A method for promoting carbon sequestration in cement-based materials

Abstract

The application discloses a method for promoting carbon sequestration process of cement-based materials, and comprises the following steps: step one, adsorbing nano-porous materials on the surface of iron-containing solid waste to form surface modified materials of the iron-containing solid waste; step two, preparing two bar magnets, adsorbing the surface modified materials on the surface of the bar magnets, and then fixing the bar magnets on the inner walls of the left and right sides of a mold; step three, pouring the cement-based slurry material from the pouring entrance at the lower bottom of the mold to the top of the mold, and demolding the cement-based material after hardening; and step four, transmitting the environmental temperature signal collected by a temperature sensor to an energizing device, comparing the received temperature value with the required temperature of the carbonation target value, and energizing the cement-based material after demolding in step three to supplement the temperature difference, so as to create favorable microenvironment conditions for promoting carbonation of the cement-based material. The application can promote the carbonation and carbon sequestration process of the cement-based material, and reduce the time required for carbon neutralization of the cement industry.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of building materials, and relates to a method for promoting the carbon sequestration process of cement-based materials. BACKGROUND

[0002] Carbonation of cement-based materials is an important way of mineral carbon sequestration, and its essence is that CO2 reacts with cement clinker particles and hydration products to generate stable carbonates stored in the material. As a CO2 sequestration technology, carbon sequestration curing of cement-based materials can absorb and sequestercarbon dioxide in the cement use stage. Through carbon sequestration curing, cement-based materials not only absorb and sequester CO2, but also improve their performance. However, carbon sequestration of cement-based materials through the chemical process of calcium hydroxide in the hydration product and carbon dioxide to generate carbonates is a relatively long process. SUMMARY

[0003] The purpose of the present application is to provide a method for promoting the carbon sequestration process of cement-based materials, which accelerates the carbonation reaction by controlling to promote the carbon sequestration process, and has important significance for realizing carbon neutralization of the cement industry.

[0004] The purpose of the present application is achieved by the following technical scheme:

[0005] A method for promoting the carbon sequestration process of cement-based materials, comprising the following steps:

[0006] Step one, modifying the iron-containing solid waste, adsorbing nano-porous materials on the surface of the iron-containing solid waste to form a surface modified material of the iron-containing solid waste, wherein:

[0007] The iron content in the iron-containing solid waste is 10-16%, the particle size is 80-120 mu m, and the dosage is 20-30% of the mass of the cement;

[0008] The nano-porous material is a carbon-based nano-porous material such as nano-biochar;

[0009] The particle size of the nano-biochar is 230-300 nm, the pore volume is 0.04-0.08 cm 3 / g, and the dosage is 8-10% of the specific volume;

[0010] The modification method is a ball milling method or an electrostatic adsorption method; when the ball milling method is used to modify the iron-containing solid waste, zirconia balls with an equal particle diameter of 3-5 mm are selected, the ball milling time is 60-120 minutes, the revolution speed of the ball milling tank is 200-220 revolutions per minute, the rotation speed is 350-400 revolutions per minute, the volume ratio of balls to materials is 2.1:1.1, and the volume ratio of the ball materials to the ball milling tank is 4:5; when the electrostatic adsorption method is used to modify the iron-containing solid waste, an electrostatic generator is used to generate static electricity, the voltage is 6.5-8 kV, the boost is 1.2 kV, the discharge mode is air discharge, the discharge mode is automatic discharge, the interval is 1 s, and the total number of times is 6000-8000 times;

[0011] Step two, control the modified material with a magnetic material: prepare two strip magnets, adsorb the surface modified material of the iron-containing solid waste obtained in step one on the surface of the two strip magnets, and then fix the two strip magnets on the left inner wall and the right inner wall of the mold respectively;

[0012] Step three, pour the cement-based slurry material from the pouring inlet at the lower bottom of the mold to the top of the mold, and after hardening, demold to form a cement-based material, wherein:

[0013] The material of the mold is polymethyl methacrylate, and the color is transparent;

[0014] The cement-based slurry material is composed of ordinary Portland cement, water, a water reducing agent and the like, the cement fineness is 32-38 mu m, the water-cement ratio is 0.25-0.19, the water reducing agent is a polycarboxylic acid water reducing agent, and the dosage is 0.5-2.5% of the mass of the cement;

[0015] The ascending speed of the cement-based slurry material is 1.5-2.5 mm / s, and the demolding time is 60-90 hours;

[0016] Step four, transmit the environmental temperature signal collected by the temperature sensor to the power supply device, compare the received temperature value with the required temperature of the carbonization target value, supply power to the cement-based material demolded in step three, and supplement the temperature difference, so as to create favorable microenvironment conditions for promoting carbonization of the cement-based material.

