Production system for efficiently preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid

Abstract

The utility model discloses a production system for efficiently preparing high-purity electronic grade sulfuric acid from waste sulfuric acid, which comprises a waste acid storage tank, the waste acid storage tank is sequentially communicated with a filter device, an oxidation tank and an incinerator through pipelines, and the incinerator is communicated with a flue gas treatment system, a heat exchanger and a washing tower through pipelines. The washing tower is sequentially communicated with the catalytic oxidation tower, the SO3 absorption tower, the concentration tower, the rectifying tower, the condenser, the ion exchanger, the ultrafiltration device and the high-purity sulfuric acid storage tank through pipelines. According to the utility model, waste sulfuric acid is recycled, so that the procurement cost of original sulfuric acid is reduced; energy consumption is reduced through a heat energy recovery system, and overall economic benefits are improved; organic matters and harmful impurities are thoroughly degraded through high-temperature incineration and catalytic oxidation, and environmental pollution is reduced; multiple purification technologies such as rectification, ion exchange and ultrafiltration are adopted, the purity of the prepared sulfuric acid is higher, meanwhile, trace impurities such as Fe < 3 + >, Cu < 2 + >, SiO2 and NOx are effectively removed, and the high quality of the product is ensured.

Description

Technical Field

[0001] This utility model belongs to the technical field of electronic-grade sulfuric acid preparation and electronic waste liquid recycling, specifically relating to a production system for efficiently preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid. Background Technology

[0002] Currently, the global consumption of electronic-grade sulfuric acid has reached 1.5 million tons. After being used with SPM solution, the amount reaches more than 1.8 million tons. As chip manufacturing processes gradually improve from 28nm to 14nm and 7nm, the amount of waste sulfuric acid discharged is increasing year by year. Due to its high treatment difficulty and environmental protection requirements, its treatment cost is increasing, which increases the environmental and production and operation burden on enterprises.

[0003] Currently, semiconductor factories typically neutralize waste sulfuric acid with acid before outsourcing its disposal to specialized organizations. This process is not only costly and difficult but also results in a significant waste of non-metallic sulfur resources. At present, electronic-grade waste sulfuric acid is transferred to qualified organizations for disposal at a cost of additional payment for transportation and disposal fees. However, achieving high purity and removing metal ions are difficult in existing electronic-grade sulfuric acid production processes. Therefore, a high-efficiency production system for producing high-purity electronic-grade sulfuric acid from waste sulfuric acid is needed to address these issues. Utility Model Content

[0004] The purpose of this invention is to provide a production system for efficiently preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a production system for efficiently preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid, comprising...

[0006] A waste acid storage tank, wherein the waste acid storage tank is connected in sequence to a filtration device, an oxidation tank and an incinerator via pipelines;

[0007] The incinerator is connected to the flue gas treatment system, heat exchanger and scrubbing tower via pipelines;

[0008] The washing tower is connected in sequence to a catalytic oxidation tower, an SO3 absorption tower, a concentration tower, a distillation tower, a condenser, an ion exchanger, an ultrafiltration device, and a high-purity sulfuric acid storage tank via pipelines.

[0009] Preferably, the filtration device uses a ceramic filter element or a polytetrafluoroethylene membrane.

[0010] Preferably, in any of the above embodiments, the flue gas treatment system is a wet scrubbing tower.

[0011] In any of the above embodiments, it is preferred that the catalyst in the catalytic oxidation tower is V2O5.

[0012] In any of the above embodiments, it is preferred that the inner lining of the concentration tower is made of graphite or tetrafluoroethylene.

[0013] In any of the above embodiments, it is preferred that the condenser uses a quartz cooling tube.

[0014] Preferably, in any of the above embodiments, the pore size of the ultrafiltration device is 0.1 μm.

[0015] The technical effects and advantages of this utility model are as follows: This production system for efficiently preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid utilizes waste sulfuric acid recycling and reuse, reducing the procurement cost of virgin sulfuric acid; it reduces energy consumption and improves overall economic efficiency through a heat recovery system; high-temperature incineration and catalytic oxidation thoroughly degrade organic matter and harmful impurities, reducing environmental pollution; and it employs multiple purification technologies such as distillation, ion exchange, and ultrafiltration to produce sulfuric acid with higher purity, while effectively removing Fe. 3+ Cu 2+ SiO2, NO x To ensure high product quality, trace impurities are removed. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the system structure of this utility model.

[0017] In the diagram: 1. Waste acid storage tank; 2. Filtration device; 3. Oxidation tank; 4. Incinerator; 5. Heat exchanger; 6. Flue gas treatment system; 7. Scrubber; 8. Catalytic oxidation tower; 9. SO3 absorption tower; 10. Concentration tower; 11. Distillation tower; 12. Condenser; 13. Ion exchanger; 14. Ultrafiltration device; 15. High-purity sulfuric acid storage tank. Detailed Implementation

[0018] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding of this utility model, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.

[0019] In the description of this utility model, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this utility model and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.

[0020] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature.

