coal, its main raw material is unique high quality anthracite, with characteristic of low ash and low sulfur.Gas Calcined Anthracite Coal, Carbon additive has two main uses, namely as the fuel and additive. When being used as the carbon additive of steel-smelting, and casting. Besides, it is used extensively in water filtration and in water treatment because of its excellent filtration properties. Anthracite coal is a top quality coal that consists of hard, durable coal particles that come in various sizes. Anthracite is used along with silica sand (dual media system) or with silica sand and filter rock (mixed media system) or by itself (mono media system).