[0017] Compared with the prior art, the present application has the following advantages:

[0018] (1) The present application can promote the carbonization and carbon sequestration process of the cement-based material, and reduce the time required for carbon neutralization in the cement industry.

[0019] (2) The present application makes full use of the mineral composition characteristics of the iron-containing solid waste, fully utilizes the function of the solid waste, and improves the application value of the iron-containing solid waste.

[0020] (3) The addition of the iron-containing solid waste in the present application reduces the cement dosage, and indirectly reduces the carbon emissions generated by the use of cement. Attached Figure Description

[0021] Figure 1 A schematic diagram of cement-based material casting;

[0022] Figure 2 This is a schematic diagram of the controlled modification of materials using magnetic materials. Detailed Implementation

[0023] The technical solution of the present invention will be further described below with reference to the accompanying drawings, but it is not limited thereto. Any modifications or equivalent substitutions to the technical solution of the present invention that do not depart from the spirit and scope of the technical solution of the present invention should be covered within the protection scope of the present invention.

[0024] Example 1

[0025] This embodiment provides a method for promoting the carbon sequestration process of cement-based materials, the method comprising the following steps:

[0026] Step 1: Modify iron-containing solid waste using ball milling to create nano-biochar on the surface of the iron-containing solid waste particles, wherein:

[0027] The iron-containing solid waste contains 12% iron, has a particle size of 120μm, and is added at a rate of 10% of the cement mass.

[0028] The nano-biochar has a particle size of 250 nm and a pore volume of 0.05 cm³. 3 / g, with a dosage of 10% of the mold volume;

[0029] The grinding balls are zirconia balls with an equal particle diameter of 4 mm. The grinding time is 100 minutes. The revolution speed of the grinding jar is 200 rpm and the rotation speed is 400 rpm. The ball-to-material volume ratio is 2.1:1.1 and the ball-to-material to grinding jar volume ratio is 4:5.

[0030] Step 2: Controlling the modified material with magnetic materials: Prepare two bar magnets and attach the surface modified material from the iron-containing solid waste obtained in Step 1 to their surfaces. Then, fix the two bar magnets to the left and right inner walls of the mold, respectively, as shown in the diagram. Figure 2 As shown.

[0031] Step 3, during casting and shaping, if Figure 1 As shown, cement-based slurry material is poured from the bottom inlet of the mold upwards to the top of the mold. After hardening, it is demolded to form a cement-based material, wherein:

[0032] The mold is made of polymethyl methacrylate and is transparent in color.

[0033] The cement-based paste material is composed of ordinary Portland cement, water, water reducing agent, etc., the cement fineness is 35 pm, the water-cement ratio is 0.22, the water reducing agent is a polycarboxylic acid water reducing agent, and the dosage is 1.5% of the mass of the cement;

[0034] The cement-based paste material has an ascending speed of 2.0 mm / s and a demolding time of 70 h;

[0035] Step four, the implementation method for promoting the carbon sequestration process is that the ambient temperature signal collected by the temperature sensor is transmitted to the power supply device, the power supply device compares the received temperature value with the required temperature of the carbonation target value, and supplies power to the cement-based material after demolding in step three to supplement the temperature difference, thereby creating favorable microenvironment conditions for promoting carbonation of the cement-based material.

[0036] Example 2

[0037] The embodiment provides a method for promoting the carbon sequestration process of a cement-based material, and the method comprises the following steps:

[0038] Step one, the iron-containing solid waste is modified by using an electrostatic adsorption method to make the surface of the iron-containing solid waste particles have a nano-porous material, wherein:

[0039] The iron content in the iron-containing solid waste is 15%, the particle size is 100 pm, and the dosage is 8% of the mass of the cement;

[0040] The nano-porous material is nano-biochar, the particle size of the nano-biochar is 280 nm, the pore volume is 0.06 cm 3 / g, and the dosage is 8% of the mold specific volume;

[0041] The voltage of the electrostatic generator is 7 kV, the boost is 1.2 kV, the discharge mode is air discharge, the discharge mode is automatic discharge, the interval is 1 s, and the total number of times is 7000.

