The performance of prototype magnetic resonance sensors suited to mineral measurement in conveyor, slurry or portable applications is described. The sensors can be positioned around conveyors and modified slurry pipes, providing deep penetration of the sensing field, relative insensitivity to ore surface conditions and high mineral discrimination. Measurements on slurry, concentrates and ores sourced from mine operations are presented for two applications. Firstly, the quantitative measurement of chalcopyrite in slurry was demonstrated in laboratory measurements. In a calibration test, a standard error of 0.1 wt per cent and detection limit of 0.3 wt per cent was obtained._x000D_
Secondly, results were obtained for the discrimination of iron ore texture._x000D_
Signals were readily observed using measurement integration times of seconds to several minutes, depending on ore material. The results demonstrate the feasibility of online quantitative analysis of selected minerals in processing applications using magnetic resonance.