针对湿法磷酸渣酸难以利用的问题,提出一种利用渣酸制备饲料级磷酸氢钙的工艺路线,并以产品的磷氟比[m（P₂O₅）/m（F）]为指标对工艺参数进行优化。实验结果表明,在脱氟工序pH为2.8时,溶液磷氟比大于250,渣酸中的杂质离子富集于白肥中,从而达到净化杂质离子的目的,使得溶液中的各元素指标达到生产饲料级磷酸氢钙的要求。采用石灰乳对脱氟后的酸液进行中和,可得到w（F）<1.8×10^-3、磷氟比大于300且铬、砷、铅等杂质含量都较低的磷酸氢钙产品,满足GB/T 22549—2017《饲料添加剂磷酸氢钙》的要求。

In order to solve the problem of difficult utilization of residue acid of wet process phosphoric acid,a new process for preparation of feed grade dicalcium phosphate from residue acid was put forward.The process parameters were optimized based on the ratio of phosphorus to fluorine of the product.The experimental results showed that when the pH of the defluorination process was 2.8,the ratio of phosphorus to fluorine of the solution was more than 250,and the impurity ions in the sludge acid were enriched in the white fertilizer to achieve the purpose of purification of impurity ions,and made the element content in the solution meet the requirements of feed grade dicalcium phosphate.The defluorinated acid solution was neutralized with lime milk to obtain dicalcium phosphate products with w（F） lower than 1.8×10^-3,the ratio of phosphorus to fluorine more than 300,and low content of chromium,arsenic,lead and other impurities,which met the GB/T 22549—2017 “feed additive dicalcium phosphate”.