Production method for preparing low-carbon cementing material based on micro-nano ultrafine powder
Through grinding and surface modification treatment of slag and fly ash, the problem of insufficient mixing and dispersion in traditional cement production is solved, and the goal of uniform mixing with cement aggregates and low-carbon production is achieved.
Patent Information
- Application Number
- CN202411569474.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-05
- Publication Date
- 2025-02-11
AI Technical Summary
When adding fly ash and slag in traditional cement production, the mixing dispersion is insufficient, resulting in poor performance of the final product, and the nanoparticles are prone to agglomeration and high viscosity, making it difficult to mix evenly with cement aggregates.
Charge neutralization and secondary grinding are performed by grinding slag and fly ash into nanomixtures and adding negative and positive charge surface modifiers, including nanosilicon dioxide and polyethyleneimine, to form a modified mixture with cement aggregates mix.
The uniform mixing of slag and fly ash with cement aggregate is achieved, the agglomeration problem is avoided, the carbon emission efficiency of cement production is improved, and the carbon dioxide emissions are reduced by 10% or even more.
Smart Images
Figure CN119409450A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of cementitious materials, and in particular to a technology for realizing low-carbon production of cementitious materials based on modification and uniform material mixing. Background Art
[0002] Cementitious materials are a class of materials that can form gels through chemical reactions or physical changes under certain conditions. These materials can usually transform between solid and liquid and have the ability to adhere, solidify and maintain shape. Cementitious materials are widely used in construction, civil engineering and other fields. For example, cement is a typical cementitious material.
[0003] Cement production is one of the main sources of greenhouse gas emissions worldwide. The production process of cement usually results in significant carbon dioxide. It is estimated that global cement production accounts for about 7% to 8% of total greenhouse gas emissions. In the context of global climate change, reducing carbon emissions in cement production is one of the challenges faced by many countries. One of the effective ways to solve the problem of cement production is to use alternative raw materials: using industrial waste (such as fly ash, slag, etc.) as a cement substitute to reduce the demand for new raw materials.
[0004] However, in practice, when adding fly ash and slag materials to cement aggregate, there are the following problems: insufficient dispersibility of the mixture of the two. This is because the particles of the conventional fly ash and slag materials are usually large, so it is difficult to achieve uniform dispersion and mixing when mixed with cement aggregate powder, which inevitably leads to insufficient performance of the final cement product. In order to solve this technical problem, attempts will be made to grind the fly ash and slag materials into nanoparticles, so that their fineness is small and it is easier to achieve the purpose of uniform mixing when mixed with cement aggregate powder. However, when grinding fly ash and slag materials, due to the influence of electric charge, it is easy to cause agglomeration of nanoparticles; furthermore, the viscosity of these ground nano fly ash and slag materials is high, so there is still a problem of insufficient mixing with cement aggregate, so it is necessary to modify these nanoparticles to reduce the surface charge and viscosity, so as to better mix with cement aggregate to present better uniformity. Summary of the invention
[0005] In order to solve the problems existing in the above-mentioned technologies, the present invention provides a technology for obtaining a building gel material in a low-carbon manner and ensuring that the fluidity and uniformity of the material are met.
[0006] The present invention first provides a production method for preparing a low-carbon gelling material based on micro-nano ultrafine powder, which comprises the following steps:
[0007] Step 1: Mix slag and fly ash for the first time and obtain nano-mixture by grinding;
[0008] Step 2: adding a negatively charged surface modifier, wherein the negatively charged surface modifier is nano-silicon dioxide and a stabilizer, bentonite;
[0009] Step 3: adding a positively charged surface modifier, wherein the positively charged surface modifier is polyethyleneimine and a stabilizer, bentonite;
[0010] Step 4: performing secondary grinding to obtain a modified mixture;
[0011] Step 5: The modified mixture is combined with cement aggregate to form a cementitious material for building materials.
