磷尾矿热分解动力学机理与煅烧工艺研究  

SStudy on thermal decomposition kinetic mechanism and calcination process of phosphorus tailings

作　　者：周强 武斌[1] 陈葵[1] 纪利俊[1] 吴艳阳[1] ZHOU Qiang;WU Bin;CHEN Kui;JI Lijun;WU Yanyang(School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学化工学院,上海200237

出　　处：《无机盐工业》2023年第3期47-54,共8页Inorganic Chemicals Industry

摘　　要：磷尾矿中的钙、镁、磷资源含量丰富。使用煅烧-浸出法以磷尾矿为原料生产镁盐时,首先需要将磷尾矿煅烧分解为氧化钙和氧化镁,达到活化、提纯的目的。磷尾矿的热分解机理对生成镁盐的质量以及煅烧工艺的选择等都具有重要意义。对磷尾矿热分解动力学特性与煅烧工艺进行了探究,为磷尾矿资源的回收利用提供理论指导。研究表明,在升温速率为10℃/min条件下煅烧温度由25℃升高至1000℃的过程中,磷尾矿非等温热分解过程可分为两个阶段,即400~500℃白云石分解为碳酸钙与氧化镁的第一阶段和700~900℃碳酸钙分解为氧化钙的第二阶段,并分别确立了相应的热分解动力学方程。较优煅烧条件:煅烧温度为900℃、煅烧时间为4 h、升温速率为15℃/min、尾矿粒度小于0.150 mm。Relatively high content of calcium,magnesium and phosphorus exists in phosphorus tailings.To produce magnesium salt from phosphorus tailings by calcination-leaching process,it is necessary to calcine and decompose phosphorus tailings into CaO and MgO to achieve the purpose of activation and purification.The thermal decomposition mechanism of phosphorus tailings is of great significance to the quality of magnesium salt and selection of calcination process.The thermal decomposition kinetic characteristics and calcination process of phosphorus tailings were explored,so as to provide theoretical guidance for the recycling of phosphorus tailings resources.The results showed that the non isothermal thermal decomposition process of phosphorus tailings could be divided into two stages in the process of heating rate of 10℃/min and calcination temperature rising from 25℃to 1000℃.Dolomite was decomposed into the first stage of calcium carbonate and magnesium oxide at 400℃to 500℃,and calcium carbonate was decomposed into the second stage of calcium oxide at 700℃to 900℃.The corresponding kinetic equations of thermal decomposition were established respectively.The better calcination conditions were calcination temperature of 900℃,calcination time of 4 h,heating rate of 15℃/min,tailings size of less than 0.150 mm.

关 键 词：磷尾矿 煅烧 热分解 机理 非等温动力学 

分 类 号：TF046[冶金工程—冶金物理化学]