The slag from power plants is a mixture of the remainder of the completely burntcoal and the partly burntcoal, which can neither be used as fuel, nor be used as raw material for cement industry.
燃煤火力发电厂炉渣是燃烧完全的灰烬与燃烧不完全的煤块组成的混合物。
2
A hot coal fell out of the fire and burnt the carpet.
一块燃烧着的煤块从火炉里掉出来把地毯烧了。
《牛津词典》
3
Banned in today's cosmetics, the cancer-causing tar residue can be found in burnt substances and foods such barbecue, coffee, cigarette smoke, and coal tar.