New Developments of the NKK's Environmental and Recycling Technologies for the Municipal Wastes

Abstract

NKK has started operation of following pilot plants at NKK Environment R&D Center located in NKK Tsurumi Works, Yokohama, Japan in September, 1996. These plants represent NKK's response to the need from the society for recycle of various wastes so that such imminent problems are solved as limitation of landfill sites, rapid increase of municipal wastes and air-contamination with dioxins. The Center consists of the following plants.
1. the slag resistance electric furnace for melting ash from municipal waste incinerator turns ash into slag to be used in road construction and so on, while stabilizing heavy metals originally contained in the ash,
2. the direct waste melting furnace burns combustibles and non-combustibles with the help of coke, while melting the residue into slag, all in one furnace,
3. the waste-to-solid fuel (RDF) processing facility enables the waste to be used as fuel at cement kilns and power generation plants, so as to avoid the Dioxins problems in small scale incinerators, and
4. the waste sorting/recovery system sorts out glass bottles, cans and plastic containers respectively for re-use, consisting of the original air-assisted separator, color-sorter for glass bottles and other components.
In addition, NKK has also been operating the facility for waste plastics recycling in a blast furnace at NKK Keihin steal Works since October, 1996, injecting industrial waste plastics into the blast furnace as raw material. Now expectations are high for the facility in the area of processing waste container and package plastics.
In this report, these plants are introduced in detail, as well as NKK's research and development in the waste recycling technologies.