Method for extracting lithium from low grade lithium-containing clay mineral

Abstract

The invention provides a new technology of 'modifying roasting-dump leaching' for large-scale low grade lithium-containing clay mineral in north of Henan province, solving the problem of utilization of low grade lithium-containing clay in the area. The new technology overcomes the defects of long technological process and high production cost of traditional lithium extraction technology, and the lithium leaching efficiency reaches 91%.

Description

Technical field [0001] The patent of the invention relates to a method for extracting lithium from low-grade lithium-containing clay minerals. Background technique [0002] At present, the process of extracting lithium from minerals at home and abroad mainly targets spodumene and lepidolite. There are few studies on the extraction of lithium from lithium-containing clay minerals. [0003] The lithium extraction process for spodumene and lepidolite mainly includes 1. Sulfuric acid production process: spodumene-high temperature roasting-cooling and grinding to 0.152mm mixed with sufficient sulfuric acid (93%-98%), and sent to 250°C for acidification Rotary furnace for acidification roasting. 2 Sulfate mixed sintering production process: adding potassium sulfate (or calcium sulfate or a mixture of both), mixing and sintering at a certain temperature, and then leaching and separating the sintered clinker. 3. Sodium carbonate pressure leaching production process: firstly process spod...

AI Technical Summary

Problems solved by technology

[0005] 1. Sulfuric acid production process: After the roasting reaction, sulfuric acid and soda ash become sodium sulfate with low value, the process is long and the process energy consumption is high

[0006] 2. Sulfate mixed sintering production process: If sodium sulfate cannot be used instead of potassium sulfate, a large amount of potassium salt will be consumed, resulting in higher production costs and products often contaminated by potassium

[0007] 3. Sodium carbonate pressure leaching production process: the cost of pressure leaching is relatively high

[0008] 4. Chlorination roasting production process: Lithium chloride is difficult to collect, furnace gas is highly corrosive, and reagent consumption is large

[0009] 5. The production process of limestone roasting method: the lithium content in the leaching solution is low, the evaporation energy consumption is large, the recovery rate of lithium is low, and the ore slime obtained after leaching is cohesive, which brings difficulties to equipment maintenance

[0010] All the above methods need to grind the spodumene finely, which increases the cost

Images