Process for recovering magnesium and manganese elements in industrial waste water

Abstract

The invention relates to a process for recovering magnesium and manganese elements in industrial waste water. The process comprises the following steps: step 1, determining elements in the waste water; step 2, precipitating manganese chloride; step 3, performing acidification for precipitating salts; step 4, performing distillation crystallization: performing reduced-pressure distillation on a filtrate obtained in the step 3, performing cooling to the temperature of 55 DEG C at the speed of 8-12 DEG C / h, performing heat preservation for 0.9-1.1h at the temperature of 55 DEG C, and continuing to perform cool to the temperature of 0-10 DEG C at the speed of 8-12 DEG C / h, so as to obtain a pulp; step 5, performing centrifugation and drying: pressing the pulp prepared in the step 4 into a centrifugation machine, performing centrifugation drying until no mother liquid is centrifuged out from a centrifugation outlet, so as to obtain a mother liquid and a wet product material, putting the wetproduct material into an oven, performing first drying at the temperature of 205-215 DEG C, taking out the dried material, performing smashing, and continuing to perform second drying at the temperature of 205-215 DEG C, so as to obtain anhydrous manganese chloride; and step 6, performing recovery. The process provided by the invention has the advantages of low costs, high purity and a high yield.

Description

Technical field [0001] The invention relates to the technical field of waste water recovery, in particular to a process for recovering magnesium and manganese elements from industrial waste water. Background technique [0002] Manganese has a very important strategic position in my country's economy. It is mainly used as a deoxidizer and desulfurizer in the process of ironmaking and steelmaking, and used to make alloys. my country is a big country with manganese ore, ranking second in the world. The high concentration of manganese and ammonium ion in manganese-containing wastewater makes it difficult to meet the standards, which not only causes pollution to the surrounding environment, but also affects the company's environmental image. The existing treatment technologies for manganese-containing wastewater mainly use iron filings reduction method and lime neutralization method to treat it, but the above technologies do not recycle manganese and ammonia nitrogen. [0003] The man...

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Problems solved by technology

[0004] Insufficient existing technology: The existing technology is to separate magnesium from manganese ore to obtain higher-purity manganese products. The magnesium-rich solution produced in the method still contains divalent manganese ions, which belongs to manganese-containing high-salt wastewater. The treatment is difficult and there is no Fundamentally solve the problem of manganese and magnesium separation

And when containing a small amount of divalent manganese ions in the magnesium salt solution, due to the large concentration of divalent magnesium ions, adding bicarbonate will co-precipitate the divalent magnesium ions, the amount of bicarbonate is large, and the higher purity cannot be obtained. manganese products

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