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Hair-protection unhairing and liming waste liquor recycling method

A technology for hair-preserving depilation and waste liquid recycling, which is applied in the fields of hair-preserving depilation and liming waste liquid recycling, can solve the problems of low protein content and high processing cost, achieve low organic content, complete shed hair shape, and overcome cleanliness. limited effect

Inactive Publication Date: 2013-10-16
CHINA LEATHER & FOOTWEAR IND RES INST
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The advantage of this method is that the recovered sulfides are of high purity, the reuse in production will not affect the product quality, and the pollution of organic matter can be reduced while recovering sulfides, but the disadvantage is that the protein content in the waste liquid is relatively low, and the treatment relatively high cost

Method used

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  • Hair-protection unhairing and liming waste liquor recycling method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0050] (1) Weighing: Weighing the cow salt wet skin, which is used as the basis for the following materials;

[0051] (2) Pre-soaking water: 300wt% of water, the combination of rotating and stopping the drum for 8 hours, and controlling to dry;

[0052] (3) De-meat: remove the meat;

[0053] (4) Soaking in water: 200wt% of water, combined with the drum turning and stopping for 18 hours, and controlling to dry;

[0054] (5) Hair preservation and depilation, liming: water 150wt%, sodium thioglycolate 2%, rotate for 1 hour, add lime 1%, rotate for 30 minutes and start bath liquid circulation to filter and remove hair, stop bath liquid circulation after depilation for 1 hour , add 2% sodium sulfide, 2% lime and 100% water to carry out liming treatment, stop for a total of 15 hours, the gray skin comes out of the drum, collect liming waste liquid, filter to remove solid impurities, and set aside.

Embodiment 2

[0056] (1) Weighing: Weighing the cow salt wet skin, which is used as the basis for the following materials;

[0057] (2) Pre-soaking water: 250wt% of water, the combination of rotating and stopping the drum for 10 hours, and controlling to dry;

[0058] (3) De-meat: remove the meat;

[0059] (4) Soaking in water: 250wt% of water, combined with the rotating and stopping of the drum for 20 hours, controlled to dry;

[0060] (5) Hair preservation and depilation, liming: water 150wt%, mercaptoethanol 1.5%, rotate for 1 hour, add lime 1.5%, rotate for 30 minutes and start bath circulation to filter hair removal, stop bath circulation after depilation for 1 hour, Add 1% sodium sulfide, 1% lime and the liming waste liquid in 100% embodiment 1 and carry out liming process, stop for 18 hours altogether, the gray skin goes out drum, collect liming waste liquid, filter and remove solid matter impurity, wait use.

Embodiment 3

[0062] (1) Weighing: Weighing the cow salt wet skin, which is used as the basis for the following materials;

[0063] (2) Pre-soaking water: 250wt% of water, the combination of rotating and stopping the drum for 10 hours, and controlling to dry;

[0064] (3) De-meat: remove the meat;

[0065] (4) Soaking in water: 250wt% of water, combined with the rotating and stopping of the drum for 20 hours, controlled to dry;

[0066] (5) Hair preservation and depilation, liming: water 150wt%, mercaptoethanol 1.5%, rotate for 1 hour, add lime 1.5%, rotate for 30 minutes and start bath circulation to filter hair removal, stop bath circulation after depilation for 1 hour, Add 1% sodium sulfide, 1% lime and 100% liming waste liquid in Example 1 to carry out liming treatment, stop for a total of 18 hours, the gray skin will go out of the drum, collect liming waste liquid, and filter to remove solid impurities.

[0067] (6) Reuse the liming waste liquid collected in (5) for the second time i...

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Abstract

The invention provides a hair-protection unhairing and liming waste liquor recycling method in the tanning industry. In the method, an organic sulfur unhairing material is used to carry out hair-protection unhairing; sodium sulfide and lime are used to carry out liming processing; after solid impurities in liming waste liquor are removed, the liming waste liquor replaces water to be reused in the liming processing; after being circulated for 1 to 5 times, the liming waste liquor is processed by acid, so that sodium sulfide in the waste liquor is converted into hydrogen sulfide and proteins also generate precipitates; the generated sodium sulfide is adsorbed by using sodium hydroxide and is reused in the liming processing; after the proteins in the processed waste liquor are filtered, the processed waste liquor is reused for pre-soaking, so that the complete circulation of the liming waste liquor is realized.

Description

[0001] method field [0002] The invention belongs to a clean tanning production method in the technical field of leather production, and in particular relates to a method for hair preservation and depilation and recycling of liming waste liquid. Background technique [0003] The pollution in the leather industry mainly comes from the preparation section, and the pollution in the preparation section mainly comes from the depilation process. In addition to the sulfide pollution completely from the sulfide depilation and liming process, there are more than 65% of the total evaporation. Residue, more than 61% organic matter, more than 40% total nitrogen and more than 70% chemical oxygen demand (COD Cr ) also comes from the depilation and liming process. [0004] The sulfide hair removal method occupies an absolute dominant position in the hair removal methods of leather production today, because the sulfide hair removal method has incomparable advantages over other hair removal ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): C14C1/06C14C1/04
Inventor 丁志文谢少达谢胜虎魏世林
Owner CHINA LEATHER & FOOTWEAR IND RES INST
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