Ultrafine mills of the HGM series are equipment designed for the production of fine and ultrafine powder from non-flammable, non-explosive and fragile materials with a Mohs hardness up to 6 units, such as calcite, chalk, limestone, dolomite, kaolin, bentonite, talc, mica, magnesite, vermiculite, sepiolite, barite, gypsum, alunite, graphite, fluorite, phosphate and others.