The answer is Yes definitely! Coal is one of the necessary raw materials in cement production line. The cement production process is complex and requires a variety of raw materials and fuels. Coal is one of the main fuels in cement production. It is necessary to heat the cement clinker in a huge rotary kiln. In this process, the high temperature generated by the combustion of coal causes the cement clinker to sinter into cement clinker balls through chemical reactions. Therefore, coal is an indispensable fuel in the cement production process.
The core role of coal in traditional cement production:
In cement production, coal is mainly used as fuel to provide the necessary heat. High-temperature calcination is an indispensable part of cement production, and coal can stably and efficiently provide the required heat to ensure a smooth production process. In addition, the reducing atmosphere produced by coal combustion assists the formation of minerals in cement clinker.
- Provide heat source: Coal can generate a lot of heat at high temperature, which can be used in the firing process of cement kiln to melt raw materials (raw materials of cement) and react chemically to obtain finished cement.
- Auxiliary raw material firing: Some auxiliary materials need to be mixed with coal to obtain a balanced and appropriate chemical reaction
- Power generation: Electricity is needed in factories to drive equipment, lighting, etc., and coal can be used as fuel to generate electricity.
The relationship between cement production process innovation and coal demand:
Coal is one of the necessary raw materials in the cement production process, and there is a close connection between the two.
1. Basic concepts of cement and coal:
What is cement?
Cement is a basic building material used to bond building materials. It is made by calcining limestone, clay and other materials and mixing them under appropriate conditions.
What is coal?
Coal is a fossil fuel mainly used in power generation, heating and other industrial fields. It is formed by plants in the natural process of millions of years and contains carbon, hydrogen, oxygen and a small amount of other elements.
2. Cement production requires coal consumption:
In the process of cement production, coal is one of the indispensable raw materials. The production of cement requires a large amount of heat source, and the heat energy generated by coal combustion can provide these heat sources. At the same time, coal can also provide by-products such as coal gas and kerosene, which can be used in other links in cement production.
3. The relationship between cement and coal:
Since cement production requires a large amount of coal, there is a close relationship between cement and coal. On the one hand, the price of coal directly affects the production cost and price of cement. On the other hand, cement production also has a certain impact on the coal market, especially in the peak season of cement sales, the demand for the coal market will also increase accordingly.
The impact of coal consumption on cement production:
1. The importance of coal consumption to cement production
In the process of cement production, coal is one of the important sources of energy. It is mainly used in the coal mill, kiln head and other process links in the cement burning process. The amount of coal not only affects the cost and efficiency of cement production, but also affects environmental protection and energy saving.
2. How much coal is needed to burn one ton of cement?
The amount of coal required to burn one ton of cement is not fixed and will be affected by multiple factors. Generally speaking, according to the process flow of cement production and the calorific value of coal and other parameters, about 0.2-0.3 tons of standard coal is required to burn one ton of ordinary Portland cement. However, the actual situation will also be affected by factors such as the coal price in the local market and the coal consumption level of cement production enterprises. For example, in some areas with energy shortages, due to various reasons such as coal supply and price, the amount of coal used to burn one ton of cement may be higher.
3. Factors affecting coal consumption on cement production
In addition to the factors mentioned above, there are some other production factors that can affect coal consumption, including the following:
- Cement production equipment and technical level: Different production equipment and technology have different effects on coal consumption.
- Types and grades of cement products: The amount of coal used in the production process of different types and grades of cement will be different.
- Coal quality: Factors such as calorific value and ash content will affect the amount of coal used.
- Temperature and time: The burning temperature and burning time have different effects on the amount of coal used.
The impact of different types of coal on cement quality:
Coal is one of the most important fuels in the cement production process, and its composition will have a great impact on the quality of clinker and production process. In terms of composition, coal mainly contains carbon, hydrogen, oxygen, nitrogen and other elements, in addition to some impurities and ash. These components will directly affect the combustion efficiency of coal and the impact on clinker. Therefore, cement production mainly uses bituminous coal and anthracite. The selection of coal types needs to consider factors such as calorific value, ash content, and sulfur content to optimize the production process and product quality. As an indispensable raw material in the construction industry, cement production involves complex processes such as mixing and grinding of multiple raw materials. Among them, coal, as an important source of energy, plays a important role in cement production. So, what kind of coal will be used in cement production?
