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Chrome slag detoxifying comprehensive utilization method

A technology of chromium slag and sodium chromate, applied in the removal of iron oxide, solid waste, iron oxide/iron hydroxide, etc., can solve the problems of high recovery cost, incomplete reduction, environmental pollution, etc., and achieve the effect of easy treatment

Active Publication Date: 2016-12-14
重庆昌元化工集团有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Using the above method, the recovery and utilization of chromium is more complicated, the recovery cost is higher, and the reduction is not complete
If it will contain Cr after processing 3+ Discharge or landfill the waste residue, in the long run, it will also cause pollution to the environment

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] The chromium slag detoxification comprehensive utilization method of the present embodiment comprises the following steps:

[0019] 1) Press-filter the chromium slag produced during the preparation of sodium chromate in a pneumatic fluidization tower, and then add water at 60°C to the chromium slag after pressure filtration to make a chromium slag slurry; the particle size of the chromium slag is 200 mesh; Cr in chromium slag 6+ The weight content of NaOH is equal to 0.10%, the weight content of NaOH is equal to 0.30%, Fe 2 o 3 The weight content is 35.0%.

[0020] 2) Add acid to the chromium slag slurry to make a chromium slag slurry solution, control the pH value of the chromium slag slurry solution to 6.5, and fully stir the chromium slag slurry solution, so that the chromium slag slurry is immersed in the solution melt;

[0021] 3) Add ferrous sulfate reducing agent to the chromium slag slurry solution until Cr in the chromium slag slurry solution after leaching...

Embodiment 2

[0025] The chromium slag detoxification comprehensive utilization method of the present embodiment comprises the following steps:

[0026] 1) Press-filter the chromium slag produced during the preparation of sodium chromate in a pneumatic fluidization tower, and then add water at 50°C to the chromium slag after pressure filtration to make a chromium slag slurry; the particle size of the chromium slag is 700 mesh; Cr in chromium slag 6+ The weight content of NaOH is equal to 0.05%, the weight content of NaOH is equal to 0.60%, Fe 2 o 3 The weight content is 30.0%.

[0027] 2) Add acid to the chromium slag slurry to make a chromium slag slurry solution, control the pH value of the chromium slag slurry solution to 7.5, and fully stir the chromium slag slurry solution, so that the chromium slag slurry is immersed in the solution melt;

[0028] 3) Add sodium metabisulfite reducing agent to the chromium slag slurry solution until Cr in the chromium slag slurry solution after soa...

Embodiment 3

[0032] The chromium slag detoxification comprehensive utilization method of the present embodiment comprises the following steps:

[0033] 1) Press-filter the chromium slag produced in the preparation of sodium chromate in a pneumatic fluidization tower, then add water at 85°C to the chromium slag after pressure filtration to make a chromium slag slurry; the particle size of the chromium slag is 400 mesh; Cr in chromium slag 6+ The weight content of NaOH is equal to 0.01%, the weight content of NaOH is equal to 0.20%, Fe 2 o 3 The weight content is 42.0%.

[0034] 2) Add acid to the chromium slag slurry to make a chromium slag slurry solution, control the pH value of the chromium slag slurry solution to 8.5, and fully stir the chromium slag slurry solution, so that the chromium slag slurry is immersed in the solution melt;

[0035] 3) Add ferrous sulfate reducing agent to the chromium slag slurry solution until Cr in the chromium slag slurry solution after leaching 6+ The c...

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Abstract

The invention discloses a chrome slag detoxifying comprehensive utilization method. The chrome slag detoxifying comprehensive utilization method is characterized by comprising the following steps that (1) chrome slag generated when sodium chromate is prepared through a pneumatic fluidized column is subjected to filter pressing, then water at the temperature of 50-85 DEG C is added into the filter-pressed chrome slag, and chrome slag slurry is obtained, specifically, the granularity of the chrome slag is 200-700 meshes; (2) acid is added into the chrome slag slurry, a chrome slag slurry solution is obtained, the pH value of the chrome slag slurry solution is controlled to be 6.0-8.5, the chrome slag slurry solution is stirred sufficiently, and the chrome slag slurry is leached in the solution; (3) reducing agents such as ferrous sulfate and sodium pyrosulfite are added into the chrome slag slurry solution till the Cr<6+> content in the leached chrome slag slurry solution is lower than 1.2 ppm; and (4) the chrome slag slurry solution subjected to reduction treatment is pressed and dried through a filter press, and filter residues obtained after filter pressing are ferric oxide powder. According to the chrome slag detoxifying comprehensive utilization method, the technical purpose of chrome slag detoxifying can be achieved, the detoxified chrome slag is the ferric oxide powder, and the solid waste standard requirements are met.

Description

technical field [0001] The invention belongs to the technical field of solid waste treatment, in particular to a method for comprehensive utilization of chromium slag detoxification. Background technique [0002] Chromium slag and chromium-containing pollutants mainly refer to the residues produced in the production process of metal chromium and chromium salt production enterprises, as well as soil, rocks, construction waste, etc. polluted by such residues, which are heavy metal hazardous wastes. Among them, hexavalent chromium The toxicity of hexavalent chromium is far greater than that of trivalent chromium. Hexavalent chromium has strong carcinogenic and mutagenic properties. It is one of the 129 key pollutants confirmed by the EPA. If it is not harmlessly treated, it will seriously affect the health of the surrounding people. In good health. [0003] Currently, Cr 6+ The harmless treatment of waste residue is mainly to convert the highly toxic Cr 6+ Reduction to less ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B09B3/00B09B5/00C01G49/06
CPCB09B3/00B09B5/00C01G49/06
Inventor 张仁义李守昌李全忠张国洪梁华鼎
Owner 重庆昌元化工集团有限公司