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CN-122010515-A - By CO2Preparation method of mineralized reinforced phosphogypsum concretion functional material

CN122010515ACN 122010515 ACN122010515 ACN 122010515ACN-122010515-A

Abstract

The invention provides a preparation method of a phosphogypsum consolidated body functional material by utilizing CO 2 mineralization, which comprises the following steps of mixing phosphogypsum with water to form slurry in a CO 2 mineralization reaction stage, adding a magnesium ion solution to obtain suspension, adding a composite mineralization enhancer, introducing CO 2 gas at 20-80 ℃ to carry out mineralization reaction for 10-60 minutes to obtain phosphogypsum mineralization slurry, and mixing the phosphogypsum mineralization slurry with a cementing material and an interface modifier in a large-doped phosphogypsum consolidated body preparation stage, regulating the water content, stirring, forming and curing to obtain the phosphogypsum consolidated body functional material.

Inventors

  • WANG HAOJIE
  • YANG YANWEN
  • HUANG XUQUAN
  • XUE FEI
  • CHEN XIN

Assignees

  • 三峡大学

Dates

Publication Date
20260512
Application Date
20260123

Claims (10)

  1. 1. The preparation method of the functional material for enhancing phosphogypsum concretion by CO 2 mineralization is characterized by comprising the following steps: (a) Mixing phosphogypsum and water to form slurry, adding a magnesium ion solution to obtain suspension, adding a composite mineralization enhancer, and introducing CO 2 gas at 20-80 ℃ to carry out mineralization reaction for 10-60 minutes to obtain phosphogypsum mineralized slurry; (b) And in the preparation stage of the phosphogypsum consolidated body with large doping amount, the phosphogypsum mineralized slurry is mixed with a cementing material and an interface modifier, the water content is regulated, and the phosphogypsum consolidated body functional material is obtained through stirring, molding and curing.
  2. 2. The method of claim 1, wherein the phosphogypsum slurry in step (a) has a liquid to solid ratio of 1:5 to 1:20, or is a saturated leachate.
  3. 3. The method of claim 1, wherein the magnesium ion solution in step (a) comprises any one or a combination of magnesium chloride, magnesium sulfate, magnesium acetate.
  4. 4. The method of claim 1, wherein the composite mineralization enhancer in step (a) is added in an amount of 1% -5% by mass of the phosphogypsum slurry, and the composite mineralization enhancer comprises a mixture of ammonium chloride and carbide slag.
  5. 5. The method of claim 4, wherein the flow rate of the CO 2 gas in step (a) is 0.2 to 1.0L/min.
  6. 6. The method of claim 1, wherein the binder in step (b) is added in an amount of 10% -18% by mass of the phosphogypsum mineralized slurry, and the binder is a slag-steel slag based binder.
  7. 7. The method of claim 1, wherein the interfacial modifier is added in step (b) in an amount of 0.2% to 1.0% by mass of the phosphogypsum mineralized slurry.
  8. 8. The method of claim 7, wherein the interface modifier is sodium alginate and/or silane coupling agent KH550.
  9. 9. The method of claim 1, wherein step (b) further comprises a water reducer in an amount of 0.05% -0.1% by mass of the phosphogypsum mineralized slurry, and the water reducer is selected from the group consisting of polycarboxylate water reducers.
  10. 10. The method of claim 1, wherein the molding mode in the step (b) is high-pressure molding or pouring molding, and the curing is performed under standard curing conditions, and the curing age is 3-28 days.

Description

Preparation method of functional material for enhancing phosphogypsum concretion by CO 2 mineralization Technical Field The invention belongs to the technical field of recycling of industrial solid waste resources and emission reduction of CO 2, and particularly relates to a preparation method for enhancing performance of phosphogypsum consolidated functional materials by using a CO 2 gas mineralization technology. Background Phosphogypsum is industrial waste residue generated in the phosphoric acid production process, the annual production amount of phosphogypsum in China is about 8000 ten thousand tons, and the accumulated accumulation amount is more than 8 hundred million tons. The phosphogypsum piled up in large quantity occupies a large amount of land and can cause the source pollution of phosphorus and fluorine in soil and water. Although the phosphogypsum piling and pollution problems are solved through the approaches of building material production, agricultural application, mine backfilling and the like, the large-scale application of the phosphogypsum has bottlenecks. Phosphogypsum contains a certain amount of unreacted CaSO 4·2H2 O and impurities, so that the phosphogypsum has poor gelatinization property, low strength and poor water resistance, and the large-scale application is limited. Therefore, the mechanical property of phosphogypsum is enhanced, and the research and development of phosphogypsum consolidated functional materials are carried out on a large scale, so that the method has important significance for sustainable development of the phosphorus chemical industry in China. CO 2 mineralization and sequestration is a promising CCUS technology, and the principle is to react alkaline solid waste containing calcium and magnesium with CO 2 to generate stable carbonate. On the one hand, the technology can fix CO 2, on the other hand, the generated calcium carbonate crystal can fill the pores of the material, and the microstructure is improved, so that the mechanical property and durability of the material are improved. At present, phosphogypsum mineralizes CO 2 to produce calcium carbonate whiskers, and the method firstly prepares a high-concentration phosphogypsum calcium solution and then purifies CO2 mineralized products. The process has the advantages of higher energy consumption, lower phosphogypsum consumption scale, complex front-end treatment of phosphogypsum, and lower practical application potential than alkali residues. At present, research has been conducted on the use of CO 2 in cement-based materials, alkaline residues, and the like, to drive the high performance of materials through mineralization. However, there is relatively little research on mineralization of CO 2 for high-doped phosphogypsum concretions. The traditional phosphogypsum concretion body has the problems of low early strength, low softening coefficient (poor water resistance) and the like, and the pure physical compression molding or traditional steam curing has limited improvement on the phosphogypsum performance, and the synergistic benefit of carbon emission reduction cannot be realized. Therefore, the invention aims to provide a novel material and a preparation method capable of synchronously solving two problems of phosphogypsum resource utilization and CO 2 emission reduction, and the mechanical property and durability of the phosphogypsum concretion body are obviously improved through an optimized CO 2 mineralization process, so that technical support can be provided for large-scale phosphogypsum digestion. Disclosure of Invention The primary aim of the invention is to provide a preparation method of the CO 2 mineralized and reinforced phosphogypsum consolidated body material with excellent performance and low cost, which is simple and efficient, and can realize bulk absorption of phosphogypsum and effective sealing and storage of CO 2. According to the phosphogypsum concretion functional material and the preparation method thereof, the CO 2 gas and the composite mineralizer are required to be used for generating the polymorphic micro-nano carbonate, and finally the mechanical compression is utilized to improve the concretion strength and the durability. The method is characterized in that a large amount of phosphogypsum is needed to be used as a core raw material, and a mineralization reaction and a composite gelation system are combined to realize the synergy of solid waste recycling and CO 2 mineral sealing, and the concrete steps are divided into a. CO 2 mineralization reaction stage and b. A large amount of phosphogypsum concretion body preparation stage. A. CO 2 mineralization reaction stage (1) And preparing phosphogypsum slurry, namely mixing phosphogypsum with water to form slurry, adding a magnesium ion solution to obtain suspension, and adding a composite mineralization enhancer to prepare phosphogypsum slurry for standby. (2) CO 2 mineralizing reaction, namely placing the prepared phosphogy