1. Commonly used coal types in cement production
In the cement production process, commonly used coal types mainly include bituminous coal and anthracite. Bituminous coal has a higher calorific value and lower ash content, and can provide sufficient heat to meet the heat demand in the cement production process. Anthracite has the characteristics of low sulfur and low volatile matter, which is conducive to reducing pollutant emissions and improving cement quality.
2. The impact of different types of coal on cement production
- Calorific value impact: The calorific value of coal directly affects the energy consumption of cement production. Coal with higher calorific value can reduce energy consumption in the production process and improve production efficiency.
- Ash content impact: The ash content of coal will directly affect the quality of cement. Once the ash is mixed into the clinker, it will have an adverse effect on the clinker composition and physical properties. Too high ash content in cement will lead to reduced strength of cement and affect the quality of the building.
- Sulfur content impact: Coal with high sulfur content will produce a large amount of harmful gases such as sulfur dioxide during combustion, which will harm the environment and human health.
3. Principles and development trends of coal selection
When selecting coal, cement production enterprises need to comprehensively consider factors such as coal calorific value, ash content, sulfur content, as well as local coal resources and environmental protection policies. With the continuous improvement of environmental protection requirements, more and more companies have begun to pay attention to the environmental performance of coal and choose high-quality coal with low sulfur and low ash content. In the process of using coal, it is also necessary to pay attention to the particle size of coal powder. Fine coal powder is easy to accumulate dust, which has a greater impact on combustion efficiency and clinker. Therefore, the particle size of coal powder needs to be properly controlled to ensure that it meets production requirements.
Okay, the above content has introduced the types of coal and their role in cement production. The next question to be discussed is whether coal can be used directly in cement production.
Can raw coal be used directly in cement production?
We know that the size of coal blocks is usually 2 cm to 5 cm or even larger. Do such coal blocks need to be processed before they can be used in cement production? Next, we will introduce two types of equipment for coal processing. Because only coal that has been crushed can be used as fuel in cement production lines. These two types of equipment are a ball mill for grinding coal (wind-swept coal mill) and a VRM mill for grinding coal (coal vertical roller mill).
1. What is an air-swept ball mill for coal grinding?
The air-swept coal mill is a device used in cement plants to process coal powder. It is mainly used to grind raw coal into coal powder and dry the ground coal powder to reduce the moisture content for later use.
What are the main components of a coal grinding ball mill?
The air swept coal grinding ball mill is mainly composed of a feeding device, a main bearing, a rotating part, a transmission device, a selling device, a high-pressure starting device and a lubrication system.
What are the main components of a coal grinding ball mill?
The raw material is loaded into the mill through the feeding device, and the hot air enters the mill through the air inlet pipe. As the mill cylinder rotates, the coal and the hot air exchange heat in the mill, and the coal is crushed and ground in the mill. While the coal is ground, the fine powder is passed through the hot air in the mill and taken out of the mill through the discharging device.
