摘要
现有的黏土型锂矿草酸浸出提锂法仅研究了浸出阶段的影响因素,缺乏对浸出液后续提锂的系统研究。通过光照沉铁、过量生石灰法、碳酸钠除钙沉锂等方法对浸出液进行处理,考察光照时间、氧化钙用量、碳酸钠用量、反应温度及反应时间等因素对杂质离子沉淀分离的影响。试验结果表明,在光照7 h、氧化钙用量4 g(30 mL光照后的溶液)下75℃反应2.5 h、碳酸钠40 mg(30 mL过量生石灰法处理后的溶液)下75℃反应20 min,铝的沉淀率达到99.91%,铁、镁和钙的沉淀率达到99.99%。碳酸钠除钙液经浓缩和高温沉淀后得到碳酸锂。机理分析表明,光照后铁主要以FeC2O4形式沉淀;过量生石灰法使铝、镁等以氢氧化物形式沉淀,有效减少了无定形氢氧化铝对锂的吸附;碳酸钠则使钙以碳酸钙形式沉淀、锂沉淀得到粗碳酸锂。通过研究,获得了一种从黏土型锂矿的焙烧-草酸浸出液中制备粗碳酸锂的方法。
At present,the lithium extraction by oxalic acid leaching of clay-type lithium ores has only studied the influencing factors in the leaching stage,and lacks a systematic study on the subsequent lithium extraction from the leach solution.The leachate was treated through methods including light to precipitate iron,excess lime method,and calcium removal by the sodium carbonate to precipitate lithium.The effects of light time,calcium oxide dosage,sodium carbonate dosage,reaction temperature and reaction time on the precipitation separation of impurity ions were investigated.The experimental results indicate that under the conditions of 7 h of light exposure,2.5 h of reaction at 75℃with 4 g of calcium oxide(per 30 mL of solution after light exposure),and 20 min of reaction at 75℃with 40 mg of sodium carbonate(per 30 mL of solution after excess quicklime method),the precipitation rate of aluminum reaches 99.91%,while that of iron,magnesium,and calcium reaches 99.99%.Sodium carbonate calcium removal solution is concentrated and precipitated at high temperatures to obtain the lithium carbonate.Mechanistic analysis shows that iron is mainly precipitated as FeC2O4 after light exposure.The excess quicklime method makes aluminum and magnesium precipitate in the form of hydroxide,which effectively reduces the adsorption of lithium by amorphous aluminum hydroxide.Sodium carbonate,on the other hand,causes calcium to precipitate as the calcium carbonate and lithium to precipitate to give crude lithium carbonate.A method for preparing crude lithium carbonate from roasting-oxalic acid leach solution of clay-type lithium ores is obtained by experimental study.
作者
杨宇春
杨敏
YANG Yuchun;YANG Min(School of Chemistry and Chemical Engineering,Guizhou University,Guiyang 550025,Guizhou,China)
出处
《中国冶金》
CAS
CSCD
北大核心
2024年第11期117-123,135,共8页
China Metallurgy
基金
贵州省锂资源高效分离提取关键技术研究与示范项目([2022]ZD007)。
关键词
光照时间
氧化钙
碳酸钠
碳酸锂
草酸亚铁
lighting time
calcium oxide
sodium carbonate
lithium carbonate
ferrous oxalate
作者简介
杨宇春(1999-),女,硕士生,E-mail:18035201310@163.com;通信作者:杨敏(1978-),女,博士,副教授,E-mail:myang6@gzu.edu.cn。
