Critical commodities: metals, non-metals and minerals for a high-tech world
Critical commodities are metals, non-metals and minerals that are considered vital for the economic well-being of the world's major and emerging economies, yet whose supply may be at risk due to geological scarcity, geopolitical issues, trade policy or other factors. Among these important commodities are metals and semi-metals used in the manufacture of mobile phones, flat screen monitors, wind turbines, electric cars, solar panels, and many other high-tech applications.
The commodities ranked as most critical by the United States, Japan, Republic of Korea, and the European Union including the United Kingdom, are as follows (ranked by Geoscience Australia based on synthesis of individual country rankings):
Rare-earth elements (REE), gallium (Ga), indium (In), tungsten (W), platinum-group elements (PGE) including platinum (Pt) and palladium (Pd), cobalt (Co), niobium (Nb), magnesium (Mg), molybdenum (Mo), antimony (Sb), lithium (Li), vanadium (V), nickel (Ni), tantalum (Ta), tellurium (Te), chromium (Cr) and manganese (Mn).
Although these commodities are critical for the world's major industrial economies, Australia's perspective is different in that domestic demand for most major and minor mineral commodities is relatively small and is far outstripped by Australian production of those commodities. There are two notable exceptions, however. Phosphate and potash, used in fertilisers, are essential for Australia's agricultural industries yet the nation is, at present, not self-sufficient in these commodities.
Australia is well known as one of the world's leading suppliers of iron ore, coal, gold, bauxite, copper, zinc, lead, manganese, and a number of other commodities. Australia also holds large resources, or has potential for significant resources, of many of the critical commodities. Australia therefore is well placed as a safe and reliable supplier of these commodities to world markets.
Geoscience Australia recently undertook a comprehensive assessment of Australia's potential to supply critical commodities to global markets. This study by Geoscience Australia is described below. Other studies by Geoscience Australia on critical commodities, including rare-earth-elements, thorium and commodities related to salt lake systems (potash, uranium, lithium, boron), are available by following the links and downloading maps and reports.
The Mineral Systems of Australia section is also undertaking a study of Mineral systems related to mafic-ultramafic magmatism, including the critical commodities: PGE, Ni, Cr and V.
Geoscience Australia study of critical commodities
This report presents the first systematic and geoscientific evaluation of Australia's range of critical commodities and of the nation's opportunities to supply critical commodities to world markets. For each of 34 metals, non-metals and minerals the level of opportunity or 'resource potential' in Australia is assessed based on: (a) the level of criticality assigned by the United Kingdom, European Union, United States of America, Japan and Republic of Korea; (b) Australia's known resources as well as potential for discovery of new resources; (c) demand in terms of global market size; and (d) growth outlook.
Part 1 of the report presents an overview of the definition and uses of critical commodities; a summary listing of the commodities considered to be critical by the European Union, Japan, South Korea, United Kingdom and United States of America; and an evaluation of the opportunities and resource potential of critical commodities in Australia.
Part 2 is a detailed technical description of the geological settings in which critical metals, non-metals and minerals occur, and their occurrence and known resources in Australia. This section is presented within a `mineral systems' framework which groups particular mineral deposit types according to their broad geological settings and processes of formation. Importantly some inferences are also presented on the potential for undiscovered resources of many of the critical commodities in Australia.
The report also includes an extensive Appendix with summaries for each of the 34 commodities of their characteristics and uses; supply data with global and Australian resources and production; and global demand data based on country import values.
The key results of the critical commodities assessment are as follows.
Commodities assessed with category one (high) resource potential in Australia are (in alphabetical order): chromium, cobalt, copper, nickel, platinum-group elements (PGE), rare-earth elements (REE), and zirconium. This assessment does not consider non-critical commodities such as ferrous metals, most base metals, and energy commodities. Australia has category one resource potential in many of these non-critical commodities.
Commodities assessed as having category two moderate to high resource potential in Australia are (in alphabetical order): antimony, beryllium, bismuth, graphite, helium, indium, lithium, manganese, molybdenum, niobium, tantalum, thorium, tin, titanium, and tungsten.
Some of the category one and category two metals and semi-metals (antimony, indium), as well as gallium, germanium, cadmium, tellurium and selenium, are primarily by-products of refining of the major commodities zinc, copper, lead, gold, aluminium and nickel. Australia's high global ranking in resources of all of these major commodities implies that there is significant potential for new or increased production of the minor-element by-products listed above. Where recovery is currently uneconomic, opportunities may exist for improvements in mineral processing of ores to extract critical commodities as by-products.
A further conclusion of the study is that most of the critical commodities can be grouped into three families of mineral systems, as follows.
