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CN-120923179-B - Phosphogypsum-containing phosphorus-fluorine curing agent and preparation method thereof

CN120923179BCN 120923179 BCN120923179 BCN 120923179BCN-120923179-B

Abstract

The invention relates to a novel phosphorus fluorine curing agent for phosphogypsum and a preparation method thereof, belonging to the technical field of industrial solid waste treatment and resource utilization. The curing agent comprises slag micropowder, anhydrous sodium sulfate, water glass, water, sodium hydroxide and Fe 3 O 4 @SiO 2 @Zr-Al bimetallic oxide stabilizer, wherein the Fe 3 O 4 @SiO 2 @Zr-Al bimetallic oxide stabilizer is of a core-shell structure, magnetic ferroferric oxide particles are used as cores, an amorphous silicon dioxide protective layer and an active layer are sequentially coated on the surfaces of the magnetic ferroferric oxide particles, and the active layer is of amorphous and porous zirconium-aluminum bimetallic oxide with a network structure. The preparation method of the curing agent is simple, mild in condition and easy for industrial production, the main raw material is industrial solid waste slag, the purpose of treating waste by waste is realized, the adding amount of the agent is small, and the comprehensive treatment cost is low.

Inventors

  • SHI ZHENFENG
  • WANG HONGWU
  • CHEN QILIN
  • WANG XIAOHONG
  • LI BAOLU
  • WEI WENXIN
  • XU WEIHONG
  • WANG QUANDING
  • HE SONGTAO
  • QI CUIHONG
  • Gao Longqun
  • ZHANG YAN
  • DUAN YUNCHAO
  • ZHANG YUMIAN

Assignees

  • 山东环瑞生态科技有限公司
  • 贵州磷化绿色环保产业有限公司

Dates

Publication Date
20260505
Application Date
20251010

Claims (9)

  1. 1. The phosphorus-fluorine curing agent for phosphogypsum is characterized by comprising, by mass, 300-500 parts of slag micropowder, 10-20 parts of anhydrous sodium sulfate, 150-200 parts of sodium silicate, 10-20 parts of sodium hydroxide, 50-200 parts of Fe 3 O 4 @SiO 2 @Zr-Al bimetallic oxide stabilizer and 400-800 parts of water; The Fe 3 O 4 @SiO 2 @Zr-Al bimetallic oxide stabilizer is of a core-shell structure, takes magnetic ferroferric oxide crystal grains as cores, and an amorphous silica protective layer and an active layer which are sequentially wrapped on the surfaces of the magnetic ferroferric oxide crystal grains; The active layer is an amorphous and porous zirconium-aluminum bimetallic oxide with a network structure; The surface of the amorphous silicon dioxide protective layer contains Si-OH bonds, and the amorphous silicon dioxide protective layer is connected with the active layer through chemical bonds.
  2. 2. The phosphorus fluorine curing agent according to claim 1, wherein the Fe 3 O 4 @SiO 2 @ Zr-Al bimetallic oxide stabilizer is prepared by the following method: providing a magnetic ferroferric oxide nanoparticle dispersion; Adding an ethyl orthosilicate solution into the magnetic ferroferric oxide nanoparticle dispersion liquid for reaction, forming a silicon dioxide protective layer on the surface of the magnetic ferroferric oxide nanoparticle to obtain Fe 3 O 4 @SiO 2 composite particles, and re-suspending the Fe 3 O 4 @SiO 2 composite particles in water to obtain Fe 3 O 4 @SiO 2 composite particle dispersion liquid; dropwise adding the mixed metal salt solution into the Fe 3 O 4 @SiO 2 composite particle dispersion liquid under the stirring action, then dropwise adding an ammonia water solution serving as a precipitator, controlling the solution to be alkaline, performing heating reaction, and forming an amorphous zirconium-aluminum hydroxide gel layer on the surfaces of the composite particles; Heating and roasting the obtained precursor powder to obtain the Fe 3 O 4 @SiO 2 @Zr-Al bimetallic oxide stabilizer; the zirconium source is selected from zirconium oxychloride; the aluminum source is selected from one or more of aluminum nitrate, aluminum chloride or aluminum sulfate; And heating reaction, wherein the temperature is 60-80 ℃ and the time is 3-6 hours.
  3. 3. The phosphorus-fluorine cured agent according to claim 2, wherein the concentration of the magnetic ferroferric oxide nanoparticle dispersion liquid is 15-25 wt%; the concentration of the tetraethoxysilane solution is 5-10wt%.
  4. 4. The phosphorus-fluorine curing agent according to claim 2, wherein the reaction conditions of adding an ethyl orthosilicate solution to the magnetic ferroferric oxide nanoparticle dispersion liquid and reacting are that the temperature is 25-30 ℃ and the time is 3-5 h; the concentration of the Fe 3 O 4 @SiO 2 composite particle dispersion liquid is 10-30 mg/ml.
  5. 5. The phosphorus fluorine curing agent according to claim 2, wherein the molar ratio of the zirconium source to the aluminum source is 1 (1-2); the concentration of the ammonia water solution is 25-28wt%.
  6. 6. The phosphorus fluorine curing agent according to claim 2, wherein the temperature of the heat baking is 400 to 550 ℃ for 2 to 4 hours.
  7. 7. The method for preparing a phosphorus fluorine curing agent according to any one of claims 1 to 6, comprising the steps of: uniformly mixing slag micropowder with anhydrous sodium sulfate to obtain a dry mixed material; Fully dissolving and hydrolyzing sodium silicate and sodium hydroxide in water to obtain an alkaline excitation solution; Adding the obtained alkaline excitation solution into the dry mixed material, uniformly stirring, adding the Fe 3 O 4 @SiO 2 @Zr-Al bimetallic oxide stabilizer, stirring and mixing step by step to obtain slurry, heating, standing and aging to obtain the phosphorus fluorine curing agent.
  8. 8. The method according to claim 7, wherein the conditions of heating, standing and aging are 50-60 ℃ and 20-30 hours.
  9. 9. The method according to claim 7, wherein the step-by-step stirring is performed at a speed of 450-500 rpm for 10-12 min, at a speed of 250-300 rpm for 10-12 min, and at a speed of 100-150 rpm for 15-25 min.

