Unlock instant, AI-driven research and patent intelligence for your innovation.

A method for resource utilization of chromium-containing pickling sludge

A sludge and chromic acid technology, applied in chemical instruments and methods, chromate/dichromate, water/sludge/sewage treatment, etc., can solve the problem of inability to separate harmful heavy metal chromium, unresolved hazards, recycling Complex process and other problems, to achieve the effect of solving the problem of heavy metal pollution, solving pollution problems, and obvious economic benefits

Active Publication Date: 2021-08-06
CHANGZHOU WUJIN YOUBANG WATER PURIFICATION MATERIALS
View PDF4 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The technical problem to be solved by the present invention is to overcome the defects and deficiencies such as the inability to separate the harmful heavy metal chromium from the existing pickling waste liquid treatment sludge recovery, not solving the hazards, and the recovery process is complicated, and to provide a chromium-containing pickling sludge resource The method of chemical utilization, by converting trivalent chromium ions that are easy to precipitate together with iron in sludge into soluble hexavalent chromium, and then effectively separated from iron ions, and recovering ferric chloride water purifier and chromate products

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0033] A method for resource utilization of chromium-containing pickling sludge, comprising the following steps:

[0034] S1. Alkalinity adjustment: 100g of chromium-containing pickling sludge (chromium content 4%, iron content (as Fe 2 o 3 Total) 68%) with 300g of 25% sodium hydroxide solution to dissolve the sludge powder into a slurry liquid, the amount added is 3 times the mass of the sludge, and its pH value is adjusted to ≥ 12;

[0035] S2. Oxidation treatment: Stir and add 25% hydrogen peroxide to the slurry in S1 above, the amount added is 1.5 times the mass of the chromium-containing pickling sludge, and react for 2 hours at a water bath temperature of 50°C;

[0036] S3. Alkaline chromate recovery: filter the mud in the above S2 to obtain chromate filtrate and iron-containing filter cake, and fully wash the filter cake with clear water. After three times of washing, the chromium content in the filter cake is 3ppm, and the washing liquid and Concentrate and crystalli...

Embodiment 2

[0040] A method for resource utilization of chromium-containing pickling sludge, comprising the following steps:

[0041] S1. Alkalinity adjustment: 100g of chromium-containing pickling sludge (chromium content 9%, iron content (as Fe 2 o 3 Total) 52%) with 500g of 30% sodium hydroxide solution to dissolve the sludge powder into a slurry liquid, the amount added is 5 times of the sludge mass, and its pH value is adjusted to ≥12;

[0042] S2. Oxidation treatment: Stir and add 28% hydrogen peroxide to the slurry in S1 above, the amount added is 3.0 times the mass of the chromium-containing pickling sludge, and react for 2.5 hours at a water bath temperature of 60°C;

[0043] S3. Alkaline chromate recovery: filter the mud in the above S2 to obtain chromate filtrate and iron-containing filter cake, and fully wash the mud cake with clear water. After three times of washing, the chromium content in the filter cake is 0.9ppm, and the washing liquid and Concentrate and crystallize a...

Embodiment 3

[0047] A method for resource utilization of chromium-containing pickling sludge, comprising the following steps:

[0048] S1. Alkalinity adjustment: 100g of chromium-containing pickling sludge (chromium content 6%, iron content (as Fe 2 o 3 Total) 65%) with 350g of 28% sodium hydroxide solution to dissolve the sludge powder into a slurry liquid, the amount added is 3.5 times the sludge mass, and its pH value is adjusted to ≥ 12;

[0049] S2. Oxidation treatment: Stir and add 30% hydrogen peroxide to the slurry in S1 above, the amount added is 2.0 times the mass of the chromium-containing pickling sludge, and react for 3 hours at a water bath temperature of 55°C;

[0050] S3. Alkaline chromate recovery: filter the mud in the above S2 to obtain chromate filtrate and iron-containing filter cake, and fully wash the mud cake with clean water. After washing three times, the chromium content in the filter cake is 2ppm, and the washing liquid and filtrate Concentrated and crystalliz...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

PropertyMeasurementUnit
particle size (mesh)aaaaaaaaaa
Login to View More

Abstract

The invention discloses a resource utilization method of chromium-containing pickling sludge. The utilization method comprises the following steps: alkalinity adjustment; oxidation treatment; alkaline chromate recovery; and water purifying agent ferric chloride recovery. The method for resource utilization of chromium-containing pickling sludge of the present invention oxidizes trivalent chromium into soluble hexavalent chromium through oxidation treatment, thereby realizing the separation of chromium and iron in the pickling sludge, and crystallizing the chromium-containing filtrate to obtain chromate , and the discus filter residue can be adjusted correspondingly to the acid solution to prepare ferric chloride water purifier, the chromium content in ferric chloride is lower than 5ppm, and the iron content (as FeCl 3 ) is higher than 38%, and the acidity value is lower than 0.40%, which meets the relevant national standards (GB4482-2006). The resource utilization of chromium-containing pickling sludge of the present invention can recycle the chromium resources in the pickling sludge on the one hand, and solve the problem of Heavy metal pollution. On the other hand, the iron-containing pickling sludge is made into inorganic water purifying agent ferric chloride, which can solve the pollution problem and obtain obvious economic benefits. It can be popularized and applied in the field of related ferrochromium-containing wastewater treatment.

Description

technical field [0001] The invention relates to the technical field of pickling sludge treatment, in particular to a method for resource utilization of chromium-containing pickling sludge. Background technique [0002] In the steel industry, the pickling process is an inevitable step, and a large amount of steel pickling waste is produced every day. The waste liquid of iron and steel pickling contains high concentration of acid and iron ions, the content of free acid in the pickling waste liquid is about 6~10%, and the main component of iron ion is Fe 2+ , the content is between 80~150g / L, and there is also a small amount of Fe 3+ And some impurities, in addition, some pickling waste liquid also contains a small amount of PO 4 3- , Zn 2+ Wait. These waste acids, which have the characteristics of high iron ion concentration, high acid concentration, strong corrosion, and high environmental pollution, have been managed as hazardous waste by various countries. The United S...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Patents(China)
IPC IPC(8): C01G49/10C01G37/14C02F1/52
CPCC01G37/14C01G49/10C02F1/5236
Inventor 朱松锋蒋银峰居银栋蒋浩徐峰
Owner CHANGZHOU WUJIN YOUBANG WATER PURIFICATION MATERIALS