Goldfields-Esperance
The Goldfields-Esperance region is one of the nine regions of Western Australia. It is located in the south eastern corner of Western Australia, comprises the local government areas of Coolgardie, Esperance, Kalgoorlie-Boulder, Leonora, Menzies and Ravensthorpe, it incorporates the area along the Great Australian Bight to the South Australian border known as the Nullarbor. The Goldfields-Esperance region is the largest of Western Australia's regions, with an area of 770,488 square kilometres, 70,800 square kilometres, larger than the U. S. state of Texas or the combined area of Texas and North Dakota. It is a low and flat plateau of ancient Precambrian rocks which have been stable since long before the Paleozoic; because of the extreme geological stability and the absence of glaciation since the Carboniferous, the soils are infertile and quite saline. The region supports the lowest stocking rates in the world: it is considered that one sheep per square mile is the maximum sustainable rate except in the small wetter area near Esperance.
There are no rivers. The climate is hot and dry. Annual rainfall is around 250 mm per year and can be variable, except in the small area near Esperance and Cape Arid National Park where reliable winter rainfall can give annual totals as high as 635 mm falling in the winter months. Most rainfall is produced by thunderstorms in spring or summer or by cloudbands from the northwest in autumn and winter, but sometimes cyclones from the Pilbara decay into rain depressions and produce heavy rainfall. Climate change has had a major impact: in the Kalgoorlie – Eucla – Wiluna – Giles area annual rainfall has increased by over 40 percent since 1967 – due to lower frequencies of anticyclones located over the interior of Australia instead of the adjacent oceans; the Little Sandy Desert and the Gibson Desert are found in the northern part of the region with the Great Victoria Desert in the south east. It has a population of just under 60,000 people, about half of whom live in the City of Kalgoorlie-Boulder.
Another quarter live in the Shire of Esperance, the remaining shires are sparsely populated. Nearly 10% of the region's population are of Aboriginal descent, higher than the state as a whole; the economy of the Goldfields sub-region is based on the extraction and processing of various mineral resources gold and nickel. In 2012 the mining of gold and platinum yielded just under A$9 billion. Pastoralism in the northern goldfields commenced in the early 1900s with Yundamindera Station being established by Dr. Laver. In 1923 Yundmindera was purchased along with Mount Celia Station with a combined area of over 1,000,000 acres by T. H. Pearse who stocked the property with sheep. Between 1925 and 1928 more eastern states pastoralists scores of leases were established and over £1,500,000 were invested in properties in the northern and eastern goldfields. In three months of 1925 over 40,000 sheep were railed to the area and in one month of 1927 seven trains carrying sheep arrived. By 1934 the goldfields were stocked with over 25,000 cattle.
Shearing the same year produced 11,667 bales of wool valued at £243,600. Further south near Esperance, the economy is based on agriculture with wheat and barley grown and make up about 80% of the areas agricultural economy; these crops require huge inputs in fertilisers because of the sandy nature of the soils and are a major threat to the region's great plant diversity. Pastoralism is common with both sheep and cattle stations being common in the area. Along the coast fishing and aquaculture are common with fisheries for abalone and sharks. Goldfields Esperance Development Commission
Homestake Mining Company
The Homestake Mining Company was one of the largest gold mining businesses in the United States from the 19th century through the beginning of the 21st. It was merged into the Canadian-based Barrick Gold Corporation in 2002. Homestake's first and most famous operation was the Homestake Mine in Lead, South Dakota. George Hearst, Lloyd Tevis, James Ben Ali Haggin, bought the Homestake Mine property from its discoverers for $70,000, incorporated the Homestake Mining Company, on 5 Nov. 1877, to operate it. They began selling shares in 1879 on the New York Stock Exchange, the first mining stock listed. Homestake would become the longest-listed stock in the history of the New York Stock Exchange; the company diversified in the 1950s, operating or becoming the major investor in the Buick Mine, Compania Minera del Madrigal, Bulldog Mine, United Nuclear-Homestake Partners. Subsidiary income amounted to $83 million of Homestake's $135 million in 1976; the Homestake Mining Company started with ten acres in 1877.
