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Method for recycling chromium sludge from waste liquor obtained through leather tanning

A technology of chromium mud and waste liquid, which is applied in chemical instruments and methods, small raw hide/big raw hide/leather/fur treatment, small raw hide/large raw hide/leather skin/fur chemical treatment, etc., which can solve resource waste and environmental pollution and other issues to achieve the effect of saving production costs

Inactive Publication Date: 2012-02-01
镇江吉盛皮业有限公司(中外合资)
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the chrome tanning waste liquid, the residual amount of chromium is generally 20% to 30% of the dosage during chrome tanning, and the concentration of trivalent chromium is as high as 2500mg / l to 4500mg / l. If it is discarded and discharged, it will pollute the environment on the one hand. More importantly, it also causes a waste of resources

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0009] Example 1 After the waste liquid discharged after tanning is filtered through a grid and a screen (80 mesh), it is deposited in a liquid storage tank, and the residual amount of chromium in the waste liquid is determined to be 2500 mg / l-3000 mg / l, and concentrated to obtain chrome sludge Cake, and then move the chromium mud cake into the acidification tank, add 1% concentrated sulfuric acid with a concentration of 98% by weight percentage, and fully stir it. The pH value is controlled at 5.5--6.5 to obtain Cr-containing +3 higher Cr 2 (SO 4 ) 3 Chromium sludge can be recycled.

Embodiment 2

[0010] Example 2 After the waste liquid discharged after tanning is filtered through a grid and a screen (80 mesh), it is deposited in a liquid storage tank, and the residual amount of chromium in the waste liquid is determined to be 3001 mg / l-3500 mg / l, and the chromium sludge is obtained by concentration Cake, and then move the chromium mud cake into the acidification tank, add 1.5% concentrated sulfuric acid with a concentration of 98% by weight percentage, and fully stir, and its pH value is controlled at 5.5--6.5 to obtain Cr-containing +3 higher Cr 2 (SO 4 ) 3 Chromium sludge can be recycled.

Embodiment 3

[0011] Example 3 After the waste liquid discharged after tanning is filtered through a grid and a screen (80 mesh), it is deposited in a liquid storage tank, and the residual amount of chromium in the waste liquid is determined to be 3501 mg / l-4000 mg / l, and concentrated to obtain chrome sludge Cake, and then move the chromium mud cake into the acidification tank, add 2% concentrated sulfuric acid with a concentration of 98% by weight percentage, and fully stir, and its pH value is controlled at PH value 5.5--6.5 to obtain Cr-containing +3 higher Cr 2 (SO 4 ) 3 Chromium sludge can be recycled.

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Abstract

The invention discloses a method for recycling chromium sludge from waste liquor obtained through leather tanning, and belongs to a technology for recycling waste liquor obtained through leather tanning. The method comprises the following steps of: filtering the waste liquor discharged after tanning by using a grate and a screen, settling in a liquid storage tank, and concentrating to obtain chromium sludge cakes, and is characterized by also comprising the following step of: transferring the chromium sludge cakes into an acidification tank, adding 1 to 3 weight percent of 98 percent concentrated sulfuric acid, and fully stirring to obtain Cr2(SO4)3 recyclable chromium sludge with higher Cr+3 content. The pH value of the recyclable chromium sludge obtained after the concentrated sulfuric acid is added and fully stirred is controlled to be 5.5-6.5. Primary implementation prove that: a tanning agent prepared from the recyclable chromium sludge and newly added chromium powder in a ratio of 2:1 is used for a tanning procedure, so that the waste liquor discharged after tanning is reduced by 98 percent, resources are recycled and production cost is saved; and if 40 tons of waste liquor discharged after tanning is treated daily, 100kg of chromium can be recycled, and the production cost is saved by 0.72 million yuan each year based on 300 days a year.

Description

technical field [0001] The invention belongs to a technology for recovering and treating waste liquid after tanning fur leather, in particular to a method for reusing chrome sludge from the waste liquid after tanning fur leather. Background technique [0002] Chromium was the only heavy metal pollutant in tannery wastewater. Chromium and its compounds are carcinogenic and allergenic substances that enter the human body through water and food and endanger human health. If they are discharged directly, they will cause serious pollution to the environment. Therefore, the treatment of chromium-containing wastewater has always been the focus of individual treatment of tannery wastewater. In the chrome tanning waste liquid, the residual amount of chromium is generally 20% to 30% of the dosage during chrome tanning, and the concentration of trivalent chromium is as high as 2500mg / l to 4500mg / l. If it is discarded and discharged, it will pollute the environment on the one hand. Mo...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/04C14C3/06C02F1/52C02F101/22C02F103/24
Inventor 夏良丁道奇
Owner 镇江吉盛皮业有限公司(中外合资)
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