【摘要】 以硫酸钠-硫酸钙复合硫酸盐作为焙烧剂，采用焙烧-水浸法提取中低品位锂云母矿（0.93%Li）中的锂。探讨了焙烧工艺参数对锂浸出率的影响，并研究了焙烧过程的热力学和动力学、焙烧熟料的微观形貌和物相变化。结果表明，最佳焙烧条件为：锂云母、Na₂SO₄、CaSO₄的质量比为1∶0.197∶0.703、焙烧温度950℃和焙烧时间2 h,在此条件下用纯水浸出，锂浸出率可达94.8%。在最佳焙烧条件下，锂云母稳定结构被破坏，并与硫酸钙、硫酸钠反应主要生成钙长石、钠长石和可溶性锂盐。用未反应收缩核模型来描述硫酸钠和硫酸钙存在下锂云母焙烧的动力学，在825～900℃时计算出焙烧过程的表观活化能为52.1 kJ/mol,判定焙烧过程受化学反应控制。更多还原

【Abstract】 Lithium in medium to low-grade lepidolite（0.93% Li） was extracted by roasting-water leaching method with sodium sulfate-calcium sulfate composite sulfate as roasting agent.The effects of roasting process parameters on the leaching rate of lithium were discussed.The thermodynamics and kinetics of the roasting process, the microscopic morphology and phase change of the roasted clinker were studied.The results show that the optimum roasting conditions are as follows: the mass ratio of lepidolite, Na₂SO₄ and CaSO₄ is 1∶0.197∶0.703,roasting temperature is 950 ℃ and roasting time is 2 h.Under these conditions, the leaching rate of lithium can reach 94.8% by leaching with pure water.Under the optimum roas-ting conditions, the stable structure of lepidolite is destroyed, and its reactions with calcium sulfate and sodium sulfate mainly produce anorthite, albite and soluble lithium salt.Using unreacted shrinking core model to describe the kinetics of lepidolite roasting in the presence of sodium sulfate and calcium sulfate, the apparent activation energy of the roasting process is calculated to be 52.1 kJ/mol at 825～900 ℃,indicating that the roasting process is controlled by chemical reaction.更多还原