Industrial-grade anhydrous sodium sulfate preparation device and method

Abstract

The invention discloses an industrial-grade anhydrous sodium sulfate preparation device and method, and relates to the field of recycling sodium sulfate from light salt brine as industrial-grade anhydrous sodium sulfate. The device is characterized in that the device comprises a membrane concentration system, a continuous flow salting-out crystallization system, a centrifugal machine and a dryingmachine system which are connected in sequence. The membrane concentration system is used for concentrating the light salt brine containing sodium sulfate and discharging a concentrated solution containing supersaturated sodium sulfate. The continuous flow salting-out crystallization system is mainly used for crystallizing large-particle sodium sulfate crystals in a supersaturated sodium sulfate concentrated solution discharged by the membrane concentration system at normal temperature by a salting-out method and accurately controlling the supersaturation degree to separate out large-particlesodium sulfate crystals, and meanwhile, the purity of anhydrous sodium sulfate is ensured by utilizing a reflux design, and the centrifugal machine and drying machine system is used for drying. According to the invention, continuous preparation of large-particle high-purity anhydrous sodium sulfate is realized, and equipment investment and energy consumption are low when the anhydrous sodium sulfate is prepared at normal temperature.

Description

technical field [0001] The invention relates to the field of recovering sodium sulfate from light brine as industrial-grade sodium sulfate, in particular to a preparation device and method for industrial-grade sodium sulfate. Background technique [0002] In the chlor-alkali industry, the sulfate radicals in the light brine must be removed after electrolysis, otherwise it will affect the electrolysis efficiency. The main process for removing sulfate radicals in the light brine in the early stage is barium method or calcium salt-chemical precipitation method or membrane concentration plus freezing process . [0003] The chemicals added by the chemical precipitation method are mainly barium salt or calcium salt. The barium salt itself is toxic, which will cause great harm to the environment and people, and will cause serious environmental pollution. The chemical precipitation method of calcium salt is prone to sulfuric acid. Calcium scaling phenomenon, blockage of pipes, high...

AI Technical Summary

Problems solved by technology

However, in the above-mentioned process, sodium sulfate often occurs when sodium chloride is added to separate out and run, and sodium chloride is added excessively, which causes sodium chloride to be mixed with sodium chloride in the sodium chloride powder, so that the product purity cannot meet the needs of the industrial process. The addition of sodium chloride is controlled by weight ratio, the operation error is relatively large, and the operation process is discontinuous, which will cause excessive sodium chloride addition and excessive supersaturation, resulting in the precipitation of a large number of fine sodium sulfate crystals in the system, which cannot be quickly It is better to produce large particles of sodium sulfate. These fine particles of sodium sulfate will produce dust during drying and subsequent use, polluting the environment

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