Low-carbon cement clinker containing industrial waste residues and preparation method thereof

Abstract

The invention belongs to the technical field of cement clinker, and particularly relates to low-carbon cement clinker containing industrial waste residues and a preparation method thereof, the technical scheme is that the low-carbon cement clinker containing the industrial waste residues and the preparation method thereof comprise the following components: 45-55% of limestone, 5-15% of clay, 15-25% of blast furnace slag, 4-6% of fly ash, 4-6% of waste glass powder and 15-25% of red mud; according to the invention, through the blast furnace slag, fly ash and waste glass powder partially replacing natural limestone and clay, the carbon footprint of the raw materials is reduced, and the emission of COs in the calcination process is reduced. And the calcining temperature is reduced to 1200-1350 DEG C from 1450 DEG C in the prior art, so that the energy consumption is greatly reduced.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of cement clinker, and particularly relates to a low-carbon cement clinker containing industrial waste residues and a preparation method thereof. BACKGROUND

[0002] Cement clinker is a key intermediate product in the cement production process, which is formed by calcining a mixture of limestone, clay, and iron raw materials at high temperatures. Its main chemical components include calcium oxide, silicon dioxide, aluminum oxide, and iron oxide. Among them, tricalcium silicate and dicalcium silicate are the main mineral components that determine the strength and hydration performance of cement.

[0003] The production process of traditional cement clinker involves high-temperature calcination, usually at a temperature range of 1300°C to 1450°C, to ensure that the mineral components fully react and form a stable cement clinker structure. However, this process is accompanied by a large amount of carbon dioxide emissions, mainly from two aspects: limestone decomposition and fuel combustion. First, limestone decomposes into calcium oxide and carbon dioxide at high temperatures, which accounts for more than 50% of total carbon emissions in cement production. Second, a large amount of fuel is consumed during the calcination process, which further releases a large amount of CO2, making the cement industry one of the main sources of global carbon emissions. SUMMARY

[0004] To solve the above problems, the present application provides a low-carbon cement clinker containing industrial waste residues and a preparation method thereof.

[0005] The technical solutions adopted by the present application are as follows: The present application provides a low-carbon cement clinker containing industrial waste residues, which includes the following components: limestone 45-55%, clay 5-15%, blast furnace slag 15-25%, fly ash 4-6%, waste glass powder 4-6%, and red mud 15-25%.

[0006] Further, the components include limestone 50%, clay 10%, blast furnace slag 20%, fly ash 5%, waste glass powder 5%, and red mud 10%.

[0007] Further, limestone is used for basic cementing components.

[0008] Further, clay is used to adjust the silicon-aluminum ratio in cement clinker and improve the microstructure of the clinker.

[0009] Further, blast furnace slag is used to partially replace limestone and clay, has hydration activity, and reduces carbon emissions.

[0010] Further, fly ash is used to provide silicon, aluminum, and iron components, plays a fluxing role in the calcination process, promotes the formation of clinker minerals, and utilizes industrial waste residues.

[0011] Further, the waste glass powder is used to provide a high-activity silica source.

[0012] The present application also discloses a preparation method of low-carbon cement clinker containing industrial waste residues, mainly comprising the following steps: Step one: crushing, screening and fine grinding of limestone, clay, blast furnace slag, fly ash, red mud and waste glass powder to ensure uniform particle size distribution of all raw materials and keep them dry; Step two: accurately weighing each component according to the above ratio, and putting all pretreated raw materials into a high-speed mixer for dry mixing to obtain a homogeneous raw material mixture; Step three: heating the dry-mixed raw materials to 800-900°C using a preheater to decompose part of the carbonates in the mixture in advance, thereby increasing the subsequent reaction rate; Step four: sending the preheated mixture into a rotary kiln for calcination at 1200-1350°C; Step five: after calcination, rapidly cooling the clinker to room temperature to stabilize its microstructure and special properties; Step six: the cooled clinker is ground to a specified fineness by ball milling and can be directly used for cement production.

[0013] The present application has the following beneficial effects by adopting the above structure: (1) The blast furnace slag, fly ash and waste glass powder partially replace natural limestone and clay, thereby reducing the carbon footprint of raw materials and reducing CO2 emissions during calcination. The reduction of calcination temperature (from the traditional 1450°C to 1200-1350°C) greatly reduces energy consumption.

[0014] (2) The conductive network formed by the metal particles contained in the fly ash after calcination can make the clinker exhibit the characteristic that the resistance changes with the stress in the concrete, thereby realizing the self-sensing monitoring of the structure health and early crack warning.

[0015] (3) The waste glass powder and blast furnace slag both have high hydration activity, which promotes the densification of the microstructure during the later cement hydration process; at the same time, part of the microcracks may be repaired by secondary hydration products under the action of the environment, which helps to improve the crack resistance and durability. DETAILED DESCRIPTION

[0016] The following are specific embodiments of the present application, which further describe the technical solutions of the present application, but the protection scope of the present application is not limited to these embodiments. Any changes or equivalent replacements without departing from the concept of the present application are included in the protection scope of the present application.

