A kind of method that glauberite prepares sodium bicarbonate by-product ammonium sulfate and calcium carbonate

Abstract

The invention provides a method for preparing sodium bicarbonate by-product ammonium sulfate and calcium carbonate from glauberite, specifically: (1) introducing carbon dioxide into the salting-out mother liquor for calcification reaction, and separating solid and liquid to obtain sodium bicarbonate and bicarbonate Sodium mother liquor; (2) Ammonia gas is passed into the sodium bicarbonate mother liquor for ammoniation reaction to obtain ammoniated mother liquor; (3) Glauber’s salt raw material, sodium sulfate and ammoniated mother liquor are mixed for salting-out reaction, solid-liquid separation, and obtained The first double salt, calcium carbonate and salting-out mother liquor; (4) Mix double salt and water for reaction, solid-liquid separation to obtain sodium sulfate and separation mother liquor; (5) Mix ammonium sulfate mother liquor and separation mother liquor for cooling crystallization, solid-liquid Separation to obtain the second double salt and crystallization mother liquor; (6) Evaporation and crystallization of the crystallization mother liquor, solid-liquid separation to obtain ammonium sulfate and ammonium sulfate mother liquor. The method uses glauberite as a raw material to prepare sodium bicarbonate, realizes high-value conversion of sodium sulfate and calcium sulfate, and solves the problem of glauberite tailings stockpiling.

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 bicarbonate, in particular to a method for preparing sodium bicarbonate by-product ammonium sulfate and calcium carbonate from glauberite. Background technique [0002] As a mineral resource rich in sodium sulfate and calcium sulfate, glauberite is an important raw material for the preparation of anhydrous sodium sulfate. China has abundant glauberite reserves. The traditional mining method is to extract sodium sulfate from it by dissolving it in water, and then produce sodium sulfate, but the calcium sulfate cannot be effectively utilized and is mainly stockpiled. In addition, due to the small application fields of anhydrous sodium sulfate, and the impact of industrial by-product sodium sulfate and the impact of reduced demand from downstream industries, the market demand has gradually shrunk. In order to rea...

AI Technical Summary

Problems solved by technology

However, due to the low conversion rate of sodium sulfate metathesis reaction, the utilization rate of sodium sulfate is less than 60%, and it is impossible to obtain ammonium sulfate with pure phase, the cost is high, so the technology of sodium sulfate to prepare soda ash is at a standstill

Some studies have added organic amines to the reaction system of sodium sulfate to prepare sodium carbonate to promote the metathesis reaction. This method can increase the conversion rate to more than 90%, but because the organic amine is easily soluble in water, it is extremely difficult to separate, and Due to the residue of organic matter in ammonium sulfate and sodium carbonate, the loss of organic amine is large, the cost is high, and the product quality is low

[0005] CN101544385A discloses a kind of method that takes sodium sulfate as raw material and supplements organic amine to prepare sodium carbonate to co-produce calcium sulfate, described method can realize the conversion rate of sodium reaches more than 90%, but organic amine has high boiling point, high viscosity, evaporation recovery energy The consumption is high, and the entrainment of organic amine in sodium bicarbonate and calcium sulfate is much, the recovery is difficult, the loss is large, and the production cost is high

[0006] CN104355326A, CN102198953A and CN202016881U all disclose a method for preparing sodium bicarbonate and co-producing ammonium sulfate by metathesis. Using sodium sulfate and ammonium bicarbonate as raw materials, sodium bicarbonate is obtained through metathesis, and the separated mother liquor is deaminated at high temperature. Evaporate and concentrate at 130°C to obtain sodium sulfate crystals. After separation, the mother liquor is cooled and crystallized to obtain the double salt of sodium sulfate and ammonium sulfate. The mother liquor is then evaporated and crystallized to obtain ammonium sulfate products. However, the process of the method is complicated and requires multiple high temperatures, cooling, etc. process, high energy consumption, low utilization rate of sodium ions and sulfate radicals, large evaporation depth, large material circulation, high production cost, and no industrialized precedent at present

[0007] CN105000579A and CN105712382A all disclose a kind of precipitation method, and this method prepares sodium bicarbonate by double decomposition reaction of ammonium bicarbonate and sodium sulfate, then adds lime in sodium bicarbonate mother liquor, reclaims wherein ammonia, but in this process ammonia The recovery rate is only about 50%, resulting in waste of resources and increased operating costs, and the by-product calcium sulfate has a large output, low value, and poor quality, which makes it difficult to sell and easily causes secondary pollution

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