Method for recovering hexavalent chromium resources from chromium slag

A technology of hexavalent chromium and chromium slag, which is applied in the field of recycling hexavalent chromium resources, can solve the problems of wasting chromium resources, surrounding environmental pollution, etc., and achieve the effect of reducing the total residual chromium

Inactive Publication Date: 2011-09-21
刘杰
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

[0003] The present invention aims at that the chromium-containing waste slag generally contains water-soluble and acid-soluble hexavalent chromium, so that the chromium slag is subjected to weathering and groundwater leaching for a long time during the transfer and ...

Method used

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  • Method for recovering hexavalent chromium resources from chromium slag
  • Method for recovering hexavalent chromium resources from chromium slag

Examples

Experimental program
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Embodiment 1

[0033] The chromium-containing waste slag and water are wet-milled into chromium slag powder with a fineness of more than 200 mesh at a weight ratio of 2.5, and water is added to the chromium slag powder to make chromium slag slurry. The weight of the chromium slag slurry is Percentage concentration is 20%; Add hydrochloric acid in described chromium slag slurry and make chromium slag slurry solution, control the pH value of chromium slag slurry solution to be 4.5, fully stir chromium slag slurry solution simultaneously, make chromium slag slurry Dip in hydrochloric acid for 2 hours; carry out solid-liquid separation of the chromium slag slurry after leaching to obtain a filtrate containing hexavalent chromium, add hydrochloric acid to the filtrate of hexavalent chromium to make its pH value 3.5; A reducing agent is added to the filtrate of the hexavalent chromium added with acid, and then sodium carbonate or sodium hydroxide is added to make the pH value 6.5, followed by washi...

Embodiment 2

[0035] After the waste slag containing chromium and water are milled into chromium slag powder with a fineness of more than 200 mesh by wet ball milling at a weight ratio of 2.7:1, water is added to the chromium slag powder to make chromium slag slurry, and the chromium slag slurry is The weight percentage concentration is 25%; Add sulfuric acid in described chromium slag slurry and make chromium slag slurry solution, control the pH value of chromium slag slurry solution to be 5, fully stir chromium slag slurry solution simultaneously, make chromium slag The slurry is soaked in sulfuric acid for 3 hours; the solid-liquid separation of the chromium slag slurry after soaking is carried out to obtain a filtrate containing hexavalent chromium, and sulfuric acid is added to the filtrate of hexavalent chromium to make its pH value 3 Add a reducing agent to the filtrate of the hexavalent chromium added with acid, then add sodium carbonate or sodium hydroxide to make the pH value 7, th...

Embodiment 3

[0037] After the waste slag containing chromium and water are milled into chromium slag powder with a fineness of more than 200 mesh by wet ball milling at a weight ratio of 3:1, water is added to the chromium slag powder to make chromium slag slurry, and the chromium slag slurry is The weight percentage concentration is 30%; Add hydrochloric acid in described chromium slag slurry and make chromium slag slurry solution, control the pH value of chromium slag slurry solution to be 4, fully stir chromium slag slurry solution simultaneously, make chromium slag The slurry was soaked in hydrochloric acid for 5 hours; the chromium slag slurry after soaking was subjected to solid-liquid separation to obtain a filtrate containing hexavalent chromium, and hydrochloric acid was added to the filtrate of hexavalent chromium to make its pH value 3 Add a reducing agent to the filtrate of the hexavalent chromium added with acid, then add sodium carbonate or potassium hydroxide to make the pH v...

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Abstract

The invention relates to a method for recovering hexavalent chromium resources from chromium slag. The method comprises the following steps of: subjecting chromium-containing slag to wet-process ball milling to obtain chromium slag powder, and adding water into the chromium slag powder to prepare chromium slag slurry; adding acid into the chromium slag slurry to prepare a chromium slag slurry solution, and simultaneously stirring the chromium slag slurry solution sufficiently to ensure that the chromium slag slurry is leached in the acid; subjecting the leached chromium slag slurry to solid-liquid separation to obtain hexavalent-chromium-containing filtrate, and adding acid into the hexavalent-chromium-containing filtrate; and adding a reducing agent into the hexavalent-chromium-containing filtrate added with the acid, adding base, washing and filtering to finally recover chromium hydroxide. By adopting the method for recovering the hexavalent chromium resources from the chromium slag, 60-80% of the hexavalent chromium resources can be recovered from the chromium slag, the total chromium residual amount in the chromium slag can be greatly reduced, and the residual amount of hexavalent chromium in the filtrate subjected to separation of the chromium hydroxide is below 0.5mg/L.

Description

technical field [0001] The invention relates to a method for recovering hexavalent chromium resources from chromium slag. Background technique [0002] The chromium-containing waste residue produced in the industrial production process of chromium salt generally contains water-soluble and acid-soluble hexavalent chromium (as Cr 6+ In total, it is about 0.8% to 1.3%. They have been weathered and groundwater leached for a long time during the transfer and storage of chromium slag, and will gradually diffuse and be lost. This not only wastes a lot of valuable chromium resources, but also affects The surrounding environment has caused serious pollution. Contents of the invention [0003] The present invention aims at that the chromium-containing waste slag generally contains water-soluble and acid-soluble hexavalent chromium, so that the chromium slag is subjected to weathering and groundwater leaching for a long time during the transfer and storage of the chromium slag, whic...

Claims

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Application Information

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IPC IPC(8): C22B34/32C22B3/06C22B3/44
CPCY02P10/20
Inventor 刘杰
Owner 刘杰
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