摘要
以中国某盐湖的锂精矿为原料,研究了水洗法脱除锂精矿中可溶性杂质的规律及机理。主要探索了水洗温度对可溶性杂质脱除的影响,结合扫描电镜(SEM)、X射线衍射(XRD)和能谱仪(EDS)等表征方法,研究了可溶性杂质的赋存形式及物相转化规律。结果表明:在液固质量比为3∶1、水洗温度为60℃、水洗时间为4 h条件下,可将锂精矿中的钠、钾、氯质量分数分别降低至2.5%、0.35%、2.65%。锂精矿中的可溶性杂质主要以氯化钠(NaCl)和复盐氯碳酸钠镁石[Mg_2Na_6(CO_3)_4Cl_2]两种物相存在。常温下水洗仅可溶解氯化钠,而复盐氯碳酸钠镁石几乎不溶。复盐氯碳酸钠镁石在40℃开始溶解,60℃及以上完全溶解。水洗过程中发生了复盐氯碳酸钠镁石向碱式碳酸镁的转变反应,且升高温度有利于该反应的正向进行。
Taking lithium concentrate from a salt lake in China as raw material,the rule and mechanism of removing soluble impurities in lithium concentrate by water washing method were studied.The influence of water washing temperature on the removal of soluble impurities was mainly explored.Combining with scanning electron microscope(SEM),X-ray diffraction(XRD)and energy spectrometer(EDS),and other characterization methods,the occurrence form and the law of phase transformation of soluble impurities were studied.The experimental results showed that under the conditions of liquid solid ratio of 3∶1,temperature of 60 ℃,and water washing time 4 h,the mass fractions of Na,K,Cl could be reduced to 2.5%,0.35% and 2.65% respectively.Soluble impurities mainly existed as NaCl and Mg2Na6(CO3)4Cl2,but only NaCl dissolved at room temperature in washing process.Mg2Na6(CO3)4Cl2 began to be dissolved at 40 ℃ and completely dissolved above 60 ℃.The conversion of Mg2Na6(CO3)4Cl2 to Mg5(CO3)4(OH)2·4H2O was enhanced by the increase of temperature.
作者
蒿紫阳
袁波
李芯
易美桂
Hao Ziyang;Yuan Bo;Li Xin;Yi Meigui(School of Chemical Engineering,Sichuan University,Chengdu 610065,China)
出处
《无机盐工业》
CAS
CSCD
北大核心
2019年第3期49-52,共4页
Inorganic Chemicals Industry
关键词
锂精矿
碳酸锂
可溶性杂质
lithium concentrate
lithium carbonate
soluble impurities
