Method for preparing water soluble sylvite

Abstract

The invention discloses a method for preparing water soluble sylvite. The method includes the steps that A, inorganic base salt and smashed potassium-rich rock are mixed to obtain a first mixture, acid radical negative ions of the inorganic base salt correspond to negative ions of the water soluble sylvite, and the potassium-rich rock is the silicate mineral with the mass percent larger than or equal to 8% in terms of K2O; B, the first mixture is heated to be at the temperature smaller than or equal to 300 DEG C and melted, and a second mixture is obtained; C, the second mixture is heated to be at the temperature of 500 DEG C to 1,200 DEG C in a microwave mode, the temperature is kept for 10 min to 2 h, and a third mixture is obtained; D, the third mixture is cooled to be at the temperature of 80 DEG C to 120 DEG C, then water is led into the cooled third mixture, a fourth mixture is obtained, the temperature of the fourth mixture is kept for 6 h to 48 h at the temperature of 50 DEG C to 90 DEG C, solid-liquid separation is carried out, and then first filtered liquid is obtained; E, the first filtered liquid is concentrated and cooled, and the soluble sylvite is separated out. According to the preparing method, the potassium-rich rock serves as a raw material, a water solution of the soluble sylvite is obtained through two-time extracting, the technology is simple, the preparing cost is low, and the technology is safe.

Description

technical field [0001] The invention belongs to the technical field of inorganic salt preparation, and in particular relates to a preparation method of water-soluble potassium salt. Background technique [0002] my country is a large agricultural country, and potash fertilizer, as an important strategic agricultural resource, is related to the country's food supply security. At present, the annual demand of my country's crop potassium fertilizer market is about 4.6 million tons (in K 2 O meter), plus industrial potassium and reasonable stocks, the total annual demand for potassium salt is about 6.49 million tons. It is estimated that by 2020, my country's market demand for crop potassium fertilizer alone will reach 10 million tons. At present, my country's potash fertilizer production capacity is limited, and the annual production capacity is only about 3.2 million tons (in K 2 (2) cannot satisfy the demand of the domestic market, and about 30% of the annual potassium fer...

AI Technical Summary

Problems solved by technology

Thus there are problems such as high energy consumption and complicated operation; moreover, by the activation of potassium-rich rocks by the above method, the resulting products are mostly mineral potassium fertilizers containing silicon, calcium and other elements, without further separation and purification, in order to prepare water-soluble Potassium salts generally need to be added with conversion agents, and undergo multi-step conversions such as acidification, neutralization, and other metathesis, which greatly increases production costs

In addition, in the above methods, when heating is required, conventional heating is generally used, which has problems such as slow heating rate, long time consumption, low heat energy utilization efficiency, and difficult product separation; Poor absorption, if the microwave heating method is directly used to treat potassium-rich rocks, etc., the purpose of heating the mixed material cannot be achieved; and the existing microwave technology for treating potassium-rich rocks also needs to add water, acid and other wave-absorbing media. , acid and other microwave-absorbing media are easy to evaporate and decompose at high temperatures, so the microwave reaction temperature is generally low, and it is difficult to achieve the expected heating effect

Images