湿法冶金

研究了氨水-双氧水氧化沉淀法制备高纯氢氧化铈,考察了各条件对氢氧化铈氧化率、收率、重金属杂质质量分数的影响,并与Ce2(SO4)3-Na2SO4-氢氧化钠转化、Ce2(CO3)3-氢氧化钠转化2种方法制备的产品进行对比。结果表明,氨水-双氧水氧化沉淀法所制备的氢氧化铈的组成为Ce(OH)4,最佳工艺条件下制备的氢氧化铈产品中∑REO质量分数为82%⁸3%,氧化率大于98.5%,重金属杂质质量分数小于1.0×10-5。

Preparation of high-pure cerium hydroxide by precipitation oxidization process with aqueous ammonia and hydrogen peroxide was studied.Influences of preparation conditions on oxidation rate,yield,content of heavy metal impurities in cerium hydroxide were examined.Two products made by cerium sulfate-sodium sulfate-sodium hydroxide transformation process and cerium carbonate-sodium hydroxide transformation process were contrasted with the product made by the precipitation oxidization process.The structure and composition of cerium hydroxide made by precipitation oxidization process with aqueous ammonia and hydrogen peroxide were determined.The results show that the chemical formula of the product is Ce(OH)4.Under reasonable conditions,∑REO mass fraction in the pure cerium hydroxide product is 82%-83%,oxidation rate of cerium is more than98.5%,the contain of heavy metal impurities is less than 1.0×10-5.