摘要
为有效回收隐爆角砾岩筒型锂云母矿中的锂,采用焙烧—浸出工艺提取锂,并与花岗岩型锂云母中的锂提取进行对比研究。通过L_9(3~3)正交试验得到最优锂浸出条件,并探讨了锂的浸出率影响因素和锂浸出机理。研究结果表明,在硫酸质量分数15%、液固比4 mL/g、焙烧时间4 h的条件下,角砾岩筒型锂云母中锂浸出最优条件为焙烧温度450℃、反应时间4h、浸出温度200℃,而花岗岩型锂云母中锂浸出最优条件为焙烧温度900℃、反应时间4h、浸出温度200℃。最优条件下锂浸出率分别为99.65%和94.11%。不同因素对于锂浸出率的影响程度大小依次为浸出温度、焙烧温度、反应时间。进一步研究发现,焙烧—浸出过程中,锂云母结构被破坏,锂转化为可溶性硫酸盐扩散到溶液中。同时,高温焙烧后硫酸中氢离子更易置换锂云母结构中锂离子和其他金属离子,使锂的浸出率升高。角砾岩筒型锂云母中因含有萤石和托帕石等含氟矿物,其在适当温度(450℃)焙烧后再浸出时,氟与H~+即可发生反应破坏其结构,有利于锂的溶出。花岗岩型锂云母需高温(900℃)焙烧脱羟基后,才能使其结构中锂易于与H~+置换,从而获得较高的锂浸出率。焙烧—浸出工艺使用硫酸浓度较低,对设备腐蚀性较小,且工艺简单高效,具有工艺优越性。
In order to recover lithium from cryptoexploded breccia tube type lepidolite ores effectively,roasting-leaching process was used to extract lithium,and a comparative study was carried out with lithium extraction from granite type lepido-lite.The optimal lithium leaching conditions were obtained by L9(33)orthogonal experiments,and the factors affecting the lith-ium leaching rate and the lithium leaching mechanism were explored.The results show that under the conditions of sulfuric acid mass fraction of 15%,liquid-solid ratio of 4 mL/g and roasting time of 4 h,the optimal leaching conditions for lithium from breccia tube type lepidolite are roasting temperature of 450℃,reaction time of 4 h and leaching temperature of 200℃.The optimum conditions for leaching lithium from granite type lepidolite are roasting temperature of 900℃,reaction time of 4 h and leaching temperature of 200℃.Under the optimal conditions,the leaching rates of lithium were 99.65%and 94.11%,respec-tively.The influence degree of different factors on the leaching rate of lithium is in order of leaching temperature,roasting tem-perature and reaction time.It was further found that the structure of lepidolite in the sample is destroyed during the roasting-leaching process,and the lithium is converted into soluble sulfate and diffused into the solution.Meanwhile,hydrogen ions in sulfuric acid can be substituted more easily for lithium ions and other metal ions in lepidolite structure after roasting at high temperature,and lithium leaching rate can be effectively increased.Due to the fluorine-containing minerals such as fluorite and topaz in the breccia tube lepidolite,when it is roasted at an appropriate temperature(450℃)and then leached,fluorine and H+can react to destroy its structure,which is conducive to the dissolution of lithium.Granite type lepidolite requires roasting at high temperature(900℃)to dehydroxy,so that the lithium in its structure can be easily replaced with H+,so as to obtain a higher lithium leaching rate.The roasting and leaching process uses a lower concentration of sulfuric acid,which is less corro-sive to the equipment,and the process is simple and efficient with superiority.
作者
周轩平
汪洋
赵昊
陈瑜
左可胜
程宏飞
ZHOU Xuanping;WANG Yang;ZHAO Hao;CHEN Yu;ZUO Kesheng;CHENG Hongfei(School of Earth Science and Resources,Chang′an University,Xi′an 710054,China)
出处
《金属矿山》
CAS
北大核心
2024年第1期244-250,共7页
Metal Mine
基金
国家自然科学基金项目(编号:42172043)
山西省科技重大专项(编号:20181101003)。
关键词
锂云母
锂
硫酸
焙烧—浸出工艺
正交试验
lepidolite
lithium
sulfuric acid
roasting and leaching process
orthogonal experiments