Mineral system family (1): Mafic-ultramafic igneous-related nickel, PGE, chromium and cobalt - The occurrence of these commodities is closely related to mafic-ultramafic igneous rocks derived from the mantle. Based on known resources in Australia, the continent appears to be under-represented in world-class intrusion-hosted nickel, PGE and chromium deposits despite Australia's favourable geology for such deposits.
Mineral system family (2): Felsic igneous-related REE, tungsten, niobium, tantalum, molybdenum, beryllium, tin and bismuth - All of these metals occur (albeit not exclusively) in association with felsic igneous intrusions, in particular with highly-fractionated granitic rocks and with alkaline igneous rocks. Australia's potential for such deposits is unrealised at present.
Mineral system family (3): Heavy mineral sand-hosted zirconium, titanium, REE and thorium - New discoveries of heavy mineral sand provinces recently in Australia attest to the potential of the continent for further delineation of major resources of heavy mineral sands and their contained critical commodities.
Lithium in Australia
The large majority of Australia's Lithium (Li) resources are contained within pegmatites, most of which are Archean in age. Available information on pegmatites is variable, making exploration targeting potentially difficult. A number of direct and proxy datasets are available that can be of assistance. These include:
Lithium prospects and occurrences in Australia
Locations of Li prospects and occurrences in Australia can be downloaded from the Australian Mines Atlas website and individual State and Territory Geological survey sites. The Mines Atlas site also includes information on Li prospects in Australia and current (to 2015) Lithium Resource figures for Australia.
Whole rock felsic igneous geochemistry
Extensive analyses exist for felsic igneous rocks in Australia. Pegmatites are not commonly analysed, and increasingly neither is Li because of the use of fused beads made with lithium-bearing fluxes for ICP-MS analysis. Notwithstanding, available geochemical datasets are still very useful to explorationists. Firstly, older geochemical datasets often include data from AAS analysis which have reliable Li analyses. Secondly, many Li-bearing pegmatites are genetically related to and spatially associated with granites for which geochemical data does exist. Accordingly, granite geochemical data can be used to target potential regions that may contain Li-rich pegmatites. By the same token, related elements that can typically co-occur with Li, or are indicators of magmatic fractionation, are commonly routinely analysed, for example, Nb, Ta, Sn and Rb. Geochemical data for Australian rocks is available from Geoscience Australia and the State and Territory Surveys.
The National Geochemical Survey of Australia (NGSA) project collected transported regolith samples at the outlet of large catchments covering more than 80 per cent of Australia using an ultra low sampling density approach. Catchment outlet sediments (similar to floodplain sediments in most cases), were sampled at two depths (0-10 centimetres below the surface as well as between, on average, 60 and 80 centimetres depth). Sample analysis consisted of total element content by XRF and ICP-MS analyses, as well as acid leach analysis, e.g., aqua regia digestion, MMI® extraction. Lithium data were collected for the aqua regia digestion and MMI® extraction. These analyses provide a summary of Li within individual catchments across the continent, highlighting catchments with elevated concentrations that may indicate the presence of rocks with elevated Li, either exposed or under cover. Both the geochemical data (along with accompanying report) and/or individual Lithium maps are available here. The geochemical maps can be viewed online and/or downloaded here.
Data and maps for elements commonly associated with Li, e.g., Ta, Sn, can also be downloaded via the National Geochemical Survey of Australia Project webpage.
Many Li-bearing pegmatites appear to be genetically and spatially associated with (volumetrically much larger) differentiated granites. The latter, where outcropping, can be readily identified using gamma-ray data, as these granites are commonly elevated in K2O, and U and also Th (depending on granite type). An apposite example is the Pilbara Craton where late potassic granites are very readily identified by their gamma-ray signature. Geoscience Australia and the respective State and Northern Territory Geological Surveys have systematically surveyed most of Australia over the past 40 years using airborne gamma-ray spectrometry. These surveys have been combined into a Radiometric Map of Australia, comprising of potassium, uranium and thorium grids of the continent at 100 metre resolution. The data are available for free download through the Geophysical Archive Data Delivery System (GADDS).
Lithium in salt lakes
Geoscience Australia recently produced 'A Review of Australian Salt Lakes and Assessment of their Potential for Strategic Resources'. The review overviews the occurrence of lithium deposits in salt lakes globally and the mineral-hydrogeological systems wherein such lithium deposits can accumulate and also assesses lithium prospectivity within Australia. This synthesis report is accompanied by a hydrochemical database and maps of salt lake systems prospective for evaporitic commodities, including lithium.