The use of microwave radiation as an alternative energy source in mineral processing and extractive metallurgy has been studied since the initial work of Worner at the Univ. of Wollongong in 1986. Microwaves deliver heat directly to the interior of a sample, avoiding the usual slow heating mechanisms of thermal and convective heat transfer. Furthermore, the depth to which the microwaves penetrate and the amount of heat deposited at depth is dependant on the complex dielectric constant of the material which means that by careful choice of materials, a microwave heating system can deliver heat to specific chosen materials, while much reducing the heating of others, such as thermal insulation and oven walls, and thus improving efficiency. In the current study, the carbothermic reduction of a hematitic nickeliferous laterite was investigated, both by large-scale microwave oven experiments, and by measuring the complex dielectric constant (real (epsilon') and imaginary (epsilon '') permittivities) of small samples at 2.45 GHz over the temperature range 5-980 degrees C, using the cavity perturbation method. The microwave oven heating behavior of the laterite-lignite mixture was explored using a 2.45 GHz ThermWave 1.3, variable power, microwave furnace, fitted with an optical pyrometer and an infrared thermal camera. The carbothermic reduction of laterite (i.e. the reduction of hematite contained in laterite) was attempted, and the effect of heating time, power, carbon content and sample mass was studied in detail. Using twice the stoichiometric carbon content (i.e. double the amount of carbon required to fully reduce the hematite to metallic iron), about 70% reduction degree was achieved at temperatures somewhat above 900 degrees C. The use of scanning electron microscopy and Mossbauer spectroscopy gave evidence of a lack of microstructural homogeneity in the reduced samples and the presence of phases which are not stable in the same temperature ranges, indicating some thermal inhomogeneity. (C) 2012 Elsevier Ltd. All rights reserved.