More than 80% of nickel production is used in alloys. When alloyed with other elements, nickel imparts toughness, strength, resistance to corrosion and various electrical, magnetic and heat resistant properties. About 65% of world nickel output is consumed in the manufacture of stainless steel, which is used widely in the chemical industry, motor vehicles, the construction industry and in consumer products such as sinks, cooking utensils, cutlery and white-goods.
Australia's Economic Demonstrated Resources (EDR) of nickel increased by 7.3% from 17.7 million tonnes (Mt) in 2012 to 19 Mt in 2014 as a result of mining companies revising their resources. Australia's EDR of nickel can be subdivided as follows:
- About 37% of Australia's EDR comprises Reserves as defined under the Joint Ore Reserves Committee (JORC) Code.
- About 63% is made up of published JORC Code compliant Measured and Indicated Resources.
Western Australia (WA) retains the largest nickel resources with 95.3% of total Australian EDR. Queensland (Qld) is the second largest with 4.5%, followed by Tasmania (Tas) with 0.2%. The EDR in WA comprises both sulfide and laterite deposits, while EDR in Qld is associated with laterite deposits.
Subeconomic Demonstrated Resources (Paramarginal plus Submarginal Demonstrated Resources) accounted for about 17.7% of total Identified Resources in 2014. Paramarginal Resources decreased from 4.2 Mt (2012) to 4.0 Mt, while Submarginal Resources decreased from 0.2 Mt to 0.1 Mt. A total of 76.6% of the subeconomic nickel resources are in WA.
Inferred Resources decreased from 17.8 Mt (2012) to 20.0 Mt in 2014 with WA maintaining its dominance with 89.1% of the total followed by NSW with 5.7%.
The ratio of Inferred Resources to EDR in 2012 was 1:1.05.
Currently, all nickel EDR is accessible for mining. At the rate of production in 2014, Accessible Economic Demonstrated Resources (AEDR) of nickel is sufficient for about 78 years.
About 37% of AEDR is made up of JORC Code Reserves. The remaining 63% of EDR represents resources assessed by Geoscience Australia from the Measured and Indicated categories of industry reported mineral resources as defined under the JORC Code and other classification systems used by companies not listed on the Australian Securities Exchange.
Total JORC Code Reserves of nickel are adequate for 29 years at current rates of production.
Expenditure on nickel-cobalt exploration for 2014 as reported by the Australian Bureau of Statistics was $89.2 million, a decrease of 30.5% on 2013 ($128.3 million). WA attracted most of this expenditure with $85.1 million.
All of Australia's nickel production in 2014 was from WA and amounted to 246 kilotonnes (kt), compared to 234 kt in 2013, as reported by the Australian Office of the Chief Economist.
Based on figures published by the United States Geological Survey and the latest Australian resource figures, world economic resources of nickel increased to 81 Mt in 2014 from 74 Mt in 2013. Australia's share of world economic resources of nickel was 23% in 2014. It remained the largest holder of economic resources followed by New Caledonia (14.8%), Brazil (11.2%), Russia (9.8%) and Cuba (6.8%).
In 2013, Indonesia with 440 kt (17.7%), Philippines with 440 kt (17.7%) and Russia with 250 kt (10.1%) were the largest producers, followed by Australia and Canada with 240 kt (9.7%) and 225 kt (9.1%), respectively.
Intrusion-hosted Ni-Cu-PGE sulfide deposits
Australia's known resources of nickel are contained mainly within komatiitic volcanic-hosted Ni-Cu-PGE sulfide deposits in Western Australia, lateritic Ni deposits and, to a lesser extent, within tholeiitic intrusion-hosted Ni-Cu-PGE sulfide and hydrothermal deposits. This distribution contrasts with global nickel resources which are dominated by intrusion-hosted Ni-Cu-PGE deposits. Mineral resources of this type may be very large and extremely valuable, for example the ~$1 trillion Noril'sk (Russia), Voisey's Bay (Canada) and Jinchuan (China) deposits. Although several medium to small tholeiitic intrusion-hosted deposits are known in Australia (e.g. the Nebo-Babel deposit in central Australia and Nova-Bollinger deposit in southeast Western Australia), no giant deposits have so far been discovered in Australia despite the abundance of appropriate mafic and ultramafic host rocks spanning the Archean, Proterozoic and Phanerozoic.
A study of the potential for intrusion-hosted Ni-Cu-PGE deposits completed by Geoscience Australia in 2016 has identified many geological provinces with highly favourable prospectivity. This study is the first continent-scale assessment of Australia's Ni potential using a GIS-based prospectivity modelling method. The knowledge-driven (cf. data-driven) approach is based on a conceptual model of the entire ore-forming 'mineral system', incorporating lithospheric- to deposit-scale geological factors that control where and when an ore deposit forms. A wide range of geophysical, geological, geochronological and geochemical datasets were used as inputs in the spatial modelling. The analysis successfully identifies regions of known intrusion-hosted Ni-Cu-PGE deposits and also highlights a number of 'greenfields' regions with high potential for discovery although currently lacking known deposits.
This evaluation suggests that a key impediment to discovery of major new intrusion-hosted Ni-Cu-PGE resources in Australia is not a deficit in geological 'fertility' but the concealment of such deposits beneath extensive regolith and basin cover. The broad areas identified with high potential in this study should assist regional area selection and exploration targeting by the mineral industry, and are recommended for more detailed follow-up investigations to test for the presence of mineralisation and, ultimately, giant deposits.
An information package is available online for free download, including a Geoscience Australia Record on the methodology and results, digital maps (Geodatabase rasters) of selected input datasets and results, and a computer programming script used for the GIS modelling.