Recycling and treating method for pickling waste water of iron and steel

A technology for iron and steel pickling and waste water recycling, which is applied in photography technology, equipment, photography auxiliary technology, etc., can solve the problems that have not been seen in the report, achieve full utilization, increase hydrogen evolution overpotential, and reduce environmental pollution.

Active Publication Date: 2016-12-14
ZHUZHOU SMELTER GRP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, it is limited to the treatment of iron-containing pickling wastewater with a pH>2
However, the report of directly treating steel pickling wastewater with pH<2 by electrolysis has not yet been seen.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0028] (1) Add dodecyltrimethylammonium chloride (cationic surfactant) to iron and steel sulfate pickling wastewater to obtain an electrolytic mixture. Fe in the electrolyte mixture 2+ The concentration is 160g / L, the concentration of the cationic surfactant is 2g / L, and the pH of the electrolytic mixture is 1-2.

[0029] (2) Put the electrolytic mixture solution into the diaphragm electrolyzer for electrolysis. The anode is a rolled lead plate (inert electrode), the highly polished stainless steel plate is a cathode, the cell voltage is controlled to 0.9V, and the current density is controlled to 300A / m 2 , The electrolysis temperature is controlled at 30°C to 40°C, and the electrolysis cycle is 72h. The cathode of the diaphragm electrolyzer precipitates high-purity iron, and the anode waste acid is regenerated. The current efficiency of the electrolysis process is 94%, and the power consumption is 920t / KW.h. Fe in solution after electrolysis 2+ The concentration of the ...

Embodiment 2

[0033] (1) Add dodecyltrimethylammonium chloride to iron and steel sulfate pickling wastewater to obtain an electrolytic mixture. Fe in the electrolyte mixture 2+ The concentration is 140g / L, the cationic surfactant concentration is 4g / L, and the pH=1 of the mixed solution.

[0034] (2) Put the electrolytic mixture solution into the diaphragm electrolyzer for electrolysis. The anode is a rolled lead plate, the highly polished stainless steel plate is a cathode, the cell voltage is controlled at 1.1V-1.2V, and the current density is controlled at 400A / m 2 , The electrolysis temperature is controlled at 30°C to 40°C, and the electrolysis cycle is 72h. The cathode of the diaphragm electrolyzer precipitates high-purity iron, and the anode waste acid is regenerated. The current efficiency of the electrolysis process is 95%, and the power consumption is 900t / KW.h. Fe in solution after electrolysis 2+The concentration of the iron was 26.1g / L, and the recovery rate of iron was 81...

Embodiment 3

[0038] (1) Add dodecyltrimethylammonium chloride to hydrofluoric acid and nitric acid steel pickling waste water (which contains 10% hydrofluoric acid and 40% nitric acid by mass fraction) to obtain an electrolytic mixture. Fe in the electrolyte mixture 2+ The concentration is 100g / L, the cationic surfactant concentration is 6g / L, and the pH of the mixed solution is 0.5-1.

[0039] (2) Put the electrolytic mixture solution into the diaphragm electrolyzer for electrolysis. The anode is a graphite electrode (inert electrode), the highly polished stainless steel plate is a cathode, the cell voltage is controlled at 1.2V, and the current density is controlled at 450A / m 2 , The electrolysis temperature is controlled at 30°C to 40°C, and the electrolysis cycle is 72h. The cathode of the diaphragm electrolyzer precipitates high-purity iron, and the anode waste acid is regenerated. The current efficiency of the electrolysis process is 98%, and the power consumption is 980t / KW.h. F...

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Abstract

The invention discloses a recycling and treating method for pickling waste water of iron and steel. The recycling and treating method comprises the following steps of adding a cationic surfactant in the pickling waste water of the iron and the steel to obtain an electrolyzed mixed solution; electrolyzing the electrolyzed mixed solution in a diaphragm electrolytic cell, separating out high-purity iron at a cathode, and regenerating waste acid at an anode; breaking, annealing and reducing the separated high-purity iron to obtain high-purity iron powder; and enabling the waste acid regenerated at the anode to return to a pickling step of the iron and the steel for recycling. The recycling and treating method for the pickling waste water of the iron and the steel is simple in technique and high in iron recovery rate; the high-purity iron can be obtained and no secondary pollution is caused; after recycling and treatment, the acidity of the waste water is not reduced, and the pickling waste water can be regenerated for recycling; and in addition, the recycling and treating method is suitable for treating the pickling waste water of which the pH value is smaller than 2 of the iron and the steel.

Description

technical field [0001] The invention relates to the technical field of wastewater treatment, in particular to a method for recycling and treating steel pickling wastewater. Background technique [0002] Steel option blanks are generally pickled before surface electroplating and spraying to remove oxides on the surface, thus generating pickling wastewater. The acid concentration in steel pickling wastewater is relatively high, and its pH value is generally less than 1. Different components or different processing requirements, the type and concentration of acid used are also different. Sulfuric acid is generally used to clean steel workpieces or blanks. The waste liquid contains sulfuric acid, ferrous sulfate, iron oxide scale and oil stains. [0003] At present, the sulfuric acid washing liquid treatment process in the iron and steel industry mainly includes neutralization method, ferric sulfate method, organic solvent extraction method, dialysis method, ion exchange metho...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C23G1/36C25C1/06
CPCC23G1/36C25C1/06Y02P10/20
Inventor 刘敏刘一宁廖贻鹏彭双义周萍
Owner ZHUZHOU SMELTER GRP
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