A compound salt treatment and comprehensive utilization process of insoluble potassium-rich minerals

Abstract

The invention discloses a composite salt treatment and comprehensive utilization process of insoluble potassium-enriched minerals. The process comprises the following steps: mixing insoluble potassium-enriched minerals with composite salt containing calcium salt and sodium salt, and then roasting at high temperature; performing water leaching on a roasted product, and then performing solid-liquid separation I to obtain a solid I and a liquid I, wherein the solid I is used for preparing aerated bricks or Portland cement additives, the liquid I is used for separating out precipitates by adjusting a pH value and is subjected to solid-liquid separation II to obtain a solid II and a liquid II, and the solid II is further prepared into Al2(SO4)3 or Al2O3; and preparing K2SO4 or K2CO3 by performing condensation crystallization or salt precipitation on the liquid II. According to the process disclosed by the invention, the insoluble potassium-enriched minerals are subjected to roasting treatment by the composite salt containing the calcium salt and sodium salt, and water leaching is combined to ensure that potassium, aluminum and silicon in the insoluble potassium-enriched minerals are fully separated, and meanwhile, aluminum products and potassium products with relatively high purity can be obtained; and by adopting the process, the comprehensive recovery and utilization of insoluble potassium-enriched mineral resources can be achieved.

Description

technical field [0001] The invention relates to a compound salt treatment and comprehensive utilization process of insoluble potassium-rich minerals, and belongs to the technical field of comprehensive utilization of insoluble potassium-rich mineral resources. Background technique [0002] The potassium-containing minerals of insoluble potassium-rich rocks are mainly microplagioclase, whose crystal chemical formula is K[AlSi 3 o 8 ], theoretical composition (mass fraction): SiO 2 64.7%, Al 2 o 3 18.4%, K 2 O16.9%, triclinic system, crystal structure [Si(Al)O 4 ] Tetrahedrons link into four-membered rings. Therefore, the goal of comprehensive utilization of potassium-rich rocks is to destroy the structure of potassium feldspar with the lowest energy and to realize SiO 2 、Al 2 o 3 、K 2 O resource utilization of the three components, of which potassium is the most valuable. [0003] Although potassium is widely used, more than 90% of the world's potassium salt produc...

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Problems solved by technology

[0007] Although there are a large number of technical developments and patents, most of the above-mentioned processes are difficult to achieve large-scale industrial production. Comprehensive analysis shows the following shortcomings: (1) energy consumption and material consumption are large, such as high-temperature sintering method, using Na 2 CO 3 / K 2 CO 3 The high-temperature sintering still has problems such as high cost of raw materials and complicated separation of impurities; (2) acid treatment due to high impurity content leads to high cost, severe equipment corrosion, and poor environmental compatibility, especially acid treatment containing fluoride , this problem is especially serious; (3) The tailings discharge problem is a difficult point in the acid process, and for the alkali process, the cost can be reduced because the silicon-calcium slag can by-produce Portland cement; (4) the current research is more The main disadvantage of the hydrothermal method is that the decomposition of potassium feldspar is not complete, and the product K 2 O has low nutrient content and strong alkaline (pH ≥ 10), long reaction cycle and low efficiency, making it difficult to realize large-scale industrial production

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