Silicon and related compounds such as ferrosilicon are rapidly gaining in importance, with increasing demand from the electronic and energy sectors and from manufacturers of a wide range of silicon-based products. Silicon is obtained by smelting silica, SiO2 which occurs as the mineral quartz, one of the most common elements found on earth.
Silica deposits are widespread in Southland and Otago and have been investigated over several decades as feedstock for various silicon-based industries as well as for roading aggregate and mounding sands. The largest silica resources are in the form of loose quartz gravel and sand, with minor deposits of quartzite.
Work to date suggests that at least some of the Southland quartz gravel and sand deposits are of grade and quality suitable for silicon and ferrosilicon manufacture. Quantities in the order of 1000 million tonnes (Mt) may be available for potential refinement and smelting and the establishment of value-added manufacturing opportunities associated with silicon wafer and photo voltaic panel manufacturing.
As well as coal, lignite and silicon, Southland has a range of minerals which are worthy of consideration for extraction or other value added opportunities.
These minerals include a range of limestone deposits in the central and western Southland areas as well as other minerals such as dunite which is commercially quarried in the Greenhills area between Invercargill and Bluff.