Chromium slag roasting oxidation comprehensive detoxification cleaning process

Abstract

The invention relates to a comprehensive detoxification and cleaning process for chromium slag by roasting and oxidation. The technical solution adopted is: a comprehensive detoxification and cleaning process of chromium slag roasting and oxidation, characterized in that: chromium slag is used as raw material, chromite and soda ash are auxiliary materials, and the material ratio is: chromium slag: chromite ore: soda ash=2:1 :0.6, at the roasting reaction temperature of 1050°C, the chromium trioxide in the mixed material is roasted and oxidized at high temperature to form sodium chromate, the conversion rate is more than 80%, and the extraction liquid is used as the mother liquor for the production of red alum sodium products. The main process flow: roasting and oxidation + ball mill leaching + plate and frame filter press dehydration + liquid production red alum sodium production + filter cake secondary beating to extract supernatant + acidification solidification + landfill or building materials. The total chromium content in the detoxification slag is low, and the comprehensive utilization rate is high, which solves the post-disposal problem existing in the traditional dry and wet chromium slag detoxification process, and the cost is low. The method is also applicable to the roasting production with calcium, less calcium and calcium-free in chromium salt production enterprises, and the effect is equally remarkable.

Description

[0001] technical field [0002] The invention relates to a comprehensive detoxification and cleaning process for chromium slag by roasting and oxidation. Background technique [0003] At present, various chromium salt production enterprises in my country have calcium, calcium-less and calcium-free roasting. The chromium-containing waste residue produced by roasting is detoxified by dry and wet methods. The content of chromium compounds in the slag is high, and reversible reactions are prone to occur, especially the solidified chromium slag. When used in the production of building materials, trivalent chromium is oxidized to hexavalent chromium at high temperature, resulting in incomplete detoxification, prone to secondary pollution and affecting the quality of building materials. [0004] In the dry detoxification process of chromium slag, due to the low detoxification yield, slow speed, incomplete detoxification, low comprehensive utilization rate after detoxification, no de...

AI Technical Summary

Problems solved by technology

The leaching solution is used as the mother liquor for the production of red alum sodium products. The total chromium content in the detoxification residue is low and the comprehensive utilization rate is high.

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