Introduction to the characteristics of ladle magnesia carbon bricks

1. The melting point of the graphite magnesia-carbon brick manufacturer is 3850℃±50℃, and the boiling point is 4250℃. Even if the magnesia-carbon brick is burned by an ultra-high arc, the loss of quality is very small, and the coefficient of linear expansion is also very small. The strength of graphite increases with the increase of temperature. At 2000℃, the strength of graphite doubles

2. Electrical and thermal conductivity. The conductivity of graphite is twice as high as that of ordinary non-metallic minerals. The thermal conductivity exceeds that of metal materials such as steel, iron, and lead. The thermal conductivity decreases as the temperature increases, and even at a temperature of 100 °C, graphite is a hot body. Burnt magnesia brick

3. Lubricity. The lubricity of graphite depends on the size of the graphite flakes. The larger the flakes, the smaller the friction coefficient and the better the lubricating performance.

4. Chemical stability, graphite has good chemical stability at room temperature, and is resistant to acid, alkali and solvent corrosion

5. Plasticity. Graphite is very tough and can be rolled into very thin sheets.

6. Thermal shock resistance. When graphite is used at high temperature, it can withstand severe changes in temperature without damage. When the temperature changes suddenly, the volume of graphite does not change much, and cracks will not occur.

The binder plays the role of connecting the matrix and the particles. In the actual production and use process, the matrix and the binder system are the two weak links of magnesia-carbon bricks.

The loosening effect caused by the expansion of the iron gunning material oxides to form spinel can be converted to magnesia-carbon bricks, and the synthetic co-sintering material can also be used to make magnesia-chrome bricks. Regenerative bricks, in addition, there are unburned magnesia-chrome bricks, for example, unburned magnesia-chrome bricks combined with inorganic magnesium salt solutions. The production process of unburned magnesia-chrome bricks is simple, the cost is low, and the thermal stability is good, but the high temperature strength is far less than that of fired bricks. In the late 1950s, a so-called "direct-bonded" magnesia-chrome brick was developed. The characteristics of this kind of brick are pure raw materials, high firing temperature, direct bonding between high temperature phases such as periclase and spinel, and low melting phases such as silicate are distributed in islands. Therefore, the high temperature of the brick is significantly improved. Strength and slag resistance. The production process of fired magnesia-chrome bricks is generally similar to that of magnesia bricks.

Magnesia brick is an alkaline refractory material whose content of magnesia is more than 90%, and the main crystal phase of magnesia-carbon brick for furnace conversion is periclase. Ladle magnesia-carbon bricks can generally be divided into two categories: sintered magnesia bricks (also known as fired magnesia bricks) and chemically combined magnesia bricks (also known as unburned magnesia bricks). For magnesia bricks with high purity and firing temperature, due to the direct contact of periclase grains, magnesia-chrome bricks are called directly bonded magnesia bricks; bricks made of fused magnesia as raw materials are called fused recombined magnesia bricks. Suitable for all kinds of rotary kilns, sleeve kilns, shaft kilns and other large and medium-sized lime kilns. Magnesia brick has the advantages of strong alkali erosion resistance, strong erosion resistance, good thermal stability, high compressive strength, and high softening temperature under load. The fired magnesia brick uses high-quality sintered magnesia as the main raw material and pulp as the binder. After kneading and high pressure molding, it is fired in a high temperature tunnel kiln above 1550°C. Has good thermal stability, corrosion resistance and peeling resistance. It is widely used in industrial kilns such as converters and electric arc furnaces as lining refractories.