ZJTL air-swept coal mill main specifications and models:
| Specification and Model | Rotational Speed of Cylinder (r/min) | Ball Loading Quantity (t) | Feed Particle Size (mm) | Discharge Particle Size (mm) | Output (t/h) | Motor Power (kW) | Weight (t) |
| φ1500 × 3135 | 29 | 6.5 | ≤25 | Sieve residue 7–10% (4900/cm²) | 2.5–4.5 | 95 | 14 |
| φ1700 × 2500 | 29 | 8 | ≤25 | Sieve residue 7–10% (4900/cm²) | 3–5 | 95 | 18 |
| φ2200 × 3000 | 22.9 | 17 | ≤25 | Sieve residue 10–12% (4900/cm²) | 5–6 | 180 | 28 |
| φ2200 × 3800 | 22.9 | 18 | ≤25 | Sieve residue 10–12% (4900/cm²) | 6.5–8 | 210 | 33 |
| φ2200 × 4400 | 22.9 | 20 | ≤25 | Sieve residue 10–12% (4900/cm²) | 8–10 | 245 | 38 |
| φ2400 × 4750 | 20.4 | 28 | ≤25 | Sieve residue 10–12% (4900/cm²) | 11–14 | 285 | 45 |
| φ2500 × 3900 | 20.4 | 30 | ≤25 | Sieve residue 10–12% (4900/cm²) | 9–10 | 320 | 52 |
| φ2800 × 5000+3 | 18 | 45 | ≤25 | Sieve residue 10–12% (4900/cm²) | 16–17 | 480 | 95 |
| φ2900 × 4100 | 17 | 37 | ≤25 | Sieve residue 10–12% (1900/cm²) | 18–20 | 480 | 88 |
2. What is a Vertical roller mill for coal grinding?
Coal vertical roller mill is a large-scale advanced high-efficiency energy-saving grinding product, which integrates grinding, grading, drying and conveying. It is suitable for grinding cement raw materials, clinker, desulfurized quicklime powder, slag, steel slag manganese ore, coal mine and other materials.
Main components of coal vertical roller mill
Coal vertical mill is mainly composed of base, grinding disc, grinding roller, pressure device, upper and lower shells, powder selector, sealed feeding device, lubrication device, motor, reducer, etc.
Main working principle:
Coal vertical mill is driven by electric motor, and the planetary reducer drives the mill grinding disc to rotate. The 2-4 grinding rollers on the grinding disc rotate under the drive of the grinding disc. The raw coal coming in through the coal drop pipe is distributed on the grinding disc. Due to the action of hydraulic loading force, the grinding roller and the grinding disc are squeezed to crush the large particles of raw coal. The small coal particles are crushed by the sliding friction generated by the relative movement of the grinding roller and the grinding disc. While the raw coal is being ground in the mill, the hot air (generally below 300°C) from the vertical mill is passed to dry out the moisture of the raw coal to meet the requirements of the finished coal powder. The ground coal powder is transported to the separator through the primary air for separation. The qualified coal powder is transported to the coal powder bin, and the unqualified coarse coal powder is returned to the mill for re-grinding.
TONGLI ZJTL MPS series vertical roller mill technical specification table:
| Vertical Mill Specification | Output (t/h) | Fineness (Residue on 80um Sieve) | Moisture | Power (kw) |
| ZJTL1720C | 16～18 | R≤8% | ≤0.5% | 250 |
| ZJTL2020C | 20～23 | R≤8% | ≤0.5% | 355 |
| ZJTL2220C | 30～35 | R≤8% | ≤0.5% | 500 |
| ZJTL2520C | 40～45 | R≤8% | ≤0.5% | 710 |
| ZJTL2820C | 55～58 | R≤8% | ≤0.5% | 900 |
| ZJTL3230C | 75～78 | R≤8% | ≤0.5% | 1250 |
| ZJTL3640C | 110～115 | R≤8% | ≤0.5% | 1800 |
What are the advantages of vertical mill and ball mill for coal grinding?
Air-swept coal mill ball mill is a kind of coal grinding equipment commonly used in cement plants. It impacts and grinds the materials through the steel balls inside the rotating cylinder, so as to achieve the purpose of grinding the materials. Air-swept coal mill ball mill has the following advantages:
- Strong adaptability: The wind-swept coal mill can process coal of various hardnesses. Whether it is hard coal or soft coal, it can adapt to different coal grinding needs by adjusting the operating parameters of the ball mill.
- High grinding efficiency: The wind-swept coal mill uses steel balls to impact and grind coal, with high grinding efficiency and can produce coal powder with uniform fineness.
- Controllable product particle size: By adjusting the parameters such as the mill speed, steel ball size and filling amount, the particle size of the coal powder can be controlled to meet the needs of different industrial applications.
- Easy operation: The operation is relatively simple, maintenance is convenient, and the operation is stable and reliable.
