CIESC Journal ›› 2020, Vol. 71 ›› Issue (10): 4792-4799.DOI: 10.11949/0438-1157.20200672

• Energy and environmental engineering • Previous Articles     Next Articles

Research on leaching rate enhancement and organic matter removal in wet-process phosphoric acid

Changyuan TAO1,2(),Xiuxiu WANG1,2,Zuohua LIU1,2,Renlong LIU1,2,Jinhua LUAN3   

  1. 1.Schollge of Chemistry and Chemical Engineering, Chongqing University, Chongqing 400044, China
    2.State Key Laboratory of Coal Mine Disaster Dynamics and Control, Chongqing University, Chongqing 400044, China
    3.Chongqing Institute of Geology and Mineral Resources, Chongqing 400044, China
  • Received:2020-06-03 Revised:2020-07-14 Online:2020-10-05 Published:2020-10-05
  • Contact: Changyuan TAO

湿法磷酸浸出强化及有机质去除研究

陶长元1,2(),王秀秀1,2,刘作华1,2,刘仁龙1,2,栾进华3   

  1. 1.重庆大学化学化工学院,重庆 400044
    2.重庆大学煤矿灾害动力学与控制国家重点实验室,重庆 400044
    3.重庆地质矿产研究院,重庆 400044
  • 通讯作者: 陶长元
  • 作者简介:陶长元(1963—),男,博士,教授,taocy@cqu.edu.cn
  • 基金资助:
    国家重点研发计划项目(2019YFC1905802);重庆市教委科学技术研究计划项目(KJZD-M201900101);重庆市规划和自然资源局科技项目(KJ-2019036)

Abstract:

In the process of wet-process phosphoric acid leaching, the product phosphoric acid appears black due to the incomplete carbonization of some organic matter. A novel type of catalytic oxidation wet-process phosphoric acid purification technology was proposed in this work. During the leaching process, the oxidant (H2O2) and catalyst (MnO2) was added to form the peroxides such as ·OH and HO2· in the transformation process, which can enhance the removal rate of organic matter and strengthen the leaching rate of phosphate rock. The different reaction conditions that affected the leaching rate of wet-phosphoric acid and the removal of organic matter were investigated. The results indicated that 96.9% of phosphate rock were leached under the optimum conditions of H2O2 dosage 0.08 ml/g, MnO2/P mass ratio of 0.04, 80℃ and for 40 min. At the same time, the TOC remove rate reached 79%. The analysis mechanism showed that H2O2 will form H3PO4 · H2O2 peroxide with H3PO4 in the solution, and MnO2 will react with it like Fenton to generate a large amount of ·OH, and then fully oxidized the black organic matter into CO2 and H2O. Organic matter “wrapped” on the surface of the phosphate rock is broken by ·OH, which promoted the leaching of phosphoric acid and enhanced the removal of organic matter.

Key words: wet-process phosphoric acid, black organic matter, catalytic oxidation

摘要:

在湿法磷酸浸出过程中由于部分有机物碳化不彻底,使产品磷酸呈现黑色。本文提出了一种新型的催化氧化湿法磷酸净化技术,即在湿法磷酸浸出过程中引入氧化剂(H2O2)及催化剂(MnO2),基于转化过程中形成的·OHHO2·等过氧化物实现对有机物的去除与浸出过程的强化。重点考察不同反应条件对湿法磷酸浸出率及有机质去除的影响。结果表明,浸出时间为40 min、反应温度为80℃、H2O2用量为0.08 ml/g、催化剂与磷矿的质量比为0.04时,磷矿浸出率可达96.9%;同时测定得到的TOC去除率达到79%。分析机理可得,H2O2会与溶液中的H3PO4形成H3PO4·H2O2过氧化物,MnO2与之发生类Fenton反应,产生大量·OH,进而将黑色有机物充分氧化为CO2和H2O,打破有机物对磷矿颗粒表面的“包裹”,促进磷酸的浸出和有机物的去除。

关键词: 湿法磷酸, 黑色有机物, 催化氧化

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