Description

Phosphogypsum-containing phosphorus-fluorine curing agent and preparation method thereof Technical Field The invention relates to the technical field of industrial solid waste treatment and resource utilization, in particular to a phosphorus fluorine curing agent for phosphogypsum and a preparation method thereof. Background Phosphogypsum generally contains residual phosphorus, fluorine, heavy metals, organic matters and other harmful impurities. The existing phosphogypsum treatment mode mainly comprises (one) a water washing method, namely, a method which has high energy consumption, generates a large amount of wastewater, has high cost and can not completely and thoroughly remove impurities. The second neutralization method is to neutralize the acidity of the alkali materials such as lime, cement and the like and solidify a part of impurities, but has the problems of poor stability of the solidifying agent, poor long-term effect, large capacity increase caused by excessive addition amount, easy occurrence of're-dissolution' phenomenon (the fixed phosphorus and fluorine are dissolved out again along with the time) and the like. And (III) the high-temperature calcination method has extremely high energy consumption and difficult bearing of cost, and is not suitable for large-scale application. Curing agents (such as ordinary Portland cement and lime) conventionally used in the prior art mainly depend on physical package of hydration products and precipitation reaction in alkaline environment, have weak specific chelating ability to phosphorus and fluorine and lower curing efficiency, and phosphorus and fluorine ions can have serious retarding effect on the hydration process of cement, so that the strength of a cured body is slow to develop and even does not solidify. Therefore, there is an urgent need to develop a curing agent which is efficient, stable, low-cost, and capable of specifically chemically bonding phosphorus-fluorine impurities. Disclosure of Invention In order to solve the technical problems, the invention provides a phosphorus fluorine curing agent for phosphogypsum and a preparation method thereof. The Fe 3O4@SiO2 @Zr-Al bimetallic oxide stabilizer can be added to convert soluble and highly-mobile harmful fluorine (F -) and phosphorus (mainly existing in the form of H 2PO4-/HPO42- and the like) in phosphogypsum into stable and indissolvable compounds (such as indissolvable precipitates of zirconium fluoride, aluminum fluoride, zirconium phosphate, aluminum phosphate and the like) or inner layer surface complexes by utilizing various mechanisms of chemical adsorption, complexation precipitation, physical coating and the like, so that the soluble and highly-mobile harmful fluorine (F -) and phosphorus are locked in a solid phase, and are prevented from being released when rainwater is leached or environmental conditions are changed, thereby causing secondary pollution. The invention provides a phosphorus-fluorine curing agent for phosphogypsum, which comprises, by mass, 300-500 parts of slag micropowder, 10-20 parts of anhydrous sodium sulfate, 150-200 parts of sodium silicate, 10-20 parts of sodium hydroxide, 50-200 parts of Fe 3O4@SiO2 @Zr-Al bimetallic oxide stabilizer and 400-800 parts of water; The Fe 3O4@SiO2 @Zr-Al bimetallic oxide stabilizer is of a core-shell structure, takes magnetic ferroferric oxide crystal grains as cores, and an amorphous silica protective layer and an active layer which are sequentially wrapped on the surfaces of the magnetic ferroferric oxide crystal grains; the active layer is an amorphous porous zirconium-aluminum bimetallic oxide with a network structure, and the surface of the amorphous silicon dioxide protective layer contains Si-OH bonds which are connected with the active layer through chemical bonds. In some embodiments of the present invention, the Fe 3O4@SiO2 @ Zr-Al bimetallic oxide stabilizer is prepared by the following method: providing a magnetic ferroferric oxide nanoparticle dispersion; Adding an ethyl orthosilicate solution into the magnetic ferroferric oxide nanoparticle dispersion liquid for reaction, forming a silicon dioxide protective layer on the surface of the magnetic ferroferric oxide nanoparticle to obtain Fe 3O4@SiO2 composite particles, and re-suspending the Fe 3O4@SiO2 composite particles in water to obtain Fe 3O4@SiO2 composite particle dispersion liquid; under the action of intense stirring, dropwise adding the mixed metal salt solution into the Fe 3O4@SiO2 composite particle dispersion liquid, then dropwise adding an ammonia water solution serving as a precipitator, controlling the solution to be alkaline, performing heating reaction, and forming an amorphous zirconium-aluminum hydroxide gel layer on the surfaces of the composite particles; and (3) heating and roasting the obtained precursor powder to obtain the Fe 3O4@SiO2 @Zr-Al bimetallic oxide stabilizer. In some embodiments of the invention, the concentration of the magnet