Chromite Sand Chrome Ore Price Grit/grain/sand Foundry chromite sand for foundry use as a highly fireproof sharpener for moulds and cores. Originally from South Africa. The sand is produced by crushing chrome ore and its washing in spiral concentrators, subsequent drying, dust cleaning, screening and sorting as per grain size. Chemical composition Cr2O3 46.0%min SiO2 1.0%max FeO 26.5%max CaO 0.3%max MgO 10.0%max Al2O3 15.5%max P 0.003%max S 0.003%max Cr/Fe 1.55/1