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CN-121990805-A - Environment-friendly low-carbon preparation method of iron-rich tailing heavy metal stabilization and waterproof mortar

CN121990805ACN 121990805 ACN121990805 ACN 121990805ACN-121990805-A

Abstract

The invention provides a green low-carbon preparation method of iron-rich tailing heavy metal stabilization and waterproof mortar, and belongs to the field of resource utilization. The slurry prepared by the invention forms a nano-level structure of 'skeleton support-interface bridging-gel bonding', and has excellent performance when the tailing doping amount is up to 75 wt%, namely, the compressive strength reaches 15.5MPa after curing for 1 day, and the compressive strength increases to 20.0MPa after 28 days. The mortar is maintained for 1 day, the fixing rates of leachable heavy metals Mn, zn and Pb in the tailings respectively reach 99.74%, 98.10% and 99.55%, the requirements of GB/T30760-2014 are met, the toxic solid waste is realized, the harmlessness is realized, and the compact nano-level structure endows the mortar with excellent waterproof performance far exceeding that of common mortar. The method has low carbon and economic value, the emission of CO 2 is about 285.6-292.1 kg/t, and the production cost is about 293.5-583.3 CNY/t.

Inventors

  • LV XUEBIN
  • FENG WENLI
  • YU ZHIHAO
  • ZHANG YAHAO
  • LI JIAXUAN
  • Sun Yanuo

Assignees

  • 西藏大学
  • 天津大学

Dates

Publication Date
20260508
Application Date
20260309

Claims (10)

  1. 1. The method for quickly preparing the iron-rich tailing waterproof mortar based on mechanochemistry is characterized by comprising the following steps of: Mixing tailing sand, quicklime, water, glacial acetic acid and a silane coupling agent, and then performing ball milling on the obtained mixture to generate hydrolysis and polymerization of the silane coupling agent and self-assembly to generate a cementing material with a multistage ordered structure, thereby obtaining slurry, wherein the tailing sand comprises one or two of iron tailing sand and copper tailing sand; curing the slurry to obtain the iron-rich tailing waterproof mortar; The iron-rich tailing waterproof mortar comprises a plurality of nano units, wherein each single nano unit comprises silicon dioxide and calcium-iron-aluminum silicate hydrate coated on the surface of the silicon dioxide; The silicon dioxide and the calcium iron aluminosilicate hydrate are connected through a silanol compound; The connected nano units are bonded through the calcium iron aluminum silicate hydrate.
  2. 2. The method of claim 1, wherein the iron tailings comprise Na 2 O 0.395%、MgO 2.315%、Al 2 O 3 8.256%、SiO 2 38.959%、P 2 O 5 0.129%、SO 3 10.591%、Cl 0.048%、K 2 O 0.655%、CaO 12.887%、TiO 2 0.367%、MnO 3.926%、Fe 2 O 3 20.462%、Co 3 O 4 0.041%、CuO 0.078%、ZnO 0.46%、Rb 2 O 0.01%、SrO 0.01%、ZrO 2 0.015%、PbO 0.395% and the balance impurities in mass fractions.
  3. 3. The method of claim 1, wherein the copper tailings sand comprises Na 2 O 0.538%、MgO 1.949%、Al 2 O 3 8.211%、SiO 2 46.697%、P 2 O 5 0.33%、SO 3 0.39%、Cl 0.037%、K 2 O 1.03%、CaO 30.89%、TiO 2 0.311%、MnO 0.427%、Fe 2 O 3 8.924%、CuO 0.169%、ZnO 0.016%、Rb 2 O 0.008%、SrO 0.014%、ZrO 2 0.011%、PbO 0.047% and the balance impurities in mass fractions.
  4. 4. The method of claim 1, wherein the mass of the quicklime is 18-22.48% of the total mass of the tailing sand, the quicklime, the water, the glacial acetic acid and the silane coupling agent; the mass of the tailing sand is 50-55% of the total mass of the tailing sand, quicklime, water, glacial acetic acid and a silane coupling agent; The mass of the water is 25.36-25.8% of the total mass of the tailing sand, the quicklime, the water, the glacial acetic acid and the silane coupling agent; The mass of the silane coupling agent is 0.55-1.28% of the total mass of the tailing sand, the quicklime, the water, the glacial acetic acid and the silane coupling agent.
  5. 5. The method of claim 1, wherein the silane coupling agent comprises one or both of 3-aminopropyl triethoxysilane and allyl triethoxysilane.
  6. 6. The method according to claim 1, wherein the mass of the glacial acetic acid is 0.4-0.87% of the total mass of the tailing sand, the quicklime, the water, the glacial acetic acid and the silane coupling agent.
  7. 7. The method according to claim 1, wherein the ball milling is performed in a high-energy oscillating impact ball mill using steel balls with a ball radius of 10mm, and the slurry volume is 1/8~1/7 of the ball milling container volume. The rotation speed of the ball milling is 800-900 r/min, and the time is 2-11 min.
  8. 8. The method of claim 1, wherein the curing is at a temperature of 20-30 ℃, a relative humidity of 50-60%, and a time of 1-28 days.
  9. 9. The iron-rich tailing waterproof mortar prepared by the method of any one of claims 1 to 8, which is characterized by comprising a plurality of nano units, wherein each single nano unit comprises silicon dioxide and calcium-iron-aluminum silicate hydrate coated on the surface of the silicon dioxide; The silicon dioxide and the calcium iron aluminosilicate hydrate are connected through a silanol compound; The connected nano units are bonded through the calcium iron aluminum silicate hydrate.
  10. 10. Use of the iron-rich tailing waterproof mortar of claim 9 in waterproof wall bricks or road filling.

