Electrolysis of Iron Ores: Most Efficient Technologies for Greenhouse Emissions Abatement

Abstract

Electrolysis of iron ore has not been developed in the past because of the energetic balance and energy expenses. In addition, until now, its application in iron production has been hindered due to the difficulty in finding a suitable anode material capable of weathering the challenging conditions. The recent development of this process is motivated by the production of iron metal from an iron oxide containing electrolyte as a carbon neutral approach to replace current pyrometallurgical processes that result in copious amounts of greenhouse gas emissions. Iron ore electrolysis, as well as hydrogen direct reduction, has been recognized as the preferred future steelmaking technology across different perspectives. In the present chapter, the most innovative trends in electrolysis of iron ore such as electrowinning and molten oxide electrolysis are described. Since electrolysis produces no CO2, it could theoretically be zero-carbon, but only if the electricity needed to power, the process is produced without generating CO2 emissions. The energy consumption is dependent on the cell configuration, the chemistry of the electrolyte, and the process temperature. Several engineering problems still need to be solved before electrolysis becomes economically viable. This includes the development of a cheap, carbon-free inert anode that is resistant to the corrosive conditions in molten oxide electrolysis. Molten oxide electrolysis (MOE) has been identified by the American Iron and Steel Institute (AISI) as one of four possible breakthrough technologies to alleviate the environmental impact of iron and steel production.