About 35% of the world's lithium resources come from lithium-rich minerals and clay, so lithium can be extracted from lithium-rich minerals to meet the needs of the market. Its main beneficiation technology mainly includes three kinds: gravity separation, magnetic separation and flotation.
In general, gravity separation is mainly used to remove coarse gangue, or to extract lithium from high-grade ores; flotation is mainly used to purify fine-grained materials; magnetic separation can be used to remove iron-containing gangue in lithium-rich minerals, To further improve the concentrate grade.
Because of the different types of lithium-rich ores, the beneficiation process used is also different. The three enrichment methods of spodumene, lepidolite, and spodumene will be introduced to you below.
As an important raw material for lithium extraction, the methods for extracting lithium from spodumene mainly include flotation and chemical leaching.
Spodumene flotation method: The flotation method has wide applicability and is widely used in the purification of spodumene with industrial value. However, the flotation agent is one of the important factors affecting the flotation effect of spodumene, so it can be replaced with an efficient and environmentally friendly collector. For example, sodium oleate/tributyl can be used to separate spodumene from feldspar by flotation 140,000-based phosphorus chloride, which is a new type of mixed anion/cation collector, can obtain better flotation separation effect.
Spodumene chemical leaching method: one of the commonly used methods for spodumene purification during chemical leaching, but pre-activation treatment of the ore is required. Among them, destroying the structure of aluminum silicate is the key to extracting lithium by chemical leaching of spodumene. Since spodumene is similar to illite, the Bayer process can be introduced to treat natural α-spodumene. The ore decomposes under alkaline conditions, adding Calcium oxide and increased temperature can accelerate the decomposition of spodumene, and the leaching rate of lithium can be increased to about 93% after optimization.
Chemical leaching is one of the main methods for extracting lithium from lepidolite ore. The use of different activators can result in different leaching rates. For example, when potassium sulfate is used as the activator, the structure of lepidolite does not change significantly, and the leaching rate of lithium can reach 98.7%; if potassium salt is used as the activator, the leaching rate of lepidolite can reach 99.1%. . Therefore, it is necessary to choose the appropriate type of activator and the mass ratio to the concentrate.
Lithium phosphate ore beneficiation extraction generally refers to a mineral rich in lithium and phosphate to obtain lithium phosphate concentrate by flotation, then enter the mill for grinding pretreatment, and use concentrated sulfuric acid for leaching, which can make Lithium and aluminum are converted into soluble sulfate, and fluoride and phosphate are extracted to obtain an enriched leachate. Acidic impurities can be precipitated by adding limestone, lime, monovalent carbonate or hydroxide to remove impurities in the lithium-containing filtrate, and recover lithium as a lithium-containing salt product.
The above is a brief introduction to the lithium extraction method of spodumene, lepidolite and lithium phosphate aluminum. Because there are large differences in the types and properties of ore in different deposits, analysis is required to determine the appropriate beneficiation process plan.
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