Common sense of magnesia carbon brick manufacturers

Magnesia-aluminum-carbon bricks PN series aluminum-magnesium-carbon bricks use special grade bauxite or corundum as aggregates, and emphasize on strengthening the matrix, using phenolic resin as the binder, and machine compression molding. It has the characteristics of corrosion resistance, peeling resistance, high strength, etc., suitable for On the bottom and wall of the ladle. Magnesia carbon brick price

PN series magnesia-aluminum-carbon bricks are based on aluminum-magnesium-carbon bricks. The process and technology are adjusted to enhance the corrosion resistance and peeling resistance of the material. It is suitable for the bottom and wall of the ladle, and can significantly improve the use of the ladle. life. The application of carbon in refractory materials has been widely used in the current metallurgical industry. In the past, in order to adapt to the development of new metallurgical processes and refractory materials technology, many new products have been developed. Experts in refractory materials have long learned about the excellent properties of magnesia-aluminum-carbon bricks that different forms of carbon exhibit in refractory materials. In refractory oxides, carbon can reduce the wettability of slag, molten steel and refractory materials, increase their thermal conductivity, and reduce their expansion, so that refractories have excellent thermal shock resistance. In addition, carbon has high thermal stability, and its sublimation temperature is about 4000°C. Under the pressure of 110~140bar, the three-phase point (solid/liquid/gas) of carbon in the phase diagram is close to 4020℃. Therefore, when the pressure is lower than 110bar, the carbon sublimates without melting. Because carbon oxidizes at high temperatures, the above research results can only be applied under specific conditions.

At present, the most important application areas of carbon-containing refractories are:

1. Working lining of converter, electric furnace and ladle

2. Crucible for smelting metal

3. Key components for continuous casting

4. Refractory materials for blast furnace ironmaking

5. By adding carbon, a variety of refractory bricks can be produced, especially magnesia-carbon advanced alkaline refractory materials.

There are many ways to add carbon to refractory materials:

1. Tar pitch or synthetic resin impregnated magnesia aluminum carbon brick

The open porosity of sintered oxide refractories is about 12%, and most of these pores can be filled with tar pitch or resin. Due to the relatively low density of volatile matter, the residual carbon rate of these products is about 2% to 3%. Using special grade bauxite clinker, fused magnesia, phenolic resin and high-purity graphite as the main raw materials, with various additives, the aluminum-magnesium-carbon bricks are used in the 80-ton converter ladle of Xuangang Steelmaking Plant and have achieved good results. , To meet the requirements of production. 1 Wet gunning is to mix refractory aggregates, binders, additives and water to form a slurry with a certain consistency, and then spray the slurry to the gunning machine with compressed air magnesia-aluminum-carbon bricks. A method on the surface. Its characteristics are simple operation, high adhesion rate and rapid sintering. However, due to the high water content and finer grain size, the shrinkage is also greater. At the same time, because the gunning layer is thinner, the durability is not very good.

2 Semi-dry gunning is a method in which refractory aggregates, binders, additives, etc. are mixed with water through the water ring holes on the spray gun and sprayed onto the gunning surface by compressed air. The dosage can be adjusted at any time according to the spraying situation, and generally fluctuates between 10-20%, which is much lower than that of wet spraying. Therefore, the gunning layer has a large volume density, less shrinkage, and a thicker gunning layer can be obtained. It has better durability, but the rebound amount is slightly higher than that of the wet method. This gunning method is more commonly used.

3 Flame gunning is to use compressed oxygen to transport the mixture of refractory aggregate, flux or heating agent to the nozzle, mix it with high calorific value fuel and burn it, and instantly heat the surface of the magnesia-aluminum-carbon brick fire-resistant aggregate particles to melt or half. Molten state, and then spray adhered to the repair method of the furnace lining. The gunning layer obtained by this construction method has a compact structure, high strength, strong erosion resistance, erosion resistance, and durability. But the flame gunning device is expensive, the technology is complicated, and the construction consumes a lot of energy