عنوان مقاله [English]
The calcium removal from Jajarm bauxite ore by acid leaching in order to bauxite enrichment was investigated in this research. The results of XRD, XRF, ICP and chemical studies indicated that Diaspore (AlO(OH)) is the major mineral phase and Hematite (Fe2O3), Quartz (SiO2), Anatase (TiO2), Calcite (CaCO3) are minor phases in the sample ore. At first, calcination experiments were carried out to optimize calcination parameters. The experimental results suggested 900ºC and 60 minutes as optimizing calcination parameters; leaching tests with hydrochloric acid were performed subsequently and 90ºC, 30 min, 3M acid concentration, solid liquid ratio of 1:6, 300 rpm agitation speed and 150 - 500µm particle size as optimizing leaching parameters were obtained. Temperature and acid concentration showed strong effect on the calcium removal. In the optimum conditions removal of more than 95.45% of calcium content was achieved from basic mineral and the calcium content was decreased below 0.05% within the residue bauxite and made it desirable for refractory and abrasives industries.