A kind of Glauber's salt continuous freezing crystallization process

Abstract

The invention discloses a continuous freezing and crystallization process of Glauber's salt, which relates to the technical field of Glauber's salt freezing and crystallization. The process comprises the following steps: A. Precooling: cooling to 40-50°C first, then cooling to 25-35°C; Freezing: cooling to 5-15°C; C, primary sedimentation; D, primary separation; E, secondary freezing: cooling to -10-0°C; F, secondary sedimentation; G, secondary separation. The beneficial effect of the invention is to realize the continuous feeding and discharging of the whole crystallization process, thereby realizing the continuous production of Glauber's salt; The scarring speed of Glauber's salt in the process effectively improves the utilization rate of equipment and improves production efficiency. At the same time, due to the high temperature and high refrigeration efficiency of the primary freezing crystallization, energy consumption can be effectively reduced; the nitrate analysis rate is high, and the cumulative nitrate analysis rate of the primary freezing crystallization and secondary freezing crystallization is over 90%.

Description

technical field [0001] The invention relates to the technical field of Glauber's salt freezing and crystallization, in particular to a continuous freezing and crystallization process of Glauber's salt. Background technique [0002] In the sulfuric acid metallurgical process, such as the production of lithium carbonate and lithium hydroxide monohydrate by the spodumene sulfuric acid method, a large amount of sodium sulfate is produced due to the use of sulfuric acid and soda ash or liquid caustic soda. Whether sodium sulfate can be removed from the product solution with high efficiency and low consumption often affects the production capacity and cost of the enterprise. At present, two methods of evaporative crystallization and freeze crystallization are often used to remove sodium sulfate in the product solution. [0003] In the production process of lithium hydroxide monohydrate, the method of freezing and crystallization is generally adopted, and a higher primary crystall...

AI Technical Summary

Problems solved by technology

However, the traditional batch process has the disadvantages of low equipment capacity, large number of equipment, large investment, large land occupation, cumbersome manual operation, large fluctuation of operating parameters and unstable product quality.

[0005] The single-stage freezing and continuous freezing crystallization process that has emerged in recent years has realized continuous production, reduced the number of equipment and land occupation, and reduced labor intensity and other problems. However, because there is no scar melting process, the scar will gradually thicken until it is replaced The heat exchanger loses its heat exchange capacity, so it needs to be stopped and cleaned repeatedly during the production process, resulting in low equipment utilization

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