Through land purchases and acquisitions of the Highland, Terra and Father De Smet Mining Companies, the land area was increased to two thousand six hundred and twenty-four acres. The mine created forty-one miles of underground trams. In 1898 a lumber mill was built by the company in South Dakota. A more modern mill ran until the 1930s when a new mill was built in Spearfish. Homestake Mining Company formed a hydro-electric plant in 1910 and another in 1917 referred to as Plant #1 and Plant #2; the Homestake Mining company uses a gold cyanidation technique, banned in many countries including Germany, Czech Republic, Costa Rica and some Argentine provinces. In the United States Montana and Wisconsin have bans but courts in Colorado and South Dakota have ruled against bans. 1906 - 1,500,00 tons, $5,000,000 1925 - 1,589,701 tons, $5,999,074 1933 - 1,432,195 tons, $13,000,000 1880 - $450,000 1891 - $1,175,000 1899 - $1,175,000 1878-1884 Samuel McMaster 1884-1914 Thomas J. Grier 1914-1944 Edward H. Clark 1944-1960 Donald H. McLaughlin 1960-1970 John K. Gustafson 1970-1977 Paul C.
Henshaw 1914-1918 Richard Blackstone 1918-1936 Bruce C. Yates 1936-1953 Guy N. Bjorge 1953-1957 Abbott H. Shoemaker 1957-1972 James O. Harder 1972-1975 Donald T. Delicate
Roasting (metallurgy)
Roasting is a process of heating of sulfide ore to a high temperature in presence of air. It is a step of the processing of certain ores. More roasting is a metallurgical process involving gas–solid reactions at elevated temperatures with the goal of purifying the metal component. Before roasting, the ore has been purified, e.g. by froth flotation. The concentrate is mixed with other materials to facilitate the process; the technology is useful but is a serious source of air pollution. Roasting consists of thermal gas–solid reactions, which can include oxidation, chlorination and pyrohydrolysis. In roasting, the ore or ore concentrate is treated with hot air; this process is applied to sulfide minerals. During roasting, the sulfide is converted to an oxide, sulfur is released as sulfur dioxide, a gas. For the ores Cu2S and ZnS, balanced equations for the roasting are: 2 Cu2S + 3 O2 → 2 Cu2O + 2 SO2 2 ZnS + 3 O2 → 2 ZnO + 2 SO2The gaseous product of sulfide roasting, sulfur dioxide is used to produce sulfuric acid.
Many sulfide minerals contain other components such as arsenic that are released into the environment. Up until the early 20th century, roasting was started by burning wood on top of ore; this would raise the temperature of the ore to the point where its sulfur content would become its source of fuel, the roasting process could continue without external fuel sources. Early sulfide roasting was practiced in this manner in "open hearth" roasters, which were manually stirred using rake-like tools to expose unroasted ore to oxygen as the reaction proceeded; this process released large amounts of acidic and other toxic compounds. Results of this include areas that after 60–80 years are still lifeless exactly corresponding to the area of the roast bed, some of which are hundreds of metres wide by kilometres long. Roasting is an exothermic process; the following describe different forms of roasting: Oxidizing roasting, the most practiced roasting process, involves heating the ore in excess of air or oxygen, to burn out or replace the impurity element sulfur or by oxygen.
For sulfide roasting, the general reaction can be given by: 2MS + 3O2 = 2MO + 2SO2 Roasting the sulfide ore, until complete removal of the sulfur from the ore, results in a dead roast. Volatilizing roasting, involves careful oxidation at elevated temperatures of the ores, to eliminate impurity elements in the form of their volatile oxides. Examples of such volatile oxides include Sb2O3, ZnO and sulfur oxides. Careful control of the oxygen content in the roaster is necessary, as excessive oxidation forms non volatile oxides. Chloridizing roasting transforms certain metal compounds to chlorides, through oxidation or reduction; some metals such as uranium, titanium and some rare earths are processed in their chloride form. Certain forms of chloridizing roasting may be represented by the overall reactions: 2NaCl + MS + 2O2 = Na2SO4 + MCl, 4NaCl + 2MO + S2 + 3O2 = 2Na2SO4 + 2MCl2The first reaction represents the chlorination of a sulfide ore involving an exothermic reaction; the second reaction involving an oxide ore is facilitated by addition of elemental sulfur.
