The Impact of Microwave Pre-Treatment on the Liberation of Nb/Ta Minerals from a Tin Oxide Ore

Abstract

Liberation of Nb/Ta minerals from Cassiterite ore during comminution is difficult. Microwave pre-treatment of cassiterite ore using batch multiple mode microwave was done. The ore was characterized and the effects of various parameters affecting the liberation of Nb/Ta minerals were investigated. It was found that the ore contains 76. 1%wt of SnO2 and traces of Nb2O5 (0.62% wt) and Ta2O5 (0.81% wt). The major phases in the cassiterite ore after pre-treatment were Pyrochlore, Cassiterite, Sillimanite, Ferrotapiolite, Niobium Tantalum, Niobium Titanium, Iron Tin, Niobium Tin, Iron Tantalum and Niobium tin silicide. The ore displayed a significant liberation of the Nb and Ta minerals at 100% irradiation and the high temperature of 540 C was achieved. Significant changes were observed from the SEM/EDS and the Mapping of the distribution of the Nb/Ta minerals showed that there was an improvement in the liberation of these minerals. It is concluded that the use of microwaves brings changes in the matrix pattern of the cassiterite ore, favouring the liberation of microwave susceptible minerals phases.