Device and process for producing low-salt calcium chloride through alkaline calcium

Abstract

The invention relates to a device and a process for producing low-salt calcium chloride by using alkaline calcium. The device comprises a 56wt% calcium liquid evaporation tank, a sedimentation centrifuge, a high-temperature evaporation tank, a cooling flaker and a calcium tablet drying and packaging device which are sequentially connected through pipelines. According to the process, the concentration of the calcium liquid is increased from 42% to 56% by increasing the evaporation and concentration concentration of the calcium liquid, the solubility of sodium chloride is reduced and separated out due to the increase of the concentration of calcium chloride by utilizing the same ion effect of calcium chloride and a sodium chloride solution, and then the 56% calcium liquid is selected as a process node; the sedimentation centrifuge is adopted to carry out centrifugal sedimentation separation on solid salt in a calcium liquid phase, and a strong centrifugal force field generated by mechanical force of the sedimentation centrifuge is utilized to remove the solid salt in the calcium liquid phase to the maximum extent, so that the content of salt and sodium chloride in a subsequent calcium chloride product is reduced, and finally calcium chloride with the salt content lower than 3.5% is obtained. The requirements of customers on low-salt calcium chloride products on the market are met.

Description

technical field [0001] The invention belongs to the field of chemical industry, and in particular relates to a device and a process for producing low-salt calcium chloride through an alkaline calcium method. Background technique [0002] At present, the content of salt and sodium chloride in calcium chloride products produced domestically by using the ammonia distillation mother liquor of the alkali factory (that is, the alkaline calcium production process) is relatively high, all at about 4%-5%. [0003] The main components of the mother liquor for the production of calcium chloride products are calcium chloride and sodium chloride. For calcium chloride products, salt is the main impurity. The general production process of alkaline calcium production process is as follows: figure 1 shown. [0004] In production, the calcium mother liquor is first evaporated and concentrated to a calcium chloride content of about 42%, and then the impurities of sodium chloride, calcium car...

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Problems solved by technology

[0005] Because the clarification and separation method is commonly used in the production of alkaline calcium, this process generally places the clarification tank at the place where the calcium solution is concentrated to 42%, so as to facilitate its sedimentation and separation. Occasionally, crystallization occurs and it is not suitable to be clarified by clarification tanks, which leads to high salt content in calcium chloride products produced by alkaline calcium method, which is above 4%.

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