Substance Flow Analysis And Its Application In Steel Industry

Substance flow analysis (SFA) is an effective tool for studying the industrial metabolism of specific substances (e.g. aluminum, copper) or group of substances(e.g. heavy metals) on a certain spatial scale, for example, on the scale of a country, a region or a firm. The purpose of SFA is looking for the potentials and measures of resource conservation and environment protection, and encouraging industrial system to meet the requirement of sustainable development. Thus, the proposals offered in SFA can be of assistance to decision makers.Static SFA (s-SFA) and dynamic SFA (d-SFA) are two methods of SFA. Usually, the west countries prefer the s-SFA. But we adopt the d-SFA in this paper. The d-SFA, developed by prof Lu Zhongwu, is based on the substance flow diagram of a product life cycle. Its notable characteristic is that the inventory of substance flow begins with the starting point of a product life cycle, resource acquisition, and ends with the recovery of obsolete products. Thus, product life cycles are connected one by one.The main difficulty of d-SFA is the determination of the average life-span of products. This paper gives two methods to determine average life-span of steel products: weighted average method (WAM) and graphic shifting method (GSM) . The average life-span of steel products is 20-22 years in China in 1950-1987 calculated by the WAM (the steel products are divided into 12 sorts by category) . And the average life-span of steel products is 22 years in 2002 (the steel products are divided into 42 sections by use) . The average life-span of steel products in USA determined by GSM is 24 years in this paper.Based on the iron-flow diagram of steel product life cycle, the inventory of iron flow of China in 2001, including the old scrap generated from steel products 22 years ago, was made. Two diagrams of iron-flow in 2001 were drawn and analyzed according to s-SFA and d-SFA methods, respectively. The iron resource efficiencies were compared between China and other chief steel-producing countries (such as USA, Japan, Germany and Russia, etc.). Some idiographic ways to improve the iron resource efficiency for China, whose steel output is rapidly increasing, were puts forward.After intensive research and analysis of the status of scrap resources, the amount of domestic and overseas steel scraps were estimated. The amount of scrap resources and the EAF share of steel production for China in 2010-2020 were forecasted. The results are: China will be the largest consumer of steel scraps in the world after 2010, a huge steel scrap industry will, probably, appear in China. Some strategical suggestions for the development of steel scrap industry in China were mentioned, which will be...