Anthracite  coal is commonly referred to as white coal or red coal. It is the coal with the most coal. Anthracite has high fixed carbon content, low volatilization rate, high density, high hardness, high ignition point, and no smoke when burning. Black hard, metallic luster. It is not stained with grease friction, cut into seashells, flame short while burning and smoke less. No coking. Generally carbon content is above 90%, volatile content under 10%. No gelatinous layer thickness. The heat value is about 6,000-6500 KGS. Sometimes the volatile content is called semi-anthracite; Small is called anthracite.

It is used for the filtration and purification of water supply and industrial water supply. According to the form of the filter in the use of the parameters, the pavement thickness of the normal double layer filter is 300-400mm; Normal filter speed 10-14m/h, force filter speed 14-1 8m/h; The thickness of the three-layer filter is 450mm, the normal filter speed is 18-20m/h, and the filter speed is 20 ~ 25m/h. Water flushing, water vapor flushing or surface rinsing is used in the filter backwash.