| Abstract Scope |
Jamaica’s bauxite reserves are primarily from pocket deposits with highly variable mineral characteristics. Traditionally, local refineries process low phosphate hematite-rich bauxites however current resources tend towards higher phosphate concentrations which are primarily goethitic. Bauxites from different mining locations may have identical total phosphorus concentrations but differ widely in their caustic soluble phosphorus. This study compares bauxites with similar total phosphorus concentrations and examines the impacts of their phosphorus, alumina, iron, calcium, silica and titanium mineralogies on phosphorus extraction during low temperature digestion. Bauxite elemental concentrations were determined via XRF while mineralogy was characterized using XRD and the XDB programme. Caustic soluble phosphorus was measured using the molybdenum blue ascorbic acid spectrophotometric procedure. The phosphorus and calcium mineralogies were found to have the greatest impacts on low temperature caustic soluble phosphorus concentrations and, along with other parameters, have been used to predict caustic soluble P-concentrations for bauxites of widely differing characteristics. |