Method for preparing agricultural potassium sulfate from potassium-rich rock

Abstract

The invention discloses a method for preparing agricultural potassium sulfate from a potassium-rich rock. The method comprises the following steps of: performing crushing and mineral separation on the potassium-rich rock so as to prepare powder taking potassium feldspar as a main phase; grinding mixed powder of potassium feldspar powder and sodium carbonate, calcining at the temperature of between 700 and 900 DEG C, adding a proper amount of water into the calcined clinker powder, and fully stirring and mixing for water leaching; filtering and separating, introducing excessive CO2 into the filtrate for an acidification and neutralization reaction, and filtering the precipitate, wherein the solution is mainly solution of mixed potassium and sodium salt; evaporating, crystallizing and separating to obtain a sodium bicarbonate crystal and adding in a raw material calcining stage for recycling; continuously crystallizing to form composite potassium and sodium salt which can be added with carbon components for circulation of the solution and also can be used as a calcining ingredient for recycling; and adding a proper amount of concentrated sulfuric acid or introducing SO3 gas into theresidual solution of potassium-rich solution to prepare suspension of potassium sulfate, wherein the suspension can be directly dried to prepare the qualified agricultural potassium sulfate product and also can be filtered and dried to prepare high-grade agricultural potassium sulfate product.

Description

Technical field [0001] The invention relates to a method for preparing agricultural potassium sulfate by using non-water-soluble potassium-rich rocks. Background technique [0002] my country is a large agricultural country, and the demand for non-chlorine-based potash fertilizer is large. The domestic production capacity of potassium sulfate is limited and most of them rely on imports. The reason is that the domestic water-soluble potassium ore resources are extremely scarce, and the raw materials for the production of potassium sulfate are heavily dependent on imports. However, my country's water-insoluble potash minerals are rich in resources and have a wide range of types, including potash feldspar, leucite, illite, potash-rich shale, potash-rich volcanic rock, nepheline syenite, pegmatite and potassium-rich slate, etc. . According to statistics, the total amount of non-water-soluble potassium mineral resources in the country is at least about 20 billion tons. Therefore, ex...

AI Technical Summary

Problems solved by technology

Domestic production capacity of potassium sulfate is limited, and most of them rely on imports. The reason is that domestic water-soluble potassium ore resources are extremely scarce, and raw materials for the production of potassium sulfate are heavily dependent on imports.

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