盐酸法湿法磷酸循环生产工艺研究

摘要

Wet-process phosphoric acid was produced by hydrochlorice acid method using mid-low-grade phosphate rock.The condensation ratio of reaction mother liquor,circle washing process of slag and recycle process of production of phosphoric acid by using concentrated solution decomposing phosphoric rock were studied.The results showed that,the precipitation rate of total phosphorus was 96.08% when the condensation ratio was 0.35;the silicon content of the slag in circle washing process was above 50%,which could be extracted and used.The chlorine content of the slag was low,which could be used in dry stockpiling process.The P2 O5 content of the wet-process phosphoric acid reached 58% after 10 cycles,which was up to the factory standard. The circle process can avoid the pollution of environment and save resources.Therefore the method has the po-tential social and economic benefit.%采用盐酸法利用中低品位磷矿制备湿法磷酸。对反应母液的浓缩比例、矿渣循环水洗工艺以及浓缩滤液循环分解磷矿制备磷酸工艺进行了研究。结果表明，浓缩比例为0.35时，总磷沉淀率达到96.08％；循环水洗所得矿渣中硅含量大于50％，可进行硅的提取利用，矿渣中氯含量低，可直接进行干堆处理，浓缩滤液循环10次后制得的湿法磷酸经净化后P2 O5含量达到58％，达到工业级磷酸标准。该循环工艺可避免环境污染，节约资源，具有潜在的经济效益和社会效益。