由钛白废酸和硫铁矿烧渣制备饲料级硫酸亚铁

Preparation of feed-grade ferrous sulfate by waste acid from titanium dioxide production and pyrite cinder

研究了以钛白废酸和硫铁矿烧渣为原料,经酸浸、除杂、还原制得精制硫酸亚铁溶液,再经过滤、冷冻结晶、洗涤、真空干燥制备饲料级硫酸亚铁的新工艺。重点考察了酸浸条件对浸出率的影响及除杂还原条件对产品质量的影响。结果表明:采用硫酸质量分数为30%的废酸浸取,控制液固质量比为5∶1,浸出时间2 h,可使铁浸出率达到96%;采用铁屑还原浸出液,可得到硫酸亚铁溶液,对溶液进行冷冻结晶和真空干燥可制备达到化工行业标准HG/T 2935—2000的饲料级硫酸亚铁产品。综合利用了钛白废酸和硫铁矿烧渣,具有原料价格低廉、来源广泛、生产成本低等优势。

New technology for the preparation of feed＇grade ferrous sulfate by waste acid from titanium dioxide production and pyrite cinder was studied. Process for preparation of feed,grade ferrous sulfate included acid-leaching, purifying, reduction,filtrating,frozen crystallization,washing,and vacuum drying. Effects of acid-leaching conditions on leaching rate as well as on the influences of puriiying and reducing conditions on product quality were investigated emphatically. Results showed that iron leaching rate could reach 96% when mass fraction of waste sulfuric acid was 30% , mass ratio of liquid to solid was 5： 1, and leaching time was 2 h. Iron scurf could be used as reducing agent to get ferrous sulfate solution. Through rozen crystallization and vacuum drying feed grade ferrous sulfate could be obtained, which could meet the requirement of China chemical Industry Strandard HG/T 2935--2000. The new technology utilized waste acid from titannium dioxide production and pyrite cinder, therefore, it has the advantages of cheap raw materials,widespread sources of raw materials,and low production cost etc..