| 摘要 |
A manufacturing method of cerium oxide having a high purity is provided to guarantee a quality of electronic products using a wafer because scratches are not nearly generated at a surface of the wafer which is a main part grinding object. A manufacturing method of cerium oxide having a high purity comprises steps of: a first refining step of collecting a first precipitated material by classifying a first supernatant and the first precipitated material and filtering the first supernatant by dropping NaOH in order to make an acidity of a cerium chloride composition pH 9~10; a second refining step of collecting a second precipitated material by classifying a second supernatant and the second precipitated material and filtering the second supernatant by dropping NaOH in order to make an acidity of the first precipitated material pH 10~11; a washing step of obtaining a solid phase of cerium precursor of which a Pr content is 100 ppm or less by jetting and filtering the purified water in order to reduce Praseodymium(Pr) contained in the second precipitated material; a step for forming a cerium nitrate hydrate(Ce(NO3)3À6H2O) by dropping a nitric acid in the cerium precursor; a step for collecting the third precipitated material by mixing the cerium nitrate hydrate and carbonic acid precursor aqueous solution and precipitating-reacting it and classifying the third supernatant and the third precipitated material; and a step for forming the cerium oxide of which the Praseodymium(Pr) is 100 ppm or less by plasticizing and pulverizing the third precipitated material at 900~1000 ‹C . |
