Process method for producing sodium chromate with carbon ferrochrome with high temperature soda fusion liquid phase oxidation method

Abstract

The invention discloses a process method for producing sodium chromate with carbon ferrochrome with a high temperature soda fusion liquid phase oxidation method. The process method comprises the following process steps: smashing, heating and drying carbon ferrochrome for later use, transferring heated fusion liquid phase soda into a preheated vertical oxidation furnace, uniformly adding carbon ferrochrome powder into the oxidation furnace, guiding pure oxygen into the oxidation furnace for an oxidation reaction at the temperature of 1,000-1,300 DEG C, so as to generate anhydrous sodium chromate and ferric oxide after the reaction, wherein a main reaction equation is: 4CrFe+4Na2CO3+XO2=4Na2CrO4+Y(FeO.Fe3O4)+4CO2; after chilling separation, soaking solid sodium chromate into water, filteringresidues, performing pre-carbonation with carbon dioxide for removing impurities and directly taking solution as a chromium system chemical material, or producing sodium chromate tetrahydrate or anhydrous sodium chromate through concentration and crystallization, or producing sodium dichromate through deep carbonization. The process method has the advantages that an original chromium salt production process route is changed fundamentally, the technological process of production is shortened, the product quality is improved, the production and manufacturing cost can be lowered, and the processmethod is energy-saving and environmentally friendly.

Description

technical field [0001] The invention relates to the technical field of production methods of chromium salts, in particular to a process for producing sodium chromate by carbon ferrochromium high-temperature soda ash molten liquid-phase oxidation. Background technique [0002] The industrial production of sodium chromate generally adopts two processes of "roasting with calcium" and "roasting without calcium". ) for high temperature oxidation roasting, trivalent chromium Cr 3+ Oxidized to hexavalent chromium Cr 6+ , generating soluble sodium chromate. However, "calcium-free roasting" only uses calcium-free returned slag as filler, and the amount of slag produced is 70% lower than that of "calcium-containing roasting". 6+ The content of chromium is reduced by 90%, and the problem of environmental pollution has not been completely solved. However, the conversion rate of chromium in the oxidation roasting process of this method is low, and the subsequent process is exactly the...

AI Technical Summary

Problems solved by technology

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a process for producing sodium chromate by a high-temperature soda ash molten liquid-phase oxidation of ferrochrome carbon, which fundamentally changes the production process route of the original chromium salt and shortens the production process. The production process improves product quality, reduces manufacturing costs, and there is no Cr in the later slag 6+ Pollution generation, completely solved the Cr 6+ The pollution problem is completely in line with the national industrial policy. It is a typical new clean production process and is easy to promote and use.

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