Technology for producing highly pure potassium nitrate through reaction of sodium nitrate and potassium chloride

Abstract

A technology for producing highly pure potassium nitrate through a reaction of sodium nitrate and potassium chloride comprises the following steps: 1, adding clear water or a mother liquor into a reactor, dosing raw materials potassium chloride and sodium nitrate according to a molar ratio of 1:0.9-1.5, and carrying out a metathesis reaction at 70-150DEG C under normal pressure or an elevated pressure for 0.5-5h; 2, carrying out solid-liquid separation; 3, carrying out solid-liquid separation; 4, crystallizing; 5, dissolving crude potassium nitrate in water at 50-120DEG C to obtain a potassium nitrate solution; 6, filtering the potassium nitrate solution obtained in step 5 through a filtering device, or adding a flocculating agent to clarify the potassium nitrate solution; 7, re-crystallizing; and 8, washing purified potassium nitrate, centrifuging, and drying to obtain potassium nitrate. The technology has the advantages of realization of continuous or intermittent production, stable and reliable quality of the above product, and low energy consumption. The product meets superior product requirements, and the main content of potassium nitrate reaches 99.9% or above.

Description

technical field [0001] The invention relates to a process for producing high-purity potassium nitrate by reacting sodium nitrate and potassium chloride. Background technique [0002] Potassium nitrate is mainly used in the following aspects in industry: [0003] a) Industrially used in gunpowder, fireworks, fuses, matches, metal solders, ammonia catalysts, etc.; [0004] b) Used in the pharmaceutical industry to produce diuretics, sweating agents, cooling agents, penicillin potassium salts, and rifampin; [0005] c) Because it does not contain iron ions and nitrite ions, high-purity natural potassium nitrate is the preferred raw material for the production of high-quality glass products. It is also used in ceramics and precision instrument glass in the light industry. It is also used in the mobile phone touch screen industry. getting bigger; [0006] d) The demand for potassium nitrate in the fast-growing photovoltaic glass, solar glass and solar energy storage industries...

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Problems solved by technology

[0011] The Chinese patent application with the application number 200710035688.7 discloses a vacuum crystallization process for producing potassium nitrate by converting potassium chloride from sodium nitrate. It is mentioned that the purity of the obtained potassium nitrate meets the requirements of superior products, that is, the purity of potassium nitrate reaches more than 99.7%. , there are no potassium chloride and recrystallization steps in the process, and at the same time, the converted mother liquor has no filtration steps, and it is impossible to reach 99.8%, so it is not suitable for high-end markets such as glass and mobile phone touch screens.

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