CN-122010474-A - Coal-based solid waste mineralized material reinforced by multi-wall carbon nano tubes and preparation method thereof

CN122010474ACN 122010474 ACN122010474 ACN 122010474ACN-122010474-A

Abstract

The invention discloses a coal-based solid waste mineralization material reinforced by multi-wall carbon nanotubes and a preparation method thereof, wherein the coal-based solid waste mineralization material comprises, by weight, 5-30 parts of alkaline excitation solution, 0.01-5 parts of multi-wall carbon nanotube suspension, 10-140 parts of fly ash and 10-50 parts of slag. The multi-wall carbon nano tube is doped in the coal-based solid waste mineralization material, the multi-wall carbon nano tube is utilized to serve as an effective nucleation site in the hydration process of the coal-based solid waste material, deposition and growth of hydration products at microscopic holes and microcracks are promoted, defect filling is achieved, a bridging effect is exerted, the multi-wall carbon nano tube can better adsorb CO 2 , the adsorbed CO 2 and active ions such as calcium oxide and magnesium oxide in solid waste are mineralized to form a compact filling body, the strength of the coal-based solid waste mineralization material is further improved, and the high heat conducting property of the multi-wall carbon nano tube can be utilized, so that the coal-based solid waste mineralization material also has the high heat conducting property.

Inventors

WU YIHUI
WU YONGHUI
MA LIQIANG
Peng Chengkun
Zhang Hemeng
YU KUNPENG
YANG RUIZHI
ZHAO ZHIYANG
ZHANG ZHISHANG
CAO GUANGHUI

Assignees

中国矿业大学
新疆工程学院

Dates

Publication Date: 20260512
Application Date: 20260228

Claims (10)

1. The coal-based solid waste mineralization material reinforced by the multi-wall carbon nano tubes is characterized by comprising, by weight, 5-30 parts of alkaline excitation solution, 0.01-5 parts of multi-wall carbon nano tube suspension, 10-140 parts of fly ash and 10-50 parts of slag.
2. A method for preparing the coal-based solid waste mineralized material reinforced by multi-wall carbon nano tubes as set forth in claim 1, which comprises the following specific steps: Step 1, mixing sodium hydroxide particles and water according to the mass ratio of (1-20): 100 to obtain sodium hydroxide solution, adding sodium silicate into the sodium hydroxide solution after the temperature of the sodium hydroxide solution is reduced to room temperature, and stirring uniformly to obtain alkaline excitation solution, wherein the mass ratio of the sodium silicate to the sodium hydroxide solution is (1-15): 100; Step 2, mixing the multi-wall carbon nano tube, a surfactant and water according to the mass ratio of (0.01-5) (0.1-20) (100), stirring the mixed solution at the rotating speed of 200 r/min for 1-10 min, and then performing ultrasonic treatment for 10-60 min to obtain a multi-wall carbon nano tube suspension; Step 3, grinding the fly ash to the particle size of 0.1-250 mu m, grinding the slag to the particle size of 0.1-250 mu m, and uniformly mixing the fly ash and the slag according to the mass ratio of (1-14) (1-5) to obtain a solid material; Step 4, adding the alkaline excitation solution and the multiwall carbon nanotube suspension prepared in the step 1 and the step 2 into the solid material in the step3, and stirring to obtain coal-based solid waste slurry, wherein the mass ratio of the alkaline excitation solution to the multiwall carbon nanotube suspension to the solid material is (5-30) (0.01-5) (20-190); Step 5, injecting carbon dioxide gas into the coal-based solid waste slurry obtained in the step 4 under normal temperature and normal pressure, and carrying out mineralization reaction under stirring to obtain coal-based solid waste mineralized slurry, wherein the flow of the injected carbon dioxide and the flow of the carbon dioxide flowing out are recorded during the preparation process; And 6, pouring the coal-based solid waste mineralized slurry subjected to mineralization reaction in the step 5 into a die, and curing to obtain the coal-based solid waste mineralized material.
3. The method for preparing a coal-based solid waste mineralized material reinforced by multi-wall carbon nanotubes according to claim 2, wherein in the step 1, sodium silicate is Na 2 O·nSiO 2 , wherein the content of Na 2 O is 10% -19.8% and the content of SiO 2 is 20% -35.6%.
4. The method for preparing a coal-based solid waste mineralized material reinforced by multi-walled carbon nanotubes according to claim 2, wherein in the step 2, the multi-walled carbon nanotubes have a length of 1 μm to 50 μm, an outer diameter of 1 nm to 15 nm, an inner diameter of 0.5 nm to 5nm, a specific surface area of 50m 2 /g～2500 m 2 /g, and a density of 0.01 g/cm 3 ～15 g/cm 3 .
5. The method for producing a coal-based solid waste mineralized material reinforced with multi-walled carbon nanotubes according to claim 2, characterized in that in step 2, the surfactant is a water-soluble high molecular surfactant or an ionic surfactant, wherein the surfactant is at least one selected from polyvinyl alcohol, polyvinylpyrrolidone, sodium dodecyl sulfate, and polycarboxylate.
6. The method for preparing a coal-based solid waste mineralized material reinforced by multi-walled carbon nanotubes according to claim 2 or 5, characterized in that in the step 2, the ultrasonic dispersion instrument performs ultrasonic treatment on the obtained mixed solution in a pulse mode of 3 s-3 s, the ultrasonic treatment frequency is 20 kHz-40 kHz, the accumulated ultrasonic time is 10 min-60 min, and during the ultrasonic treatment, water in the ultrasonic dispersion instrument is replaced every 2 min-5 min to control the water temperature during the ultrasonic treatment to be lower than 45 ℃.
7. The method for preparing the coal-based solid waste mineralized material reinforced by the multi-wall carbon nano tubes according to claim 2, wherein in the step 4, the stirring speed is 120 r/min-1000 r/min, the stirring time is 2 min-10 min, the yield stress of the prepared coal-based solid waste slurry is 4.5 Pa-80 Pa, and the expansion degree is 195 mm-350 mm.
8. The method for preparing the coal-based solid waste mineralized material reinforced by the multi-wall carbon nano tubes according to claim 2, wherein in the step 5, when the coal-based solid waste slurry is 100 g-3500 g, the flow rate of injected carbon dioxide is 0.1L/min-10L/min, the stirring rate is 100 r/min-850 r/min, the reaction time is 5 min-60 min, and the mineralization rate of carbon dioxide is 2 mgCO 2 /g～40 mgCO 2 /g.
9. The method for preparing the coal-based solid waste mineralized material reinforced by multi-wall carbon nanotubes according to claim 2, wherein in the step 6, the curing temperature is 20-25 ℃, the curing humidity is 90-95%, and the curing time is 3-28 days.
10. The method for producing a coal-based solid waste mineralized material reinforced with multiwall carbon nanotubes according to claim 9, wherein the coal-based solid waste mineralized material has a compressive strength of 1.85 MPa~13.76 Mpa, a thermal conductivity of 0.24W/(m·k) to 0.75W/(m·k), a specific heat capacity of 0.57 KJ/(kg·k) to 1.89 KJ/(kg·k), and a thermal storage coefficient of 4.28W/(m 2 ·K)～12.46 W/(m 2 ·k).

