Views: 66 Author: Site Editor Publish Time: 2025-08-13 Origin: Site
Silicon nitride is a strong and dependable refractory brick material. It works well in places with high heat because it does not rust and stays steady. Many industries use silicon nitride because it lasts long and works well. These include iron and steel metallurgy, ceramics, and waste incineration. Asia Pacific uses silicon nitride the most. This is because factories are growing fast and they use new ways to make things. Knowing what each refractory brick can do helps companies pick the right one for their jobs.
Silicon nitride bricks are very strong. They can handle heat, chemicals, and damage. This makes them good for hard jobs in factories. People use them in steelmaking, glass making, and kilns.
These bricks keep their shape at high heat. They stay strong even when it gets very hot. They do not crack when the heat changes fast. They last longer than fireclay or alumina bricks.
Silicon nitride bricks help save energy. They stop heat from escaping. They make heat stay steady. This helps factories use less fuel. It also helps lower carbon emissions.
Silicon nitride bricks cost more at first. But they last a long time. They do not need much fixing. This saves money and time later.
Factories can recycle silicon nitride bricks. They crush and use them again. This saves materials and makes less waste. It also helps the environment.
Silicon nitride is made from silicon and nitrogen atoms. Its chemical formula is Si₃N₄. This means three silicon atoms join with four nitrogen atoms. The density of silicon nitride matters for many jobs in factories. It has a molar mass of about 140 grams per mole. About 60% of it is silicon, and 40% is nitrogen. These facts help engineers compare silicon nitride to other refractory brick materials like high alumina fire bricks and fireclay refractories.
Element | Symbol | Number of Atoms | Approximate Mass Percent |
|---|---|---|---|
Silicon | Si | 3 | 60.06% |
Nitrogen | N | 4 | 39.94% |
The density of silicon nitride can change depending on how bricks are made. Most silicon nitride bricks have a density between 2.9 and 3.2 g/cm³. These bricks are lighter than some other refractory products. They are still strong enough for high temp fire brick jobs.
Silicon nitride has a special crystal structure. It comes in two main types: alpha (α) and beta (β). Both types have silicon atoms joined to nitrogen atoms in a strong pattern. The β type has a hexagonal shape with channels along one side. This shape gives silicon nitride its hardness and strength. The strong Si-N bonds make it stable even when it gets very hot. Silicon nitride does not melt under normal pressure. Instead, it breaks down by sublimation at about 1900°C. This is important for refractory brick products used in kilns, furnaces, and other high temp fire brick places.
Note: The strong covalent bonds in silicon nitride stop grains from growing and keep the bricks from changing shape at high heat. This makes it a great choice for industries that need bricks to last in extreme heat.
Factories use several steps to make silicon nitride bricks. The main way is called reaction sintering. They start with silicon carbide sand as the main material. Metallic silicon powder is added to the mix. Workers shape the mix into bricks and dry them. Next, they fire the green body in a nitrogen atmosphere. During firing, silicon nitride forms and holds the silicon carbide pieces together. This makes a network that gives the bricks their strong refractory properties.
Key steps in production:
Mix silicon carbide sand and metallic silicon powder.
Shape and dry the green body.
Fire in a nitrogen atmosphere to form silicon nitride bonds.
This method helps keep the cost of bricks low and the quality high. Silicon nitride bricks from Yufeng Refractory and other suppliers work well in high temp fire brick jobs. These bricks compete with high alumina fire bricks and fireclay refractories in many industries. Their special structure and how they are made make them a good choice for monolithic refractory systems and other tough uses.
Silicon nitride refractory brick is known for being strong and tough. Engineers pick it for hard jobs because it lasts long and does not wear out easily. The brick has lots of silicon carbide and silicon nitride inside. This makes it dense and hard. Silicon nitride density is between 2.65 and 3.2 g/cm³. These bricks are lighter than some others but still very strong.
Property | Value |
|---|---|
Compressive Strength (MPa) | 150 |
Silicon Carbide Content (%) | 72 |
Silicon Nitride Content (%) | 22 |
Porosity (%) | 17 |
Density (g/cm³) | 2.65 |
Silicon nitride refractory brick can handle up to 150 MPa pressure. This is more than most regular bricks like fireclay and high alumina fire bricks. The brick does not have many holes, so hot metal and slag cannot get inside. This helps the brick last longer. Companies like Yufeng Refractory use special ways to make these bricks. Their bricks work well in monolithic refractory systems and high temp fire brick jobs.
