Energy expenditures associated with the production and recycle of metals

摘要: Since the presently used resources of our structural metals are being depleted, equivalent coal energy requirements associated with production Mg, Al, Fe, Cu, and Ti for varying grades ore deposits have been evaluated. Future Mg Fe will remain essentially constant at 91,000 kWh/ton 3600 kWh/ton, respectively. Use poorer-grade bauxite ores not significantly change Al (approximately 55,000 kWh/ton); however, eventual use clays anorthosite increase consumption by more than 35 percent. The Cu 13,530 126,300 both limited resources, expenditures considerably as poorer grade must be used. Recycle from scrap metal requires 1560 39,000 respectively, which is lower that required to process their virgin ores. Sulfuric acid, gold, silver, selenium, tellurium principal by-products copper ores, while zirconium pig iron can recovered titanium deposits. recovery these also (auth)