[0012] Preferably, the weight ratio of the slag to fly ash is 1:2 to 2:1; the weight ratio of the modified mixture to cement aggregate is 1:10 to 3:10.
[0013] Preferably, the amount of the nano-silicon dioxide is 0.001% to 0.01% of the nano-mixture; the amount of the polyethyleneimine is 0.001% to 0.01% of the nano-mixture; the weight ratio of the stabilizer bentonite to the polyethyleneimine is 0.1:1 to 1:1.
[0014] Preferably, the slag and pulverized coal are ground by using a NMZ30 nano sand mill or a MSK-SFM-ABM1000 nano grinder, and the size of the nano mixture after grinding is controlled to be below 500 nanometers.
[0015] The technical effect of the present invention is that slag and fly ash are both industrial wastes. After certain treatment, they are mixed with cement aggregates, so that they can play the role of building materials. Each ton of cement produced will emit 0.511 tons of carbon dioxide, and by adding industrial waste, the carbon emission can be reduced by about 10% or even more, achieving the purpose of low-carbon production. In addition, since slag and fly ash are easily carried with electric charges during industrial grinding, these charges are distributed on the surface of the powder, so when they are mixed with cement aggregate, they are easy to form local agglomeration or uneven distribution problems. The present invention, on the one hand, obtains powders with lower particle size through grinding, and on the other hand, adds different types of surface charge modifiers respectively, thereby eliminating the surface charge of the powder, so that when mixed with cement aggregate, the uniformity of the mixing is guaranteed and the agglomeration problem is avoided. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] Figure 1 The invention is a low-carbon gelling material obtained by the production method of the prior art without charge treatment.
[0017] Figure 2 The invention discloses a low-carbon gelling material obtained by subjecting micro-nano ultrafine powder to charge treatment. DETAILED DESCRIPTION
[0018] The present invention first provides a production method for preparing a low-carbon gelling material based on micro-nano ultrafine powder, which comprises the following steps:
[0019] Step 1: Mix slag and fly ash for the first time and obtain nano-mixture by grinding;
[0020] Step 2: Add a negatively charged surface modifier, which is nano-silicon dioxide and a stabilizer, bentonite; the nano-silicon dioxide is negatively charged nano-silicon dioxide obtained on the market, for example, purchased from Guangzhou Taishun Materials Co., Ltd.; bentonite is used to stabilize the charge stability of the nano-silicon dioxide to avoid the charge disappearing too quickly during the application process, and the bentonite also helps to disperse the nano-silicon dioxide.
[0021] Step 3: Add a positively charged surface modifier, which is polyethyleneimine and a stabilizer, bentonite; the polyethyleneimine material itself has a positive charge, which is used to neutralize the negative charge.
[0022] Step 4: performing secondary grinding to obtain a modified mixture;
[0023] Step 5: The modified mixture is combined with cement aggregate to form a cementitious material for building materials.
[0024] Preferably, the weight ratio of the slag to fly ash is 1:2 to 2:1; the weight ratio of the modified mixture to cement aggregate is 1:10 to 3:10.
[0025] Preferably, the amount of the nano-silicon dioxide is 0.001% to 0.01% of the nano-mixture; the amount of the polyethyleneimine is 0.001% to 0.01% of the nano-mixture; the weight ratio of the amount of the stabilizer bentonite to the polyethyleneimine is 0.1:1 to 1:1. In addition, the weight ratio of the amount of the stabilizer bentonite to the nano-silicon dioxide is 0.1:1 to 1:1.
[0026] Preferably, the slag and pulverized coal are ground by using a NMZ30 nano sand mill or a MSK-SFM-ABM1000 nano grinder, and the size of the nano mixture after grinding is controlled to be below 500 nanometers.