[0042] Step two, the modified material is controlled by using a magnetic material: two bar magnets are prepared, the surface modification material of the iron-containing solid waste obtained in step one is adsorbed on the surface of the two bar magnets, then the two bar magnets are respectively fixed on the left inner wall and the right inner wall of the mold, and a schematic diagram is as shown in Figure 2 .

[0043] Step three, when pouring and forming, as shown in Figure 1 , the cement-based paste material is poured upward from the pouring inlet of the lower bottom surface of the mold to the top of the mold, and the cement-based material is formed after demolding after hardening, wherein:

[0044] The material of the mold is polymethyl methacrylate, and the color is transparent;

[0045] The cement-based paste material is composed of ordinary Portland cement, water, water reducing agent, etc., the cement fineness is 38 μm, the water-cement ratio is 0.20, the water reducing agent is a polycarboxylic acid water reducing agent, and the mixing amount is 2.0% of the mass of the cement;

[0046] The cement-based paste material has an ascending speed of 2.5 mm / s and a demolding time of 80 h;

[0047] In step four, the temperature signal collected by the temperature sensor is transmitted to the energizing device, the energizing device compares the received temperature value with the required temperature of the carbonation target value, and the cement-based material after demolding in step three is energized to supplement the temperature difference, thereby creating favorable microenvironment conditions for promoting carbonation of the cement-based material.

Claims

1. A method of promoting the carbon sequestration process of a cement-based material, characterized in that The method comprises the following steps: Step one, modifying the iron-containing solid waste: adsorbing nano-porous material on the surface of the iron-containing solid waste to form a surface-modified material of the iron-containing solid waste, wherein: the content of the iron-containing solid waste is 20-30% of the mass of the cement, the content of the nano-porous material is 8-10% of the volume of the mold; the iron content in the iron-containing solid waste is 10-16%, and the particle size is 80-120 μm; the modification method is a ball milling method or an electrostatic adsorption method; the nano-porous material is a carbon-based nano-porous material; the carbon-based nano-porous material is nano-biochar, the particle size is 230-300 nm, and the pore volume is 0.04-0.08 cm 3 / g; Step two, controlling the modified material with a magnetic material: preparing two bar magnets, adsorbing the surface-modified material of the iron-containing solid waste obtained in step one on the surface of the two bar magnets, and then fixing the two bar magnets on the left inner wall and the right inner wall of the mold, respectively. Step three, pouring the cement-based slurry material from the mold lower bottom pouring inlet upward to the mold top, and demolding after hardening to form a cement-based material; Step four, transmitting the ambient temperature signal collected by the temperature sensor to the energizing device, comparing the received temperature value with the required temperature of the carbonization target value, and energizing the cement-based material after demolding in step three to supplement the temperature difference and create favorable microenvironment conditions for promoting carbonization of the cement-based material.

2. The method of claim 1, wherein In step one, the modification method for the iron-containing solid waste is a ball milling method, zirconia balls with an equal particle diameter of 3-5 mm are selected, the ball milling time is 60-120 minutes, the revolution speed of the ball milling tank is 200-220 rpm, the rotation speed is 350-400 rpm, the ball-to-material volume ratio is 2.1:1.1, and the ball-to-tank volume ratio is 4:

5.

3. The method of claim 1, wherein In step one, the modification method for the iron-containing solid waste is an electrostatic adsorption method, an electrostatic generator is used to generate static electricity, the voltage is 6.5-8 kV, the boost is 1.2 kV, the discharge mode is air discharge, the discharge mode is automatic discharge, the interval is 1 s, and the total number of times is 6000-8000.

4. The method of facilitating the carbon sequestration process of cementitious materials of claim 1, wherein The material of the mold is polymethyl methacrylate.

5. The method of facilitating the carbon sequestration process of cementitious materials of claim 1, wherein The cement-based slurry material is composed of ordinary portland cement, water, and water reducing agent, the cement fineness is 32-38 μm, the water-cement ratio is 0.25-0.19, and the water reducing agent dosage is 0.5-2.5% of the cement mass.

6. The method of facilitating the carbon sequestration process of cementitious materials according to claim 5, wherein The water reducing agent is a polycarboxylic acid water reducing agent.

7. The method of facilitating the carbon sequestration process of cementitious materials of claim 1, wherein The cement-based slurry material has an ascending speed of 1.5-2.5 mm / s, and the demolding time is 60-90 h.

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