REFRACTORY LINING SELECTION FOR THE REDUCTION OF ILMENITE SAND IN ROTARY KILNS AT ILUKA RESOURCES, GERALDTON, WESTERN AUSTRALIA.

摘要

Iluka Resources Pty Ltd operates a number of rotary kilns at Geraldton and Capel in Western Australia for the production of synthetic rutile employing the Becher process. This involves the calcination and subsequent reduction of mineral (ilmenite) sand, which in the case of the Geraldton operation, is supplied from the Eneabba mine located 260 km north of Perth. Historically the refractory lining chosen for the high temperature zone of rotary kilns have been based on a typical mid-alumina low cement castable installed via rotor casting. In order to improve the service performance, a greater understanding of the refractory performance was achieved through kiln inspection, conventional failure analysis and finite element modelling. A number of refractory compositions of nominally similar chemistry were characterised with emphasis on thermal expansion behaviour and Young's modulus of elasticity in addition to conventional physical properties. This was in addition to satisfying other criteria such as the ability to withstand the disintegrating effect of carbon deposition in reducing atmospheres. The consequence of this investigation has led to the "rediscovery" of a conventional castable refractory formulation, which is shown to exhibit greater tolerance to the operational practices employed. Installation trials were commenced in early 1999 and to date, the service performance has greatly improved.