Mineral preconcentration using near infrared sensor-based sorting

This paper predicts qualitatively and quantitatively the near infrared activity of individual minerals in simple and complex mineral associations using mixtures of common alteration minerals found in a copper ore. It was found that spectra dominance in most cases is dependent on any or combination of mineral composition, relative proportion or concentration and/or mineral accessibility or sensitivity to near infrared radiation. The analysis of results also indicated that, in most cases, only freely occurring waste, such as clays (kaolinite and/or muscovite) and calcite, can be targeted for discrimination. In this paper, a strategy for the application of near infrared for preconcentration of copper bearing minerals like chrysocolla and malachite from coarse ore particles was proposed. Other applications also considered in this paper include preconcentration of hematite from associated clays and carbonate waste, and the determination of moisture content in kaolinitic clays.