Resourceful treatment method for pickling waste liquor in steel industry

A technology of pickling waste liquid and treatment method, which is applied in the field of recycling sulfuric acid and ferrous sulfate in pickling waste liquid in the iron and steel industry, can solve the problems of complex process, secondary pollution, high operating cost, etc., and achieve simple process and high recovery rate , easy-to-operate effect

Inactive Publication Date: 2012-12-19
NANJING COLLEGE OF CHEM TECH
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  • Summary
  • Abstract
  • Description
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  • Application Information

AI Technical Summary

Problems solved by technology

[0018] The disadvantage of this method is: in order to obtain higher purity α-Fe 2 o 3 , the waste acid liquid must be refined in advance, and the equipment investment required for this process is high, and the maintenance and management are difficult
[0019] Each of the above technologies has problems, such as secondary pollution, serious corrosion of equipment, complicated process, difficult operation, large investment, high operating cost, and large floor area, etc.
These factors limit the popularization and application of existing technologies

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0038]The pickling waste liquid obtained from the above separation is passed through the strongly basic anion exchange resin at a flow rate of 10mL / min, and the liquid feeding stops after 10 BV; the resin is desorbed and regenerated with distilled water, and the regeneration is completed after 15 BV, and the desorption solution For dilute sulfuric acid, it is used for acid pickling. The recovery rate of sulfuric acid was 82.4%.

Embodiment 2

[0040] The pickling waste liquid obtained from the above separation is passed through the strongly basic anion exchange resin at a flow rate of 10mL / min, and the liquid feeding stops after 11 BV; the resin is desorbed and regenerated with distilled water, and the regeneration is completed after 15 BV, and the desorption solution For dilute sulfuric acid, it is used for acid pickling. The recovery rate of sulfuric acid was 82.7%.

Embodiment 3

[0042] The pickling waste liquid obtained from the above separation is passed through the strongly basic anion exchange resin at a flow rate of 10mL / min, and the liquid feeding stops after 9 BV; the resin is desorbed and regenerated with distilled water, and the regeneration is completed after 15 BV, and the desorption solution For dilute sulfuric acid, it is used for acid pickling. The recovery rate of sulfuric acid was 80.4%.

[0043] Table 1 Test results

[0044] Example Adsorption volume (BV) Desorption volume (BV) Recovery rate(%) 1 10 15 82.4 2 11 15 82.7 3 9 15 80.4

[0045] As can be seen from Table 1, the recovery rate of this method is high and stable, which can reach more than 82.4%; no secondary pollution will be generated.

[0046] What adopted in the embodiment is the sulfuric acid pickling waste liquid of certain iron and steel enterprise, contains the ferrous sulfate of 5% sulfuric acid and 220~250g / L about in e...

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Abstract

The invention discloses a method for recycling sulfuric acid and ferrous sulfate from pickling waste liquor in the steel industry, and belongs to the technical field of resourceful treatment for waste liquor. The method mainly includes a technology for recycling ferrous sulfate by a freezing crystallization method, a technology for recycling sulfuric acid by a strong caustic anion exchange resin acid blocking principle and a technology for preparing polymeric ferric sulfate by a one-step catalysis method. The method has the advantages that the process and operation are simple, secondary pollution is prevented, resourceful treatment for the sulfuric acid pickling waste liquor is realized, the sulfuric acid is recycled and can be used for production, the ferrous sulfate is also recycled, polymeric ferric sulfate water purifier is prepared, and zero pollution emission of a steel enterprise is realized; recovery rates of the sulfuric acid and the ferrous sulfate are high and reach 82% and 97% respectively; and the quality of the polymeric ferric sulfate water purifier meets a type-I standard of the Polymeric Ferric Sulfate Water Purifier (GB14591-2006).

Description

technical field [0001] The invention belongs to the technical field of waste liquid resource treatment, and in particular relates to a method for recycling sulfuric acid and ferrous sulfate in pickling waste liquid in the iron and steel industry. Background technique [0002] Before use, the steel pipe needs to be pickled to remove the oxide layer on its surface. The condition of pickling is that the concentration of sulfuric acid is 20-25%, and the temperature of pickling is 50-65°C. When the concentration of sulfuric acid in the pickling solution is lower than 5%, and the concentration of ferrous sulfate reaches 250g / L, the production requirements cannot be met, and the pickling solution needs to be replaced. The replaced pickling solution is what is commonly referred to as pickling waste. Due to its severe corrosiveness, it has been included in the "National List of Hazardous Wastes". [0003] At present, there are seven main types of treatment technologies for (sulfuric...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23G1/36C22B7/00
CPCY02P10/20
Inventor 翟建姜春华
Owner NANJING COLLEGE OF CHEM TECH
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