Slag, also known as Ground Granulated Blast-furnace Slag (GGBS), is composed of minerals floating on the surface when smelting steel. Its formation cannot be separated from water quenching, either. By drying and grinding, slag powder (or GGBS powder) can be got.
White slag powder is relatively clean while grey or blackish slag powder must be added with some cheap impurities that can be easily ground, such as fly ash, furnace clinker and lime soil.
The slag processing plant usually includes two major steps — crushing process and grinding process respectively.
After crushing, the water slag material is ground in grinding mills. There are actually a variety of distinct grinding mills, including rod and ball mills, semiautogenous mills and autogenous mills. Within the grinding mills, the minerals are ground each other and the minerals are ground by steel balls.