Industrial minerals, namely, alumina, andalusite, attapulgite, ball clay, barium sulphate, bauxite, bentonite, borates, calcium carbonate, calcined kaolin, calcium silicate, carbon black, carbon, carbonate, ceramic powders, chromium corundum, clay, cordierite, diatomaceous earth, diatomite, dolomite, feldspar, ferriferous sandstone, graphite, kaolin, lime, magnesia, magnesium oxide, marble, metakaolin, mica, montmorillonite, mullite, pegmatite, perlite, refractory clays, sialon, sialon, silic...