Steel for a wide range of uses, but the steel consists of a variety of organic compounds, and scrap is often stuck with pollutants such as oil and grease, do not immediately evaporated grease and oil can cause molten metal pollution. Open storage of scrap humidity, due to the inclusion of moisture and other lubricating greases and oils will cause molten metal pollution. Open storage of scrap humidity, due to the inclusion of moisture and other lubricating grease for easy vaporization of material, will burst and the rapid expansion in the furnace, nor join the furnace. To do so, for scrap recycling need to be cautious and to take reasonable measures. Many steel mills use of steel scrap preheating method, using the direct baking of scrap iron and steel, burnt to the water and oil, then into the steel furnaces. In preheating system of metals, mainly two problems to be solved: incomplete combustion of oil can produce large amounts of hydrocarbons, can cause air pollution, must try to solve as scrap on the conveyor belt sizes, thicknesses, Preheat and burn caused uneven, sometimes cannot be thoroughly cleaned of pollutants on the steel scrap.