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Processing method of sodium bisulfate waste liquid in chromic anhydride preparation process

A sodium bisulfate, preparation technology, applied in the direction of chromate/dichromate, water/sewage treatment, chemical instruments and methods, etc., to achieve the effect of saving and efficient waste treatment methods

Active Publication Date: 2012-01-18
CHONGQING MINFENG CHEM
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0004] The present invention intends to provide a treatment method for sodium bisulfate waste liquid in the preparation process of chromic anhydride, to solve the problem of waste materials produced in the preparation process of chromic anhydride in the prior art, and to propose a new efficient and economical treatment method

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Embodiment Construction

[0022] The specific structures and characteristics known in the following schemes will not be described here. The steps of this embodiment are:

[0023] 1) Send neutral sodium chromate solution into the pre-acidification pot as reaction vessel;

[0024] 2) Send the sodium bisulfate turbid liquid produced in the chromic anhydride preparation process into the pre-acidification pot, and continuously analyze the acidification rate and Baume degree of the solution in the pre-acidification pot through the laboratory until the acidification in the pre-acidification pot The rate is 70%, and the Baume degree is 30°Be';

[0025] 3) Use steam to heat the pre-acidification pot to 95°C to carry out the precipitation transformation process;

[0026] 4) Keep the temperature of the pre-acidification pot and let it stand for 1.7 hours to heat and ripen;

[0027] 5) Send the solution in the pre-acidification pot to the pre-acidification filter, and send the filter cake to the basic chromium ...

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Abstract

The invention relates to the pre-acidification processing of a chromium compound, which aims to provide a processing method of sodium bisulfate waste liquid in a chromic anhydride preparation process for solving the processing problem of waste generated in a chromium compound preparation process of the prior art and provide a new high-efficient energy-saving processing method. The processing method comprises the following steps: neutral sodium chromate solution is added into a reaction vessel; sodium bisulfate turbid liquid which is generated in a chromic anhydride preparation flow is added into the reaction vessel; the reaction vessel is heated; the temperature of the reaction vessel is maintained and the reaction vessel is kept standing for 1.5 to 2 hours; and the solution in the reaction vessel is transferred into a filter. In the technical scheme, the sodium bisulfate leftover turbid liquid which is generated in the chromic anhydride preparation flow and the sodium chromate neutral water which is generated in the chromium compound preparation process is pre-acidized (with the pH being 6.0 to 6.5), and indissoluble hydrated chromic chromate deposition can be generated by trivalent chromium in the sodium bisulfate leftover and CrO42.

Description

technical field [0001] The invention relates to a pre-acidification waste treatment of chromium-containing compounds. Background technique [0002] Specifically, a large amount of waste sodium bisulfate is produced in the process of producing chromic anhydride, and 1.3 tons of waste sodium bisulfate is produced to produce 1 ton of chromic anhydride. In addition to sodium bisulfate, the waste also contains a large amount of free sulfuric acid, chromic acid, chromium sulfate and insoluble Na-Cr sulfuric acid comprehensive salt. Their respective proportions in the whole depend on the reaction conditions during the production of chromic anhydride, and sodium bisulfate waste has long been a major source of pollution in the production of chromium salts. In sodium bisulfate waste, the acid content is large and the chromium content is high. Therefore, the waste liquid is highly corrosive and contains hexavalent chromium ions. The pollution is serious. The amount of waste liquid i...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F1/58C01G37/14
Inventor 袁代建王成业张金聪谢继云
Owner CHONGQING MINFENG CHEM