Novel method of zero discharging of chromium and absolute utilization of resource

Abstract

A complete utilization new method of zero discharging chromium poison and resource is used to process the waste residue which is discharged in metal chromium and chromium salt producing process. The Cr6+ in the chromium residue is virulent matter as the main reason of polluting the environment. The chromium residue administer project belongs to environment technical field, which concerns with the subjects of environment science technique, environment engineering and solid pollution matter prevention and treatment project. The Poison Cr6+ is restored to Cr3+ through decomposing the chromium residue rich acid to produce chromic hydroxide. Magnesium hydrate, ferric hydroxide, calcium chloride, aluminium hydroxide and sodium chloride are separated from the solution and little remained chromium iron original slag is melted for reuse. The Cr6+ residual quantity of six products is lower than the national standard (GB5085.3-1996). The art is applicable to chromium residue discharged from different producing arts, completely detoxicates the Cr6+ in the chromium residue and recovers six useful industrial grade products.

Description

Technical field [0001] Chromium slag is the waste slag discharged during the production of metallic chromium and chromium salt. Chromium-containing solid waste residue is the most dangerous solid waste. It will cause continuous pollution to the surrounding ecological environment. The toxic components in chromium residue are mainly water-soluble sodium chromate, acid-soluble calcium chromate and other hexavalent chromium ions. The main cause of pollution to the environment. [0002] The treatment of chromium slag in the present invention belongs to the field of environmental technology, and the subjects studied are environmental science and technology, environmental engineering and solid pollutant prevention and smelting engineering. Background technique [0003] In the process of chromium salt production (with calcium method), the waste residue discharges at least 2 tons of slag containing 4% of total chromium per ton, and Cr is also taken away by the slag 2 O 3 It is 0.08 tons, ...

AI Technical Summary

Problems solved by technology

However, the chromium slag used for brick making needs to be digested, and the chromium slag has different particle sizes, which affects the reduction effect. The degree of mechanization is low, and workers have many opportunities to contact chromium slag, which is easy to cause harm to the human body.

[0015] (4) The effect of treating chromium slag with cyclone furnace is better, but the production cost is high, there is a certain amount of chromium slag particles, and its hexavalent chromium content reaches 20-50mg / kg, which exceeds the national emission standard