Tip: Because silicon nitride bricks are strong and have few holes, they can hold heavy things and do not crack easily, even in tough places.
New ideas in the last ten years made silicon nitride refractory brick better. Adding pure β-Si₃N₄ to Al₂O₃-SiC-C bricks helps stop slag and air from hurting the brick. These changes help the bricks last longer in steelmaking and other hot jobs.
Silicon nitride refractory brick works well in very hot places. The brick stays strong and keeps its shape up to 1550°C. Sometimes it can work safely between 1650°C and 1750°C, depending on the air around it. This makes it great for kilns, furnaces, and blast furnaces where other bricks might break.
The brick’s crystal structure has strong Si-N bonds. These bonds stop grains from growing and keep the brick steady. Fireclay refractories can bend or crack when hot, but silicon nitride bricks do not. They can handle quick changes in heat without breaking. Using silicon nitride in sliding plates for ladle bottoms makes them last longer and saves money in steelmaking.
Silicon nitride bricks do not melt under normal pressure. They turn into gas at about 1900°C, which is much hotter than most factories need.
The brick can handle heating and cooling over and over. This makes it a good pick for monolithic refractory systems and high alumina fire bricks in busy factories.
Note: Refractory bricks cost different amounts, but buying silicon nitride bricks is worth it because they last longer and need less fixing.
Silicon nitride refractory brick is very good at fighting chemicals. These bricks work well where there are strong chemicals like hot metals and slag. Silicon nitride bonded silicon carbide bricks do not get damaged by coal-water slurry coal slag and other harsh stuff. Slag does not stick to the brick easily. A silicon dioxide layer forms on the brick, making slag thicker and harder to get in.
Silicon nitride bricks have very few holes. This stops slag and hot metal from getting inside. It helps the brick last longer in tough places.
Compared to other bricks like high chromia, fused AZS, and high zirconia, silicon nitride bricks let the least slag get through.
Silicon nitride ceramics also fight corrosion in hot salt. They do not corrode much. This keeps metal containers safe and means less time fixing things.
Factories use silicon nitride in ceramic cements to fix surfaces in metal plants. These cements stop corrosion at high heat and help machines last longer. The cement blocks holes so hot salt cannot get in.
Callout: Silicon nitride refractory brick fights chemicals better than many old bricks. It is a smart choice for places with hot metals, slag, and strong chemicals.
New technology has made silicon nitride bricks even better at fighting chemicals. Silicon nitride bonded silicon carbide kiln furniture now stops swelling problems from oxidation in old clay supports. These new bricks are more reliable and save money for today’s factories.
Silicon nitride refractory brick is important in very hot jobs. Many industries use it because it is strong and lasts a long time. It does not break down from heat or chemicals. These bricks help factories run all the time, even in hard places.
Steelmaking plants put silicon nitride bricks where it gets very hot. These bricks line ladles, tundishes, and sliding gates. Molten steel flows here at over 1500°C. The bricks are dense, so they do not crack or break under heavy weight.
Steel plants like silicon nitride bonded silicon carbide bricks. These bricks do not break when the temperature changes fast. This means fewer stops for repairs. The bricks have few holes, so slag and hot metal cannot get inside. This makes the lining last longer. It also saves money and keeps work going.
Note: The bricks fight off chemical attacks. A layer forms on the brick’s surface. This layer blocks slag and metal from getting in. This helps the brick last longer and need less fixing.
Glass factories use very high heat. Silicon nitride bricks work better than old fireclay and high alumina fire bricks. They stay strong at 1770°C to 2000°C. Old bricks can fail at 1400°C to 1600°C.
Some key benefits are:
They let glass melt at higher heat.
They do not crack when heated or cooled fast.
They do not break down in air and heat.
They move heat quickly, so less energy is wasted.
They do not get damaged by molten aluminum or fluoride salts.
They do not change size much when heated and cooled.
They last longer, so there are fewer stops and less fixing.
Reports say glass plants get 30% better shock resistance. They also get 40% better oxidation resistance than with old bricks. Furnace work time goes up by 15%. There are fewer repairs because the bricks fight off slag and heat damage.
Kilns and furnaces need bricks to keep heat in and stay safe. Silicon nitride bonded silicon carbide bricks are a good choice. They are very hard and strong, even when hot. They do not crack when the temperature changes fast. They move heat well, so firing is even and uses less energy. They do not corrode, so kiln furniture lasts longer. Lighter kiln furniture heats and cools faster, making kilns work better. The bricks do not wear away easily, so there is less downtime.
