A kind of recycling method of electrode foil corrosion waste sulfuric acid

A waste sulfuric acid and electrode foil technology, which is applied to aluminum sulfate, chemical instruments and methods, sulfur trioxide/sulfuric acid, etc., can solve the problems of resource waste, high cost, and environmental pollution, and achieve improved recovery efficiency, long equipment life, No secondary pollution effect

Active Publication Date: 2020-10-30
常州中源工程技术有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] Usually waste acid-ion exchange resin-adding lime to adjust pH-precipitation-discharge is used to treat waste acid. However, although this process can absorb part of sulfuric acid through the resin, the concentration of sulfuric acid after washing with water is less than 20%, which is lower than that of corrosion. The concentration of sulfuric acid required by the process, and the concentration of aluminum ions in it exceeds the standard. When recycling, not only must add concentrated sulfuric acid, but also consider the impact of the concentration of aluminum ions on the corrosion process, resulting in part of the recovered acid that cannot be reused; on the other hand, the lime precipitation process produces A large amount of gypsum solid waste has to be sent to the solid waste treatment center for treatment, which is expensive. At the same time, a large amount of waste water still needs to be discharged every day, which is a waste of resources
[0005] There are mainly two methods for the production technology of existing aluminum sulfate: one is to use aluminum ore and sulfuric acid to react to produce aluminum sulfate. During the production process, the aluminum ore will be crushed and fed, and more dust and dust will be generated in these processes. The ore waste slag seriously pollutes the environment, and the product preparation grade is low, which requires finishing; secondly, using sulfuric acid and aluminum hydroxide to synthesize aluminum sulfate, waste acid vapor will be generated during the synthesis process, and the waste acid vapor needs to be reprocessed before it can be discharged , this synthesis method requires a lot of raw material input and high cost

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  • A kind of recycling method of electrode foil corrosion waste sulfuric acid

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Effect test

Embodiment 1

[0031] The recycling method of electrode foil corrosion waste sulfuric acid of the present invention, concrete steps are as follows: its technological process is as follows figure 1 Shown:

[0032] (1) Preheating: the electrode foil corrosion waste acid from the waste sulfuric acid storage tank is pumped into the preheater for preheating, in which the uncondensed steam and concentrated high temperature produced by the two-effect three-stage Acid is the heat source for preheating;

[0033] (2), evaporation:

[0034] One-effect evaporation: the waste acid enters the first-effect evaporation tower, uses the heat provided by the steam pipe network, controls the evaporation temperature between 90-100°C, and controls the pressure at 70-100KPa for evaporation, and the evaporated steam is used as secondary steam to the second effect heat supply, and the remaining materials enter the second-effect evaporation tower;

[0035] Two-effect evaporation: Use the heat generated by the firs...

Embodiment 2

[0047] The recycling method of electrode foil corrosion waste sulfuric acid of the present invention, concrete steps are as follows: its technological process is as follows figure 1 Shown:

[0048] (1) Preheating: the electrode foil corrosion waste acid from the waste sulfuric acid storage tank is pumped into the preheater for preheating, in which the uncondensed steam and concentrated high temperature produced by the two-effect three-stage Acid is the heat source for preheating;

[0049] (2), evaporation:

[0050] One-effect evaporation: the waste acid enters the first-effect evaporation tower, uses the heat provided by the steam pipe network, controls the evaporation temperature between 90-100°C, and controls the pressure at 70-100KPa for evaporation, and the evaporated steam is used as secondary steam to the second effect heat supply, and the remaining materials enter the second-effect evaporation tower;

[0051] Two-effect evaporation: Use the heat of the first-effect e...

Embodiment 3

[0063] The recycling method of electrode foil corrosion waste sulfuric acid of the present invention, concrete steps are as follows: its technological process is as follows figure 1 Shown:

[0064] (1) Preheating: the electrode foil corrosion waste acid from the waste sulfuric acid storage tank is pumped into the preheater for preheating, in which the uncondensed steam and concentrated high temperature produced by the two-effect three-stage Acid is the heat source for preheating;

[0065] (2), evaporation:

[0066] One-effect evaporation: the waste acid enters the first-effect evaporation tower, uses the heat provided by the steam pipe network, controls the evaporation temperature between 90-100°C, and controls the pressure at 70-100KPa for evaporation, and the evaporated steam is used as secondary steam to the second effect heat supply, and the remaining materials enter the second-effect evaporation tower;

[0067] Two-effect evaporation: Use the heat of the first-effect e...

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Abstract

The invention belongs to the technical field of resource recycling, and particularly relates to a method for recycling electrode foil corrosion waste sulfuric acid. The specific steps are: preheating,evaporating, adding sulfuric acid, cooling, performing condensation crystallization, separating by pressure filtration, and preparing aluminum sulfate. The invention simultaneously realizes the recovery of sulfuric acid, hydrochloric acid and aluminum sulfate in the corrosive waste acid is realized, realizes zero discharge during production is realized, no secondary pollution exists, and high environmental protection performance is realized. According to the invention, sulfuric acid is added before cooling to reduce the concentration of aluminum sulfate in a waste acid liquid, overcomes the problem that the waste acid after cooling completely becomes solid due to the high concentration of aluminum sulfate in waste acid and is difficult to separate, so that sulfuric acid and aluminum sulfate are easier to separate, thereby improving the recovery efficiency of sulfuric acid and aluminum sulfate. The use of two-effect three-stage evaporation realizes the full utilization of the residualheat of steam generated during an evaporation process, and the device has long service life and low energy consumption.

Description

technical field [0001] The invention belongs to the technical field of resource recovery, and in particular relates to a recycling method for electrode foil corrosion waste sulfuric acid. Background technique [0002] Aluminum electrolytic capacitors are widely used in household appliances, computers, communications, industrial controls, electric vehicles, electric locomotives, and military and aerospace equipment. The production process of aluminum electrolytic capacitors includes aluminum foil corrosion, oxide film formation, aluminum foil cutting, etc. Among them, the key to determine the performance of aluminum electrolytic capacitors is to corrode aluminum foil. After corrosion, the surface area of ​​aluminum oxide film doubles, making its capacity Can be big. At present, chemical etching is often used to expand the surface area of ​​aluminum foil. [0003] The electrode foil is made of high-purity aluminum foil as the main raw material, and the finished product is ob...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): C01F7/74C01B7/07C01B17/90
CPCC01B7/0706C01B17/90C01F7/74
Inventor徐晨姚洪齐
Owner常州中源工程技术有限公司