Australian Silica Quartz Group Ltd (ASQ) has focused on the acquisition, exploration and development of bauxite mineral deposits in the Darling Range, Western Australia, with the aim of capitalising on developing markets in China.
The key to commercial success in the mining sector is long-term, sustainable demand for the commodity. ASQ is well positioned to take advantage of favourable market conditions:
To support these fundamentals, ASQ is focused on the commercial development of its bauxite resources to supply the direct shipment ore (DSO) export market to international customers.
Aluminium prices have been depressed by a persistent global oversupply and high stocks of aluminium. However, strong aluminium demand, rising energy costs (around 40% of production costs) and raw material costs (such as carbon and alumina) are forecast to lift the aluminium price in the medium term.
Growth in aluminium demand is expected to be driven mainly by China. Constraints imposed by the Indonesian government on the export of unprocessed bauxite are forecast to increase bauxite prices, resulting in higher alumina and aluminium prices.
Aluminium is now the second most used metal in the world after steel. Its unique combination of properties makes it suitable for many applications, especially in the automotive industry, due to its high strength-to-weight ratio. It is also unique in being 100% recyclable, with nearly three-quarters of all aluminium ever produced still in use today.
Bauxite is ore from which aluminium can be extracted. Most bauxite, including Australian bauxite, is lateritic, formed by intense weathering of various rock formations. The alumina in lateritic bauxite is mainly in the form of gibbsite, an aluminium oxide trihydrate. Other bauxites contain higher levels of boehmite, known as monohydrates, and require significantly higher levels of energy to process.
The three structural forms of bauxite are gibbsite, boehmite and diaspore. Gibbsite is a true aluminium hydroxide; boehmite and diaspore are both aluminium-oxide-hydroxides.
Extreme lateritic weathering in the Darling Range has resulted in the formation of the trihydrate bauxite Al(OH)₃, gibbsite.
In an alumina refinery, bauxite is digested using the Bayer Process, which involves washing the ore with a pressurised, hot solution of sodium hydroxide (caustic soda). Refineries using Darling Range bauxite operate with lower production costs for two reasons:
Process requirements for the extraction of alumina
Bauxite from Darling Range
Gibbsite
Boehmite
Diaspore
Temperature °C
145°C
250°C
Higher (1)
Pressure psi
75 psi
550 psi
(1) Diaspore bauxite is extracted using the Bayer Sinter process; temperature and pressure requirements are materially higher than for gibbsite and boehmite digestion.
ASQ remains committed to the identification and development of high-quality bauxite resources throughout the Darling Range, Western Australia – a proven bauxite and alumina producing region. Resources display low reactive silica and very high available-alumina-to-reactive-silica ratios, making them extremely attractive for refining.
The Darling Range remains the largest alumina producing region in the world due to two key features. First, the majority of alumina present is the tri-hydrate mineral gibbsite, which is readily extracted at lower temperatures than the mono-hydrate mineral boehmite found in other bauxite regions, significantly reducing refining costs. Second, the bauxite in the Darling Range typically occurs at or close to surface, allowing low-cost, efficient open-pit mining.
ASQ and its partners' resources are located on large private landholdings (cleared farmland), with close access to road and rail infrastructure. The bauxite is shallow, typically with less than two metres of loose overburden, requiring limited pre-stripping. These attributes support the potential for long-life, low-cost bauxite production. In summary, Darling Range bauxite is:
The Darling Range Project is comprised of three deposits, each held through ASQ's joint venture with HD Mining & Investments. Further detail on each deposit, and on the resource estimates underpinning them, is available via the links below:
Competent Persons Statement & Original Assessments
