A kind of method for producing potassium sulfate and aluminum chloride by metathesis of potassium alum mixed solvent

Abstract

The invention discloses a method for producing potassium sulfate and aluminum chloride by double decomposition of a potassium alum mixed solvent. The method comprises the following steps: taking an ethanol-water mixed solvent as a solvent, adding the potassium alum and potassium chloride with certain proportions for dissolving; carrying out double decomposition reaction to obtain a potassium sulfate crystal and a potassium sulfate crystal mother solution; washing and drying the potassium sulfate crystal to obtain a finished product potassium sulfate; carrying out evaporating, concentrating, crystallizing, solid-liquid separation, washing and drying on the potassium sulfate crystal mother solution to obtain a finished product aluminum chloride. According to the method disclosed by the invention, the characteristic that the solubility of the potassium sulfate is different from that of the aluminum chloride in ethanol is utilized, and the potassium alum is directly utilized for preparingthe potassium sulfate crystal and an aluminum chloride crystal, so that the problems that reaction conditions are difficult to control and the potassium sulfate is difficult to separate and precipitate in a traditional process of producing by taking water as a solvent are solved; in addition, the method has the advantages of high yield of potassium and aluminum, high purity of a product, easinessin recovery of the solvent, low energy consumption, less investment, closed whole process, no discharge of three wastes, direct production of aluminum alt with high added value, good economic benefits, easiness in enlargement of the device and suitability for industrial development.

Description

technical field [0001] The invention belongs to the technical field of potassium sulfate and aluminum chloride production, and in particular relates to a method for producing potassium sulfate and aluminum chloride by metathesis of a potassium alum mixed solvent. Background technique [0002] Potassium, as one of the three major nutritional elements needed by plants, is the most abundant cation in plants, and plays an irreplaceable role in the activation of various enzymes in plants, photosynthesis, regulation of osmotic pressure, synthesis and operation of nutrients, etc. role. However, most of the soils in our country are generally deficient in potassium, and the long-term potassium fertilization is insufficient, and the growth of potassium-loving crops that are sensitive to chloride ions can only be applied with chlorine-free potassium fertilizers. Potassium sulfate contains 50% potassium oxide and 18% sulfur. As a high-quality chlorine-free potassium fertilizer, the dem...

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Problems solved by technology

[0004] In order to solve the technical problem that the prior art cannot simply and efficiently utilize potassium alum to convert potassium sulfate and aluminum chloride, the invention provides a method for producing potassium sulfate and aluminum chloride by metathesis of a mixed solvent of potassium alum, which utilizes potassium sulfate The characteristics of the solubility of aluminum chloride in ethanol solution are different, so that the potassium sulfate produced by the reaction is directly precipitated in the form of solid crystals, while aluminum chloride is dissolved in ethanol solution, which has the advantages of short process flow, mild conditions, less evaporated water, The solvent is easy to recover, the product is of high purity, and high value-added aluminum chloride crystals can be directly prepared, without producing three wastes, simple production equipment, low energy consumption, and good benefits, so it is more suitable for industrial production

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