Why are silicon carbide refractory bricks so expensive? This is related to the preciousness of the raw materials, the use requirements and the production process. Today, the editor of Rongsheng Refractories has sorted out the composition of silicon carbide bricks and related information for everyone. Please see the detailed introduction below.
What is silicon carbide?
The silicon carbide in silicon carbide bricks refers to silicon carbide (SiC) which is made by high temperature smelting of raw materials such as quartz sand, petroleum coke (or coal coke), wood chips (salt is needed to produce green silicon carbide) through a resistance furnace. Silicon carbide has stable chemical properties, high thermal conductivity, low thermal expansion coefficient, and good wear resistance. In addition to being used as abrasives, silicon carbide is also used to make advanced refractory materials.
Silicon carbide is a kind of carbide accidentally discovered in the laboratory by Acheson (American) during the electrofusion diamond experiment in 1891. At that time, it was mistaken for a mixture of diamonds, so it was named emery. In 1893, Acheson A method of industrial smelting of silicon carbide has been researched out, which is known as the Acheson furnace, which has been used until now. The resistance furnace with carbonaceous material as the core body is energized to heat the mixture of quartz SIO2 and carbon to produce silicon carbide.
What are the composition of silicon carbide bricks?
Silicon carbide brick is a kind of silicon carbide material formed by mixing high-purity silicon carbide coarse powder and high-activity silicon carbide fine powder, grouting and forming, vacuum sintering at a high temperature of 2450°C to recrystallize it. SiC is covalently bonded and does not have the so-called sinterability, but relies on chemical reactions to generate new phases to achieve sintering, that is, reaction sintering.
Features
Silicon carbide bricks are wear-resistant, corrosion-resistant, thermally stable, strong, and have high thermal conductivity. They can be used for aluminum electrolytic cell linings, molten aluminum pipes and ceramic kiln furniture, large and medium-sized blast furnace lower parts, furnace waists and Furnace, aluminum refining furnace lining, zinc distillation tank lining, etc.
The characteristics and application of clay bonded silicon carbide brick
The first grade silicon carbide brick product with clay as the binder contains 87% of sic, the refractoriness can reach 1800℃, and the load softening point is 1620℃;
The main component of silicon carbide bricks, silicon carbide deoxidizer has the advantages of rapid deoxidation, early slag formation, dense reducing atmosphere, rich foam, etc. It can also effectively increase the recovery rate of elements, and also has a carbon increase effect, replacing part of the recarburizing agent. The molten iron is stable, thus reducing the cost of steelmaking;
1. The use of silicon carbide deoxidizer to react with oxygen compared to ferrosilicon powder, carbon powder, and calcium carbide can shorten the reduction time, reduce power consumption, and increase labor productivity;
2. The decomposition and oxidation of silicon carbide deoxidizer at high temperature is an exothermic process. The positive pressure in the furnace is strong, which can provide the necessary conditions for deoxidation and desulfurization and reduce the sulfur content;
3. As the reduction period is shortened, the chance of inhalation of molten steel in the later stage is reduced, the generation of impurities is reduced, and the quality of molten steel is improved;
4. Reduce the amount of quicklime and fluorite powder added, reduce costs, reduce the concentration of harmful fluorine gas and smoke and dust environmental pollution, which is conducive to the improvement of operating conditions;
5. The foamed slag is rich and active. At the same time, the foam includes arc light, which reduces the arc radiation, thereby improving the life of the furnace lining and furnace cover, and also reducing the thermal shutdown time and the consumption of auxiliary materials.
The relevant content of silicon carbide bricks is introduced here, and I hope it will be helpful to everyone. If you have any other questions, please inquire or technical exchanges.
