The company has received several inquiries from overseas. Nippon Steel researchers plan to construct a test plant in Kitakyushu that can reduce dust from shredders into slag and iron. About 1.3 million tons of motor vehicles, refrigerators and other electrical appliances, and electronic equipment end up in scrap yards in Japan every year, Ogawa says. The vertical-shaft melting furnace performs combustion, gasification, and melting. It has no interior moving parts, which makes maintenance easy, Ogawa says.
Exhaust heat is used for power generation and other purposes.
Refuse, coke, and limestone are fed through the top of the furnace. Limestone neutralizes hydrogen chloride, sulfur oxide, and other harmful elements in gases that generate during thermal decomposition in the furnace. It also helps maintain an adequate viscosity of the melt. As the material is exposed to high heat in the absence of oxygen, its organic components gasify into combustible gases containing monoxide, hydrogen, and methane. Instead of burning them at the same time, we let organic elements gasify first.