carbon additive classification

1. Artificial graphite: Among the recarburizers, the best quality is artificial graphite. Artificial graphite is calcined petroleum coke, adding asphalt as a binder, and adding other auxiliary materials. After high temperature graphitization at 2500-3000℃, the ash, sulfur and gas content are greatly reduced. Artificial graphite is expensive to manufacture, so the general recarburizer is made from cutting particles when manufacturing electrodes or pulverized from waste electrical electrodes. In addition, tailings of negative electrode materials are also a good source of recarburizers. The most important indicator of artificial graphite is that the sulfur content is very low, between 0.01-0.07.

2. Petroleum coke: Calcined petroleum coke is currently a widely used recarburizer. After the raw petroleum coke is calcined at 1200-1350°C, it becomes a calcined petroleum coke that can be used as a recarburizer. The sulfur content of calcined petroleum coke is between 0.02-3%, and the calcined petroleum coke that can be used as a recarburizer is between 0.02-0.5%.

3. Natural graphite: natural graphite flake graphite and microcrystalline graphite. Microcrystalline graphite has high ash content and is generally not used as a recarburizer for cast iron; flake graphite is generally used as a recarburizer for medium carbon flake graphite

4. Coke and anthracite: When the cupola makes iron, coke is used to increase the carbon at the bottom, so the cupola uses recarburizers rarely. In the process of electric furnace steelmaking, coke or anthracite is added as a recarburizer, and anthracite is more commonly used as a recarburizer. Due to the relatively high ash and volatile content of the two, they are rarely used as recarburizers for smelting cast iron in induction furnaces.