摘要
Material flow analysis is an analysis of the flow of a material into and out of a particular region. The flow analysis also includes estimation of energy expended and of environmental emissions at each stage of the material life cycle, i.e. from extraction, processing, consumption and recycling to disposal. This analysis informs resource policy, energy planning, environmental and waste management. This paper reports on a historical material flow analysis of the world iron ore and steel industry in which the material flow of iron ore and of crude steel products are quantified for the period from 1950 to 2005. On the basis of this analysis, the future production of iron and steel for the world is estimated. The historical analysis shows that the world iron ore production increased from 274 million tons (Mt) in 1950 to 1554 Mt in 2005, whereas the steel production increased from 207 to 1259 Mt. In addition, it is found that at the current level of production the world's identified iron ore reserves containing 230 billion tons of iron would last for nearly 50 years. Global CO2 emissions from steel production from the different manufacturing routes are estimated to be 3169 Mt from approximately 1781 Mt of steel production by 2020, whereas the specific energy consumption is estimated to be 14.43 GJ/tcs.The analysis of historical production trends of iron ore and crude steel for the major iron ore and steel producing countries indicates that, incidentally, the major iron ore producing countries are not the major steel producing countries and vice-versa. For example, in 2005, Brazil's iron ore production was 322 Mt whereas its steel production was approximately 10 % of its iron ore production. For the same period, Japan's steel production was 124 Mt though; it had no domestic iron ore production. The world flows of iron ore and steel clearly indicate that the weak end of the iron and steel industry is the time, cost and environmental emissions associated with the sea borne transport of materials. Further, a substance flow model for the year 2006 indicating the net flows of iron ore, crude and finished steel products across the continents demonstrates that these flows of materials is not environmentally sustainable, and the iron and steel sector could do a lot to contribute to sustainable development.