Recycling. Thermal Processing Technology of Shredder Residue. Incineration.

Abstract

Shredder residue consists of many types of plastics, glasses and heavy metals. When it is landfilled, waste water which contains heavy metals is generated. Thermal processing technology should be developed in order to prevent environmental pollution and reduce its volume. Incinerating technology of shredder residue has been investigated by Nippon Mining & Metal group as a national project since November in 1996. Incineration pilot test plant was constructed by using the zinc smelting equipment which had already shut down in Nikko Mikkaichi Recycle. The incinerating capacity of the plant is 3 t/hr., and 1.5 t/hr. of shredder residue and 1.5 t /hr. of liquid waste are practically incinerated in the pilot test operation. Some operational troubles of the incineration caused by shredder residue have ocurried. Especially, the dust trouble in the off-gas treating plant was serious, However, the pilot plant has been improved, and most of the problems have been already solved.The generation of pollutants from the incineration plant has been kept as extremely low level by the off-gas treating plant and the waste water treating plant. Most of copper in shredder residue is distributed in the bottom ash, and 40% of lead and 30% of zinc are mostly distributed in the fly ash. The bottom ash and the fly ash are treated in the zinc smelting plant in order to recover zinc, lead and copper. Industrial technology of the incineration of shredder residue has been developed.

Reducing Copper in ASR by Dry Towermilling and Electrostatic Separation

“…Further analysis of other metals such as zinc, lead and aluminum in the products with the fraction of −1 mm was carried out and reported in Table 7. These metals react to chlorine contained in ASR and the chlorides might cause the problem of adhesion in the flue of exhaust gas when ASR is incinerated 5) . No variation is observed for the grade of each metal in non conductors although that in conductors slightly increases.…”