ball mill
Isao Ota, Nei-gun (Japan); Kenji Tanimoto, Nei-gun (Japan); Gen Yamada, Nei-gun (Japan); and Noriyuki Takakuma, Nei-gun (Japan)
Assigned to Nissan Chemical Industries, Ltd., Tokyo (Japan)
Appl. No. 10/518,769
PCT Filed Jul. 03, 2003, PCT No. PCT/JP03/08475
§ 371(c)(1), (2), (4) Date Dec. 21, 2004,
PCT Pub. No. WO2004/004910, PCT Pub. Date Jan. 15, 2004.
Claims priority of application No. 2002-195742 (JP), filed on Jul. 04, 2002.
Prior Publication US 2005/0253001 A1, Nov. 17, 2005
Int. Cl. B02C 1/00 (2006.01); B02C 11/08 (2006.01); B02C 21/00 (2006.01); B02C 23/00 (2006.01)
U.S. Cl. 241—21  [241/184] 11 Claims
 
1. A method of milling cerium compound, comprising:
providing the cerium compound and a milling medium in a cylindrical ball mill container of a ball mill, the milling medium having a Hb/r ratio between 1.2 and 1.9 where Hb is the depth of the milling medium in the ball mill container and r is the radius of the ball mill container; and
rotating the ball mill container at a rotational speed 50% or less of a critical rotational speed of the ball mill container, the critical rotation speed being defined as Nc=299/r1/2 where Nc is expressed in rpm and r is expressed in cm.