Inorganic Chemicals Industry ›› 2022, Vol. 54 ›› Issue (10): 96-101.doi: 10.19964/j.issn.1006-4990.2022-0103

• Research & Development • Previous Articles     Next Articles

Leaching behavior of phosphate ore in phosphoric acid

ZHENG Hanxiao(),LÜ Li(),TANG Shengwei,HE Yanjun,ZHANG Tao   

  1. School of Chemical Engineering,Sichuan University,Chengdu 610065,China
  • Received:2022-03-07 Online:2022-10-10 Published:2022-11-03
  • Contact: Lü Li E-mail:18860381132@163.com;lily@scu.edu.cn

Abstract:

In order to improve the production process of wet-process phosphoric acid,improve the quality of by-product phosphogypsum,and relieve the environmental pressure caused by the solid by-products in the wet-process phosphoric acid,the research on phosphorus-sulfur two-step decomposition of phosphate ore to produce phosphoric acid was conducted.The leaching behavior of a phosphate ore in GuiYang in phosphoric acid was especially studied.The results showed that when the particle size of phosphate ore was less than 75 μm,the stirring speed was 500 r/min,the reaction temperature was 70 ℃,the w(P2O5) was 40% and the reaction time was 60 min,the decomposition rate of phosphate ore reached 98.5%.The decomposition rate of phosphate ore in 40% P2O5 could be described by the Drozdov kinetic empirical model well.The reaction retardation coefficient was large,and the apparent activation energy of the reaction was 6.048 kJ/mol.It was shown that the decomposition of phosphate ore by 40% P2O5 was controlled by diffusion.SEM and EDS analysis of the residues showed that the crystallization of calcium dihydrogen phosphate was the main factor affecting the diffusion.

Key words: phosphate ore, wet phosphoric acid, calcium dihydrogen phosphate, kinetics

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