Development of Shaft-type Scrap Melting Process Characterized by Massive Coal and Plastics Injection
A shaft-type scrap melting process in which a large amount of pulverized coal and waste plastics are used as a heat source has been newly proposed. To confirm the characteristics of this process, an experimental furnace with 2 m<sup>3</sup> inner volume was continuously operated. The main results are as follows:<br> (1) Pulverized coal and plastics could be effectively used to melt steel scrap, and a newly designed oxygen burner enabled massive injection of such fuels. <br>(2) Combustion efficiency of coarse plastics was higher than pulverized coal due to the its accumulation effect in the raceway. Hydrogen chloride during polyvinylchloride injection was about 5 ppm in the gas cleaning system.<br> (3) Top charge of plastics generated tar derived from decomposition of plastics in the shaft with low temperature.<br> (4) Zinc charged with scrap was carried over as zinc oxide with dust in the upward gas, and no adhesion was recognized within the furnace.<br> (5) Maximum productivity was estimated to be 14 t/dm<sup>3</sup> from the viewpoints of flooding and melting rate of scrap. <br>On the basis of the above operation results of the experimental furnace, the operating condition of the commercial process was investigated.
- ISIJ international
ISIJ international 37(10), 977-985, 1997-10-15
The Iron and Steel Institute of Japan