Sulfur-containing waste gas treatment method

Abstract

The invention relates to the field of household garbage treatment and processing, and discloses a sulfur-containing waste gas treatment method which comprises the following steps: primarily screening collected kitchen garbage to remove inorganic matters and refractory organic matters in the kitchen garbage, and crushing the kitchen garbage by a crusher until the particle size reaches 1-3 cm; mixing the obtained kitchen garbage and biogas residues according to a mass ratio of 1: 1, then uniformly adding 1% of a decomposition microbial inoculum and a certain amount of a composting auxiliary agent, and uniformly mixing to obtain a composting raw material; and finally, adding the obtained composting principle into a composting box for composting treatment, and obtaining the organic fertilizer after 40 days. The kitchen garbage treatment device has the effect of improving the utilization rate of kitchen garbage.

Description

Technical Field

[0001] This invention relates to the field of waste gas treatment technology, and in particular to a method for treating sulfur-containing waste gas. Background Technology

[0002] Sulfuric acid production from pyrite (mainly FeS2) is a traditional process in industrial sulfuric acid production, which generates various waste gases. These waste gases contain sulfur dioxide, sulfur trioxide, arsenic trioxide, hydrogen fluoride, and heavy metals such as lead and mercury. If these gases are emitted directly without effective treatment, they will cause serious harm to the atmospheric environment, ecosystems, and human health.

[0003] Chinese invention patent CN115624851B discloses a process and apparatus for treating tail gas from electronic-grade sulfuric acid production, including a waste gas tank, an ammonia storage tank, and multiple absorption tanks. The waste gas in the waste gas tank and the ammonia in the ammonia storage tank flow sequentially through the multiple absorption tanks. After a preset time, the pH value H of the ammonia after absorbing the waste gas in the lower part of the absorption tank is obtained to determine the absorption effect of the ammonia on sulfur dioxide in the waste gas. The desulfurization effect of the ammonia is ensured by adjusting the height of the spray assembly. Although the above invention can ensure the desulfurization effect of the ammonia by adjusting the height of the spray assembly, it cannot effectively remove harmful substances such as arsenic compounds and heavy metals from the waste gas. Summary of the Invention

[0004] The purpose of this invention is to provide a method for treating sulfur-containing waste gas, which has the effect of tiered purification of various harmful substances in the waste gas.

[0005] The above-mentioned technical objective of the present invention is achieved through the following technical solution, including the following steps:

[0006] (1) The waste gas generated during the production process is sent to a cyclone dust collector to separate the dust particles in the waste gas;

[0007] (2) Pass the waste gas obtained in step (1) into the acid washing device to remove the fluorine-containing compounds in the waste gas;

[0008] (3) Pass the waste gas obtained in step (2) into a photocatalytic reaction device to remove heavy metal impurities from the waste gas;

[0009] (4) Pass the waste gas obtained in step (3) into an alkaline washing device to remove sulfur-containing compounds from the waste gas;

[0010] (5) The exhaust gas discharged from the alkaline washing device in step (4) meets the emission standards.

[0011] A further provision of the present invention is that the acid detergent used in the pickling apparatus is water.

[0012] A further provision of the present invention is that the acidic detergent also includes lime milk.

[0013] A further feature of the present invention is that the photocatalytic reaction device uses a Pt / TiO2 photocatalyst.

[0014] A further feature of the present invention is that the photocatalytic reaction device uses an ultraviolet lamp with a wavelength of 254 nm.

[0015] A further provision of the present invention is that the alkaline detergent used in the alkaline washing device is ammonia.

[0016] The beneficial effects of this invention are:

[0017] 1. This invention treats sulfur-containing waste gas generated during the production of sulfuric acid from pyrite using a classified removal and tiered purification method. On the one hand, it can sequentially remove Fe2O3 dust, arsenic compounds, fluorine compounds, heavy metal impurities, and sulfur compounds from the waste gas, ensuring that the treated waste gas meets environmental protection requirements. On the other hand, the Fe2O3 dust recovered by the cyclone dust collector can be used as raw material for iron smelting or as pigment. In the acid washing device, SiF4 reacts with water to generate H2SiF6 (fluorosilicic acid), which can be further processed into fluorosilicate products. The by-products generated by the ammonia desulfurization process in the alkaline washing device can be used to make nitrogen fertilizer, thereby achieving the purpose of resource recycling and reuse.

