氯化镁从钨酸钠溶液中除去氟和磷工艺研究  

Process Study on Removal of Fluorine and Phosphorus from Sodium Tungstate Solution by Addition of Magnesium Chloride

作　　者：邹爱忠 杨亮[2] 张新英 万林生[2] ZOU Ai-zhong;YANG Liang;ZHANG Xin-ying;WAN Lin-sheng(Ganzhou Haichuang Tungsten Co.,Ltd.,Dayu 341500,China;Faculty of Materials Metallurgy and Chemistry,Jiangxi University of Science and Technology,Ganzhou 341000,China)

机构地区：[1]赣州海创钨业有限公司,江西大余341500 [2]江西理工大学材料冶金化学学部,江西赣州341000

出　　处：《稀有金属与硬质合金》2020年第6期5-8,13,共5页Rare Metals and Cemented Carbides

基　　金：国家自然科学基金(51964019);中国博士后面上项目(2018M632594)。

摘　　要：低品位白钨矿采用磷酸钠-氢氧化钠-氟化钙协同浸出,能够实现钨的高效浸出,但得到的粗钨酸钠浸出液中含有一定量的杂质氟和磷。采用氯化镁作为除杂试剂,将粗钨酸钠溶液中的氟和磷沉淀除去。考察了氯化镁用量、温度、溶液pH值、初始氟浓度和反应时间对除杂效果的影响。实验结果表明:提高氯化镁用量和反应温度、延长反应时间均有利于改善氟和磷的除杂效果,但pH值过大或者过小均不利于除杂。当溶液中初始氟浓度为1.35~2.85 g/L、磷浓度为0.18g/L时,最佳工艺条件为:氯化镁加入量控制为镁与氟的摩尔比nMg/nF=0.9、温度80℃、溶液pH值11.8、反应时间为30min,氟和磷的去除率分别达到98.3%和97.2%,沉淀渣中钨的损失率约为0.15%。因此,氯化镁沉淀法能够实现低钨损条件下钨酸钠溶液中氟和磷的高效脱除。Tungsten can be efficiently leached from low grade scheelite by sodium phosphate-sodium hydroxide-calcium fluoride synergistic leaching,but the crude sodium tungstate leaching solution contains a certain amount of impurities of fluorine and phosphorus.Magnesium chloride was used as impurity removal agent to remove fluorine and phosphorus from the crude sodium tungstate solution in the form of precipitate.The effects of magnesium chloride dosage,temperature,pH value,initial fluorine concentration and reaction time on impurity removal were investigated.The experimental results show that increasing the amount of MgCl2,reaction temperature and reaction time is beneficial to improving the removal effect of fluorine and phosphorus,but too large or too small pH value is not conducive to the removal of impurities.When initial fluorine concentration is 1.35~2.85g/L and initial phosphorus concentration is 0.18g/L,the optimal process conditions are as follows:the molar ratio of magnesium to fluorine is nMg/nF=0.9,the temperature is 80℃,the pH value of solution is 11.8,and the reaction time is 30min.The removal rates of fluorine and phosphorus reach 98.3%and 97.2%,respectively,while the loss rate of tungsten in the precipitation slag is about 0.15%.Therefore,magnesium chloride precipitation method can effectively remove fluorine and phosphorus from sodium tungstate solution with low tungsten loss.

关 键 词：钨酸钠溶液 氯化镁 氟 磷 除杂 白钨矿浸出液 

分 类 号：TF841.1[冶金工程—有色金属冶金]