[0027] The technical effect of the present invention is that slag and fly ash are both industrial wastes. After certain treatment, they are mixed with cement aggregates, so that they can play the role of building materials. Each ton of cement produced will emit 0.511 tons of carbon dioxide, and by adding industrial waste, the carbon emission can be reduced by about 10% or even more, achieving the purpose of low-carbon production. In addition, since slag and fly ash are easily carried with electric charges during industrial grinding, these charges are distributed on the surface of the powder, so when they are mixed with cement aggregate, they are easy to form local agglomeration or uneven distribution problems. The present invention, on the one hand, obtains powders with lower particle size through grinding, and on the other hand, adds different types of surface charge modifiers respectively, thereby eliminating the surface charge of the powder, so that when mixed with cement aggregate, the uniformity of the mixing is guaranteed and the agglomeration problem is avoided.
[0028] The application principle of the present invention is that slag and fly ash will inevitably generate charges during the grinding process, which may be positive or negative charges. The two substances are applied successively for different neutralization, so as to achieve the purpose of quickly removing the charges and make the material as a whole present a neutral state; then when mixed with cement aggregate, the problem of easy agglomeration caused by the existence of charges is avoided. Furthermore, the particle size of the mixture obtained after grinding and crushing is very small, less than 500 nanometers. Such a fine powder particle size can be well penetrated and filled into the cement aggregate to form a good dispersion state.
[0029] Table 1, observations of gel materials obtained from different examples and control groups. The amount of stabilizer bentonite used is 0.1 times that of nano-silicon dioxide or polyethyleneimine.
[0030]
[0031] As can be seen from the table above, in Examples 1-3, the nano-mixture is in a neutral state by sequentially neutralizing the negatively charged nano-silicon dioxide and the positively charged polyethyleneimine. Thus, when the nano-mixture is mixed with cement aggregate, no agglomeration phenomenon is found. Figure 2 Correspondingly, in Comparative Examples 1 and 2, only one type of neutralizing material is used, so the product still has the problem of agglomeration, but the amount of agglomeration is not high, that is, one plus sign; in addition, in Comparative Example 3, no corresponding neutralizing material is used, and agglomeration occurs after mixing with cement aggregate, and there are two plus signs, which is more serious than Comparative Examples 1 and 2, that is, Figure 1 In comparative example 4, very low doses of negatively charged nano-silicon dioxide and positively charged polyethyleneimine were used for sequential neutralization, but the obtained product still had agglomeration, because the doses used were too low to effectively remove the charge.
Claims
1. A method for preparing low-carbon gelling material based on micro-nano ultrafine powder, characterized in that: The following steps are included: Step 1: Mix slag and fly ash for the first time and obtain nano-mixture by grinding; Step 2: adding a negatively charged surface modifier, wherein the negatively charged surface modifier is nano-silicon dioxide and a stabilizer, bentonite; Step 3: adding a positively charged surface modifier, wherein the positively charged surface modifier is polyethyleneimine and a stabilizer, bentonite; Step 4: performing secondary grinding to obtain a modified mixture; Step 5: The modified mixture is combined with cement aggregate to form a cementitious material for building materials.
2. The method for preparing low-carbon gelling material based on micro-nano ultrafine powder according to claim 1, characterized in that: The weight ratio of the slag to the fly ash is 1:2 to 2:1; the weight ratio of the modified mixture to the cement aggregate is 1:10 to 3:
10.
3. The method for preparing low-carbon gelling material based on micro-nano ultrafine powder according to claim 1, characterized in that: The dosage of the nano silicon dioxide is 0.001% to 0.01% of the nano mixture; the dosage of the polyethyleneimine is 0.001% to 0.01% of the nano mixture; the weight ratio of the dosage of the stabilizer bentonite to the polyethyleneimine is 0.1:1 to 1:
1.
4. The method for preparing low-carbon gelling material based on micro-nano ultrafine powder according to claim 1, characterized in that: The slag and pulverized coal are ground using a NMZ30 nano sand mill or a MSK-SFM-ABM1000 nano grinder, and the size of the nano mixture after grinding is controlled to be below 500 nanometers.