Abstract
The recovery and leaching kinetics of lithium from lepidolite by sulfuric acid method were investigated in this study, and a new method of nanofiltration to separate Al/Li from lepidolite leaching solution was coupled. The results indicated the optimal conditions about leaching lithium from lepidolite: leaching at 433 K for 4 h with the agitation rate of 120 r min−1, sulfuric acid concentration of 60 wt%, liquid-solid mass ratio of 2.5:1, under which the Li yield could reach at 97%. The kinetics observations revealed that the leaching process was controlled by the hybrid control of solid product layer diffusion and the chemical reaction, and dominated by chemical reaction step, which improved the conclusion of single-step control in the previous literature. A successful attempt was made to couple nanofiltration separation with sulfuric acid extraction of lithium, and DK membrane was used to separate Al/Li from lepidolite leaching solution. DK membrane has shown excellent retention of Al3+ and Ca2+ and also can effectively permeate Li+, which may bring a new inspiration for lithium extraction from lepidolite in the future.
Highlights
Lithium, as a critical element of supporting new energy strategy, has been widely used in lithium high-energy batteries, nuclear power generation, glass ceramics, and grease [1,2,3,4,5] due to its unique physical and chemical properties
Salt lake brines have been the main resource for the production of lithium compounds since the late 1990s because of cost effective [7,8], while the development of lithium ores should be improved under the urgent demand for lithium products
An effective method of separating Al/Li in the lepidolite leaching solution is critical to reduce the cost of lithium extraction
Summary
As a critical element of supporting new energy strategy, has been widely used in lithium high-energy batteries, nuclear power generation, glass ceramics, and grease [1,2,3,4,5] due to its unique physical and chemical properties. In terms of roasting process, lepidolite ores are roasted with additives at high temperature to extract lithium from the stable aluminosilicate structure of lepidolite, and the roasted product is leached to obtain a lithium bearing solution. Various additives such as lime–milk, NaCl + CaCl2 , Na2 SO4 + K2 SO4 + CaO, Na2 SO4 + CaCl2 were investigated by Yan. Minerals 2020, 10, 0981 et al to extract lithium from lepidolite [12,13,14]. Compared with the conventional roasting process, the lower reaction temperature required by sulfuric acid method can save a large amount of energy, and has been widely used in lithium ore extraction. An effective method of separating Al/Li in the lepidolite leaching solution is critical to reduce the cost of lithium extraction
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