[0021] This utility model provides, for example Figure 1 The sulfuric acid production system shown includes

[0022] Waste acid storage tank 1 is connected in sequence to filter device 2, oxidation tank 3 and incinerator 5 via pipelines;

[0023] The incinerator 5 is connected to the flue gas treatment system 4, heat exchanger 6 and scrubbing tower 7 via pipelines;

[0024] The washing tower 7 is connected in sequence to the catalytic oxidation tower 8, SO3 absorption tower 9, concentration tower 10, distillation tower 11, condenser 12, ion exchanger 13, ultrafiltration device 14 and high-purity sulfuric acid storage tank 15 via pipelines.

[0025] Specifically, the filter device 2 uses a ceramic filter element or a polytetrafluoroethylene membrane.

[0026] Specifically, flue gas treatment system 4 is a wet scrubbing tower.

[0027] Specifically, the catalyst in catalytic oxidation tower 8 is V2O5.

[0028] Specifically, the inner lining of the concentration tower 10 is made of graphite or tetrafluoroethylene.

[0029] Specifically, condenser 12 uses quartz cooling tubes.

[0030] Specifically, the filtration pore size of the ultrafiltration device 14 is 0.1 μm.

[0031] This efficient production system for producing high-purity electronic-grade sulfuric acid from waste sulfuric acid collects waste sulfuric acid (containing 70%-98% H2SO4, organic impurities, metal ions, etc.) from the semiconductor, chemical, and metallurgical industries and stores it in waste acid storage tank 1. The acid then flows through pipelines to filtration device 2 (coarse filtration), where ceramic filter elements or PTFE membranes remove large particulate solids. After filtration, the acid enters oxidation tank 3 (aeration oxidation, 60-80℃), where oxygen or ozone is introduced to oxidize organic impurities, reducing color and organic pollution. Next, it enters incinerator 5 (850-1100℃), where natural gas or coke oven gas is used to burn the waste acid, decomposing H2SO4. During combustion, heat exchanger 6 recovers some of the combustion heat, improving energy efficiency. Flue gas treatment system 4 (wet scrubbing tower, 50-70℃) removes dust and residual impurities generated during combustion. Finally, the acid enters scrubbing tower 7 (30-50℃, packed tower), where water or dilute sulfuric acid is sprayed to remove HF, Cl2, and NO. x After the acidic impurity gases are removed, they enter the catalytic oxidation tower 8 (V2O5 catalyst, 400-450℃) to convert SO2 into SO3, improving the subsequent sulfuric acid absorption efficiency. The mixture then proceeds to the SO3 absorption tower 9 (98-99% H2SO4, atmospheric pressure, packed tower), where SO3 is absorbed by concentrated sulfuric acid, increasing the sulfuric acid concentration. The mixture then passes through the concentration tower 10 (120-200℃, negative pressure) to evaporate moisture, further increasing the sulfuric acid concentration to >99%. The concentration tower 10 is lined with acid-resistant materials such as graphite or PTFE. The mixture then enters the distillation tower 11 (low pressure, silica gel packing) for further impurity separation, removing trace amounts of moisture, nitrogen oxides, silicates, etc. The distillation temperature is controlled at approximately 300℃ to prevent decomposition. The high-purity sulfuric acid is cooled by the condenser 12 (quartz cooling tube, 0-10℃) to reduce evaporation losses. Finally, trace metal ions, such as Fe, are removed by the ion exchanger 13 (resin column, pH 1-2). 3+ Cu 2+ Al 3+ To improve electronic-grade purity, an ultrafiltration device 14 (nanofiltration, 0.1μm) removes particulate impurities, ultimately yielding ultra-high purity sulfuric acid, which is stored in a high-purity sulfuric acid storage tank 15 (PTFE-lined, 316L stainless steel).

[0032] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A production system for efficiently producing high-purity electronic-grade sulfuric acid from spent sulfuric acid, characterized by: Comprising a waste acid storage tank (1) which is communicated with a filtering device (2), an oxidation tank (3) and an incinerator (5) in sequence through pipes; the incinerator (5) is communicated with a flue gas treatment system (4), a heat exchanger (6) and a washing tower (7) through pipes; the washing tower (7) is communicated with a catalytic oxidation tower (8), a SO3 absorption tower (9), a concentration tower (10), a rectifying tower (11), a condenser (12), an ion exchanger (13), an ultrafiltration device (14) and a high-purity sulfuric acid storage tank (15) in sequence through pipes.

2. The production system for efficiently preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid according to claim 1, characterized by: the filtering device (2) adopts a ceramic filter core or a polytetrafluoroethylene membrane.

3. The production system for efficiently preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid according to claim 1, characterized by: the flue gas treatment system (4) is a wet washing tower.

4. The production system for efficiently preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid according to claim 1, characterized by: the catalyst in the catalytic oxidation tower (8) is V2O5.

5. The production system for efficiently preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid according to claim 1, characterized by: the inner wall of the concentration tower (10) adopts graphite or tetrafluoroethylene.

6. The production system for efficiently preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid according to claim 1, characterized by: the condenser (12) adopts a quartz cooling tube.

7. The production system for efficiently preparing high-purity electronic-grade sulfuric acid from waste sulfuric acid according to claim 1, characterized by: the filtration pore size of the ultrafiltration device (14) is 0.1 μm.

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