Dynamic material flow analysis of nickel and chromium associated with steel materials by using matrace

A stable supply of alloy elements is essential for steel production, and strategic management of alloy elements is important not only for the steel industry, but for every manufacturing industry However, in the current recycling system, steel scrap is mainly used as a source of iron. When scrap contains large amounts of alloy elements, they were regarded simply as impurities and dissipated Material flow analyses are useful tools for investigating material cycles and reveal important information about the structural problems including dissipation or inefficient usage of target material In this study, dynamic material flow analysis of alloy elements associated with steel materials, especially Ni and Cr was conducted using MaTrace model. The aim of the study was to evaluate the dissipation of Ni and Cr in Japan and the potential to reduce dissipation of Ni and Cr. We determined that 45.7% of Ni, and 81.0% of Cr is dissipated into physical losses and that 14.3% of Ni and 9% of Cr is lost as quality loss over 100 years The main causes of the dissipation are the low recovery rate of scrap from end of life products for Ni, the low yield of refining processes for Cr and the low horizontal recycling rate of special steel excluding Ni-type stainless steel for both elements.