High-Grade Silica Sands in The Eastern Murray Basin NSW

Abstract

Investigations in 1979 defined a sand resource at Wah Wah with three potential processing options to yield sand suitable for colourless glass making. In December 2016, further drilling was completed to infill some of the previously drilled area and extend into new areas. From this drilling, coloured and white sand resources have been defined, overlain by a clay unit. The sand has generally been considered to have a fluvial origin, but recent work suggests that the white sands may have a beach origin. White sand is defined by the 0.050% Fe2O3 contour and this resource coincides generally with higher yield, mostly underlying 6m to 8m of clay - the thinner overburden area. Estimated resources are 15 million tonnes of white sand with 0.035% Fe2O3 and 0.20% Al2O3 at a yield of 58% for 8.7 million tonnes of sand suitable for colourless glass making. Sand not suited to glass making can be used for other products. These resources are Indicated Resources for reporting under the JORC Code 2012. They are defined by drilling and testing, and found to be suited for glass and other uses. From the investigations, a number of processing techniques can be employed with the final decision dependant on user requirements. However, the 2016 work demonstrated that an attrition-gravity process will be suitable for colourless glass sand, and cheaper than the other options considered in 1979. Based on results, the sand appears to be suitable for other products, including filter media, various construction uses, and other applications depending on markets. Compared to the resource defined in 1979 this deposit is now expected to be suited to: - Selective extraction, - Reduced focus on a single market, - By-products to increase overall yield, - Lower cost processing for the higher value products, - Certainty that there is sufficient resource to meet longer term needs for a range of products.