Properties explosives, insecticides, and rubber The following alloys are important: products. In the past, tetra-ethyl lead Copper (Cu), lead (Pb) and (Zn) are Brass (copper + zinc): for hardware, was added to petrol to improve engine good electrical conductors; they are domestic ornaments and fixtures, performance. This application is malleable, ductile and moderately musical instruments (the "brass declining with the increasing use of resistant to corrosion. They can also be section"). lead-free petrol, because of its alloyed with one another, and with contribution to air pollution, and the Bronze (copper + tin): for casting various several other metals, to produce alloys harmful effects of lead fumes and dust products, including statues. Bronze was with many useful properties. to the human body. Only about 2.7 probably more important historically than World production and uses million tonnes of new lead are produced it is today. each year, the remainder being made up World production of copper is about Solder (lead + tin): the low melting point 9.5 million tonnes per year, mostly from by recycling of scrap lead. of lead is used to advantage in this alloy western North and South America, World annual zinc production is about 6.9 which is used for joining metal surfaces. Zambia, the former Soviet Union, China, million tonnes. The main use for zinc is as a Base metals in and Western Indonesia and Poland. Approximately protective agent for iron and steel Australia 60% of the copper produced is used in (galvanisedsteel). The zinc oxidises in the the electrical industry. Important uses for Australia is the fifth largest producer of air to zinc oxide which forms a protective the remainder are in the manufacture of copper, with 4% of total world coating on the iron or steel. Zinc is also alloys, fertilisers and cooking utensils. production. In 1993, Australia produced used in die-casting,and zinc compounds 392 000 tonnes of copper, mainly from About 5.4 million tonnes of lead are used are used in cosmetics, plastics, rubber Mount Isa in Queensland, Cobar in New each year, mainly in lead storage products, soaps, paints and inks. It finds a South Wales, and Olympic Dam in South batteries (for aircraft, motor vehicles major use in luminous dials (for clocks, TV Australia. Australia also produces etc.). Other uses include paints, dyes screens, fluorescent lamps, etc.). significant amounts of lead (514 000 tonnes) and zinc (990 000 tonnes). The main producing localities are Mount Isa,

WESTERN AUSTRALIA Cobar and western Tasmania. Production

PRINCIPAL COPPER, LEAD from very large deposits at Broken Hill, in AND~ZINCDEPOSITS New South Wales, has been declining in recent years as the resource is depleted. * CU =COPPER 0 Pb=LEAD However, several new deposits in the 0 NARLARLA (Pb, Zn) 0 Zn =ZINC I West Kimberley region of Western

203 CADJEBUT (Pb, Zn) Australia have been discovered in recent km 0 years. One of these, Cadjebut, commenced production of lead and zinc

BRAESIDE (Pb) in 1988, and others are planned to come MONS CUPRI (Cu) 0 NIFTY (Cu) onstream in the 1990s. Production of COPPER HILLS (Cu) UAROO (Pb) copper and zinc from the Scuddles mine 0 KOOLINE (Pb) at Golden Grove, south of Yalgoo, also began recently and a new copper mine may be established at Nifty in the 0 THADUNA (Cu) region.

Western Australia's contribution to the GERALDINE (Pb) nation's base metal production is not

(Pbr TEUTONIC BORE (Cu, Zn) great, but will improve as the West 0 GOLDEN GROVE 0 MURRIN MURRIN (Cu) NARRA TARRA (Cu,Zn) Kimberley deposits move into production, and as output increases at Golden Grove. The State's production has been sporadic, reflecting demand and other economic factors. Localities of the main deposits are shown on the opposite page.

Lead was first mined commercially in WA during 1850 from the Geraldine mine, discovered in the bed of the Murchison Following a boom in the 1950s when the the Teutonic Bore mine was opened in River by A. C. Gregory’sexploratory party Korean War produced high prices, lead 1981. Almost all of this early production in 1848. Copper and lead were mining stopped almost completely during came from the Narlarla mine in the West discovered in the Northampton area in the period 1970 to 1988. The opening of Kimberley region. Currently the metal is 1855, and mined during the 1860s and the Cadjebut mine late in 1988 saw lead mined at Cadjebut and Golden Grove. 1870s. Mining helped settle the area, as production resume as a co-product of Base metal deposits many miners turned to agriculture after zinc. Base metals occur in nature as sulphide the mines closed down in the 1880s. Western Australia’s output of zinc minerals. The main copper sulphide Other discoveries followed. Copper was amounted to less than 3 000 tonnes until minerals are chalcopyrite, bornite and found at Whim Creek (1 888), Murrin Murrin (1898) and Ravensthorpe (1899). Lead and zinc were discovered at Uaroo, Braeside and Narlarla, all in the early 1900s.

