磷石膏-硫酸渣煤基还原焙烧物相转化研究  

Study on Phase Transformation of Phosphogypsum-Pyrite Cinder under Coal Based Reduction Roasting

作　　者：刘雨浩 毛宏勃 宋文强 张鹏飞 周仙霖 余洪[1,2] Liu Yuhao;Mao Hongbo;Song Wenqiang;Zhang Pengfei;Zhou Xianlin;Yu Hong(School of Resources&Safety Engineering,Wuhan Institute of Technology,Wuhan,Hubei 430073;Hubei Key Laboratory for Efficient Utili­zation and Agglomeration of Metallurgic Mineral Resources(Wuhan University of Science and Technology),Wuhan,Hubei 430081)

机构地区：[1]武汉工程大学资源与安全工程学院,湖北武汉430073 [2]冶金矿产资源综合利用与造块湖北省重点实验室(武汉科技大学),湖北武汉430081

出　　处：《非金属矿》2023年第1期11-15,共5页Non-Metallic Mines

基　　金：冶金矿产资源综合利用与造块湖北省重点实验室(2022zy003)。

摘　　要：还原分解是磷石膏综合利用途径之一,但分解温度高、能耗高阻碍了该方法的应用。铁基添加剂有助于降低磷石膏还原分解温度,提高磷石膏分解效率。通过热力学分析、X射线衍射(XRD)仪,研究硫酸渣为铁基添加剂,磷石膏-硫酸渣在煤基条件下同步还原焙烧的物相转化。结果表明,当磷石膏、硫酸渣和煤粉配比为30∶10∶1混合还原焙烧,温度为700~900℃时,硫酸渣可以实现磁化还原生成Fe_(3)O_(4),其中800℃时,磁选可获得铁品位和回收率分别为48.33%和32.31%的磁铁矿;温度为1000~1100℃时,硫酸渣难以发生同步还原,主要以Fe_(2)O_(3)和FeS存在。磷石膏在700~1100℃范围内逐渐分解,部分CaSO4转为Ca_(5)(PO_(4))_(3)F;当温度大于1000℃后,开始转化为CaS和Ca_(5)(PO_(4))_(3)OH。研究发现,磷石膏中杂质P和F的存在,以及分解温度对磷石膏-硫酸渣在煤基条件下的同步还原分解影响较大。本研究可为磷石膏、硫酸渣同步利用提供理论参考。Reducing decomposition is one of the comprehensive utilization ways of phosphogypsum,but the application is hindered by high decomposition temperature and high energy consumption.Iron-bear additives can reduce the decomposition temperature of phosphogypsum and improve the decomposition efficiency of phosphogypsum.In this paper,the phase transformation of phosphogypsum-pyrite cinder under coal based reduction roasting using pyrite cinder as iron-bear additive was studied by thermodynamic analysis and X-ray diffraction,The results showed that phosphogypsum,pyrite cinder and coal were mixed for reduction roasting with the ratio of 30∶10∶1,when the temperature was 700-900℃,the pyrite cinder can realize magnetization reduction to generate Fe_(3)O_(4);Under 800℃,magnetite with iron grade and recovery of 48.33%and 32.31%can be obtained by magnetic separation;When the temperature was 1000-1100℃,it was difficult for the pyrite cinder to be reduced simultaneously,mainly in the form of Fe_(2)O_(3) and FeS.Phosphogypsum gradually decomposed at 700-1100℃,and part of CaSO4 was converted to Ca_(5)(PO_(4))_(3)F.When the temperature was higher than 1000℃,CaS and Ca_(5)(PO_(4))_(3)OH began to be converted.It was found that the presence of impurities P and F in phosphogypsum and the decomposition temperature had a great influence on the phosphogypsum-pyrite cinder under coal based reduction roasting.The experimental results provide a theoretical reference for the utilization of phosphogypsum and pyrite cinder simultaneously.

关 键 词：磷石膏 硫酸渣 还原焙烧 物相转变 

分 类 号：TD985[矿业工程—选矿]