为改进湿法磷酸生产工艺,提高副产石膏的品质,减少湿法磷酸固体副产物磷石膏堆存产生的经济和环保压力,进行了磷酸分解磷矿制磷酸的实验研究。采用贵州某磷矿为主要原料,研究了湿法磷酸预分解磷矿的反应条件。通过单因素实验确定了湿法磷酸分解磷矿最优反应条件：反应温度为75 ℃,磷酸与磷矿的质量比（液固比）为9,反应时间为3 h,磷酸质量分数为30%（以五氧化二磷计）。在此条件下,磷矿的分解率为98.62%。

In order to improve the production process of wet-process phosphoric acid,improve the quality of by-product phos-phogypsum,and reduce the economic and environmental pressure caused by the storage of solid by-products of wet-process phosphoric acid,the experiment of phosphoric acid decomposition of phosphate rock to produce phosphoric acid was carried out.Using a phosphate rock in Guizhou,China as the main raw material,the reaction conditions of pre-decomposition of phos-phate rock by wet-process phosphoric acid were studied.The optimum reaction conditions for the decomposition of phos-phate rock by wet process phosphoric acid were determined by single factor test,i.e.reaction temperature was 75 ℃,mass ra-tio of phosphoric acid to phosphate rock（liquid-solid ratio） was 9,reaction time was 3 h and mass fraction of phosphoric acid was 30%（in terms of P₂O₅）.Under these conditions,the decomposition rate of phosphate rock was 98.62%.