- Wide range of applications: The wind-swept coal mill is not only suitable for coal grinding, but also widely used in cement, ceramics, metallurgy, chemical industry and other industries.
- Good wear resistance: The interior of the wind-swept coal mill is usually made of wear-resistant materials, such as high manganese steel liner and wear-resistant steel balls, which prolongs the service life of the equipment.
- Continuous operation: It can operate continuously and is suitable for large-scale industrial production.
- Environmental protection performance: It is equipped with a dust removal device, which can effectively reduce the dust pollution generated during the coal grinding process.
- Relatively low energy consumption: Although the energy consumption is high at startup, once it enters a stable operating state, its energy consumption is relatively low.
- High safety: The structure is sturdy and the safety performance is high during operation.
What are the advantages of vertical mill and ball mill for coal grinding?
Coal roller vertical mill is an ideal large-scale grinding equipment, which integrates crushing, drying, grinding, and grading and conveying. It has high production efficiency and can grind block, granular and powdered raw materials into required powdered materials. Coal vertical mill has the following advantages:
- The production investment cost is greatly reduced: the vertical mill system has a simple process flow, compact layout, small building area, and occupies about 70% of the ball mill system. The building space is about 60% of the ball mill system and can be arranged outdoors, which directly reduces the investment cost of the enterprise. In addition, the vertical mill itself has a separator, and no additional powder selector and lifting equipment are required. The dust-containing gas out of the mill can be directly collected by a bag filter or an electric dust collector.
- High production efficiency, energy saving and environmental protection: The vertical mill adopts the material layer grinding principle to grind materials, with low energy consumption. The power consumption of the grinding system is 20%~30% lower than that of the ball mill, and the power saving effect is more obvious as the moisture content of the raw materials increases. The energy consumption of the vertical mill system is 30%~40% lower than that of the ball mill system. The vertical mill does not have the metal impact sound of the steel balls colliding with each other and hitting the liner in the ball mill during operation, so the noise is small, 20~25dB lower than that of the ball mill. In addition, the vertical mill adopts a fully enclosed system, the system works under negative pressure, there is no dust, and the environment is clean.
- Strong material drying capacity: The vertical mill uses hot air to convey materials. When grinding materials with high moisture content, the inlet air temperature can be controlled to make the product reach the required final moisture content. Materials with moisture content of up to 15%~20% can be dried in the vertical mill.
- Easy operation and maintenance: Equipped with an automatic control system, remote control can be realized, and the operation is simple; by inspecting the oil cylinder and flipping the boom, the roller sleeve and liner can be replaced quickly and conveniently, reducing the company's downtime losses.
- Stable product quality and easy detection: The chemical composition of the product is stable and the particle size distribution is uniform, which is conducive to calcination. The material stays in the vertical mill for only 2~3 minutes, while it takes 15~20 minutes in the ball mill. Therefore, the chemical composition and fineness of the vertical mill product can be quickly measured and corrected.
- Low wear and high utilization rate: Since there is no direct metal contact between the grinding roller and the grinding disc during the operation of the vertical mill, the wear is small, and the metal consumption per unit product is generally 5~10g/t.
Can the coal needed for cement production be replaced? What impact will alternative fuels have on cement performance?
Application of alternative fuels in the cement industry
Alternative fuels refer to the use of non-fossil energy or waste as fuel in the cement production process, replacing part or all of the traditional fossil fuels in cement production. Currently commonly used alternative fuels include waste plastics, waste tires, coal gangue, etc. The use of alternative fuels can not only reduce production costs, but also reduce carbon emissions and the amount of solid waste processed.
Advantages of alternative fuels:
- Reduced production costs: Alternative fuels are cheaper than traditional fossil fuels. If used and disposed of correctly, alternative fuels can be an effective means to reduce production costs.
- Reduced carbon emissions: Alternative fuels contain higher non-fossil carbon, and the use of alternative fuels can reduce carbon emission levels. According to experiments, the use of alternative fuels can reduce carbon dioxide emissions by about 0.8 tons.
