Negative carbon aerated product and preparation method thereof

Abstract

The invention relates to the technical field of carbon mineralization materials, and provides a negative carbon aerated product and a preparation method thereof.The negative carbon aerated product is prepared from 700-900 parts of carbonized cementing material, 70-100 parts of filler, 0.5-1 part of cellulose ether, 10-20 parts of water reducing agent, 120-200 parts of water and 0.5-5 parts of foaming agent, and then the negative carbon aerated product is obtained by carbonizing and curing the product. Compared with the prior art, the preparation method provided by the invention adopts steel slag, magnesium slag, carbide slag and other solid wastes as raw materials, overall interaction is realized through a negative carbon process, the internal pore structure of the product endows the product with the functions of permeability resistance, heat preservation and the like, meanwhile, the carbon sequestration amount in the carbonization process is increased, and the carbonization degree is deepened; and the mechanical properties (compressive strength and breaking strength) of the product are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon mineralization materials, and more specifically, to a negative carbon aerated product and a preparation method thereof. Background Art

[0002] Chinese invention patent CN116063096A provides a high-carbon autoclaved aerated concrete and its preparation method, which uses bulk solid waste steel slag and slag as the main raw materials, and prepares aerated concrete products by adding aluminum powder paste, which reduces the production cost. However, the aluminum paste powder is prone to uneven dispersion during use, resulting in a decrease in the strength of the product. In addition, if it is improperly handled during use, it will pollute the environment and cause environmental problems, which will undoubtedly limit its development; Chinese invention patent CN114394791B provides a composite porous ceramic decorative board and its preparation method, in which a foam-type foaming agent is used for foaming in the technical solution to obtain a porous ceramic material. Although the foam-type foaming agent does not cause environmental pollution, the internal pores of the prepared foamed product are interconnected, which makes the product poor in permeability resistance and thermal insulation effect, and its use is limited. Chinese invention patent CN116621529A provides a carbonized foamed concrete and its preparation method and application. Its technical solution mentions that the foaming agent is one of plant protein, animal protein and air entraining agent. In particular, the proportion of plant protein and animal protein used in combination has not been tested, and the foaming efficiency and the uniformity of the pores of the product cannot be well guaranteed. Summary of the invention

[0003] In view of this, the purpose of the present invention is to provide a negative carbon aerated product and a preparation method thereof, using carbonized cementitious materials including but not limited to steel slag, furnace slag, carbide slag, magnesium slag and other solid wastes as raw materials, and preparing aerated negative carbon products through a negative carbon process, thereby achieving full utilization of solid waste resources, increasing the added value of solid waste, using carbon dioxide for mineralization, and reducing carbon dioxide emissions.

[0004] The present invention provides a negative carbon aerated product, which comprises: 700-900 parts of carbonized gelling material, 70-100 parts of filler, 0.5-1 part of cellulose ether, 10-20 parts of water reducing agent, 120-200 parts of water, and 0.5-5 parts of foaming agent.

[0005] The carbonized cementitious material of the present invention is one or more of steel slag, magnesium slag, furnace slag and carbide slag; the filler is one or more of silica fume and lime, and the furnace slag is preferably blast furnace slag.

[0006] The foaming agent is a mixture of plant protein, animal protein and water, wherein the ratio of the total amount of plant and animal protein in the foaming agent to water is 1:40-60; the ratio of the plant protein to the animal protein is 3-5:5-7. The specific ratio of the plant protein to the animal protein is 3:7, 3.5:6.5, 4:6, 4.5:5.5, 5:5.

[0007] The animal protein described in the present invention is common commercially available animal protein, and its main raw material is keratin from animals such as cattle and sheep; the plant protein described in the present invention is common commercially available plant protein, and its main raw material is natural polymer material.

[0008] The present invention also provides a method for preparing a negative carbon aerated product, the method comprising:

[0009] Step 1: Evenly mix the carbonized gelling material, filler, cellulose ether and water reducing agent to obtain a mixed powder;

[0010] Step 2: Mixing the mixed powder with water to obtain a slurry;

[0011] Step 3: mixing vegetable protein, animal protein and water in a ratio of 1:45-55 to obtain a foaming agent, within which both foaming efficiency and foaming quality are guaranteed, and obtaining foam through a foaming device;

[0012] Step 4: adding the foam in step 3 to the slurry in step 2 to obtain a mixture;

[0013] Step 5: Pour the mixture into the forming mold and carry out natural curing;

[0014] Step 6: Demould and place in a carbonization device for carbonization curing to obtain a negative carbon aerated product.