Description

Environment-friendly low-carbon preparation method of iron-rich tailing heavy metal stabilization and waterproof mortar Technical Field The invention relates to the field of resource utilization, in particular to a green low-carbon preparation method of iron-rich tailing heavy metal stabilization and waterproof mortar. Background The tailings are rich in valuable elements such as silicon, aluminum, calcium and the like, and are potential ideal mortar raw materials. The preparation of mortar by using tailings is not only beneficial to the sustainable development of low-carbon cement and concrete, but also promotes the sustainable management of mines. However, since the original tailings are highly crystalline, these elements are generally present in an inert form, resulting in a low gelling reactivity, and the resulting mortar has a low strength, so that the use of the tailings in the mortar is limited. Disclosure of Invention The invention provides a green low-carbon preparation method of iron-rich tailing heavy metal stabilization and waterproof mortar, and the strength of the mortar prepared by the method can meet the strength requirement of M15 cement mortar, and the waterproof performance is good. The invention provides a method for quickly preparing iron-rich tailing waterproof mortar based on mechanochemistry, which comprises the following steps: Mixing tailing sand, quicklime, water, glacial acetic acid and a silane coupling agent, and then performing ball milling on the obtained mixture to generate hydrolysis and polymerization of the silane coupling agent and self-assembly to generate a cementing material with a multistage ordered structure, thereby obtaining slurry, wherein the tailing sand comprises one or two of iron tailing sand and copper tailing sand; curing the slurry to obtain the iron-rich tailing waterproof mortar; The iron-rich tailing waterproof mortar comprises a plurality of nano units, wherein each single nano unit comprises silicon dioxide and calcium-iron-aluminum silicate hydrate coated on the surface of the silicon dioxide; The silicon dioxide and the calcium iron aluminosilicate hydrate are connected through a silanol compound; The connected nano units are bonded through the calcium iron aluminum silicate hydrate. Preferably, the iron tailings sand comprises Na2O 0.395%、MgO 2.315%、Al2O38.256%、SiO238.959%、P2O50.129%、SO310.591%、Cl 0.048%、K2O 0.655%、CaO 12.887%、TiO20.367%、MnO 3.926%、Fe2O320.462%、Co3O40.041%、CuO 0.078%、ZnO 0.46%、Rb2O 0.01%、SrO 0.01%、ZrO20.015%、PbO 0.395% and the balance of impurities in terms of mass fraction. Preferably, the copper tailings sand comprises Na2O 0.538%、MgO 1.949%、Al2O38.211%、SiO246.697%、P2O50.33%、SO30.39%、Cl 0.037%、K2O 1.03%、CaO 30.89%、TiO20.311%、MnO 0.427%、Fe2O38.924%、CuO 0.169%、ZnO 0.016%、Rb2O 0.008%、SrO 0.014%、ZrO20.011%、PbO 0.047% and the balance of impurities in terms of mass fraction. Preferably, the mass of the quicklime is 18-22.48% of the total mass of the tailing sand, the quicklime, the water, the glacial acetic acid and the silane coupling agent; the mass of the tailing sand is 50-55% of the total mass of the tailing sand, quicklime, water, glacial acetic acid and a silane coupling agent; The mass of the water is 25.36-25.8% of the total mass of the tailing sand, the quicklime, the water, the glacial acetic acid and the silane coupling agent; The mass of the silane coupling agent is 0.55-1.28% of the total mass of the tailing sand, the quicklime, the water, the glacial acetic acid and the silane coupling agent. Preferably, the silane coupling agent comprises one or two of 3-aminopropyl triethoxysilane and allyl triethoxysilane. Preferably, the mass of the glacial acetic acid is 0.4-0.87% of the total mass of the tailing sand, the quicklime, the water, the glacial acetic acid and the silane coupling agent. Preferably, the ball milling is carried out in a high-energy oscillating impact ball mill, wherein the ball milling adopts steel balls with the radius of the balls being 10mm, and the volume of slurry accounts for 1/8~1/7 of the volume of a ball milling container. The rotation speed of the ball milling is 800-900 r/min, and the time is 2-11 min. Preferably, the curing temperature is 20-30 ℃, the relative humidity is 50-60%, and the curing time is 1-28 days. The invention also provides the iron-rich tailing waterproof mortar prepared by the method, which is characterized by comprising a plurality of nano units, wherein each nano unit comprises silicon dioxide and calcium-iron-aluminum silicate hydrate coated on the surface of the silicon dioxide; The silicon dioxide and the calcium iron aluminosilicate hydrate are connected through a silanol compound; The connected nano units are bonded through the calcium iron aluminum silicate hydrate. The invention also provides application of the iron-rich tailing waterproof mortar in waterproof wall bricks or road filling. The invention innovates the technological path of tailing recycling through th