Copper production was stimulated in the 1950s and 1960s by the development of a local market for fertilisers, as agriculture expanded into sand plain areas. Most mines, however, had closed by the late 1960s. In 1971, WAS last copper mine closed, at Ravensthorpe. At present, the only copper produced in WA is as a by- product from the mining of nickel, zinc and gold.

Zincjcopper concentrates is stockpiled at the Golden Grove mine. v Copper ore is loaded into 75 tonne capacity haul trucks at the Nifty open-cut mine. chalcocite. Native (elemental) copper containing volcanic rocks, in which the of about 1 400 metres in the western part also occurs, but is relatively rare. Lead copper appears to have been deposited of the Great Sandy Desert, is also hosted sulphide is called galena, and zinc as an original component of the rock by limestone. sulphide is called sphalerite. Near the assemblage. Such deposits are smaller, Extraction of base metals from natural ore Earth’s surface, oxygen-charged but generally richer than the porphyry Copper is extracted from sulphide ore by groundwater oxidises primary sulphide coppers, and are the most important crushing and forming a slurry with water. concentrations, and leaches the metal source of copper mineralisation in The process used to separate copper content, redepositing the metals near the eastern Australia. There are also some minerals from the ot6ers is called water table. Supergene deposits formed deposits of this type in Western Australia flotation. During flotation, fine sulphide in this way are commonly much richer in (e.g. Whim Creek, Mons Cupri, Nifty, particles adhere to air bubbles which are metal content than the primary ore from Teutonic Bore and Golden Grove). The deliberately produced in the slurry, and which they were derived. Supergene ores last two examples are also an important rise to the surface. The froth is then comprise oxides and carbonates of source of zinc. scraped off and dried, yielding a copper (cuprite, malachite, azurite), and concentrate containing 20% to 30% Most of Western Australia’s copper carbonates and sulphates of lead copper, (cerrusite, anglesite) and zinc production (including that from Murrin (smithsonite, goslarite). Murrin and Ravensthorpe) has come The copper concentrate is usually from large veins of uncertain affinities. roasted in two stages, with sand and Copper, lead and zinc are mined from oxygen added to each stage. Some several different types of deposits, often As with copper, most historical impurities are removed in the waste gas. in association with gold (copper) or silver production of lead and zinc in Western Others react with the sand to form a slag (lead-zinc). Much of the world’s copper Australia comes from vein deposits in which rises to the top of the melt during production is derived from open-pit igneous and metamorphic rocks. the smelting process. The slag is mining of very large, low-grade deposits However, the metals also occur in eventually skimmed off and discarded. sedimentary and volcanic rock comprising numerous, very small veins The first roasting stage produces and associations similar to those that yield and disseminations of sulphide minerals intermediate product called copper important copper deposits. Deposits of (porphyry copper deposits). The style of matte which contains between 40 and this type include all the main producers mineralisation is not important in 55% copper metal. The second stage in eastern Australia. The new Australia, but is the major source of completes the process, yielding a “blister” discoveries in the Kimberley region take copper from Papua New Guinea and copper of 93% to 98% copper. For South America. A small porphyry copper the form of sphalerite and galena in vein industrial use the copper is refined deposit occurs at Coppins Gap, in the and cavity fillings, and replacement further by electrochemical processing to Pilbara. bodies, in an ancient limestone reef. produce metal of 99.99% purity. They are similar to the famous deposits Another important source of copper is of the Mississippi Valley, USA. The large Produced by the Public Affairs Branch, from sedimentary sequences, often Admiral Bay deposit situated at a depth Department of Minerals and Energy, Western Australia. 1/96

a A section of the treatment plant at the Golden Grove zinclcopper mine.