Canadian silica resources for glass and foundry sand production: Processing studies at CANMET

Abstract

Selected samples of silica from several provinces were evaluated by CANMET as potential sources of glass and foundry sand. The samples, which included both sandstone and quartz/quartzite analyzed between 95.68% and 99.54% SiO 2, 0.04% and 0.39% Fe 2O 3, 0.08% and 0.37% TiO 2, 0.16% and 2.51% Al 2O 3. Impurities included a variety of iron oxide and alumino-silicate minerals. Beneficiation included size reduction to grain size (about 600 μm), wet mulling, attrition scrubbing and washing to remove fines. Further removal of impurities was achieved by magnetic separation and reverse flotation of iron oxide and alumino-silicate minerals employing both anionic and cationic collectors. Flotation resulted in a substantial improvement in the quality of most samples, the quartz concentrates analysing 99.30–99.80% SiO 2, 0.02–0.05% Fe 2O 3 and 0.06–0.15% Al 2O 3. On the basis of the samples submitted, silica from all of the deposits has potential as source material for glass sand and foundry purposes. Larger, more representative samples would be required to determine the full potential of these deposits.