氟磷灰石-碳还原过程热力学分析及钙、硅迁移转化  

Thermodynamic analysis of fluoroapatite-carbothermal reduction process and the transport of calcium and silicon elements

作　　者：穆刘森 马丽萍[1] 杨静[1] 郭致蓥 姚远 敖冉 隗一 杨杰 MU Liusen;MA Liping;YANG Jing;GUO Zhiying;YAO Yuan;AO Ran;WEI Yi;YANG Jie(College of Environmental Science and Engineering,Kunming University of Science and Technology,Kunming 650500,China;Yunnan Phosphate Group Co.,Ltd.,Kunming 650600,China;Chengdu University of Information Engineering,Chengdu 610200,China)

机构地区：[1]昆明理工大学环境科学与工程学院,云南昆明650500 [2]云南磷化集团有限公司,云南昆明650600 [3]成都信息工程大学资源环境学院,四川成都610200

出　　处：《磷肥与复肥》2021年第11期25-29,共5页Phosphate & Compound Fertilizer

基　　金：国家自然科学基金(21666016);国家重点研发计划项目(2018YFC1900201)。

摘　　要：利用FactSage7.1热力学软件对氟磷灰石碳热还原过程进行热力学分析,并模拟电热法制磷,采用X射线衍射(XRD)、傅立叶变换红外光谱(FT-IR)和扫描电镜(SEM)等分析还原过程及Ca、Si元素的相态转变。结果显示:主要含Ca固相Ca_(5)(PO_(4))_(3)F在1180℃时会转化为Ca_(3)(PO_(4))_(2)和CaF_(2),在1250℃时发生脱氟转变为CaSiO_(3)和Ca_(3)(PO_(4))_(2);体系中的Si在1250℃时会由固相SiO_(2)转变为CaSiO_(3),同时会有微量气相SiF_(4)逸出;随温度的升高,Ca、Si会转变为不同形式的钙硅酸盐并形成低共熔物,形成钙硅酸盐的顺序为CaSiO_(3)、Ca_(2)SiO_(4)和Ca_(3)SiO_(5);随温度的升高,体系在1400℃时发生熔融并产生含有硅酸盐系低共熔物的液相,液相的产生和扩散会影响反应的进行程度。该研究为实现热法加工全量资源化利用提供理论基础。FactSage7.1 thermodynamic software is used to conduct thermodynamic analysis on the carbothermal reduction process of fluorapatite,and the electro-thermal method is simulated.XRD,FT-IR and SEM are used to analyze the reduction process and the phase transition of Ca and Si elements.The results show that mainly containing Ca solid phase Ca_(5)(PO_(4))_(3)F converted into Ca_(3)(PO_(4))_(2) and CaF_(2) at 1180℃,and defluorinated into CaSiO_(3) and Ca_(3)(PO_(4))_(2) at 1250℃.The Si in the system will change from solid SiO_(2) to CaSiO_(3) at 1250℃,and there will be trace SiF4 escape in gas phase.With the increase of temperature,Ca and Si will change into different forms of calcium silicate and form low eutectic,and the order of formation of calcium silicate is CaSiO_(3),Ca_(2)SiO_(4) and Ca_(3)SiO_(5).The system meltes at 1400℃and produces a liquid phase containing low eutectic of silicate system.The production and diffusion of the liquid phase will affect the degree of reaction.This work provides a theoretical basis for the full utilization of thermal processing resources.

关 键 词：氟磷灰石 碳 还原过程 热力学 钙硅迁移转化 

分 类 号：TD927[矿业工程—选矿]