Comprehensive recovery method for electroplating sludge

A technology of electroplating sludge and seed crystals, which is applied in the field of solid waste resource utilization, can solve the problems of poor applicability, poor treatment effect, and difficulty in industrialization, and achieve significant economic benefits, small amount of waste residue, and operability strong effect

Active Publication Date: 2016-01-27
INST OF PROCESS ENG CHINESE ACAD OF SCI +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The advantage of this method is that it has strong adaptability to different types of electroplating sludge, and has the characteristics of high utilization rate of metal resources, high added value of products, less waste residue in the process, and thorough detoxification; the disadvantage is that the process is long and the operation is complicated. Industrialization is more

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  • Comprehensive recovery method for electroplating sludge

Examples

Experimental program
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Effect test

Embodiment 1

[0042] Mix 20g of electroplating sludge with 8g of sodium carbonate, place it in a muffle furnace for calcination, and calcine at 700°C for 3 hours. After washing, leaching and filtering, leachate and filter cake are obtained. Introducing CO into the leaching solution 2 Adding seed crystals, the seed crystal coefficient is 0.6, controlling the solution temperature to 70°C, and removing aluminum and a small amount of silicon in the solution. A reducing agent is added to the dealuminated sodium chromate solution to carry out a reduction reaction, and after the reaction, the slurry is filtered and washed to obtain a chromium hydroxide filter cake. The recovery rate of chromium is 95%, and the recovery rate of aluminum is 92%. The filter residue is leached with sulfuric acid at a ratio of acid / residue = 1.0 times, and the leached residue is iron-silicon slag. The leachate is removed to obtain ferric hydroxide. The impurity removal solution is extracted / back-extracted and crysta...

Embodiment 2

[0044] Mix 20g of electroplating sludge with 5g of sodium carbonate, place it in a muffle furnace for calcination, and calcine at 800°C for 2.5h. After washing, leaching and filtering, leachate and filter cake are obtained. Introducing CO into the leaching solution 2 And adding seed crystals, the seed crystal coefficient is 0.8, controlling the solution temperature to 50° C., and removing aluminum and a small amount of silicon in the solution. A reducing agent is added to the dealuminated sodium chromate solution to carry out a reduction reaction, and after the reaction, the slurry is filtered and washed to obtain a chromium hydroxide filter cake. The recovery rate of chromium is 99%, and the recovery rate of aluminum is 91%. The filter residue is leached with hydrochloric acid at a ratio of acid / residue = 3.0 times, and the leached residue is iron-silicon slag. The leachate is removed to obtain ferric hydroxide. The impurity removal solution is extracted / back-extracted and...

Embodiment 3

[0046] Mix 20g of electroplating sludge with 3g of sodium carbonate, place it in a muffle furnace for calcination, and calcine at 900°C for 2 hours. After washing, leaching and filtering, leachate and filter cake are obtained. Introducing CO into the leaching solution 2 And adding seed crystals, controlling the solution temperature to 30° C., the seed crystal coefficient to 0.3, and removing aluminum and a small amount of silicon in the solution. A reducing agent is added to the dealuminated sodium chromate solution to carry out a reduction reaction, and after the reaction, the slurry is filtered and washed to obtain a chromium hydroxide filter cake. Chromium recovery was 92% and aluminum recovery was 90%. The filter residue is leached with nitric acid according to the ratio of acid / residue = 2.0 times, and the leached residue is iron-silicon slag. The leachate is removed to obtain ferric hydroxide. The impurity removal solution is extracted / back-extracted and crystallized ...

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Abstract

The invention provides a comprehensive recovery method for electroplating sludge. The method comprises the following steps: (1) mixing the electroplating sludge with sodium carbonate, and then roasting a mixture; (2) performing water leaching and filtration on roasted residue obtained in the step (1) so as to obtain leaching liquid and a filter cake; (3) adding sodium hydroxide in a CO2 neutralizing solution into the leaching liquid, adding seed crystal to remove aluminum and silicon in the solution, adding a reducing agent into a decontaminated sodium chromate solution for reduction, and filtering and washing obtained slurry to obtain a chromium hydroxide filter cake; (4) mixing filter residue obtained in the step (2) with inorganic acid, and then leaching a mixture to obtain leaching liquid and filter residue; (5) regulating the pH value of the leaching liquid obtained in the step (4) to be 1.0-4.0, and then performing filtration to obtain ferric hydroxide and a mother precipitation solution; (6) extracting a water phase through the mother precipitation solution obtained in the step (5) to obtain a nickel-containing solution, and reversely extracting an oil phase to obtain a copper-containing solution. The method is environment-friendly and pollution-free, has obvious economic benefits, and is an effective way to treat the electroplating sludge.

Description

technical field [0001] The invention relates to the field of resource utilization of solid waste, in particular to a new method for separating and recovering elements such as copper, nickel, iron, chromium and aluminum in electroplating sludge. Background technique [0002] Electroplating sludge is a solid waste generated during electroplating wastewater treatment, and chromium-containing electroplating sludge is a typical hazardous waste. At present, due to many problems in my country's electroplating industry, such as many factories, small scale, low level of equipment, and low level of pollution control, most of the chromium-containing electroplating sludge is simply landfilled or even randomly piled up, which has caused serious damage to the environment. pollute. [0003] Chromium-containing electroplating sludge contains a variety of metal components, such as copper, chromium, nickel, iron, zinc, etc., and its grade is often higher than that of metal-rich ores. It is a ...

Claims

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Application Information

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IPC IPC(8): C02F11/18C22B7/00C22B34/32C22B21/00C22B15/00C22B23/00C02F103/16
CPCY02P10/20
Inventor 曲景奎魏广叶余志辉曾政皇李永利齐涛
Owner INST OF PROCESS ENG CHINESE ACAD OF SCI
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