Resource recycling method of stainless steel pickling wastewater

A technology of pickling wastewater and recycling method, applied in chemical instruments and methods, nitric acid, hydrogen fluoride and other directions, can solve problems such as environmental hazards, damage to soil vegetation structure, pollution of air and water bodies, etc., and achieve no secondary pollution and considerable economic benefits. , Guarantee the effect of stable compliance

Inactive Publication Date: 2017-05-31
张圆圆
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In addition, stainless steel slag contains Cr 6+ Toxic compounds, if not treated, the tailings discharged will also cause serious harm to the surrounding environment, destroy the structure of soil vegetation, pollute the air and water

Method used

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Examples

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Embodiment Construction

[0014] The principles and features of the present invention are described below in combination, and the examples given are only used to explain the present invention, and are not used to limit the scope of the present invention.

[0015] A kind of resource recovery method of stainless steel pickling waste water, comprises the following steps:

[0016] Recovery of iron and chromium: Add concentrated nitric acid to stainless steel pickling wastewater to adjust the pH value to 1.5-2.5; then filter the wastewater to obtain iron and chromium precipitates;

[0017] Recovery of hydrofluoric acid and nitric acid: Concentrate stainless steel pickling wastewater to obtain concentrated acid water, evaporate the concentrated acid water under reduced pressure, collect evaporated liquid to obtain hydrofluoric acid and nitric acid;

[0018] Separation and recovery of iron: cooling and filtering the solution after separating hydrofluoric acid and nitric acid to complete the recovery of iron i...

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PUM

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Abstract

The invention relates to a resource recycling method of stainless steel pickling wastewater. The resource recycling method comprises the following steps: concentrated nitric acid is added to the stainless steel pickling wastewater, and pH is regulated to 1.5-2.5; the wastewater is filtered, and iron and chromium precipitates are obtained; the stainless steel pickling wastewater is concentrated, concentrated acid water is obtained and subjected to reduced-pressure evaporation, an evaporated liquid is collected, and hydrofluoric acid and nitric acid are obtained; the solution after hydrofluoric acid and nitric acid are separated is cooled and filtered, and iron is recovered from the solution; a preneutralization agent is added to the solution obtained after acid recovery to control pH, and sedimentation and filtering are performed; a vulcanizing agent is added to a filtrate after acid removal through neutralization, vulcanizing pH is controlled, nickel-chromium separation is completed with a vulcanizing method, and nickel recovery is realized. Compared with the prior art, nickel ions can be extracted from waste liquor, and wastewater recovery can be realized without introduction of new impurities.

Description

technical field [0001] The invention relates to a resource recovery method of stainless steel pickling wastewater. Background technique [0002] Stainless steel is known as a fine steel product. With its superior corrosion resistance, unique surface and excellent processing performance, it has developed very rapidly and its application fields have become wider and wider. The pickling of stainless steel strip is a key process in the production of cold-rolled stainless steel, which plays a decisive role in ensuring the surface quality of the product. The pickling process has also developed from pure chemical pickling in the 1960s and 1970s to the current combination of chemical pickling and electrolytic pickling. Wastewater containing heavy metals nickel and chromium will be produced in stainless steel pickling. Traditionally, these wastewaters are discharged directly, seriously polluting the environment. [0003] Stainless steel slag contains a large amount of valuable met...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/10C01B7/19C01B21/46C22B7/00C22B34/32C22B23/00C02F101/14C02F101/16C02F101/20C02F101/22
CPCC01B7/195C01B21/46C02F1/046C02F1/5236C02F1/5254C02F2101/14C02F2101/163C02F2101/20C02F2101/203C02F2101/22C22B7/006C22B23/0461C22B34/32Y02P10/20
Inventor 张圆圆
Owner 张圆圆
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