These bricks keep their shape, even in tricky kiln designs. They last longer, so you do not need to replace them often. This saves money and helps the planet.
Tip: Using these bricks in kilns and furnaces can make equipment last up to 3.8 times longer. This means less waste and more steady work.
Silicon nitride bricks help save energy in hot jobs. They do not change size much, so heat does not escape. They move heat just right, so temperature stays steady. Plants use up to 15% less energy and make 18-27% less carbon when using these bricks.
Property / Strategy | Description / Mechanism | Energy Efficiency Impact / Evidence |
|---|---|---|
Minimal Thermal Expansion | These bricks do not change size much when heated. | Fewer cracks and gaps mean less heat loss; service lasts up to 30% longer, so less reheating is needed. |
Superior Thermal Conductivity Control | Heat moves through the brick at just the right speed. | Temperature stays steady; energy use drops by up to 15%. |
Exceptional Temperature Resistance | Bricks work up to 1800°C without breaking down. | Factories can run longer without stopping to cool or reheat, saving lots of energy. |
Strategic Placement in Thermal Gradient Zones | Bricks are put where heat changes fast to stop heat loss. | Energy use drops by 12-18%; less heat escapes to cooler areas. |
Hybrid Lining Systems Optimization | Bricks are mixed with other types for best results. | Energy use drops by 15-22% compared to old linings. |
Preventative Maintenance & Monitoring | Special checks find problems early, keeping heat in. | Over 95% of energy savings last for years; fewer surprise stops and less wasted energy. |
Extended Equipment Service Life | Strong bricks last 2.5-3.8 times longer than old bricks. | Fewer repairs mean less reheating and 45-65% lower costs. |
Reduced Carbon Footprint | All these things together cut fuel use and pollution. | Factories make 18-27% less carbon than with old bricks. |
Besides steel, glass, and kilns, these bricks are used in boilers and incinerators. These jobs need bricks that do not wear out, crack, or get eaten by acid or slag. Factories often use different kinds of bricks together. Some are corundum mullite, magnesia carbon, silica, and silicon carbide bricks. Silicon nitride with silicon carbide is special because it fights wear and handles heat well. This makes it a good pick for the hardest jobs.
Callout: Picking the right brick for hot jobs keeps people safe, saves energy, and saves money. Silicon nitride bricks work well in the world’s toughest places.
Alumina bricks are used in many factories. They have a lot of alumina and work well in hot places. Silicon nitride bricks move heat faster than alumina bricks. At 1000°C, silicon nitride bonded silicon carbide bricks transfer about 15.5 to 16 W/(m·K). Alumina bricks only transfer 2 to 5 W/(m·K). This means silicon nitride bricks keep heat steady in high temp fire brick jobs. Their density also makes them strong and tough. Alumina bricks can handle heat, but silicon nitride bricks do not crack as easily. They last longer in hard jobs.
Property | Alumina Brick | Silicon Nitride Brick |
|---|---|---|
Thermal Conductivity | 2-5 W/(m·K) | 15.5-16 W/(m·K) |
Max Service Temp | 1600°C | 1770-2000°C |
Thermal Shock Resistance | Moderate | Excellent |
Silicon nitride bricks are best when heat changes fast and equipment must last.
Magnesia-carbon bricks are strong in places with lots of alkali. They use silicon carbide to protect the carbon inside. These bricks fight alkali and handle heat changes well. Silicon nitride bricks resist chemicals and oxidation even better. When mixed with Y2O3, silicon nitride bricks stay strong after touching molten metal. Magnesia-carbon bricks do not fight chemicals as well as silicon nitride bricks. Silicon nitride bonded silicon carbide bricks are dense, so they block corrosion and wear.
Magnesia-carbon bricks work in cement kilns and steel ladles.
Silicon nitride bricks are used in monolithic refractory systems and high temp fire brick jobs that need top corrosion resistance.
Fire clay bricks are the most common fire brick. They cost less and make up about 60% of the market. Their price starts at $50 per ton, which is much cheaper than silicon nitride or silicon carbide bricks. Fire clay bricks work in many places but do not last long in extreme heat or strong chemicals. Silicon nitride bricks cost more but are stronger and last longer. Factories use fire clay bricks for easy jobs and silicon nitride bricks for hard jobs.
