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CN-122010496-A - Special glue powder for mine filling and preparation method thereof

CN122010496ACN 122010496 ACN122010496 ACN 122010496ACN-122010496-A

Abstract

The invention relates to the technical field of filling materials, in particular to a special glue powder for mine filling and a preparation method thereof. The raw material comprises, by weight, 20 parts of ordinary Portland cement, 65 parts of fly ash, 5.0 parts of carbide slag, 4.0 parts of mirabilite, 6.0 parts of accelerator, 5.0 parts of modified gypsum and 0.4 part of polycarboxylate water reducer. According to the invention, sodium citrate is introduced in the gypsum pretreatment stage and a silane coupling agent KH550 is used for carrying out surface modification on the pretreated gypsum, and experiments prove that the 28-day splitting tensile strength of the example 1 subjected to the surface activation treatment is as high as 2.95MPa, and the example 3 without the surface activation step is only 2.50MPa. The technical scheme successfully solves the problem of weak interface combination of the multiple solid waste systems, and improves the cracking resistance of the material.

Inventors

  • PAN BAOHONG
  • LONG YUE
  • JIANG ZHIGAO
  • JIANG MIN
  • Long Lixuan
  • GAO PINGHUI

Assignees

  • 江西江铜鼎晟环境科技有限公司

Dates

Publication Date
20260512
Application Date
20260225

Claims (9)

  1. 1. The special cementing powder for mine filling is characterized by comprising, by weight, 20 parts of ordinary Portland cement, 65 parts of fly ash, 5.0 parts of carbide slag, 4.0 parts of mirabilite, 6.0 parts of accelerator, 5.0 parts of modified gypsum and 0.4 part of polycarboxylate superplasticizer.
  2. 2. The special glue powder for mine filling of claim 1, wherein the modified gypsum is prepared by preparing pretreated gypsum and carrying out surface activation treatment, wherein the preparation step of the pretreated gypsum comprises the steps of dispersing clean gypsum in CaCl 2 solution to prepare slurry, adding sodium citrate into the slurry, reacting under hydrothermal condition, filtering, washing and drying after the reaction is finished to obtain the pretreated gypsum.
  3. 3. The special sizing powder for mine filling according to claim 2, wherein the specific step of the surface activation treatment is that a solution A containing a silane coupling agent KH550 is prepared, the solution A is uniformly sprayed on the surface of the pretreated gypsum after being reacted in a water bath, and the modified gypsum is obtained after uniform stirring and drying.
  4. 4. The mine filling special purpose binder powder according to claim 2, wherein in the preparation step of the pretreated gypsum, the concentration of the CaCl 2 solution is 26wt%, and the addition amount of sodium citrate is 0.04g sodium citrate per 100g gypsum slurry corresponding to the solid dry basis ratio of the prepared slurry.
  5. 5. The special cement powder for mine filling according to claim 2, wherein the specific parameters of the hydrothermal condition are that the temperature is 97 ℃, the stirring speed is 60rpm, the reaction time is 300 minutes, and the pretreatment gypsum is washed by hot water with the temperature of 90 ℃ and the drying temperature is 80 ℃.
  6. 6. The glue powder special for mine filling according to claim 3, wherein the solution A is formed by mixing KH550, water and ethanol according to a mass ratio of 5:45:50, and in the surface activation treatment, the solution A is reacted in a water bath at 60 ℃ for 60 minutes, the drying temperature after spraying is 80 ℃, and the drying time is 2 hours.
  7. 7. The special cement powder for mine filling according to claim 2, wherein the preparation method of the clean gypsum is characterized in that after the gypsum is ground, excessive 10% hydrochloric acid is added for acidolysis, insoluble residues are removed by filtration, 0.5mol/L sulfuric acid is added into the filtrate, and the mixture is stirred for reaction to generate gypsum precipitate, and the gypsum precipitate is obtained by filtration and washing.
  8. 8. A preparation method of the special cement powder for mine filling, which is characterized by comprising the following steps of placing ordinary Portland cement, fly ash, carbide slag and modified gypsum into a stirrer for dry mixing, adding mirabilite, an accelerator and a polycarboxylate water reducer, and stirring again to obtain the cement powder.
  9. 9. The method of claim 8, wherein the dry mixing time is 2 minutes and the mixing time after adding the mirabilite, the accelerator and the polycarboxylate water reducer is 2 minutes.

