Clinker
Clinker is the essential ingredient of Portland cement. Mineral Iran Trading Co. is specialized in exporting clinker.
Portland cement clinker is a dark grey nodular material made by где находятся Гагры heating ground limestone and clay at a temperature of about 1400 C-1500 C. The nodules are ground up to a fine powder to produce cement, with a small amount of gypsum added to control the setting properties.