Description

Coal-based solid waste mineralized material reinforced by multi-wall carbon nano tubes and preparation method thereof Technical Field The invention belongs to the technical field of utilization of coal-based solid waste resources, and particularly relates to a coal-based solid waste mineralized material reinforced by multi-wall carbon nanotubes and a preparation method thereof. Background Coal is an important basic energy source, and large-scale exploitation and utilization of coal produces huge amounts of coal-based solid wastes, and the wastes (such as slag and fly ash) contain a plurality of harmful substances, so that the ecological environment risk is caused by improper disposal. Meanwhile, coal is utilized as a main carbon dioxide emission source, and energy structure adjustment and low-carbon energy specific gravity improvement are needed for reducing carbon emission. Therefore, expanding the high-efficiency cooperative utilization way of the coal-based solid waste and the carbon dioxide is of great importance to reduce the negative influence on the environment. Geothermal energy is increasingly gaining attention as a competitive low carbon energy source for mine geothermal resource development. In order to effectively develop and utilize the geothermal energy in the whole life cycle of the mine, a strategy for mining the geothermal energy of the mine by combining a filling mining method is provided. However, the research focus in the current field is mainly focused on optimizing the heat transfer performance of the heat exchange pipeline in the filler, and no sufficient attention is paid to the key thermal performance such as high heat storage capacity, high heat conductivity coefficient and the like of the filler, so that development of a mineralized and solidified coal-based solid waste filler with high heat absorption performance is needed to promote the collaborative development of mine geothermal energy, solid waste recycling and carbon dioxide emission reduction. Disclosure of Invention The invention aims to provide a coal-based solid waste mineralization material reinforced by multi-wall carbon nanotubes and a preparation method thereof, wherein the multi-wall carbon nanotube suspension is added into the coal-based solid waste mineralization material, so that the heat absorption performance and mechanical property of the coal-based solid waste mineralization material can be improved, and the purposes of developing and utilizing geothermal energy and filling a goaf are achieved. The invention provides a coal-based solid waste mineralization material reinforced by multi-wall carbon nanotubes, which comprises, by weight, 5-30 parts of an alkaline excitation solution, 0.01-5 parts of a multi-wall carbon nanotube suspension, 10-140 parts of fly ash and 10-50 parts of slag. The invention provides a preparation method of a coal-based solid waste mineralized material reinforced by multi-wall carbon nanotubes, which comprises the following specific steps: Step 1, mixing sodium hydroxide particles and water according to the mass ratio of (1-20): 100 to obtain sodium hydroxide solution, adding sodium silicate into the sodium hydroxide solution after the temperature of the sodium hydroxide solution is reduced to room temperature, and stirring uniformly to obtain alkaline excitation solution, wherein the mass ratio of the sodium silicate to the sodium hydroxide solution is (1-15): 100; Step 2, mixing the multi-wall carbon nano tube, a surfactant and water according to the mass ratio of (0.01-5) (0.1-20) (100), stirring the mixed solution at the rotating speed of 200 r/min for 1-10 min, and then performing ultrasonic treatment for 10-60 min to obtain a multi-wall carbon nano tube suspension; Step 3, grinding the fly ash to the particle size of 0.1-250 mu m, grinding the slag to the particle size of 0.1-250 mu m, and uniformly mixing the fly ash and the slag according to the mass ratio of (1-14) (1-5) to obtain a solid material; Step 4, adding the alkaline excitation solution and the multiwall carbon nanotube suspension prepared in the step 1 and the step 2 into the solid material in the step3, and stirring to obtain coal-based solid waste slurry, wherein the mass ratio of the alkaline excitation solution to the multiwall carbon nanotube suspension to the solid material is (5-30) (0.01-5) (20-190); Step 5, injecting carbon dioxide gas into the coal-based solid waste slurry obtained in the step 4 under normal temperature and normal pressure, and carrying out mineralization reaction under stirring to obtain coal-based solid waste mineralized slurry, wherein the flow of the injected carbon dioxide and the flow of the carbon dioxide flowing out are recorded during the preparation process; And 6, pouring the coal-based solid waste mineralized slurry subjected to mineralization reaction in the step 5 into a die, and curing to obtain the coal-based solid waste mineralized material. Preferably, in the step 1, the s