低温碱焙烧-水浸法从铁锂云母中提取锂铷铯的研究  

Extraction of Lithium, Rubidium, Cesium from Zinnwaldite by Low Temperature Alkaline Roasting-Water Leaching

作　　者：王若宇 蔡振平 田希军[1,2,3] 罗鹏飞 陈松 Wang Ruoyu;Cai Zhenping;Tian Xijun;Luo Pengfei;Chen Song(National Engineering Research Center for Environment-Friendly Metallurgy in Producing Premium Non-Ferrous Metals,China GRINM Group Corp.,Ltd.,Beijing 100088,China;Grinm Resources and Environment Tech.Co.,Ltd.,Beijing 101407,China;General Research Institute for Nonferrous Metals,Beijing 10088,China)

机构地区：[1]中国有研科技集团有限公司高品质有色金属绿色特种冶金国家工程研究中心,北京100088 [2]有研资源环境技术研究院(北京)有限公司,北京101407 [3]北京有色金属研究总院,北京100088

出　　处：《稀有金属》2024年第12期1743-1754,共12页Chinese Journal of Rare Metals

基　　金：河北省重点研发计划项目(19211002D)资助。

摘　　要：目前工业上锂云母提锂焙烧的温度通常在850℃左右,焙烧温度高,能源消耗大。通过热力学计算分析了使用NaOH和CaO分解铁锂云母的可行性,研究了铁锂云母的低温碱焙烧-浸出工艺条件并进行了实验验证。结果表明:铁锂云母焙烧过程中加入适当比例的NaOH和CaO,可使铁锂云母在较低温度下发生较为彻底的分解。碱焙烧-水浸的最佳工艺条件为:Na OH∶CaO∶精矿质量比为2∶0.5∶1,焙烧温度为650℃,焙烧时间为1.5 h,浸出液固比为2,浸出时间为60 min,浸出温度为90℃,该条件下Li,Rb,Cs,Al和Si的浸出率分别为86.8%,98.7%,31.0%,20.0%和3.3%。热分析、扫描电镜-能谱(SEM-EDS)分析以及X射线衍射(XRD)分析结果表明,物料在焙烧过程中存在明显的[Al-O]和[Si-O]结构的分解,Na和Ca通过扩散进入精矿内部,促进了铁锂云母的分解。At present,the resources that could be used for industrial lithium extraction mainly include salt lake brine and lithium ore,among which lithium containing ores include spodumene and lepidolite,etc.However,zinnwaldite,which was also pegmatite lithium ore,has not received sufficient attention due to its high iron and fluoride contents.Therefore,zinnwaldite was not used for industrial lithium extraction,the current laboratory treatment of zinnwaldite methods were direct carbonation,hydrochloric acid leaching,oxalic acid leaching,calcium carbonate digestion,however,these methods still existed some disadvantages such as high energy consumption,long reaction time and corrosive gas.In this experiment,a promising process of treating zinnwaldite by molten alkali roasting at low temperature was studied,molten sodium hydroxide could effectively decompose silicate minerals,while avoiding the formation of HF,the addition of CaO could adjust the iron lithium mica from acidic rocks to basic rock,so lithium could be more easily dissociated from the mineral,while avoiding fluoride and silicon ions into the liquid phase.The effects of different roasting conditions on the leaching rate of lithium,the reaction mechanism and the migration behavior of major elements in the roasting process were discussed.It was known from the chemical element analysis that the contents of lithium,iron and fluorine of zinnwaldite were 1.34%,2.83%and 5.38%respectively.The effects of roasting temperature,time and additive on the leaching efficiency were evaluated.X-ray diffraction (XRD) was employed to characterize the sinters.The results showed that when the additive amount of NaOH was low,partial zinnwaldite did not decompose,with the increase of the additive amount of Na OH,the overall extraction rates of lithium and cesium showed a rising trend,and the sinters were mainly NaAlO_(2) and Fe_(2)O_(3);The extraction rates of lithium and cesium could be improved by adding proper amount of CaO.Different roasting temperature would lead to the change of rea

关 键 词：铁锂云母 锂 低温 碱焙烧 

分 类 号：TF826.3[冶金工程—有色金属冶金]