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铌钽沉淀母液中含有较高浓度的氟,可通过加入可溶性的稀土盐除去,其产品可制成含氟稀土抛光粉或氟化稀土,除氟后的沉淀母液可回收用作南方离子型稀土矿的稀土浸矿剂。将铌钽沉淀母液加入硫酸稀土除氟,并加入碳酸氢铵控制pH值在6.2~6.4沉淀稀土,制备含氟稀土抛光粉前驱体,沉淀后母液氟含量可达到5.0 mg·L~(-1)以下,稀土含量为30 mg·L~(-1)以下;而加氯化稀土除氟,pH值控制在6.5~6.7时,母液氟含量可达到3.0 mg·L~(-1)以下,稀土含量为20 mg·L~(-1)以下;铌钽沉淀母液加入可溶性稀土盐除氟制氟化稀土,沉淀的pH值控制在7.0为宜,除氟后沉淀母液氟含量可达到2.5 mg·L~(-1)以下,稀土含量为10 mg·L~(-1)以下;铌钽沉淀母液加入可溶性稀土盐除氟加碳酸氢铵沉淀稀土,沉淀过滤、烘干在1000~1050℃煅烧4 h,得到粒度分布均匀,粒径范围较窄,中位粒径宜中,抛蚀率较高的含氟稀土抛光粉。除氟沉淀母液经蒸发浓缩回收,得到硫酸铵或氯化铵和硫酸铵复合铵盐,产品铵盐含量达到98%以上,氟含量小于3 mg·L~(-1)。
The niobium-tantalum precipitation mother liquor contains a higher concentration of fluorine, which can be removed by adding soluble rare earth salts. The product can be made into a fluorine-containing rare earth polishing powder or a rare earth fluoride, and the precipitated mother liquor after fluorine removal can be recovered as a rare earth Mines rare earth leaching agent. The niobium-tantalum precipitation mother liquor is added into rare earth sulfate to remove fluorine, and ammonium bicarbonate is added to control the rare earth to precipitate rare earth with a pH value of 6.2 to 6.4 to prepare fluorine-containing rare earth polishing powder precursor; the fluorine content in the mother liquor after the precipitation can reach 5.0 mg · L -1 ), The content of rare earth is less than 30 mg · L -1. When fluoride is added with rare earth chloride and the pH value is controlled at 6.5-6.7, the fluorine content in the mother liquor can reach below 3.0 mg · L -1, The rare earth content is less than 20 mg · L -1. The rare earth niobium tantalum precipitation solution is added with soluble rare earth salt to remove fluoridation rare earth fluoride. The pH value of sediment is controlled at 7.0. The fluorine content of precipitation mother liquor after fluoride removal can reach 2.5 mg · L -1, the rare earth content is less than 10 mg · L -1; the rare earth niobium tantalum precipitation solution is added with soluble rare earth salt to remove rare earth fluoride and ammonium bicarbonate, the precipitate is filtered and dried at 1000-1050 ℃ Calcined 4 h, to obtain a particle size distribution, a narrow range of particle size, the median particle size should be high, the higher the rate of erosion of fluorine-containing rare earth polishing powder. The fluoride-removing mother liquor is recovered by evaporation and concentrated to obtain ammonium sulfate or ammonium chloride and ammonium sulfate composite ammonium salt, the ammonium content of the product reaches over 98% and the fluorine content is less than 3 mg · L -1.