采用氢氟酸和碳酸钠作为沉淀剂,对湿法磷酸进行了脱除金属杂质的试验研究.考察了氢氟酸和碳酸钠的添加量、搅拌速度、反应时间和温度以及静置时间对湿法磷酸中铝、镁、铁脱除率的影响.研究表明,在反应温度为40℃,搅拌速度为50r/min,反应时间为10min,氢氟酸和碳酸钠的添加量分别为化学计量的1.2倍和0.2倍,静置时间为1d的工艺条件下,铝、镁和铁的去除率分别为49.2%,26.9%和21.9%,磷酸的回收率可达到90.7%.
Using hydrofluoric acid and sodium carbonate as sediments, removal of metal impurities from WPA was studied. The effects of dosage of hydrofluoric acid and sodium carbornate, reaction time and temperature, stirring speed, static time on removal rate of aluminum, magnesium, iron from wet-phosphoric acid were also investigated. The results showed that, when reaction temperature was 40℃, stirring speed was 50 r/min, reaction time was 10 mins, dosage of hydrofluoric acid was 1.2 times, dosage of sodium carbonate was 0.2 times and static time was one day, the removal rate of aluminum,magnesium and iron were respectively 49.2%, 26.9% and 21.9% ,and the recovery rate of phosphoric acid reached 90.7 %.