A kind of method for preparing high-concentration magnesium chloride solution by continuous dissolving of bischofite in salt lake

Abstract

The invention relates to the technical field of salt chemistry, particularly relates to a method of continuous dissolution of salt lake bischofite to prepare a high-concentration magnesium chloride solution, to a production device for achieving a process of large-scale bischofite dissolution to prepare refined brine, and provides a industrial demonstration effect route for developing magnesium series oxides in the Qinghai salt lake in the future. The method includes steps of: unloading bischofite, conveying and loading the material by conveying belts, feeding, dissolving into brine, allowing crude brine to overflow, performing magnesium chloride fine grain separation, buffering the brine, thickening and depositing the brine, obtaining a first-step clear liquid, subjecting the first-step clear liquid to first-step filter pressing, obtaining a second-step clear liquid, subjecting the second-step clear liquid to second-step filter pressing, squeezing and filtering the bottom material of a thickening machine, conveying mud cake, subjecting the brine to accident handling, and conveying and storing the refined brine so as to obtain the brine with technical indexes meeting requirements of ammonia gas combined reactions. The concentration of Mg<2+> in the refined brine is 115+ / -3 g / L. The refined brine is clear, transparent and free of solid suspension impurities.

Description

technical field [0001] The present invention relates to the technical field of salt chemical industry, in particular to a method for producing high-concentration magnesium chloride solution by continuous dissolving of bischofite in salt lakes, a production device for realizing the process of preparing refined brine by large-scale industrial dissolving of bischofite, and for the future development of Qinghai Salt lake magnesium series oxides provide a way to demonstrate the effect of industrialization. Background technique [0002] The old brine discharged from the Qinghai Salt Lake after potassium extraction, through the local unique natural evaporation, enriches around the salt lake, forming bischofolite salt deposits. At present, the proven reserves of bischofolite salt deposits reach 6.5 billion tons, accounting for the More than 99% of the reserves are maintained, ranking first in the country. However, magnesium resources and potassium resources in salt lakes are closel...

AI Technical Summary

Problems solved by technology

[0005] (1) Discontinuous preparation of brine, low production capacity; large investment, high cost

[0006] (2) Although the method of using compressed air to dissolve at the bottom of the pool from time to time is adopted, the method of mechanical stirring and dissolution is not adopted, resulting in a slow speed of salt melting, which cannot meet the requirements of large-scale industrial production for preparing brine

[0007] (3) Because the fine-grain separator device is not used, the brine delivery pipeline is prone to crystallization, which leads to blockage of the pipeline during the production process

[0008] (4) Due to the lack of mechanical agitation, the pure water pipeline from the bottom of the pool to brine is easily blocked by sediments, sulfate insolubles and other sediments on the spray holes on the water pipe network, resulting in a lag in brine speed and low production capacity, resulting in shutdown phenomenon occurs

[0010] Therefore, above-mentioned method is obviously not suitable for large-scale industrial production, especially large-scale industrial production

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