Abstract: The present invention provides a cerium oxide-based abrasive ensuring high removal rate, less generation of scratches, high-precision polished surface with small surface roughness, and a safe, simple and low-cost production process. Further, the present invention provides a method for producing such an abrasive. The method of the present invention comprises (a) adding a precipitant to an aqueous cerium-containing light rare-earth salt solution to precipitate a light rare-earth salt, thereby obtaining a first slurry containing a light rare-earth salt particle; (b) adding a fluorinating agent to a slurry containing a light rare-earth salt particle to react the light rare-earth salt with the fluorinating agent, thereby obtaining a second slurry containing a light rare-earth fluoride particle; (c) mixing the first slurry and the second slurry to obtain a mixed slurry; and (d) drying and firing the mixed slurry, and a cerium oxide-based abrasive obtained by this method.

Abstract: The present invention provides a cerium oxide-based abrasive ensuring high removal rate, less generation of scratches, high-precision polished surface with small surface roughness, and a safe, simple and low-cost production process. Further, the present invention provides a method for producing such an abrasive. The method of the present invention comprises (a) adding a precipitant to an aqueous cerium-containing light rare-earth salt solution to precipitate a light rare-earth salt, thereby obtaining a first slurry containing a light rare-earth salt particle; (b) adding a fluorinating agent to a slurry containing a light rare-earth salt particle to react the light rare-earth salt with the fluorinating agent, thereby obtaining a second slurry containing a light rare-earth fluoride particle; (c) mixing the first slurry and the second slurry to obtain a mixed slurry; and (d) drying and firing the mixed slurry, and a cerium oxide-based abrasive obtained by this method.

Abstract: A mixed light rare earth compound which has been obtained by chemically removing medium-to-heavy rare earth elements, Nd and impurities other than rare earth elements from an ore containing rare earth elements is fired at 500 to 1100° C. to yield a mixed rare earth oxide. A cerium-based rare earth oxy-fluoride is added to the mixed rare earth oxide to obtain a mixture. The mixture is subjected to wet-pulverization, drying, firing, disintegration and classification to thereby yield a cerium-containing abrasive.

Abstract: The present invention provides a mixed rare earth oxide for the production of a cerium-based abrasive, in which the ignition loss after heating at a temperature of 1,000° C. for 1 hour is 0.5 mass % or less on the dry mass basis and the crystallite diameter is from 200 to 400 ?; a mixed rare earth fluoride for the production of a cerium-based abrasive, in which the ignition loss is from 3 to 15% on the dry mass basis; a process for producing a cerium-based abrasive from these mixed rare earth oxide or mixed rare earth fluoride; and a cerium-based abrasive produced by using these mixed rare earth oxide or mixed rare earth fluoride.

Abstract: A mixed light rare earth compound which has been obtained by chemically removing medium-to-heavy rare earth elements, Nd and impurities other than rare earth elements from an ore containing rare earth elements is fired at 500 to 1100° C. to yield a mixed rare earth oxide. A cerium-based rare earth fluoride is added to the mixed rare earth oxide to obtain a mixture. The mixture is subjected to wet-pulverization, drying, firing, disintegration and classification to thereby yield a cerium-containing abrasive.

Abstract: A mixed light rare earth compound which has been obtained by chemically removing medium-to-heavy rare earth elements, Nd and impurities other than rare earth elements from an ore containing rare earth elements is fired at 500 to 1100° C. to yield a mixed rare earth oxide. A cerium-based rare earth oxy-fluoride is added to the mixed rare earth oxide to obtain a mixture. The mixture is subjected to wet-pulverization, drying, firing, disintegration and classification to thereby yield a cerium-containing abrasive.

Abstract: A polish containing cerium oxide as a principal component, when dispersed in water in an amount of 10% by mass, has a precipitate bulk specific density in the range of 0.8 g/ml to 1.0 g/ml, having a primary particle size in the range of 40 nm to 80 nm and a specific surface area in the range of 2 m2/g to 5 m2/g. The thus obtained polish provides the cerium-based polish and the cerium-based polish slurry that increase the polishing speed and cause few scratches inflicted on the surface of polish and achieve high quality of the polished surfaces.

Abstract: A mixed light rare earth compound which has been obtained by chemically removing medium-to-heavy rare earth elements, Nd and impurities other than rare earth elements from an ore containing rare earth elements is fired at 500 to 1100° C. to yield a mixed rare earth oxide. A cerium-based rare earth fluoride is added to the mixed rare earth oxide to obtain a mixture. The mixture is subjected to wet-pulverization, drying, firing, disintegration and classification to thereby yield a cerium-containing abrasive.