Impact of Jamaican bauxite mineralogy on plant operations

Abstract

Over the period 2003 to 2006 the bauxite feed to the Kirkvine refinery has undergone a dramatic change in composition with severe impact on plant performance. Surprisingly, the change in composition is not directly evident from the XRF analysis of the major elements, which showed that the total Al 2O3, Fe2O3 and LOI contents of the bauxite remained largely unchanged. A more detailed examination however, shows a remarkable change in Al2O3 distribution over the various minerals, indicative of a substantial change in bauxite mineralogy. Over the same period significant changes in plant behaviour were experienced with respect to, notably alumina recovery, mud settling and liquor chemistry.