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Method for recovering chromium in chromium plating and zinc plating wastewater

A waste water, zinc sulfate heptahydrate technology, applied in chemical instruments and methods, metallurgical waste water treatment, chromate/dichromate, etc., can solve problems such as complex process, high equipment cost, and difficult operation, and achieve the goal of preparing The method is simple, the discharge of three wastes is small, and the effect of objective economic benefits

Pending Publication Date: 2021-05-28
四川银河明宏环保科技有限公司 +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

At present, the removal methods of chromium ions and zinc ions in wastewater have disadvantages such as high equipment cost, complicated process, and difficult operation. They all solve a certain kind of wastewater in a single way. In order to jointly treat sewage and reduce the cost of wastewater treatment

Method used

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  • Method for recovering chromium in chromium plating and zinc plating wastewater

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] A method for reclaiming chromium in chrome-plating and galvanizing wastewater, comprising the following steps:

[0028] Step 1, 10L 25.9g / L (calculated by sodium rufium) chromium-plating waste water is carried out evaporation concentration, obtains concentration and is the concentrated solution A of 259g / L (calculated by sodium ruthenium);

[0029] Step 2, 100L 25.4g / L (in zinc sulfate heptahydrate) galvanizing waste water is carried out evaporation concentration, obtains concentration and is the concentrated solution B of 254g / L (in zinc sulfate heptahydrate);

[0030] Step 3: Add the concentrated solution B to the concentrated solution A within 30 minutes, and add sodium hydroxide to adjust the pH to 6.2, then raise the temperature of the system to 80°C and age for 4 hours;

[0031] Step 4: Filtrate the material after heating and aging treatment to obtain filtrate A and solid, wash the solid, blow dry it at 80°C for 3 hours, and pulverize it into 300 meshes to obtain ...

Embodiment 2

[0035] A method for reclaiming chromium in chrome-plating and galvanizing wastewater, comprising the following steps:

[0036] Step 1, 5L 51.8g / L (calculated by sodium alum) is evaporated and concentrated to obtain concentrated solution A of 259g / L (calculated by sodium alum);

[0037] Step 2, 100L 25.4g / L (in zinc sulfate heptahydrate) galvanizing waste water is carried out evaporation concentration, obtains concentration and is the concentrated solution B of 254g / L (in zinc sulfate heptahydrate);

[0038] Step 3: Add the concentrated solution B to the concentrated solution A within 50 minutes, and add sodium hydroxide to adjust the pH to 6, then raise the temperature of the system to 80°C and age for 4 hours;

[0039] Step 4: Filtrate the material after heating and aging treatment to obtain filtrate A and solid, wash the solid, blow dry it at 80°C for 4 hours, and pulverize it into 250 meshes to obtain zinc chrome yellow;

[0040] Step 5, the filtrate A is added to ethanol ...

Embodiment 3

[0043] A method for reclaiming chromium in chrome-plating and galvanizing wastewater, comprising the following steps:

[0044] Step 1, 10L 25.9g / L (calculated by sodium rufium) chromium-plating waste water is carried out evaporation concentration, obtains concentration and is the concentrated solution A of 259g / L (calculated by sodium ruthenium);

[0045] Step 2, 50L 50.8g / L (in zinc sulfate heptahydrate) galvanizing waste water is carried out evaporation concentration, obtains concentration and is the concentrated solution B of 254g / L (in zinc sulfate heptahydrate);

[0046] Step 3: Add the concentrated solution B to the concentrated solution A within 30 minutes, and add sodium hydroxide to adjust the pH to 6.4, then raise the temperature of the system to 80°C and age for 4 hours;

[0047] Step 4: Filtrate the material after heating and aging treatment to obtain filtrate A and solid, wash the solid, blow dry it at 80°C for 4 hours, and pulverize it into 250 meshes to obtain z...

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Abstract

The invention discloses a method for recovering chromium in chromium plating and zinc plating wastewater, which comprises the following steps: evaporating and concentrating the chromium plating wastewater to obtain a concentrated solution A; evaporating and concentrating the zinc plating wastewater to obtain a concentrated solution B; slowly adding the concentrated solution B into the concentrated solution A, adjusting the pH value, and then carrying out heating aging treatment on the system; filtering the heated and aged material to obtain a filtrate A and a solid, and washing, drying and crushing the solid to obtain zinc chrome yellow; adding a reducing agent into the filtrate A for reaction, and conducting filtering to obtain a chromium hydroxide filter cake and a filtrate B; and concentrating the filtrate B, and conducting crystallizing to obtain anhydrous sodium sulphate. The produced zinc chrome yellow is excellent in quality and meets the quality requirements of zinc chrome yellow products of enterprises. According to the method, the wastewater of an electroplating factory is jointly and comprehensively utilized and converted into a product with economic value for the first time. The preparation method of the zinc chrome yellow is simple, safe, reliable, low in cost and low in emission of three wastes; and meanwhile, the method has objective economic benefits.

Description

technical field [0001] The invention relates to the field of environmental protection, in particular to a method for comprehensively utilizing chrome-plating and galvanizing wastewater. Background technique [0002] Chromium electroplating plants will produce a large amount of chromium-containing wastewater in the process of plating parts. In addition to a large amount of hexavalent chromium and a small amount of trivalent chromium, these wastewaters generally come from pickling of plated parts, coating of plated parts, workshop cleaning, Equipment condensate and other parts. [0003] Zinc wastewater is one of the industrial wastewater that pollutes the environment seriously and is the most harmful to humans, and its water quality and quantity are related to the production process. Zinc in wastewater generally cannot be decomposed and destroyed, but can only transfer its existing location and change its physical and chemical form. Pollution of zinc and its compounds to the...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C02F9/10C01G37/14C02F101/22C02F103/16
CPCC02F9/00C01G37/14C02F1/04C02F1/66C02F1/5236C02F1/72C02F1/001C02F2103/16C02F2101/22C02F2301/08Y02P20/54
Inventor 王斌尹春林颜欣马顺友赵安段波樊诗贤刘刚
Owner 四川银河明宏环保科技有限公司