The recycling process allows Keihin Works to increase the use of plastic, NKK executives say. The only hurdles are to widen the collection network of waste plastic from nearby plants and to increase the space available at the steelworks for accepting and storing the bulky shipments. NKK's blast furnaces each use up to 1.5 million tons of coking coal a year. The remaining 60 percent is needed to allow adequate air permeability of the feedstock inside the blast furnace. On this basis, NKK's four blast furnaces could melt up to 2.4 million tons of recycled plastic a year.
Plastic is made of carbon and hydrogen, while iron ore consists of iron and oxygen.
The thermal efficiency of plastic fuel is high at more than 80 percent, NKK says. This helps save energy and resources. The recycling process also reduces the generation of carbon dioxide. Japanese manufacturers of plastic and plastic products are under growing pressure to commercialize plastic-recycling technologies in the next two years. Japan's law for recycling containers and packaging goes into effect in April 2000.