Fire clay bricks are good for furnace linings.
Silicon nitride bricks are used in steelmaking, glass production, and kilns where strength matters.
Insulating fire bricks keep heat inside furnaces and kilns. They are light and easy to move. These bricks are not as strong or tough as silicon nitride bricks. Silicon nitride bonded silicon carbide bricks last longer and do not wear out fast. Better bricks cost more, so insulating fire bricks are cheaper but do not last as long. Silicon nitride bricks are used where heat, wear, and corrosion are big problems.
Tip: Factories use insulating fire bricks with silica fire bricks and silicon nitride bricks to save money and get good results.
Silicon nitride bricks are special because they handle high heat, move heat well, and fight corrosion and oxidation. Their nitridation bonding makes them very strong. These bricks last longer and help factories work without stopping. But silicon nitride bricks cost more than fireclay or insulating fire bricks. Factories must think about cost and performance when picking fire bricks.
Feature | Silicon Nitride Brick | Ordinary Fire Brick |
|---|---|---|
Max Service Temp | 1770-2000°C | 1200-1600°C |
Thermal Stability | Excellent | Moderate |
Oxidation Resistance | Superior | Susceptible |
Mechanical Strength | High | Limited |
Silicon nitride bricks help factories work longer, save energy, and need fewer repairs. They are the best pick for high temp fire brick jobs in tough places.
The price of refractory bricks is important for factories. Silicon nitride bricks usually cost more than fireclay or high alumina fire bricks. They are more expensive because making them needs special steps and pure materials. But these bricks last much longer than others. Factories do not have to replace them as often, so they save money over time. Many companies see that the total cost goes down when they think about how long the bricks last, not just the first price. For example, silicon carbide bricks cost about twice as much as clay bricks. But they last three to five times longer. This means factories stop less often and fix things less. The higher price of silicon nitride bricks also shows their strong performance and high density in hot jobs.
Tip: Factories should think about how long a brick will last and how much fixing it needs, not just the first price.
Silicon nitride bricks are very tough in hard places. They do not wear out, corrode, or break from heat as easily as fireclay bricks. Their strong build and high density help them keep their shape and strength, even after many times heating and cooling. This makes them a top pick for tough jobs and hot places. Factories using these bricks in steel, glass, and kilns say their machines last longer and stop less. The bricks also help save energy by keeping heat inside and stopping heat loss. In cooler jobs, silicon nitride bricks may not be needed. Fireclay or high alumina bricks might work well enough and cost less.
Factories can have problems when using silicon nitride bricks. Making these bricks can hurt the environment if not done right. Some makers use rice husk to help the planet and save resources. But burning rice husk makes fine dust that can hurt the air if not controlled. During making, silicon nitride powder and silicon powder can also get into the air. Good waste control and recycling help lower these risks. Recycling these bricks means collecting, sorting, crushing, and heating them again. This saves materials and keeps waste out of landfills. But recycling can be hard because of dirt and extra costs. Factories should know that silicon nitride bricks work best in very hot jobs. For cooler jobs, fireclay bricks may be easier and cheaper to use.
Note: New recycling and sorting tools make it easier to reuse silicon nitride bricks. This helps the planet and saves money.
Silicon nitride is one of the best bricks for very hot jobs. It has a high density and can handle quick changes in heat. It also lasts a long time. This makes it great for steel, ceramics, and monolithic refractory systems. Factories should pick silicon nitride instead of fireclay or high alumina fire bricks when they need bricks that last in tough heat or strong chemicals. Always look at the price of bricks and pick the right one for your job to get the best results.
Silicon nitride refractory brick is denser than fireclay refractories. It can handle quick temperature changes better. It lasts longer in very hot jobs. Fireclay refractories are cheaper but do not work as well in extreme heat or with strong chemicals.
Factories use silicon nitride refractory brick in steelmaking and glass production. They also use it in kilns. These bricks are good for monolithic refractory systems and very hot jobs. They are used where other bricks cannot last.
When silicon nitride density is higher, the brick is stronger. It does not wear out fast. It keeps slag and hot metal from getting inside. This helps the brick last longer in tough jobs.
Silicon nitride bricks cost more than high alumina fire bricks. Factories pay more at first. But they save money later because these bricks last longer and need less fixing.
Factories can recycle silicon nitride refractory brick by crushing it. They use the crushed brick in new mixes. This saves materials and lowers costs. Recycling also helps cut down on waste from hot jobs.
