Magnesia carbon brick:What it is & Where it’s Used

　　Magnesia carbon bricks are a type of refractory brick that is made from a mixture of high-purity magnesium oxide (MgO) and carbon. The carbon content can range from 5% to 30%, depending on the specific application requirements.

　　The production of magnesia carbon bricks involves mixing pre-calcined or fused magnesia with flake graphite, pitch, or resin to form a paste-like material. This material is then shaped into the desired brick form and fired at high temperatures to create a dense and durable finished product.

　　Magnesia carbon bricks are known for their excellent resistance to high temperatures, corrosion, and thermal shock, as well as their good mechanical strength and abrasion resistance. They are widely used in various high-temperature applications, such as steelmaking, non-ferrous metal smelting, cement kilns, and incinerators.

　　The addition of carbon to magnesia bricks enhances their thermal conductivity, improves their resistance to oxidation, and reduces their tendency to crack under thermal stress. However, excessive carbon content can also reduce the overall mechanical strength of the bricks, so the amount of carbon is carefully controlled during production to ensure optimal performance for the intended application.

　　1.High-temperature resistance

　　Magnesia carbon bricks can withstand high temperatures of up to 1800°C without losing their strength and durability.

　　2.Thermal shock resistance

　　Magnesia carbon bricks have good thermal shock resistance, which means they can withstand rapid temperature changes without cracking or breaking.

　　3.Slag corrosion resistance

　　Magnesia carbon bricks have excellent resistance to slag corrosion, making them ideal for use in steelmaking furnaces that are exposed to corrosive slag.

　　4.Low thermal expansion

　　Magnesia carbon bricks have a low coefficient of thermal expansion, which means they are less likely to deform or crack due to temperature changes.

　　5.Good electrical conductivity

　　Magnesia carbon bricks have good electrical conductivity, which makes them ideal for use in electric arc furnaces.

　　6.Good oxidation resistance

　　Magnesia carbon bricks have good oxidation resistance, which means they can maintain their properties even after prolonged exposure to oxygen-rich environments.

       The application of magnesia carbon bricks includes the following:

　　1. Steelmaking industry: One of the primary applications of magnesia carbon bricks is in the steel industry. They are used in various steelmaking processes, including:

　　Basic oxygen furnaces (BOF): Magnesia carbon bricks line the converter vessels in BOF steelmaking, where they provide excellent resistance to high temperatures, slag corrosion, and mechanical wear.

　　Electric arc furnaces (EAF): Magnesia carbon bricks are employed in the EAF for furnace linings as well as the side walls, spouts, and bottoms. They resist chemical attack from molten steel, slag, and other furnace materials.

　　Ladle linings: Magnesia carbon bricks are used to line ladles that transport and hold molten steel. They offer good resistance to thermal shock and erosion caused by the hot metal and slag.

　　2. Non-ferrous metal industry: Magnesia carbon bricks find application in non-ferrous metal smelting processes, such as copper, nickel, and aluminum production. They are used in furnaces and converters, providing durability, thermal shock resistance, and resistance to chemical corrosion from molten metals and slags.

　　3. Cement industry: Magnesia carbon bricks are utilized in cement kilns and rotary kilns due to their ability to withstand high temperatures and chemical environments. They line the burning zone and transition zone of these kilns, providing resistance to alkali attacks, thermal cycling, and abrasion.

　　4. Petrochemical industry: In the petrochemical industry, magnesia carbon bricks are used in ethylene cracking furnaces, reformers, and other high-temperature process units. They provide resistance to thermal shock, erosion, and chemical attack from hydrocarbons and other aggressive gases.

　　5. Glass industry: Magnesia carbon bricks find application in glass melting furnaces, where they line the sidewalls, arches, and bottoms. They withstand the high temperatures and harsh chemical conditions present during glass production.

　　Magnesia carbon bricks are refractory bricks made from a mixture of magnesite and graphite, along with various additives. The exact composition can vary depending on the specific application, but a typical composition of magnesia carbon bricks may include:

　　1.Magnesia: Magnesite is the primary component of magnesia carbon bricks and typically makes up around 60-80% of the brick's weight. It provides high-temperature resistance and chemical stability.

　　2.Graphite: Graphite is added to magnesia carbon bricks to improve their thermal conductivity and reduce oxidation. It typically makes up around 10-20% of the brick's weight.

　　3.Binders: Various binders can be used to hold the magnesia and graphite together in a solid form. Common binders include phenolic resin, pitch, and sodium silicate.

　　4.Additives: Other additives may be added to magnesia carbon bricks to enhance their properties, such as antioxidants, anti-spalling agents, and metal powders.

　　Magnesia carbon brick is a type of refractory brick that is made from high-purity magnesia and graphite. It has excellent corrosion resistance, thermal shock resistance, and high-temperature performance, making it widely used in steel-making applications.

　　Here are some common physical and chemical indicators of magnesia carbon brick:

　　1.Physical Indicators:

　　Bulk density: 2.9-3.2 g/cm³

　　Apparent porosity: 2-10%

　　Crushing strength: ≥50 MPa

　　Thermal conductivity: 12-15 W/(m·K)

　　2、Chemical Indicators:

　　MgO content: ≥85%

　　Carbon content: 8-20%

　　Impurity content (SiO₂, CaO, Fe₂O₃): ≤2%

　　Thermal expansion coefficient: 0.5-1.5×10⁻⁶/°C

　　Refractoriness: ≥2000°C