A kind of waste salt prepares the method for sodium carbonate by-product potassium sulfate, ammonium sulfate and ammonium chloride

Abstract

The invention provides a method for preparing sodium carbonate by-product potassium sulfate, ammonium sulfate and ammonium chloride from waste salt. The method separates waste salt after pulping to obtain dilute phase slurry and dense phase slurry; The dilute phase slurry and the dense phase slurry are subjected to solid-liquid separation respectively to obtain insoluble organic matter, prefabricated salt and treatment liquid; the prefabricated salt enters the preparation process of sodium carbonate and ammonium salt for treatment to obtain sodium carbonate, ammonium sulfate and chloride ammonium chloride; the obtained treatment solution is oxidized to obtain a purification solution; when K in the purification solution + After the concentration reaches the preset value, precipitation treatment is carried out to obtain potassium-containing precipitate and potassium-removing solution; the potassium-containing precipitate enters the potassium sulfate preparation process; and the potassium-removing solution is returned to the pulping step for recycling. The method has clean process, simple process and low cost, the utilization rate of sodium is not less than 90.8%, the purity of sodium carbonate is not less than 97wt%, and the purity of potassium sulfate, ammonium sulfate and ammonium chloride obtained can meet certain requirements for use.

Description

technical field [0001] The invention belongs to the technical field of chemical engineering and environmental protection, and relates to a method for preparing sodium carbonate by-product potassium sulfate, ammonium sulfate and ammonium chloride from salt, in particular to a waste salt purification treatment and preparation of sodium carbonate, potassium sulfate, ammonium sulfate and ammonium chloride ammonium method. Background technique [0002] At present, the output of chemical waste salt with sodium chloride and sodium sulfate as the main components is huge, and the treatment cost is high, and the high disposal cost has greatly increased the production and operation costs of related enterprises, and greatly restricted the technology of related enterprises. Upgrading and sustainable development. [0003] At present, the conventional disposal method of chemical waste salt is mainly to separate sodium sulfate and sodium chloride, mainly including salt-nitration separation...

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Problems solved by technology

[0002] At present, the output of chemical waste salt with sodium chloride and sodium sulfate as the main components is huge, and the treatment cost is high, and the high disposal cost has greatly increased the production and operation costs of related enterprises, and greatly restricted the technology of related enterprises. Upgrading and Sustainability

[0003] At present, the conventional disposal method of chemical waste salt is mainly to separate sodium sulfate and sodium chloride, mainly including salt-nitration separation method and nanofiltration separation method. Salt-nitration separation method is divided into thermal method and cold method. The circulation volume is large, the energy consumption is high, and the obtained products sodium sulfate and sodium chloride are of poor quality, low value, and poor market absorption capacity

The nanofiltration separation method can separate sodium chloride and sodium sulfate to a certain extent, but it cannot achieve complete separation of the two ions, so high-quality sodium sulfate and sodium chloride products cannot be obtained, and the process consumes a lot of energy. economy

In addition, sodium sulfate and sodium chloride are mainly upstream raw materials in the chemical industry. As by-products of solid waste treatment, due to the lack of relevant standards, the market acceptance is low and the market absorption capacity is limited. Most of them are stockpiled. As a soluble salt, it poses a serious threat to the environment

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