KTH Steel Scrap Model – Iron and Steel Flow in the Swedish Society 1889-2010

摘要

KTH Steel Scrap Model is a combined mass flow and mass balance model that calculates external scrap consumption, Swedish scrap, internal scrap and net flow of steel into the Swedish society. This paper presents the KTH steel scrap model, its input data and results. External scrap consumption is calculated based on mass balance analysis for different years and applied on production figures from 1889-2010 with additional estimations and assumptions. The external scrap usage ratio is defined as the external scrap compared to the crude steel production by the following scrap consuming processes; Martin converter, Electric arc furnace, oxygen blowing processes and foundries. Swedish collected steel scrap, internal scrap and net flow of steel into the Swedish society has also been calculated and compared to statistically obtained data. Model output on external steel scrap consumption in Sweden was compared to an earlier analysis done by Jernkontoret for the timeline 1980-2003. The results show that mass balance calculations are volume wise corresponding to consumption figures based on trade statistics. In addition the difference in trend is assumed to be mainly due to stocking effect. Furthermore it is shown that mass balance and mass flow models could be used as a tool to calculate apparent scrap consumption based on crude steel production figures by process type.