Method for recovering chromium from leather tanning waste residues

A technology of skin residue and tartar, applied in the field of chromium recovery, can solve the problems of instrument corrosion, high cost, low dechromization rate, etc., and achieve the effects of soft treatment process, low cost and large treatment capacity

Active Publication Date: 2017-05-31
SHIKEFENG CHEM IND
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem mainly solved by the present invention is: aiming at the defects of low dechrome rate, high cost, serious instrument corrosion and difficulty in recovering chromium in the current common method for dechroming tannery waste skin slag, it provides a method using tartar , white vinegar and lemon to prepare organic acid, degrade leather slag under the action of sludge and biogas liquid, and then use organic acid to deposit and recover chromium. The present invention utilizes white vinegar, lemon and tartar for mixed fermentation to acidify wine After quarrying, mixed organic acids are obtained, and then sludge and biogas liquid are used to accelerate the degradation of tannery waste skin slag, so that the complexes of collagen and chromium are exposed, and then the mixed organic acids are used to destroy the coordination bond between chromium and collagen carboxyl groups to form A new chelate of soluble chromium, the filtrate of dissolved chelated chromium is injected into the sedimentation tank, and the chromium is replaced by zinc to deposit it on the zinc plate to achieve the purpose of chromium recovery

Method used

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Examples

Experimental program
Comparison scheme
Effect test

example 1

[0020] Collect 10kg of tartar that precipitated at the bottom of the wine barrel during the wine fermentation process, transfer the tartar to the reaction kettle, add edible white vinegar that is 3 times the mass of the tartar and lemon slices of the same quality as the tartar, and heat it up to 60°C Start the agitator and stir and mix at a speed of 700r / min for 1 hour to obtain the mixed material, then transfer the mixed material into a fermenter and ferment for 5 days at 30°C; Put it into a rotary evaporator, and concentrate it to 1 / 3 of its original volume by rotary evaporation to obtain a concentrated solution. Put the concentrated solution into a high-temperature sterilization tank and sterilize it at 120°C for 10 minutes to obtain a sterilized concentrated solution for use; take 2kg Filtrate the biogas liquid, remove the filter residue to obtain the biogas liquid filtrate, add 10kg of tannery waste skin residue to be treated into the reaction tank with an aeration device ...

example 2

[0023]Collect 15kg of tartar that precipitated at the bottom of the wine barrel during the wine fermentation process, transfer the tartar to the reaction kettle, add edible white vinegar that is 4 times the mass of the tartar and lemon slices of the same quality as the tartar, and heat it up to 65°C Start the agitator and stir and mix at 750r / min for 2 hours to obtain the mixed material, then transfer the mixed material into a fermenter and ferment for 6 days at 35°C; Put it into a rotary evaporator, and concentrate it to 1 / 3 of its original volume by rotary evaporation to obtain a concentrated solution. Put the concentrated solution in a high-temperature sterilization tank and sterilize it at 120°C for 13 minutes to obtain a sterilized concentrated solution for use; take 2kg Filtrate the biogas liquid, remove the filter residue to obtain the biogas liquid filtrate, add 15kg of tannery waste skin residue to be treated into the reaction tank with an aeration device at the bottom...

example 3

[0025] Collect 20kg of tartar that precipitated at the bottom of the wine barrel during the wine fermentation process, transfer the tartar to the reaction kettle, add edible white vinegar 5 times the mass of the tartar and lemon slices of the same quality as the tartar, and heat it up to 70°C Start the agitator and mix for 2 hours at a speed of 800r / min to obtain the mixed material, then transfer the mixed material into a fermenter and ferment for 7 days at 40°C; Put it into a rotary evaporator, and concentrate it to 1 / 3 of its original volume by rotary evaporation to obtain a concentrated solution. Put the concentrated solution into a high-temperature sterilization tank and sterilize it at 120°C for 15 minutes to obtain a sterilized concentrated solution for use; take 3kg Filtrate the biogas liquid, remove the filter residue to obtain the biogas liquid filtrate, add 20kg of tannery waste skin residue to be treated into the reaction tank with an aeration device at the bottom, a...

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Abstract

The invention relates to a method for recovering chromium from leather tanning waste residues and belongs to the technical field of heavy metal treatment. The method comprises the steps: carrying out fixed fermentation on white vinegar, lemon and tartar, and acidizing the tartar to obtain a mixed organic acid; next, accelerating to degrade the leather tanning waste residues by using sludge and a biogas liquid to expose a collagen and cadmium complex; then, destroying a coordination bond between cadmium and the carboxyl of collagen by using the mixed organic acid to form a novel soluble chromium chelate; and injecting filtrate in which the chelated chromium is dissolved into a sedimentation tank, replacing chromium with zinc, and enabling the chromium to be deposited on a zinc plate to achieve the aim of recovering chromium. The method for recovering chromium from leather tanning waste residues is high in chromium removal rate, simple and easily-controlled in removal step, low in cost, capable of recovering chromium from the leather tanning waste residues and wide in application prospect.

Description

technical field [0001] The invention relates to a method for recovering chromium from tanning waste skin slag, which belongs to the technical field of heavy metal treatment. Background technique [0002] In the process of tanning, trivalent chromium combines with the carboxyl group of collagen after self-combination through oxygen bridges, so that raw hides become leather. A large amount of solid waste is inevitably generated during the tanning process. According to statistics, processing 1 ton of raw leather will produce 40% to 45% of solid waste, of which 30% to 40% are tanning waste skin residues (blocks). my country produces about 1.4 million tons of such waste every year. Although the wet white skin technology is currently promoted, about 60% of the waste skins still contain chromium, commonly known as chromium-containing waste skins. More than 90% of these chromium-containing waste skins are collagen, and at the same time contain 2% to 4% Cr 2 o 3 . Collagen is a ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22B7/00C22B34/32
CPCC22B7/006C22B34/32Y02P10/20
Inventor 吴迪丁春美赵玉林
Owner SHIKEFENG CHEM IND
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