- Reduced waste treatment costs: The use of alternative fuels can reduce waste generation. At the same time, for reducible waste, such as paint waste and waste paint, the use of alternative fuels can reduce their treatment costs.
Disadvantages of alternative fuels:
- Low energy utilization: The energy density of alternative fuels is lower than that of traditional fossil fuels, so they need to be regulated more precisely when used. Otherwise, the energy utilization rate will be low, affecting the efficiency of cement production.
- Poor stability: The composition of alternative fuels is unstable and may contain toxic and harmful substances. Exceeding the standard may cause environmental pollution. Therefore, the composition of alternative fuels must be strictly screened and processed to ensure that they meet the use standards.
- The supply may be unstable: The source of alternative fuels is usually waste, so the supply is unstable, which may affect the smooth progress of cement production.
Synergistic Utilization of Coal and Other Energy Sources in Cement Production
The synergistic utilization of coal and other energy sources refers to the mixing and burning of different types of alternative fuels with coal on the same cement production line. Through synergistic processing, the complementarity and optimization between fuels can be achieved, the combustion efficiency can be improved, and the emission of pollutants can be reduced.
What is the key to synergistic processing in cement plant?
The key to synergistic processing lies in the reasonable control of the mixing ratio and combustion conditions of the fuels. On the one hand, it is necessary to determine the appropriate mixing ratio according to the needs of cement production and the properties of the fuel. On the other hand, it is also necessary to optimize the combustion process by adjusting parameters such as combustion temperature and oxygen content to improve the combustion efficiency and thermal utilization rate of the fuel.
What are the advantages of synergistic processing?
The advantage of synergistic processing is that it can maximize the utilization of resources and minimize the impact on the environment. Through synergistic processing, not only can low-value resources such as waste and industrial by-products be utilized, but also the dependence on traditional fossil fuels can be reduced and carbon emissions can be reduced. In addition, synergistic processing can also improve the stability and reliability of the cement production process and reduce production costs.
Energy efficiency improvement technology for coal combustion in cement production
Why should we improve the combustion efficiency of coal?
The level of coal powder combustion efficiency directly affects the energy utilization effect and the degree of environmental pollution. The higher the combustion efficiency, the more heat the coal powder releases and the less pollutants are emitted. Incomplete combustion will produce a large amount of coal slag and harmful gases. Methods to improve the combustion efficiency of coal powder in cement plants include optimizing coal powder fineness, improving burner design, reasonable air distribution and applying intelligent control technology. The implementation of these methods can improve the quality of clinker and reduce production costs.
The importance of coal powder combustion efficiency, How to improve it?
In the cement production process, the combustion efficiency of coal powder directly affects the quality and production cost of clinker. Improving the combustion efficiency of coal powder can not only reduce energy consumption and environmental pollution, but also improve the quality of clinker, thereby improving product quality
1. Optimizing coal powder fineness
The fineness of coal powder has a great influence on combustion efficiency. The finer the coal powder, the larger its surface area and the larger the contact area with air, which is conducive to the full combustion of coal powder. Therefore, optimizing the grinding process of coal powder and improving the fineness of coal powder are effective means to improve combustion efficiency.
2. Improve the burner
The design of the burner is crucial to improving the combustion efficiency of pulverized coal. New high-efficiency burners usually adopt a design that combines multi-stage air distribution, swirl and direct current, so that pulverized coal and air can be mixed more fully, thereby improving the combustion efficiency. In addition, the reasonable arrangement of the position and angle of the burner can also effectively improve the combustion efficiency of pulverized coal.
3. Reasonable air distribution
A reasonable air distribution system is another key to improving the combustion efficiency of pulverized coal. By adjusting the ratio of primary air, secondary air and tertiary air, the combustion process of pulverized coal can be optimized. Primary air is mainly used for the transportation and preliminary combustion of pulverized coal, while secondary air and tertiary air are used for combustion assistance and burnout. A reasonable air distribution system can make the pulverized coal evenly distributed in the furnace and fully burned.
