Mechanical compression evaporation and re-dissolution separation nitrate production process

Abstract

A mechanical compression evaporation and re-dissolution separation nitrate production process includes the steps: taking sodium sulfate and sodium chloride solution to as raw material liquid, mixing the raw material liquid and heating salt making mother liquor, preheating mixture to reach a boiling point by mechanical compression evaporation condensed water, enabling the mixture to enter primary high-temperature mechanical compression evaporation, and separating the mixture to obtain sodium sulfate and primary high-temperature nitrate making mother liquor; enabling the primary high-temperaturenitrate making mother liquor to enter secondary high-temperature mechanical compression evaporation to obtain mixture of secondary high-temperature salt nitrate making mother liquor containing sodiumchloride and sodium sulfate solid, and performing heat exchange on the mixture and low-temperature salt making mother liquor to obtain cooling salt nitrate mixed liquid; cooling the cooling salt nitrate mixed liquid and tap water or circulating water through a forced circulation heat exchanger of a setting separator with a jacket, re-dissolve the sodium sulfate to salt out the sodium chloride, and performing solid-liquid separation solid sodium chloride and low-temperature salt making mother liquor; performing heat exchanger and heating on the low-temperature salt making mother liquor to obtain heating salt making mother liquor, returning the heating salt making mother liquor, and performing mixing and heat exchanger to take part in next primary high-temperature mechanical compression evaporation nitrate making process. According to the process, production cost is low, product quality is high, and emission of waste water, waste gas and solid waste is omitted.

Description

technical field [0001] The invention belongs to the technical field of inorganic chemical industry, in particular to a production process of mechanical compression evaporation and back-dissolution separation of nitrates. Background technique [0002] The known method of producing sodium sulfate and sodium chloride from sodium sulfate and sodium chloride solution adopts the method of discharging the nitrate mother liquor by mechanical compression and evaporation. The amount of salt enriched by circulation in salt lakes affects the quality of brine, shortens the service life of mines or salt lakes, and pollutes the environment. Therefore, the above-mentioned processes are difficult to meet the scientific development requirements of national energy conservation, emission reduction, green energy, and environmental protection. Contents of the invention [0003] The object of the present invention is to provide a production process of mechanical compression evaporation and back-...

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Problems solved by technology

[0002] The known method of producing sodium sulfate and sodium chloride from sodium sulfate and sodium chloride solution adopts the method of discharging the nitrate mother liquor by mechanical compression and evaporation. The amount of salt enriched by circulation in salt lakes affects the quality of brine, shortens the service life of mines or salt lakes, and pollutes the environment. Therefore, the above-mentioned processes are difficult to meet the scientific development requirements of national energy conservation, emission reduction, green energy, and environmental protection.

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