白钨矿连续酸浸槽内固体颗粒的流动特性实验及模型研究  

Experimental and modelling studies on flow characteristics of solid particles in a continuous tank for leaching scheelite

作　　者：曹国祥 唐忠阳 李江涛 李永立 赵中伟 伏虎 CAO Guoxiang;TANG Zhongyang;LI Jiangtao;LI Yongli;ZHAO Zhongwei;FU Hu(School of Metallurgy and Environment,Central South University,Changsha 410083,Hunan,China;Key Laboratory of Hunan Province for Metallurgy and Material Processing of Rare Metals,Changsha 410083,Hunan,China)

机构地区：[1]中南大学冶金与环境学院,湖南长沙410083 [2]稀有金属冶金与材料制备湖南省重点实验室,湖南长沙410083

出　　处：《化工进展》2018年第12期4565-4571,共7页Chemical Industry and Engineering Progress

基　　金：国家自然科学基金(51334008);国家重点研发计划(2017YFB0305401);长沙市杰出创新青年培养计划(KQ1707018)项目

摘　　要：以停留时间分布(RTD)为评价指标,对硫磷混酸浸出白钨矿的连续浸出槽内固相颗粒流动行为进行实验研究。同时探究了进料流量、搅拌转速、连续浸出槽中物料进出口位置组合对固相颗粒流动行为的影响。实验结果表明:随着进口流量的增大,一开始槽内的返混程度得到了增强,量纲为1化方差变大,但是继续增大进口流量,进口处物料的横向迁移速度加强,使槽内流体流动趋向平推流,导致量纲为1化方差减小;量纲为1化方差随着搅拌转速的增大而增大,但是此时在槽下部区域会逐渐形成循环死区,槽内死区体积分数随之增大;平均停留时间随着物料进出口位置的变化而发生变化,下进下出的进出料位置组合其平均停留时间最大,且最接近理论平均停留时间。最后利用非理想流动模型来表征实验过程中的停留时间分布,模型拟合的停留时间曲线与实验测量的曲线吻合程度良好。By using residence time distribution(RTD)as an evaluation criteria,flow behavior of solid particles in a continuous tank for leaching scheelite with sulfuric-phosphorous mixed acid was studied.The influences of factors,such as feed rate,stirring speed and combination of the inlet-outlet position,on the flow behavior of solid particles in the continuous leaching tank were investigated.The experimental results showed that the backmixing degree was enhanced with the increase of the feed rate and the normalised variance increased firstly.And then,the transverse migration velocity of the imported material increased,the RTD curve was closer to the curve of plug flow pattern,which resulted in the reduction of normalised variance.With the increase of stirring speed,the normalised variance increased,but the dead zone would be formed at the lower part of the tank gradually,and the volume fraction of dead zone increased.The mean residence time varied with the change of the combination of the inlet-outlet position and it was closest to the theoretical mean residence time when the inlet and outlet were both at the lower part of the tank.Two non-ideal flow models were used to characterize the RTD of the fluid in the continuous leaching tank.And the fitting time curves based on the models could give a good representation of the experimental curves.

关 键 词：白钨矿 固体颗粒 连续浸出槽 停留时间分布 非理想流动模型 

分 类 号：TH01[机械工程]