Method for extracting Mg, K, B and Li from mixed brine by utilizing natural energy

Abstract

The invention provides a method for extracting Mg, K, B and Li from mixed brine by utilizing natural energy. The method comprises the following steps: evaporating, freezing and evaporating carbonate salt lake brine and obtaining brine A when the content of Li in the brine is smaller than or equal to 2.5g / L or the content of lithium carbonate in precipitated solid ores is smaller than or equal to 0.5%; evaporating, freezing and evaporating sulfate salt lake brine and obtaining brine B when the content of Mg in the brine is more than or equal to 10g / L; obtaining brine C after mixing and reaction between the brine A and the brine B; obtaining brine D when naturally evaporating the brine C until the content of sulfate radicals is 5-40g / L; obtaining brine E after freezing the brine D to precipitate mirabilite; evaporating the brine E to a certain degree to obtain brine F; evaporating the brine F to precipitate sylvite and then obtaining brine G; obtaining brine H after freezing the brine G to precipitate mirabilite; mixing the brine H with mixed alkali obtained in the first step to react and then obtaining brine I when the concentration of Li in the solution is 0.5-1.5g / L; leading the brine I to a cooling tank and naturally evaporating the brine to precipitate borax.

Description

technical field [0001] The invention relates to a development and utilization process of salt lake brine, in particular to a method for extracting Mg, K, B and Li from mixed brine by using natural energy. Background technique [0002] According to the type of brine, the salt lakes in the world can be roughly divided into several categories: carbonate type, sulfate type, chloride type and nitrate type. [0003] The boron-rich lithium carbonate salt lake is a kind of resource with high value. Tibet, located on the Qinghai-Tibet Plateau, is one of the areas in the world where carbonate-type boron-rich lithium salt lakes are concentrated. Zabuye and Jiezechaka are typical representatives of them, which contain lithium, potassium, and boron resources. [0004] Existing carbonate-type boron-lithium-rich salt lakes, taking Tibet’s Jieze Chaka Salt Lake as an example, the natural evaporation (indoor) crystallization route of brine is: halite, potassium halite, potassium halite + li...

AI Technical Summary

Problems solved by technology

[0004] Existing carbonate-type boron-lithium-rich salt lakes, taking Tibet’s Jieze Chaka Salt Lake as an example, the natural evaporation (indoor) crystallization route of brine is: halite, potassium halite, potassium halite + lithium carbonate, potassium halite + Lithium Carbonate + Glauber's Salt, Lithium Carbonate + Glauber's Salt + Borax, according to this crystallization route, in the potassium salt stage, the precipitated solid phase includes potassium halite, lithium carbonate, Glauber's salt, borax, etc., and the most economically valuable carbonic acid Lithium is dispersed and multi-span during the potassium salt precipitation stage, and there is no obvious enrichment segment; boron cannot be rapidly precipitated in the form of borax due to insufficient final alkalinity. Therefore, with this natural crystallization route, potassium, lithium, and There are large technical and economic problems in boron product processing

[0005] Specifically, (1) The precipitated potassium salt exists in the form of potassium halite, potassium mirabilite, potassium sulfate and other potassium mixed salts. It is difficult to process in the lake area. Even if it is processed with existing mature technology, the transportation distance is long and the economic benefit is relatively low Difference

(2) Lithium salt is precipitated in the form of lithium carbonate, but it is too dispersed and must be re-enriched on site. With flotation, the processing capacity is large, and it is difficult to increase the grade to more than 60%, and it still needs to be shipped out for processing

(3) For boron, the type of precipitated mineral is not clear, and the processing method is difficult to determine, but according to the transportation distance of the mining area, even if the precipitated boron ore B 2 o 3 If the content is more than 20%, it needs to be enriched again, and it is difficult to process

[0006] In addition, the environment in the plateau salt lake area is harsh. For example, Zabuye Lake and Jiezechaka Lake are both at an altitude of about 4500m. The traffic is basically in a blank state; the products are far away from the market, and the same product, such as KCl, is highly profitable in Golmud, with a net profit of more than 1,000 yuan per ton, while in Tibet, even if the increase in price and cost under harsh conditions is not considered, plus It is unprofitable or even loss-making after transportation costs, so it will be very difficult to develop these salt lakes with current methods

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