After a brief summary of the history of iron making we review aspects of the current coal-based Hot Blast Furnace technology ( BF ) before focusing upon the latest research in Hydrogen Direct Reduction Furnaces ( H2DRF ) and Molten Oxide Electrolysis ( MOE ).For those unfamiliar with the science of iron smelting there are introductory chapters and appendices which adumbrate basic physics, chemistry and thermodynamics, and the principles of electrolysis illustrated by aluminum smelting.We conclude by looking at contexts in which new smelting technology may be viable.Profusely illustrated with plots, photographs and diagrams. Full algebraic elaborations and academic references. Six-hundred term index.