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Method for treating chromium slag in electroplating sludge

A technology of electroplating sludge and chromium slag, which is applied in the direction of improving process efficiency, etc., can solve problems such as inability to extract chromite powder, difficult disposal, dangerous solid waste, etc., achieve broad industrial application prospects, simple operation, and cost reduction Effect

Inactive Publication Date: 2016-04-13
倪建国
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] The existing wet technology cannot extract chromite powder, and the heavy metal content in the waste residue is high, which is a dangerous solid waste and difficult to dispose of

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0018] A method for controlling chromium slag in electroplating sludge, comprising the following steps:

[0019] A. Add water in the electroplating sludge, make the electroplating sludge quality before adding water be 10% of the electroplating sludge quality after adding water, test the amount of ferric iron in the electroplating sludge; Add sulfuric acid again, the pH value of chromium slag is adjusted to 1.5;

[0020] B. At 60°C, add sodium sulfite to the acidified electroplating sludge, the amount of sodium sulfite added is 1.1 times the equivalent of ferric iron, and stir for 1 hour;

[0021] C. Add magnesium oxide again, adjust the pH value to 3, after standing still, a precipitate is formed, extract the precipitate, and the precipitate is chromite powder.

Embodiment 2

[0023] A method for controlling chromium slag in electroplating sludge, comprising the following steps:

[0024] A. Add water in the electroplating sludge, make the electroplating sludge quality before adding water be 15% of the electroplating sludge quality after adding water, test the amount of ferric iron in the electroplating sludge; Add sulfuric acid again, the pH value of chromium slag is adjusted to 2.8;

[0025] B. At 65°C, add sodium bisulfite to the acidified electroplating sludge, the amount of sodium bisulfite added is 1.1-1.5 times the equivalent of ferric iron, and stir for 1 hour;

[0026] C. Add sodium carbonate again to adjust the pH value to 5. After standing still, a precipitate is formed, extract the precipitate, and the precipitate is chromite powder.

Embodiment 3

[0028] A method for controlling chromium slag in electroplating sludge, comprising the following steps:

[0029] A. Add water in the electroplating sludge, make the electroplating sludge quality before adding water be 11% of the electroplating sludge quality after adding water, test the amount of ferric iron in the electroplating sludge; Add sulfuric acid again, the pH value of chromium slag is adjusted to 1.6;

[0030] B. At 61°C, add sodium metabisulfite to the acidified electroplating sludge, the amount of sodium metabisulfite added is 1.2 times the equivalent of ferric iron, and stir for 1 hour;

[0031] C. Add sodium carbonate again to adjust the pH value to 4.2. After standing still, a precipitate is formed, which is filtered to obtain a precipitate, which is chromite powder; further extract other metals in the filtrate.

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PUM

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Abstract

The invention relates to the field of harmless disposal of dangerous waste, and discloses a method for treating chromium slag in electroplating sludge. The method includes the following steps of testing of the iron content, diluting of the electroplating sludge, acidification adjustment of the PH value, reduction, adjustment of the PH value and removal of chromite powder. According to the method, heavy metal chromium in the electroplating sludge is extracted, so that the content of the chromium in the waste slag meets the national common solid waste standard and is close to the primary soil environment standard, and chromium slag can be sold as the chromite powder. Compared with the prior art, the cost is greatly reduced, dangerous solid waste is turned to common solid waste through the method in combination with other patented technologies, and therefore disposal of the solid waste is facilitated. According to the method, operation is simple, the environment is protected, economy, high efficiency and nontoxicity are achieved, the concept of green chemistry is met, and the method has broad industrial application prospects.

Description

technical field [0001] The invention relates to the field of harmless disposal of hazardous waste, in particular to a method for treating chromium slag in electroplating sludge. Background technique [0002] The existing wet technology cannot extract chromite powder, and the heavy metal content in the waste residue is high, which is a dangerous solid waste and difficult to dispose of. This technology makes the waste slag meet the national general solid waste standard and is close to the first-class soil environment standard. The innovative technology enables the chromium slag to be sold as chromite ore powder, and generally reduces the disposal cost greatly compared with the existing technology. Contents of the invention [0003] Aiming at the existing disadvantages, the invention discloses a method for treating chromium slag in electroplating sludge. The method is simple, the conditions are easy to control, safe and reliable, and is suitable for industrial production. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B7/00C22B34/32C21B15/00
CPCY02P10/20
Inventor 倪建国
Owner 倪建国