CERIUM SALT, PROCESS FOR PRODUCING THE SAME, CERIUM OXIDE, AND CERIUM-BASED ABRASIVE MATERIAL

摘要

A cerium salt which, when dissolved in an amount of 20 g in a liquid mixture of 12.5 g of 6 N nitric acid and 12.5 g of 30% aqueous hydrogen peroxide solution, gives a solution in which the concentration of insolubles present therein is up to 5 ppm by mass of the cerium salt before dissolution; and a cerium oxide obtained by treating the cerium salt with a high temperature. The amount of impurities contained in cerium oxide particles and cerium salt particles to be used as a raw material for the cerium oxide is reduced to heighten the purity. Due to the purification, when a cerium-based abrasive material containing these cerium oxide particles is used in polishing, the surface being polished can be made less apt to suffer scratching.