直接法生产硝酸钾 母液的优化利用研究

硝酸与氯化钾反应制取硝酸钾工艺会产生大量母液,目前的母液处理方法存在一系列问题。为了对母液进一步优化利用,进行了母液先萃取含稀土磷矿,然后用含镁化合物和碳铵分步中和制取经济价值更高的稀土磷酸盐和缓释三元复合肥的实验研究。介绍小试及部分中试结果,磷矿萃取率大于95%,稀土磷酸盐中稀土氧化物质量分数达0.29%,三元复合肥总养分质量分数大于25%。

Study on the production method of optimal use of potassium nitrate mother liquor

In view of the large amount of mother liquor produced in the preparation of potassium nitrate both HNO3 and KCl, and some problems existing in the current disposal methods of mother liquor, further optimal utilization of the mother liquor is presented, including the decomposing phosphate rock containing rare-earth with mother liquor, then adding magnesium compounds and ammonium bicarbonate in the decomposition liquor for preparation of the rare-earth phosphate and slow release NPK compound fertilizers with high values. The results of lab. and some pilot tests are introduced： extraction rate of P2O5 is more than 95%, rare-earth oxides in rare-earth phosphate is mass fraction of 0.29%, the total primary nutrient is mass fraction of ≥25%.