4. Application of intelligent control technology
With the development of science and technology, intelligent control technology is increasingly used in cement production. By real-time monitoring of parameters such as temperature, pressure and oxygen content in the furnace, the intelligent control system can timely adjust the amount of pulverized coal, the air distribution ratio, etc. to maintain the best combustion state. This not only improves the combustion efficiency of pulverized coal, but also reduces the labor intensity of workers and improves the safety of production.
Transportation and storage management of coal in cement production
1. Use special storage and transportation equipment
Coal and cement are two different raw materials with quite different material properties. Therefore, when storing and transporting coal, special storage and transportation equipment should be used to isolate coal from cement to avoid confusion. Usually, coal storage equipment uses equipment with dustproof, explosion-proof, moisture-proof and other functions, and is classified and packaged according to standards.
2. Isolate the coal production site
During the coal production process, some harmful gases and dust and other substances may be produced, which may have adverse effects on the cement production process. Therefore, it is important to isolate the coal production site. Specific measures include the use of sealed hoods, tape isolation, static eliminators, high-pressure fans, etc. to ensure the isolation effect.
3. Establish a special emission pipeline
The gas and powder emitted during the coal production process also need to be isolated. Generally, a special emission pipeline is established, and then treated in advance to avoid these harmful substances from causing adverse effects on cement production. At the same time, it is also necessary to establish a complete monitoring system to monitor the emission pipeline in real time to ensure its normal operation.
4. Strengthen safety education and management
Although the above measures can reduce the impact of coal production on cement production to a certain extent, they cannot completely eliminate it. Therefore, strengthening the safety education and management of workers is also indispensable. Employees must be given necessary skills training to improve their awareness of related safety work, and safety management must be strengthened to ensure that various measures are effectively implemented.
FAQ Frequently Asked Question:
In theory, cement can be produced without coal. In traditional processes, coal is the main fuel for cement production. It takes about 100-130 kg of standard coal heat to produce 1 ton of cement clinker for raw material calcination. With technological advances, alternative fuels are gradually emerging, such as industrial waste and urban garbage-derived fuels, which can partially or completely replace coal. In European countries such as Denmark, some cement plants have achieved an alternative fuel utilization rate of over 90%. At the same time, new energy technologies are also being explored and applied in the cement industry, such as the use of clean energy such as solar energy and electricity. However, due to technical and cost limitations, they have not yet been widely popularized, and coal is still the mainstream fuel for global cement production.
In cement production, coal is an important source of energy. The key link in cement production, raw material calcination, requires heating the materials to a high temperature of about 1450℃. This process is mainly achieved by the heat released by coal combustion. According to industry data, the production of 1 ton of cement clinker consumes an average of about 110-130 kg of standard coal. The combustion characteristics and calorific value of coal directly affect the temperature control and calcination quality in the kiln, and are related to the performance of cement products. Although alternative energy sources such as biomass fuels and industrial waste are gradually being used, coal still accounts for more than 70% of the energy structure of cement production worldwide, and is the core energy to ensure stable cement production.
In cement production, the requirements for coal are relatively strict. From the perspective of calorific value, the low calorific value of coal is generally required to be no less than 22990kJ/kg to ensure sufficient heat for cement raw material calcination. The production of 1 ton of cement clinker requires about 100-130 kg of standard coal heat. The volatile matter of coal is usually controlled at 20%-35%. Too high volatile matter can easily lead to unstable combustion, while too low volatile matter is not conducive to the rapid start of combustion. In addition, the ash content of coal should be as low as possible, generally not exceeding 25%, because too high ash content will affect the calcination process and increase the impurity content of clinker. At the same time, the sulfur content of coal must be strictly controlled below 1.5% to avoid corrosion to equipment and environmental pollution.
Bituminous coal is commonly used in cement production. Bituminous coal has moderate volatile matter and calorific value, generally with a volatile matter content of 20% - 40% and a calorific value of about 25 - 32MJ/kg. This allows bituminous coal to burn stably in cement kilns and generate enough heat to meet the needs of cement raw material calcination. Generally, it takes about 100 - 130 kg of standard coal to produce 1 ton of cement clinker. In addition, the combustion characteristics of bituminous coal make it easy to control the combustion process and the temperature in the kiln, which is beneficial to ensure the quality of cement clinker. Its ash content is usually 10% - 20%, and it can also participate in the mineral formation process of cement to a certain extent, which has a positive impact on the performance of cement.
