Search

CN-121975556-A - Water-resistant solid waste-based ferric oxide desulfurizer for high-water vapor gas desulfurization and preparation method thereof

CN121975556ACN 121975556 ACN121975556 ACN 121975556ACN-121975556-A

Abstract

The invention relates to the technical field of desulfurizing agents, and discloses a water-resistant solid waste-based ferric oxide desulfurizing agent for high-water vapor gas desulfurization and a preparation method thereof, wherein the water-resistant solid waste-based ferric oxide desulfurizing agent comprises the steps of dry-mixing carbide slag and ferrous sulfate heptahydrate powder for pretreatment, adding water and kneading to prepare composite precursor pug; extruding, forming and cutting the pug to obtain compact green strips, performing humidity control drying on the compact green strips in a controlled temperature and humidity environment, closing the humidity control, opening forced ventilation, heating to perform oxidation, activation and drying, and cooling to room temperature. Calcium sulfate generated by utilizing the double decomposition reaction of carbide slag and ferrous sulfate heptahydrate and gel substances generated by hydration of silicon-aluminum components are mutually crosslinked to form a micro-cement skeleton network inside the desulfurizing agent. The network structure can anchor active components, resist water invasion and physical expansion in a high-water vapor environment, avoid hydration fragmentation and pulverization loss of the desulfurizing agent in operation, and solve the problem that the mechanical strength and the activity of the conventional desulfurizing agent cannot be taken into consideration.

Inventors

  • Shi Peixiang
  • SHI PEISHENG
  • ZHANG ZHONGMING
  • QIN ZHIFENG
  • HAO JIAJIA
  • ZHANG QIAN

Assignees

  • 太原理工大学
  • 山西太工科灵新材料研究院有限公司

Dates

Publication Date
20260505
Application Date
20260401

Claims (10)

  1. 1. The water-resistant solid waste-based ferric oxide desulfurizer for high-water vapor gas desulfurization is characterized by being prepared by extrusion molding, humidity control drying and oxidation activation drying of composite precursor pug; The composite precursor pug is formed by mixing and kneading carbide slag, ferrous sulfate heptahydrate and water, and the dry basis mass ratio of the carbide slag to the ferrous sulfate heptahydrate is 1 (0.8-1.5); The interior of the desulfurizer is provided with a micro-cement skeleton network structure constructed in situ by the double decomposition reaction of calcium hydroxide in carbide slag and ferrous sulfate heptahydrate and the hydration reaction of naturally associated aluminosilicate components in the carbide slag so as to anchor the desulfurization active components.
  2. 2. The water-resistant solid waste-based iron oxide desulfurizer for high-steam gas desulfurization according to claim 1, wherein the total water content of the composite precursor pug is controlled to be 35-42%.
  3. 3. The water-resistant solid waste-based iron oxide desulfurizer for high-steam gas desulfurization according to claim 1, wherein the physical form of the desulfurizer is cylindrical compact strips, and the diameter of the cylindrical compact strips is 3-6mm and the length of the cylindrical compact strips is 5-15mm.
  4. 4. The preparation method of the water-resistant solid waste-based iron oxide desulfurizer for high-steam gas desulfurization is characterized by being applied to the water-resistant solid waste-based iron oxide desulfurizer for high-steam gas desulfurization according to any one of claims 1 to 3, and comprises the following steps: Carrying out dry mixing pretreatment on carbide slag powder and ferrous sulfate heptahydrate powder, and then quantitatively adding water in the stirring process and carrying out high-shear kneading to prepare a composite precursor pug which is fine in texture, good in plasticity and completely uniform in component; Extruding the composite precursor pug under preset working pressure, and performing cutting treatment to obtain a compact raw bar; the compact green strips are subjected to humidity control and drying under the environment of controlled temperature and relative humidity, so that preliminary hydration reaction and crosslinking are caused to occur in the compact green strips, and a micro-cement skeleton is constructed in situ; And after the humidity control drying is finished, closing the humidity adjustment, starting a forced ventilation mode, heating to perform oxidation activation drying, and cooling to room temperature after the reaction is finished to obtain the water-resistant solid waste-based ferric oxide desulfurizer for Gao Shuiqi gas desulfurization.
  5. 5. The method for preparing the water-resistant solid waste-based ferric oxide desulfurizer for high-steam gas desulfurization according to claim 4, wherein the dry-mixing pretreatment is carried out in a horizontal type intensive mixer, the stirring speed is 30-60r/min, and the dry-mixing time is 5-10min; The rotational speed of the high shear kneading is 30-60r/min, and the continuous kneading time is 20-40min.
  6. 6. The method for preparing the water-resistant solid waste-based ferric oxide desulfurizer for high-steam gas desulfurization according to claim 4, wherein the quantitative water adding process is as follows: In the continuous stirring process, deionized water is added into the mixed materials at a constant speed through an atomization spraying system, and the water addition amount is monitored in real time and accurately regulated through an online moisture detector, so that the final total water content of the mixed system is controlled to be 35% -42%.
  7. 7. The method for preparing the water-resistant solid waste-based iron oxide desulfurizer for high-steam gas desulfurization according to claim 4, wherein the working pressure of extrusion molding is 3-8MPa, and stable extrusion is carried out through a porous template with the pore diameter of 3-6 mm.
  8. 8. The method for preparing the water-resistant solid waste-based ferric oxide desulfurizer for high-steam gas desulfurization according to claim 4, wherein the temperature of the humidity-controlled drying is controlled to be 80-110 ℃, the relative humidity of the environment is controlled to be 30% -60%, and the continuous drying time is 4-8h.
  9. 9. The method for producing a water-resistant solid waste-based iron oxide desulfurizing agent for high steam gas desulfurization according to claim 4, wherein the extrusion molding is performed in a screw extruder; The humidity control drying and the oxidation activation drying are continuously carried out in a mesh belt type drying furnace with a humidity adjusting function.
  10. 10. The method for preparing the water-resistant solid waste-based ferric oxide desulfurizer for high-steam gas desulfurization according to claim 4, wherein the temperature of the oxidation activation drying is controlled to be 120-150 ℃ and the continuous drying time is 4-6h.

