What exactly is cinder?

Cinder is a kind of widely used orchid matrix. Cinder planting orchid, some people say it is easy to use, some say it is bad, and others say that cinder contains carcinogens. After the news of "cinder carcinogenesis theory" spread, for a moment, the orchid friends who liked to raise orchids with cinder were worried and worried, and there was a tendency to "talk about the color change of cinder."

Coal is divided into anthracite and bituminous coal. Cinder is the residue and ash left after coal combustion. The cinders planted by hand include brick cinder, boiler cinder and honeycomb cinder. Cinder can be found everywhere in both factories and rural areas. Farmers in rural areas also use honeycomb cinder to improve the soil of vegetable gardens. The cinder used in the plant orchid should be selected to form a block of gray-black slag, but the powdered slag is not desirable. (Zhang Bingfu)