Description

Special glue powder for mine filling and preparation method thereof Technical Field The invention relates to the technical field of filling materials, in particular to a special glue powder for mine filling and a preparation method thereof. Background With the acceleration of the progress of industrialization and urbanization, the amount of solid waste generated has increased dramatically. How to effectively treat and recycle the wastes, reduce environmental pollution, realize sustainable development and become a significant subject of global attention. The carbide slag is solid waste generated in the production process of calcium carbide, and the main component of the carbide slag is Ca (OH) 2, and has the characteristics of high alkalinity, high hardness and the like. If directly discharged or accumulated, the carbide slag can have serious influence on the environment. Natrii sulfas is a mineral rich in Na 2SO4, and accumulation in soil may lead to salinization of the soil. The two wastes have certain chemical properties and application potential, and can be converted into the gel-solid powder material with excellent performance through scientific modification and treatment processes. Gypsum is a common industrial byproduct, has high yield and low price, and the main component of gypsum is aqueous calcium sulfate (CaSO 4·2H2 O), has relatively stable chemical property and is not easy to react with other substances severely, thus being helpful for ensuring the stability of the modified gel powder. At present, less research is conducted on gypsum modified setting powder. The hygroscopicity of gypsum helps to improve setting time and hardening properties of the set powder. The gypsum and the solid waste are combined to prepare the gel powder, so that the recycling of resources can be realized. The modified glue powder can not generate harmful substances in the use process, is environment-friendly, reduces the accumulation of solid wastes and environmental pollution, and can be used in various engineering application fields such as building materials, road repair and the like. Although the prior literature has a certain progress in the aspects of activation of ultrafine fly ash, optimization of low clinker proportion and alkali excitation of carbide slag, the following core technical bottlenecks are faced when the above solid wastes are mixed for use in actual mine filling application: The poor rheology caused by uncontrollable gypsum crystal forms is that the prior art mainly focuses on chemical components (such as SO 3 content) of desulfurized gypsum or phosphogypsum, and neglects the influence of gypsum crystal forms on slurry rheology. The unregulated gypsum crystals are in a long and thin needle shape or a rod shape, so that the specific surface area and the water absorption capacity of the setting powder are increased, the viscosity of the filling slurry is high, the fluidity is poor, the pumping resistance is increased, the water consumption is forced to be increased on site, and the final strength of the filling body is further deteriorated. The organic-inorganic interface compatibility is poor, and in modern cemented filling, organic additives such as a polycarboxylate water reducer and the like are generally required to be added to adjust the working performance. However, fly ash, slag and gypsum are all hydrophilic inorganic materials, the surface polarity is strong, and the compatibility with the organic water reducer has natural difference. The problem of large difference of surface properties of all components cannot be solved by a physical mixing mode in the prior literature, so that the water reducer is unevenly adsorbed and even fails, the adaptability of the gel powder to the water reducer is poor, and the efficiency of the additive is low. The stability of the synergistic excitation of multiple solid wastes is insufficient, whether the alkali excitation of carbide slag or the sulfate excitation of gypsum is carried out, and the system can be controlled under a single system. However, in a complex system consisting of fly ash, carbide slag and gypsum, the solubility and reaction rate of each component are extremely difficult to match. Particularly, soluble phosphorus and fluorine impurities which are often remained in gypsum can be seriously retarded, if deep pretreatment and surface modification are not carried out, the soluble phosphorus and fluorine impurities are directly mixed with other solid wastes, so that the phenomenon of 'pseudo coagulation' or 'non-coagulation' of the gel powder is easily caused, and the strength fluctuation is large. Therefore, development of a special cement powder for mine filling and a preparation method thereof, which can carry out crystal form reconstruction and surface organic modification on gypsum and realize efficient synergism of carbide slag, fly ash, modified gypsum and cement clinker, are needed to be developed. Disclosure of Invention The invention