Mining
high-purity silica deposits
Tasmania is blessed to have unique, high-purity silica deposits. Silica flour is formed by weathering and leaching of silicified dolomite. Unlike alluvial sand, the resource has not undergone transportation which is a source of contamination.
Tasmanian silica flour requires less melt energy than ground sand or rock of other geological origin. A combination of the weathered particles having a high specific surface energy, and particles having a residual nucleus of dolomite combine to aid melting.
The impurity characteristics vary considerably between and even within separate deposits. However we have developed our own rigorous quality assurance system to ensure stable control of quality for each grade. In addition, the resource variability allows us to tailor specifications based on customers’ needs.
Mining is open cut using excavators. Oversize is screened and crushed. In preparation for mining, a block of resource is cleaned of overburden or washed-in contaminate using the excavator bucket, samples then taken to confirm target quality. Sampling and analysis is undertaken throughout the mining process to ensure the grade, and to enable each mined lot to have its own chemical impurity profile.