Graphite Carbon Block
Graphite carbon bricks are dark gray and shiny. A well-fired carbon brick will not stain your hands, and it will have a crisp sound when hit with a small hammer. High refractoriness and load softening temperature, good thermal shock resistance, not wetted by molten slag, molten iron, etc., almost not corroded by all acid-base salts and organic chemicals, good slag resistance, high temperature stability, high mechanical strength, Good wear resistance, good electrical and thermal conductivity.
Graphite is an allotrope of carbon. It is a gray-black, opaque solid. It has stable chemical properties, corrosion resistance, and is not easy to react with chemicals such as acids and alkalis.
It can be used as an anti-wear agent and lubricant. High-purity graphite is used as a neutron moderator in atomic reactors. It can also be used to make crucibles, electrodes, brushes, dry batteries, graphite fibers, heat exchangers, coolers, electric arc furnaces, Arc lights, pencil refills, etc.
Characteristics of Graphite Carbon Block.
- Graphite Block
- Very high refractoriness
- High compressive strength
- High load softening point
- Good slag resistance
- High abrasion resistance
- Small expansion coefficient
- Good thermal conductivity
Production of graphite bricks
Graphite carbon block production process is more complicated. It selects low-ash and high-quality petroleum coke and pitch coke as main materials adds high thermal conductivity micro powder additives and is processed and refined after high-pressure molding, multiple impregnation, and roasting.
Graphite brick is a kind of artificial graphite, which is formed by molding, baking, and mechanical processing using asphalt as a binder.
High-quality graphite blocks need to be tested for each product, and the product weight is just right, in order to produce high-quality graphite blocks.
- Choose 70 to 90 parts of anthracite, choose 5 to 10 parts of a catalyst element or its compound, and 10 to 20 parts of silica;
- Crush and mix the components uniformly, put them into the press, and increase the temperature and pressure;
- Raise the temperature to 400℃～1000℃, the pressure 10～50KPa;
- Keep the temperature for 10-40 minutes; this method directly uses coal to produce artificial graphite, thereby producing graphite blocks. The process is simple and easy to implement, the energy-saving benefit is outstanding, the specific gravity of the product is slightly lighter, the particle size is 0.05-1mm, the performance is not inferior, and the lubricating performance is good.
Application of graphite carbon block
- Graphite carbon block as a conductive material: used in the electrical industry to make electrodes, brushes, carbon rods, carbon tubes, positive mercury positive currents, graphite gaskets, telephone parts, TV picture tube coatings, etc.
- Graphite block as a refractory material: Graphite and graphite block have the characteristics of high temperature resistance and high strength. It is mainly used to make graphite crucibles in the metallurgical industry. In steelmaking, graphite is usually used as a protective agent for steel ingots and metallurgical furnace linings.
- Graphite blocks are used for casting, sand turning, compression molding, and pyrometallurgical materials: Because graphite has a small thermal expansion coefficient and can withstand rapid changes, it can be used as a mold for glassware. After using graphite, ferrous metals can obtain accurate castings The size and smooth surface, high output, can be used without processing or a small amount of processing, thereby saving a lot of metal.
- Graphite block as a wear-resistant lubricating material: Graphite is usually used as a lubricant in the machinery industry. Lubricating oil usually cannot be used under high-speed, high-temperature, and high-pressure conditions, while graphite wear-resistant materials can be used without lubricants. The sliding speed works at 2000°C.
Graphite carbon bricks are not only widely used in the metallurgical industry, but also in aluminum electrolytic cells. In addition, it is widely used in pickling tanks and electroplating tanks in the electroplating industry, dissolving tanks in the paper industry, reaction tanks and storage tanks in the chemical industry, autoclaves in the petrochemical industry, ferroalloy industrial furnaces (or equipment linings), acid solutions , Lye tank lining and pipeline, and smelting non-ferrous metals (such as aluminum, lead, tin, etc.) furnace lining.
Due to the nature of carbon bricks, it is widely used in masonry blast furnace bottoms, hearths, submerged arc furnaces, and electric arc furnaces. In recent years, the scope of use has continued to expand, and carbon bricks have also begun to be used in the hearth and lower part of the furnace body. It can increase the continuous operation time of the blast furnace and prolong the service life.
The performance of refractory materials for blast furnace hearth is one of the key factors affecting the life of blast furnace. In the development of refractory materials for blast furnace hearths, one is to improve the performance and structure of carbon bricks, using high thermal conductivity, high purity, and microporous hot-pressed carbon bricks to overcome alkali corrosion, carbon deposition, molten iron penetration and other factors. Damage to the hearth. The second is to use new hearth materials to reduce heat loss, move the 800℃ isothermal layer that easily causes the embrittlement of carbon bricks to the ceramic cup masonry layer, and eliminate the tap hole caused by the increase of molten iron temperature and molten iron flow Premature destruction of the area, thereby increasing the life of the hearth.
Graphite carbon block is used for cooling method furnace lining structure
For application such as Chrome, Manganese, Magnesium, Nickel and Ferroalloy, we recommend our cooling concept lining structure (shown in the illustration below.) The structure applies highalumina brick in the upper sidewall due to lower temperature in this area; carbon blocks and graphite blocks are used for the sidewall area and the furnace bottom; The outer surface of the lining uses water spray cooling method; the Ibeam support underneath the furnace bottom allows for boiler exhaust.
Our cooling concept lining structure offers our customer the following advantages:
- Unique materials are utilized based on the needs of different areas of the furnace.
- The use of carbon block highly reduces the chemical erosion.
- The beveled shape of the carbon block prevents the bottom block from floating during operation and increases furnace strength.
- The highly thermally conductive graphite blocks lead to better cooling and protect the furnace bottom from attack by molten metal.
Graphite carbon bricks used in insulation method furnace lining structure
For application such as Ferro-silicon, industrial Silicon and Carbide, we recommend our insulation concept lining structure (shown in the illustration below). In this structure, the working layer utilizes carbon material, the permanent layer uses high-alumina or clay brick, and under the bottom and the outside uses insulation materials. The advantages of this structure include:
- The working layer can be semi-graphite block or self-baking carbon block. Both material have been proved to have good erosion resistance and good overall structure strength.
- The high-alumina and clay brick in the permanent layer is oxidation-resistant and erosion resistant.
- Product such as Carbide, Ferro-silicon, has higher melting point. The insulation layer reduces the thermal loss, increases the temperature of the molten metal and reduces the workload on the exhaust system.
- Overall this structure is able to provide higher temperature in the furnace working area and also prevent furnace bottom infiltration.