A Review of Biocarbon Substitutes in Electrodes and Refractories for the Metallurgical Industries

The chemical and thermophysical properties of carbon make it essentially irreplaceable for non-reductant uses in many high-temperature metallurgical processes. At present, biocarbon substitutes are not technically feasible for large-scale application in electrode and refractory materials that are such vital consumables in the steel, aluminum, and non-ferrous metal industries. Carbon electrodes of all types, including Söderberg, prebaked, and anodes/cathodes for Al, graphite electrodes, as well as carbon lining pastes are all similar in that they are comprised of a granular carbon aggregate bonded in a carbon-based binder matrix. Similarly, refractories such as MgO–C utilize both natural (mined) graphite and carbon-based binders. Replacement of fossil carbon materials with biocarbon substitutes has the potential to dramatically reduce the carbon footprints of these products. However, there are considerable materials engineering challenges that must be surmounted. The technological demands for these applications and potential for substitution with biogenic carbon are explored.