摘要
为高效利用磷石膏中丰富的CaSO_4资源,采用化学试剂循环利用工艺,以磷石膏为原料,制备了高纯度硫酸钙产品。首先用NaOH溶液分解磷石膏,将其中的SO_4^(2-)分离出来,得到Na_2SO_4溶液;余下的钙渣再用盐酸溶液溶解其中的Ca^(2+),除去酸不溶渣,得到CaCl_2溶液;将硫酸溶液加到CaCl_2溶液中,得到高纯度硫酸钙沉淀和盐酸溶液。盐酸溶液可循环用于溶解钙渣中的Ca^(2+)。硫酸和氢氧化钠溶液则可通过电解Na_2SO_4溶液制得。最终得到的硫酸钙产品纯度可达99.72%,CaSO_4回收率为85.99%。
In order to efficiently utilize the abundant CaSO4 resource in phosphogypsum,the high purity cal- cium sulfate product was prepared by chemical reagent recycling technology with phosphogypsum as a raw ma- terial. Firstly,phosphogypsum was decomposed by NaOH solution,and the SO4^2- was separated to get Na2SO4 solution. Then Ca^2＋ was dissolved from remaining calcium slag by hydrochloric acid solution, and the acid-insol- uble residue was removed to get CaCl2 solution. High purity calcium sulfate precipitation and hydrochloric acid solution were obtained by adding sulfuric acid solution into the CaCl2 solution. Hydrochloric acid solution could be recycled and used to dissolve Ca^2＋ from calcium slag. Sulfuric acid and sodium hydroxide solutions could be obtained by electrolysis of Na2 SO4 solution. The final purity of calcium sulfate was 99.72 %, and the recovery rate of CaSO4 was 85.99%.
出处
《化学与生物工程》
CAS
2017年第3期53-56,共4页
Chemistry & Bioengineering
基金
国家自然科学基金资助项目(51374156)
关键词
磷石膏
循环工艺
除杂
高纯硫酸钙
phosphogypsum
recycling technology
removing impurities
high purity calcium sulfate