[0015] In step 2 of the present invention, the powder and water are mixed and stirred at 120-140 r / min for 1-3 minutes.

[0016] The amount of foam used in step 4 of the present invention accounts for 5% to 12% of the mass of the slurry.

[0017] In step 4 of the present invention, foam is added and stirred at 70-90 r / min for 1-3 min to ensure uniformity of the foam and the slurry while effectively avoiding destruction of the foam; and then stirred at 120-140 r / min for 1-3 min to ensure the foaming quality after uniformly mixing with the slurry.

[0018] The natural curing time in step 5 of the present invention is 10 to 20 hours.

[0019] The carbonization curing conditions of the present invention are as follows: the volume concentration of carbon dioxide is greater than 5%, the carbonization pressure is 0.01-0.4 MPa, the carbonization time is 4-32 hours, and the carbonization temperature is 25-38°C.

[0020] The technical solution provided by the present invention has the following positive effects:

[0021] (1) The ratio of plant protein to animal protein in the foaming agent is 3-5:5-7, especially the experimental results involving the ratio of plant protein to animal protein of 3:7, 3.5:6.5, 4:6, 4.5:5.5, and 5:5, which not only have the high foaming efficiency of plant protein, but also retain the characteristic of animal protein that the bubbles emitted from the foaming machine are not connected, which can ensure both the foaming efficiency and the uniformity of the pores of the product;

[0022] (2) The internal pore structure of the product gives the product functions such as anti-permeability and thermal insulation, while increasing the amount of carbon fixation in the carbonization process, deepening the degree of carbonization, and improving the mechanical properties of the product (compressive strength and flexural strength);

[0023] (3) Using solid waste as the main raw material increases the added value of solid waste, and using carbon dioxide for mineralization reduces carbon dioxide emissions. DETAILED DESCRIPTION

[0024] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. The technical solution of the present application is further explained based on the embodiments of the present invention, which is not intended to limit the present invention and all other embodiments obtained by ordinary technicians in the field without creative work also belong to the technical scope protected by the present invention.

[0025] The present invention is further described in detail through the following examples, and the raw materials in the examples and comparative examples of the present application are calculated by weight, and the test raw materials and reagents involved are commonly available on the market.

[0026] The test methods or standards involved in the present invention are:

[0027] Carbon fixation amount: The carbon absorption effect of the sample is evaluated by the CO2 absorption rate, which is the percentage of the CO2 mass absorbed by the solid waste to the mass of the test piece. The CO2 content absorbed by the solid waste is obtained by testing the TG / DTG thermogravimetric analysis curve of the mineralization product.

[0028] Compressive strength: Compressive strength is measured according to GBT4111-2013

[0029] Flexural strength: Flexural strength is measured according to GB / T3001-2007

[0030] Specific Examples 1-5 and Comparative Examples 6-8

[0031] The negative carbon aerated product of the embodiment of the present invention includes: 800 parts of carbonized gelling material (to avoid redundancy, steel slag is taken as an example here), 85 parts of filler, 0.75 parts of cellulose ether, 15 parts of water reducer, 160 parts of water, and 3 parts of foaming agent. The foaming agent is a mixture of plant protein, animal protein and water, and the ratio of the total amount of plant and animal protein to water in the foaming agent is 1:40-60; the ratio of plant protein to animal protein is 3-5:5-7. The specific ratio of plant protein to animal protein is 3:7, 3.5:6.5, 4:6, 4.5:5.5, 5:5.

[0032] The negative carbon aerated product described in this embodiment is a test product obtained according to the preparation method provided by the present invention.

[0033]

[0034] Product performance testing

[0035] Serial number Carbon fixation (%) Compressive strength(MPa) Flexural strength(MPa) 1 21 95 10 2 25.5 109 12 3 32 118 15 4 27 112 13 5 23 101 11 6 15 75 6.5 7 17 83 7 8 13.5 65 4.5

