Cost-combined life cycle assessment of ferronickel production

Abstract

PURPOSE: Ferronickel is irreplaceable in modern infrastructure construction because of its use in stainless steel production. This study explored the cost-combined environmental impacts of ferronickel production in China which is the largest producer and consumer of ferronickel in the world. METHODS: Life cycle impact assessment was combined with life cycle costing analysis to assess the environmental and economic performance of ferronickel production in China. Both internal cost (e.g., raw materials, energy, transport, infrastructure, tax, and labor) and external cost (i.e., human health, ecosystem quality, and environmental emission) were considered. RESULTS AND DISCUSSION: The environmental burden of ferronickel production in this study was mainly attributed to the damage on resources and human health as endpoints caused by indirect processes, such as electricity supply, transportation, coke production, lateritic nickel ore acquisition, and coal mining. Carbon dioxide, mercury, particulates, methane, sulfur dioxide, nitrogen oxides, coal, and nickel ores were the substances pivotal for optimizing environmental performance. The total economic cost was 2734.8 $/t, of which 2333.3 $/t was internal cost and 401.5 $/t was external cost. Lateritic nickel ore, electricity, human health cost, and transport contributed 44.9%, 20.6%, 14.2%, and 4.8% to the total economic cost, respectively. The remaining economic burden was mainly divided to coke, coal, argon, labor, equipment, and tax. CONCLUSIONS: A win-win case for the environment and economy can be achieved by optimizing electricity and lateritic nickel ore quality, including its transport. Application of other power types (e.g., hydro, wind, and solar electricity) as a substitute for thermal power can also reduce environmental impacts considerably. Sites with high steel yield, low thermal power ratio, and high port proximity, such as Fujian Province, are the primary choices for ferronickel production. Finally, although the economic benefits of coke and coal are minimal, their efficiency in environmental improvement is crucial.