Steel Recycling Rates and In-Use Steel Stock per Capita Across Industry Sectors in the United States 1950–2060 Based on Dynamic Material Flow Models

The recycling rate of steel across different industry sectors in the United States was calculated using statistical dynamic material flow models, covering the period from 1950 to 2060. Analysis focused on four industry sectors: construction, industrial goods, automotive, and appliances. Findings indicate that steel recycling rates are consistently high across most sectors, reaching approximately 90%. However, the construction sector presents a notable exception, with a recycling rate of only 60.5% in 2016. This lower rate stems from steel in construction applications remaining in-use significantly longer than their originally intended historical service life. For 2016, the per capita in-use steel stock in the United States was calculated as follows: 6.8 tons per capita in construction, 1.7 tons per capita in automotive applications, 1.6 tons per capita in industrial goods, and 0.5s ton per capita in consumer goods. These figures demonstrate that the United States has reached a steel saturation level of approximately 9.9 tons per capita in 2016. A comparative analysis was done for the relationship between steel consumption, in-use steel stock per capita, and real GDP per capita in the United States between 1900 and 2016. The analysis reveals that in-use steel stock per capita correlates more closely with steel consumption patterns than GDP growth does. For forecasting steel demand, in-use steel stock per capita demonstrates better alignment with steel consumption patterns than GDP per capita.