Description

Water-resistant solid waste-based ferric oxide desulfurizer for high-water vapor gas desulfurization and preparation method thereof Technical Field The invention relates to the technical field of desulfurizing agents, in particular to a water-resistant solid waste-based ferric oxide desulfurizing agent for high-steam gas desulfurization and a preparation method thereof. Background In the industrial gas purification process, the use of iron oxide desulfurizing agents to remove hydrogen sulfide is a common means. Conventional iron oxide desulphurizers perform well when treating low water vapor content gas, but suffer from serious hydration failure problems when treating high water vapor content gas. The conventional ferric oxide desulfurizer has developed internal pores and strong hydrophilicity, and in a saturated high-water vapor environment, a large amount of water vapor enters the inside of particles and is condensed. The moisture invades and damages the microcosmic binding force in the desulfurizing agent, promotes the hydration expansion of materials, leads the particles to generate stress cracks from the inside and gradually crack, and loses the original structural stability. The coal gas in the desulfurizing tower is in a continuous flowing state, the compressive strength of the water-absorbed desulfurizing agent particles is greatly reduced, and the pulverization phenomenon is very easy to occur under the dual actions of airflow scouring and upper material gravity. The fine powder generated by pulverization not only runs off along with the airflow in a large quantity, but also can block the gaps of the bed layer, so that the running resistance of the system is continuously increased, and the production device is forced to stop and replace the desulfurizing agent. In order to improve the water resistance and mechanical strength of iron oxide desulphurisation agents, it is common practice to mix inorganic inert binders during the dosing phase. The addition of the inert binder, although improving the compression resistance, occupies a large amount of the internal space of the desulfurizing agent and covers the active iron sites, resulting in a decrease in desulfurizing activity. Under the condition of lacking of effective microcosmic framework support, the active ferric oxide cannot be prevented from physically agglomerating under the working condition of high temperature and high humidity by simply relying on the adhesive, so that the desulfurization contact area is continuously reduced. The existing conventional modification method can not fundamentally solve the contradiction between the mechanical property and the desulfurization activity of the desulfurizing agent under the high-vapor working condition. Disclosure of Invention Aiming at the defects of the prior art, the invention provides the water-resistant solid waste-based ferric oxide desulfurizer for high-steam gas desulfurization and the preparation method thereof, which solve the problems that the bed resistance is increased due to hydration expansion and fragmentation pulverization of the conventional ferric oxide desulfurizer in the high-steam gas environment, and the desulfurization activity is reduced due to the addition of an inert binder to occupy the inner space of particles. In order to achieve the aim, the invention is realized by the following technical scheme that the water-resistant solid waste-based ferric oxide desulfurizer for high-water vapor gas desulfurization and the preparation method thereof, In a first aspect, the invention provides a water-resistant solid waste-based ferric oxide desulfurizer for high-steam gas desulfurization, which adopts the following technical scheme: A water-resistant solid waste-based ferric oxide desulfurizer for high-water vapor gas desulfurization is prepared from composite precursor pug through extrusion molding, humidity control drying and oxidation activation drying. The composite precursor pug is formed by mixing and kneading carbide slag, ferrous sulfate heptahydrate and water, and the dry basis mass ratio of the carbide slag to the ferrous sulfate heptahydrate is 1:0.8-1:1.5. The interior of the desulfurizing agent is provided with a micro-cement skeleton network structure constructed in situ by the double decomposition reaction of calcium hydroxide in carbide slag and ferrous sulfate heptahydrate and the hydration reaction of naturally associated aluminosilicate components in carbide slag, so as to anchor the desulfurizing active components and improve the mechanical integrity and the anti-pulverization strength of the desulfurizing agent in a saturated water vapor environment. By adopting the technical scheme, the in-situ solidification and active component generation of the desulfurizing agent in the preparation process are realized by using the industrial solid waste carbide slag and ferrous sulfate heptahydrate with specific proportions as basic raw materials. The physicochemical tr