[0018] 2. This invention, by adding lime milk to an acidic detergent, can convert As2O3 into a sparingly soluble Ca3(AsO4)2 precipitate, thereby enabling the removal of arsenic compounds while acid washing the waste gas with water to remove fluorine-containing compounds.

[0019] 3. This invention can remove heavy metals such as Hg and Pb from waste gas by using Pt / TiO2 photocatalyst. Detailed Implementation

[0020] The technical solution of the present invention will now be clearly and completely described with reference to specific embodiments. Obviously, the described embodiments are merely some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0021] Example

[0022] (1) The waste gas generated during the production process is sent to the cyclone dust collector to separate the Fe2O3 dust in the waste gas. The dust removal efficiency can reach more than 99%.

[0023] (2) The waste gas obtained in step (1) is passed into an acid washing device and acid washed with lime milk solution to remove fluorine-containing compounds and arsenic-containing compounds from the waste gas.

[0024] (3) The waste gas obtained in step (2) is passed into a photocatalytic reaction device to remove heavy metal impurities such as Hg and Pb from the waste gas;

[0025] (4) Pass the waste gas obtained in step (3) into the alkaline washing device and use ammonia water for alkaline washing to remove sulfur-containing compounds from the waste gas;

[0026] (5) The exhaust gas discharged from the alkaline washing device in step (4) is tested and meets the emission standards.

[0027] The exhaust gas was tested and found to contain SO2 ≤ 400 mg / m³, particulate matter ≤ 50 mg / m³, arsenic and its compounds ≤ 0.5 mg / m³, and fluoride ≤ 9 mg / m³, which complies with the "Emission Standard of Pollutants for Sulfuric Acid Industry" (GB 26132-2010).

[0028] Comparative Example

[0029] (1) The waste gas generated during the production process is sent to the cyclone dust collector to separate the Fe2O3 dust in the waste gas. The dust removal efficiency can reach more than 99%.

[0030] (2) The waste gas obtained in step (1) is passed into an alkaline washing device and alkaline washing is performed using ammonia water to remove sulfur-containing compounds from the waste gas.

[0031] (3) The exhaust gas discharged from the alkaline washing device in step (2) is tested.

[0032] The exhaust gas was tested and found to contain SO2 ≤ 400 mg / m³, particulate matter ≤ 50 mg / m³, arsenic and its compounds > 0.5 mg / m³, and fluoride > 9 mg / m³, which does not meet the requirements of the "Emission Standard of Pollutants for Sulfuric Acid Industry" (GB 26132-2010).

[0033] The examples provided in this invention are not intended to limit the implementation. Those skilled in the art will recognize that various variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations, and any obvious variations or modifications derived therefrom are still within the scope of this invention.

[0034] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method for treating sulfur-containing waste gas, characterized in that, Includes the following steps: (1) The waste gas generated during the production process is sent to a cyclone dust collector to separate the dust particles in the waste gas; (2) Pass the waste gas obtained in step (1) into the acid washing device to remove the fluorine-containing compounds in the waste gas; (3) Pass the waste gas obtained in step (2) into a photocatalytic reaction device to remove heavy metal impurities from the waste gas; (4) Pass the waste gas obtained in step (3) into an alkaline washing device to remove sulfur-containing compounds from the waste gas; (5) The exhaust gas discharged from the alkaline washing device in step (4) meets the emission standards.

2. The method for treating sulfur-containing waste gas according to claim 1, characterized in that: The acidic detergent used in the pickling device is water.

3. The method for treating sulfur-containing waste gas according to claim 2, characterized in that: The acidic detergent also includes lime milk.

4. The method for treating sulfur-containing waste gas according to claim 1, characterized in that: The photocatalytic reaction device uses a Pt / TiO2 photocatalyst.

5. The method for treating sulfur-containing waste gas according to claim 4, characterized in that: The photocatalytic reaction device uses an ultraviolet lamp with a wavelength of 254 nm.

6. The method for treating sulfur-containing waste gas according to claim 1, characterized in that: The alkaline detergent used in the alkaline washing device is ammonia.