关键词: 胺类萃取剂, 湿法磷酸, 萃取, 脱硫

Abstract:

:Amine extractants were selected for extracting sulfate ion and purifying wet process phosphoric acid.Under fixed phosphorus sulfur ratio,the influences of phosphoric acid concentration,phase ratio（volume ratio of extraction agent to phosphoric acid）,extracting series,and impurities（Fe ³⁺ and F ^-） on sulfate ion extraction efficiency and distribution coeffi-cient of phosphorus pentoxide were investigated.Results showed that the extraction efficiency of sulfate ion and phosphoric acid and distribution coefficients will both increase with the increasing of phase ratio and extraction series and with the decreasing of phosphoric acid concentration.From the experiment,the second-stage cross-flow extraction was beneficial to extracting sulfate and reducing the loss of phosphorus pentoxide when the extraction phase ratio was 0.5 and the phosphorus pentoxide mass fraction was 20%.The extractant had poor selectivity to iron,but can remove sulfate and fluorine at the same time.

Key words: amine extractants, wet process phosphoric acid, extraction, desulfurization