Concrete itself does not contain coal. Concrete is mainly made of cement, coarse and fine aggregates, water and admixtures mixed in a certain proportion. In the process of cement production, coal is used as a large amount of fuel. Generally, about 100-130 kg of standard coal is consumed to produce 1 ton of cement clinker. The heat generated by coal combustion causes the raw materials to be calcined into clinker. When cement and other materials are used to make concrete, coal does not participate in the composition of concrete. However, in some special cases, if the aggregate or cement raw materials are contaminated, there may be a very small amount of coal residue, but this is not a normal component of concrete and does not affect the essential composition of concrete with cement as the main raw materials.
Coal gangue can be used as a raw material for cement production. It is an industrial solid waste rich in silicon, aluminum and other elements. When the amount of coal gangue added is within a reasonable range, it can effectively improve the performance of cement. Adding 10% - 20% of coal gangue that has been activated by high-temperature calcination into silicate cement can increase the early strength of cement by 5% - 10% and the later strength by 10% - 15%. This is because high-temperature treatment releases the active substances in the coal gangue, which react with the cement hydration products to generate more gel substances, thereby strengthening the cement stone structure.
Charcoal ash is difficult to use directly as cement. Cement is a complex system composed of multiple minerals. Its main components include calcium oxide, silicon dioxide, aluminum oxide and iron oxide, etc. It needs to be made through precise proportioning and high-temperature calcination. The main components of charcoal ash are potassium carbonate, calcium oxide, etc., which are very different from the mineral composition of cement, and lack key mineral phases such as calcium silicate and calcium aluminate required to form cement strength. In addition, the composition of charcoal ash fluctuates greatly, and it is difficult to ensure stable performance. Even if it is added to cement in small amounts as an admixture, it has a low activity and contributes little to the strength of cement. Excessive use will also affect the coagulation and hardening properties of cement. Therefore, charcoal ash cannot usually be used as a direct substitute for cement.
Cinder ash is used in asphalt. Cinder ash contains a certain amount of oxides such as silicon, aluminum, and iron, and has potential activity. Studies have shown that the proper addition of cinder ash can improve the performance of asphalt mixtures. For example, when the amount of cinder ash is 5% - 10%, the high temperature stability of asphalt mixtures can be improved, and its dynamic stability can be increased by about 10% - 20% compared with ordinary asphalt mixtures. At the same time, it can also enhance the water stability of asphalt mixtures to a certain extent, so that the residual stability reaches more than 80%. However, the use of cinder ash requires strict control of its quality and amount to ensure the performance and durability of asphalt pavement.
Asphalt is not made directly from coal. Asphalt is mainly divided into petroleum asphalt, natural asphalt and coal asphalt. Petroleum asphalt is made from the residue after crude oil distillation and is the most commonly used type in road construction; natural asphalt is formed in nature through complex geological processes. Coal tar is a by-product of processes such as coking and gas production. It is extracted by processes such as distillation of coal tar, and its output accounts for about 50%-60% of the processed coal tar. Although coal tar is related to asphalt, in the strict sense, asphalt is not directly made from coal, but comes from petroleum, natural resources or coal processing by-products. Different types of asphalt differ in composition, performance and application.
Conclusion:
In summary, coal plays an important role in cement production. As the main fuel, it not only provides indispensable heat for cement raw material calcination and ensures the smooth progress of the production process, but also ensures the quality and performance of cement clinker by precisely controlling combustion. Although the application of alternative fuels is gradually emerging, coal is still the core energy pillar of cement production, and its importance is unlikely to be completely replaced in the short term. At the same time, we also introduced two types of equipment for coal powder grinding, namely vertical mill and ball mill. If you need it, you can contact us at any time.
