以硅铁为还原剂制取金属锂的工艺优化

Optimization of Technological Conditions in Reduction of Lithium by Ferro-silicon Alloy

以硅铁为还原剂,采用真空热还原法制备金属锂.通过单因素实验及正交实验研究了还原温度、反应时间、制团压力、物料粒度、真空度及还原剂过量率等因素对金属锂还原率的影响.结果表明,在实验范围内各因素对还原率的影响次序为:还原温度>还原时间>还原剂过量率>制团压力>物料粒度.硅热真空还原制备金属锂的最佳工艺条件为:还原温度1293K,还原时间180min,制团压力30MPa,物料粒度80μm,还原剂过量率50%.在该条件下金属锂的还原率可达97.85%,纯度达99.24%.

Vacuum reduction with ferro-silicon alloy as reductant was used to produce lithium. The single factor and orthogonal experiments were adopted to study the effects of reduction temperature, reduction time, briquetting pressure, vacuum degree, particle size and excess coefficient of reductant on lithium reduction rate. The results indicated that the order of influential factors on the lithium reduction rate within the experimental range was obtain as follows： reduction temperature〉reduction time〉excess coefficient of reductant〉briquetting pressure〉particle size. The optimal technological parameters of lithium reduced by ferro-silicon alloy were determined as follow： reduction temperature 1293 K, reduction time 180 min, briquetting pressure 30 MPa, particle size 80 μm, and excess coefficient ofreductant 50%. Under such conditions, the reduction rate was obtained as 97.85%, the purity was 99.24%.