Abstract

The expected increase in demand for alkali metal raises a concern over the difficulty in extracting Li, Rb, and Cs from hard rock ores. A four-step process is discussed to extract alkali metal from lithium porcelain stone. The process consists of roasting, leaching, evaporation and purification of lixivium, and precipitation of lithium salts. Two types of additives are used to enhance selective conversion into salts. The Li, Rb, Cs extraction efficiencies are determined to be 98.70, 97.27, 98.40%. An Na₂SO₄/CaCl₂/ore mass ratio of 0.2/0.2/1 at 850°C for 60 min is used for the roasting step. Analysis of calcine and leach residue shows the cation ions from the reagents promote highly-chemo selective ion-exchange extraction of the alkali metals in the ores. After this process, the Li⁺ in lixivium is concentrated from 3.43 to 9.50 g/L by evaporation. A controlled amount of H₂O₂, NaOH, and Li₃PO₄ is added to the lixivium to remove the impurities. Precipitation of 94.09% of the Li in the purified solution by Na₂CO₃ is achieved. Further precipitation using Na₃PO₄ · 12H₂O is done, leaving a solution from which Rb, Cs could be recovered. This proves the process is possible and practical.

中文翻译：

---

锂瓷石中Li，Rb和Cs的选择性萃取和碳酸锂的沉淀

摘要

对碱金属需求的预期增加引起了人们对从硬岩矿石中提取Li，Rb和Cs的困难的担忧。讨论了从锂瓷石中提取碱金属的四步法。该过程包括焙烧，浸出，浸出液的蒸发和提纯以及锂盐的沉淀。两种类型的添加剂用于增强选择性转化成盐的能力。Li，Rb，Cs的萃取效率确定为98.70％，97.27％，98.40％。Na ₂ SO ₄ / CaCl ₂焙烧步骤在850℃下以0.2 / 0.2 / 1的质量比/矿石质量比进行焙烧。煅烧和浸出残余物的分析表明，试剂中的阳离子促进了矿石中碱金属的高度化学选择性离子交换萃取。在该过程之后，通过蒸发将浸液中的Li ⁺从3.43浓缩至9.50g / L。将受控量的H ₂ O ₂，NaOH和Li ₃ PO ₄添加到浸液中以除去杂质。通过Na ₂ CO ₃沉淀纯化溶液中的94.09％Li 。使用Na ₃ PO ₄  ·12H ₂进一步沉淀完成O，留下可以从中回收Rb，Cs的溶液。这证明了该过程是可行且可行的。