[0036] It can be seen from the test results of Examples 1-5 and Comparative Examples 6-8 that compared with the control group / comparative example (using only a single foaming agent), the carbon fixation, flexural strength and compressive strength test results of plant protein and animal protein used in proportion are significantly higher than those of the control group. This is because plant protein has a high foaming efficiency and animal protein has the characteristics of non-connected foaming pores. Therefore, when the two are used in proportion, the foaming efficiency is first guaranteed, and the foaming is dense, uniform and non-connected, which is conducive to the entry of carbon dioxide gas and full contact with the product, and the uniformity of the pores of the product, so the carbon fixation reaches 35%, the compressive strength is 112MPa, and the flexural strength is 13MPa. On the other hand, when animal protein or plant protein is used alone as a foaming agent, its performance indicators are relatively low, which is caused by factors such as insufficient foaming amount or uniformity and multiple connections of bubbles. In addition, the carbon fixation, compressive strength and flexural strength of the product using only aluminum powder paste as the foaming agent are the lowest. This is mainly because the aluminum powder paste is unevenly dispersed and the foaming pores are mostly connected, which makes the gas contact of the product uneven during the carbonization process, resulting in poor carbonization effect of the product, relatively low carbon fixation, and reduced product strength. Similarly, the higher the carbon fixation of the product, the better the carbonization effect, the greater the anti-permeability advantage, and the better the thermal insulation performance.

[0037] Specific Examples 9-14

[0038]

[0039] Product performance testing

[0040]

[0041]

[0042] It can be seen from the test results of Examples 9-14 that the technical solution provided by the present invention has certain practicality, and the carbon fixation amount is more than 20%, the compressive strength is 97MPa and above, and the flexural strength is 9MPa and above. In addition, it can be seen from Examples 9 and 10 that the addition of silica fume is more conducive to carbonization than lime to a certain extent, which may be due to the "ball effect" of silica fume; it can be seen from Examples 11 and 12 that the increase of foaming agent within a reasonable range is conducive to the improvement of product performance, mainly due to the increase in foam amount and non-connected characteristics; it can be seen from Examples 13 and 14 that the carbonized cementitious material is one or more of steel slag, magnesium slag, furnace slag, and carbide slag, and the technical solution involved in the present invention can be used.

[0043] The specific embodiments of the present invention described above do not constitute the scope of protection of the present invention, but are to comply with the widest scope consistent with the principles and novel features disclosed herein. Therefore, any corresponding adjustments made based on the technical concept of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A negative carbon aerated product, characterized in that: The negative carbon aerated product comprises: 700-900 parts of carbonized gelling material, 70-100 parts of filler, 0.5-1 part of cellulose ether, 10-20 parts of water reducing agent, 120-200 parts of water, and 0.5-5 parts of foaming agent.

2. The negative carbon aerated product according to claim 1, characterized in that: The carbonized gelling material is one or more of steel slag, magnesium slag, furnace slag and carbide slag; the filler is one or more of silica fume and lime.

3. The negative carbon aerated product according to claim 1, characterized in that: The foaming agent is a mixture of plant protein, animal protein and water, wherein the ratio of the total amount of plant and animal protein in the foaming agent to water is 1:40-60; and the ratio of the plant protein to the animal protein is 3-5:5-7.

4. The negative carbon aerated product according to claim 3, characterized in that: The main raw material of the animal protein is keratin from animals such as cattle and sheep; the main raw material of the plant protein is natural polymer material; the ratio of the plant protein to the animal protein is 3:7, 3.5:6.5, 4:6, 4.5:5.5, 5:

5.

5. A method for preparing a negative carbon aerated product, characterized in that: The preparation method comprises: Step 1: Evenly mix the carbonized gelling material, filler, cellulose ether and water reducing agent to obtain a mixed powder; Step 2: Mixing the mixed powder with water to obtain a slurry; Step 3: mixing vegetable protein, animal protein and water in a ratio of 1:45-55 to obtain a foaming agent, and obtaining foam through a foaming device; Step 4: adding the foam in step 3 to the slurry in step 2 to obtain a mixture; Step 5: Pour the mixture into the forming mold and carry out natural curing; Step 6: Demould and place in a carbonization device for carbonization curing to obtain a negative carbon aerated product.

6. The method for preparing a negative carbon aerated product according to claim 5, characterized in that: In the step 2, the powder and water are mixed and stirred at 120-140 r / min for 1-3 min.

7. The method for preparing a negative carbon aerated product according to claim 5, characterized in that: The amount of foam used in step 4 accounts for 5% to 12% of the mass of the slurry.

8. The method for preparing a negative carbon aerated product according to claim 5, characterized in that: In the step 4, add foam, stir at 70-90 r / min for 1-3 min, and then stir at 120-140 r / min for 1-3 min.

9. The method for preparing a negative carbon aerated product according to claim 5, characterized in that: The natural curing time in step 5 is 10 to 20 hours.

10. The method for preparing a negative carbon aerated product according to claim 5, characterized in that: The carbonization curing conditions are as follows: carbon dioxide volume concentration>5%, carbonization pressure of 0.01-0.4 MPa, carbonization time of 4-32 hours, and carbonization temperature of 25-38°C.

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