Method for producing sodium carbonate by utilizing chlor-alkali ammonia-alkali tailings

Abstract

The invention relates to a method for producing sodium carbonate, in particular to a method for producing sodium carbonate by utilizing chlor-alkali ammonia-alkali tailings. Limestone burns to emit heat, and is resolved to generate carbon dioxide gas which is sent to a compressor; the acetylene sludge slurry of the chlor-alkali tailing and calcium carbide dust are mixed to prepare lime slurry; refined salt water is prepared through light salt brine after production of chlor-alkali and mirabilite; light ammoniacal brine is sent to an absorption tower to prepare ammoniacal brine; sodium bicarbonate slurry is sent to a filtering alkali vehicle for solid-liquid separation; the solid body is sent to a sodium bicarbonate calcination procedure; the liquid is sent to a mother liquid distillation procedure; the sodium bicarbonate is conducted by heating resolving in a sodium bicarbonate calcination furnace to generate sodium carbonate, and is sent to a sodium bicarbonate production and alkali cooling procedure; the generated carbon dioxide gas returns to a carbonizer. The method produces sodium carbonate by utilizing the carbon dioxide emitted by the ammonia-alkali and the acetylene sludge slurry emitted by the chlor-alkali, realizes combined production of the two alkalis, solves the problem of emission of the alkali wastes, reduces consumption of limestone and energy, improves the utilization ratio of the carbon dioxide, and improves the production of sodium carbonate through an ammonia soda process.

Description

technical field [0001] The invention relates to a method for producing soda ash, in particular to a method for producing soda ash by utilizing chlor-alkali tailings and ammonia-soda tailings. Background technique [0002] Soda ash is an important basic chemical raw material. The ammonia-soda method is one of the main production methods of soda ash. The main raw materials are crude salt and limestone. The production of soda ash by this method accounts for more than half of the total output of soda ash in my country. The ammonia-soda method has high energy consumption. , the disadvantage of low resource utilization, especially CO 2 Large emissions and high pressure on environmental protection. [0003] As one of the main raw materials, limestone not only provides the required carbon dioxide gas for the production of soda ash, but also provides the required effective calcium oxide for the recycling of ammonia in the production process of soda ash and the refining of brine. ...

AI Technical Summary

Problems solved by technology

[0004] Chlor-alkali enterprises generally produce two kinds of tailings in the production process. One is calcium carbide slurry, a by-product of PVC production by the calcium carbide method. For each ton of PVC produced, about The calcium carbide slurry with a discharge concentration of about 1.75mol / l is about 6m3 / h. Because of its relatively narrow scope of use and inability to handle it, it has been piled up for a long time, causing serious pollution to the surrounding geographical environment; Sulfate-containing light brine, the treatment of calcium carbide slag slurry and the enrichment of sulfate radicals in caustic soda production have long been a problem for chlor-alkali plants

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