1997 Volume 83 Issue 12 Pages 850-855
Recycle of materials is expected to reduce environmental burden which accompanies the production of materials. However, the recycle may also result in concentration of tramp elements in the materials. In order to promote the recycle of materials, we have to have clear prospect for the accumulation of the tramp elements. In this study, we have collected iron scraps from various scrap yards in Japan and analyzed the concentration of such tramp elements as copper, tin and chromium. We also estimated tramp element accumulation at shredding processes. The result shows that, although Cu and Sn concentrations in the iron scraps are close to their critical levels, the tramp element accumulation at shredding processes is currently relatively small.