Abstract: Organic extraction of P2O5 from the dissolution of phosphorite tailings with a mixture of sulfuric acid and hydrochloric acid was investigated with effects of extraction and back extraction conditions. The dissolution was purified firstly by evaporation to remove impurities. P2O5 extraction rate of higher than 68% could be achieved under the optimum conditions using n-butyl alcohol as extractant under ambient temperature for 10min from sample with P2O5 concentration of 48% and the phase ratio of 3∶1. The back extraction rate of P2O5 from organic phase could be achieved to higher than 90% using water as the back extractant with water dosage of 30% of the organic phase volume under ambient temperature for 5min. Concentration of the obtained H3PO4 product was as high as 50.49% with very low content of other impurities.

摘要： 以硫酸和盐酸的混合酸分解高镁磷尾矿获得的酸解液为原料，研究不同萃取条件和反萃条件对磷酸萃取率和反萃率的影响。结果表明，对蒸发结晶除杂后的酸解液采用正丁醇进行萃取时，当萃取温度为室温、萃取原液P2O5浓度为48%、萃取相比为3︰1、萃取时间为10 min时，可达到较好的萃取效果。在此条件下， P2O5的萃取率可达68%以上。从有机相中进行H3PO4反萃时，反萃剂采用水，加入量为反萃前有机相体积的30%，反萃时间为5 min，常温下进行反萃，P2O5的反萃率可达90%以上。反萃后获得的溶液H3PO4浓度达到50.49%，其它杂质含量均较低，说明采用溶剂萃取法从高镁磷尾矿酸解液中萃取磷酸是可行的。