Rotary kiln is rotary forging kiln for short, which is one of building material equipment. It is divided into cement kiln, metallurgy and chemical kiln and lime kiln as per the different material treatment. Cement kiln is applied to carline cement clinker, which has two types,dry-type cement production kiln and wet-type cement production kiln. Metallurgy and chemical kiln is mainly used to magnetizing roast lean iron ore, oxidation roast the nickel chromium iron ore in the steel and iron plant. It is also used to roast bauxite chamotte in the refactory plant and chamotte, aluminium hydroxide in alumimium plant,crome ore in the Chemical plant. Lime kiln is use to roast active lime and soft-burned dolomite in steel plant and iron alloy plant.The cement kiln burns rawmix to produce clinker, which is then ground to make cement.