[0017] Example 1 Low-carbon cement clinker containing industrial waste residue, the raw material ratio comprises: limestone 50%, clay 10%, blast furnace slag 20%, fly ash 5%, waste glass powder 5%, and red mud 10%.

[0018] Preparation process: Step one: crush, screen and finely grind the limestone, clay, blast furnace slag, fly ash, red mud and waste glass powder to ensure that all raw materials have a uniform particle size distribution and remain dry; Step two: accurately weigh each component according to the above ratio, and put all pretreated raw materials into a high-speed mixer for dry mixing to obtain a homogeneous raw material mixture; Step three: use a preheater to heat the dry-mixed raw materials to 800-900°C to decompose part of the carbonates in the mixture in advance, increasing the subsequent reaction rate; Step four: send the preheated mixture into a rotary kiln for calcination at 1200-1350°C; Step five: after calcination, use rapid air cooling to quickly reduce the clinker temperature to room temperature to stabilize its microstructure and special properties; Step six: the cooled clinker is then ground to a specified fineness by ball milling and can be directly used for cement production.

[0019] Example 2 Low-carbon cement clinker containing industrial waste residue, the raw material ratio comprises: limestone 45%, clay 15%, blast furnace slag 15%, fly ash 4%, waste glass powder 6%, and red mud 15%.

[0020] Preparation process: Step one: crush, screen and finely grind the limestone, clay, blast furnace slag, fly ash, red mud and waste glass powder to ensure that all raw materials have a uniform particle size distribution and remain dry; Step two: accurately weigh each component according to the above ratio, and put all pretreated raw materials into a high-speed mixer for dry mixing to obtain a homogeneous raw material mixture; Step three: use a preheater to heat the dry-mixed raw materials to 800-900°C to decompose part of the carbonates in the mixture in advance, increasing the subsequent reaction rate; Step four: send the preheated mixture into a rotary kiln for calcination at 1200-1350°C; Step five: after calcination, use rapid air cooling to quickly reduce the clinker temperature to room temperature to stabilize its microstructure and special properties; Step six: the cooled clinker is then ground to a specified fineness by ball milling and can be directly used for cement production.

[0021] The foregoing description of the disclosed embodiments enables a person skilled in the art to make or use the application. Modifications of these embodiments will occur to persons of skill in the art, and that the appended claims are intended to cover all such modifications that do not depart from the true spirit and scope of the application. Therefore, the application is not limited to the embodiments shown but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. Low-carbon cement clinker containing industrial waste residue, characterized in that: It includes the following components: limestone 45-55%, clay 5-15%, blast furnace slag 15-25%, fly ash 4-6%, waste glass powder 4-6%, and red mud 15-25%.

2. The low-carbon cement clinker containing industrial waste residue according to claim 1, characterized in that: It includes the following components: 50% limestone, 10% clay, 20% blast furnace slag, 5% fly ash, 5% waste glass powder, and 10% red mud.

3. The low-carbon cement clinker containing industrial waste residue according to claim 1, characterized in that: Limestone is used as a basic cementing component.

4. The low-carbon cement clinker containing industrial waste residue according to claim 1, characterized in that: Clay is used to help adjust the silica-alumina ratio in cement clinker and improve the microstructure of the clinker.

5. The low-carbon cement clinker containing industrial waste residue according to claim 1, characterized in that: Blast furnace slag can be used to partially replace limestone and clay, and it has hydration activity, thus reducing carbon emissions.

6. The low-carbon cement clinker containing industrial waste residue according to claim 1, characterized in that: Fly ash is used to provide silicon, aluminum, and iron components, acts as a flux during calcination, promotes clinker mineral formation, and utilizes industrial waste.

7. The low-carbon cement clinker containing industrial waste residue according to claim 1, characterized in that: Waste glass powder is used to provide a source of highly reactive silica.

8. A method for preparing low-carbon cement clinker containing industrial waste residue, wherein the low-carbon cement clinker containing industrial waste residue is prepared according to claim 1, characterized in that, The main steps include the following: Step 1: Crush, screen, and finely grind limestone, clay, blast furnace slag, fly ash, red mud, and waste glass powder to ensure that all raw materials achieve a uniform particle size distribution and remain dry. Step 2: Accurately weigh each component according to the above proportions, put all the pretreated raw materials into a high-speed mixer for dry mixing, and obtain a homogeneous raw material mixture; Step 3: Use a preheater to heat the dry mixture to 800-900℃ to decompose some of the carbonates in the mixture in advance, thereby increasing the rate of subsequent reactions. Step 4: The preheated mixture is fed into a rotary kiln and calcined in the range of 1200~1350°C; Step 5: After calcination, rapid air cooling is used to quickly reduce the clinker temperature to room temperature in order to stabilize its microstructure and special properties; Step 6: The cooled clinker is then ball-milled to the specified fineness and can be used directly in cement production.