Study On The Effects Of Impurities On The Extraction Of Phosphoric Acid

Wet-process phosphoric acid (WPA) is generally used for making phosphorus fertilizers because of high impurity contents. If wet-process phosphoric acid is used to the production of high-quality phosphate, it is required to be further purified.Lots of researches on the purification of wet-process phosphoric acid have been done. One of the most successful technologies is solvent extraction which has already applied to industrial production. Some studies on this topic have been done in China, but they are nearly in lab scale. The successful reports on industrial pilot have not been seen yet. So it is necessary to develop our own technology for wet-process acid purification, in order to keep up with Chinese fast-developing wet-phosphoric acid industry, and to meet the increasing demand for industrial phosphoric acid and food phosphoric acid.Because of the different phosphoric rock and the production technology of wet-process phosphoric acid, the contents of the impurities in wet-process phosphoric acid is different. And those impurities will affect the extraction process of phosphoric acid. The main impurities in wet-process phosphoric acid are SO₄^2-,SiF₆^2-,Fe³⁺,Al³⁺,Ca²⁺,Mg²⁺. This paper suited the effects of these impurities...