为了有效脱除湿法磷酸生产的工业级磷酸二氢铵中的大部分砷,提高产品质量等级,采用五硫化二磷和硫化钠作为脱砷剂,分别进行脱砷试验,且研究了二次结晶对工业级磷酸二氢铵脱砷效果的影响.试验结果表明,五硫化二磷比硫化钠的脱砷效果佳,用量少,且对重金属的脱除效果更好,从成本考虑五硫化二磷也较硫化钠更划算;采用二次结晶得到工业级磷酸二氢铵的砷含量较一次结晶的低,但耗水量大,且产品中砷含量达不到I类产品要求的w(As)≤50 μg/g,二次结晶对重金属的脱除也不甚理想,故不建议采用二次结晶.

Ammonium sulphate,as a by-product from the sulphuric acid plant,is typically used for the subsequent production of compound fertilizer.However,the feed volume is not big,in order to avoid impact on the nutrients of the compound fertilizer product. In order to solve the problem of reuse of by-product ammonium sulphate,the feasibility of using ammonium sulphate to replace part of sulfuric acid to decompose phosphate rock to produce phosphoric acid was studied. The impact on the decomposition of phosphate rock,phosphogypsum crystallization,and nitrogen yield by adding ammonium sulphate was investigated. The maximum amount of ammonium sulfate added was obtained. The test results show that replacing part of sulfuric acid with ammonium sulfate to decompose phosphate rock can reduce the amount of sulfuric acid by 50%,and the nitrogen yield can reach more than 90%.

介绍高水溶性磷酸二铵生产原理及生产技术.通过研究浓磷酸沉降过程,采用特殊的强制性渣酸分离技术除去酸中金属离子络合物((Fe,Al)3KH14(PO4)8·4H2O)淤渣;同时,根据洗涤工段磷铵料浆特性,调节洗涤系统磷酸加入量及磷酸二铵料浆pH值,并采用强制性渣浆分离技术除去磷铵料浆中金属离子络合物沉淀,提高磷酸二铵产品水溶磷含量.对产品养分进行理论计算,产品w(总养分)为65.23％.600 kt/a高水溶性磷酸二铵生产装置投产以来,生产装置运行平稳,产品m(P2O5水溶)/m(P2O5有效)均值高达92.26％.

The clear of ejection sloped tube and exhaust gas tunnel of pelletizer is the key for insuring continuous production of DAP system. By a rational technical innovation for it, the obstruction problem of ejection sloped tube and exhaust gas tunnel has resolved, so that set in use rate increased, continuous run insured, a better benefit brought about.