Carbonate ores react in a similar manner as the oxide ore, after decomposing to their oxide form at high temperature. Sulfating roasting oxidizes certain sulfide ores to sulfates in a controlled supply of air to enable leaching of the sulfate for further processing. Magnetic roasting involves controlled roasting of the ore to convert it into a magnetic form, thus enabling easy separation and processing in subsequent steps. For example, controlled reduction of haematite to magnetite. Reduction roasting reduces an oxide ore before the actual smelting process. Sinter roasting involves heating the fine ores at high temperatures, where simultaneous oxidation and agglomeration of the ores take place. For example, lead sulfide ores are subjected to sinter roasting in a continuous process after froth flotation to convert the fine ores to workable agglomerates for further smelting operations
Burbanks Gold Mine
The Burbanks Gold Mine is a gold mine located 9 km south east of Coolgardie, Western Australia. It is owned by Barra Resources Limited; the Burbanks deposit produced over 400,000 ounces of gold from both underground and open pit mining. Small scale mining still continued in the late 1990s. From 1887 to 1914, the mine was the highest grade gold mine in Western Australia with 22.7 grams of gold per tonne. It was mined by WMC Resources in the early 1950s but closed down in 1991. Barra acquired the mine in September 2000 from WMC and mined the deposit in an underground operation, developing a decline from the existing Lady Robinson pit from July 2006. After mining 24,900 ounces of gold, Barra stopped the operation in August 2007, allowing it to pursue an exploration campaign. In late 2007, Barra believed to have made one of the most spectacular gold discoveries in Australian resources history, hitting an intersection yielding a high 10,300 grams of gold per tonne, at 350 metres below surface, in a vicinity where no drilling had been carried out before.
In June 2009, Burbanks recommenced gold production in a mining and profit-share arrangement between Barra and Mulgabbie Mining Pty Ltd. Ore will be treated at the Burbanks production facility of Ramelius Resources, which the company utilises for its own Wattle Dam Gold Mine. Production of the mine: 1 First quarter of 1999 only; the Australian Mines Handbook: 2003-2004 Edition, Louthean Media Pty Ltd, Editor: Ross Louthean Western Australian Mineral and Petroleum Statistics Digest 2008 Page 34: Principal Mineral and Petroleum Producers - Gold Place Names Search Results - Burbanks Geoscience Australia website Barra Resources website - Burbanks operation Barra Resources at Yahoo!7 Finance
Gold mining
Gold mining is the resource extraction of gold by mining. It is impossible to know the exact date that humans first began to mine gold, but some of the oldest known gold artifacts were found in the Varna Necropolis in Bulgaria; the graves of the necropolis were built between 4700 and 4200 BC, indicating that gold mining could be at least 7000 years old. A group of German and Georgian archaeologists claims the Sakdrisi site in southern Georgia, dating to the 3rd or 4th millennium BC, may be the world's oldest known gold mine. Bronze age gold objects are plentiful in Ireland and Spain, there are several well known possible sources. Romans used hydraulic mining methods, such as hushing and ground sluicing on a large scale to extract gold from extensive alluvial deposits, such as those at Las Medulas. Mining was under the control of the state but the mines may have been leased to civilian contractors some time later; the gold served as the primary medium of exchange within the empire, was an important motive in the Roman invasion of Britain by Claudius in the first century AD, although there is only one known Roman gold mine at Dolaucothi in west Wales.
Gold was a prime motivation for the campaign in Dacia when the Romans invaded Transylvania in what is now modern Romania in the second century AD. The legions were led by the emperor Trajan, their exploits are shown on Trajan's Column in Rome and the several reproductions of the column elsewhere. Under the Eastern Roman Empire Emperor Justinian's rule, gold was mined in the Balkans, Armenia and Nubia. In the area of the Kolar Gold Fields in Bangarpet Taluk, Kolar District of Karnataka state, gold was first mined prior to the 2nd and 3rd century AD by digging small pits; the Champion reef at the Kolar gold fields was mined to a depth of 50 metres during the Gupta period in the fifth century AD. During the Chola period in the 9th and 10th century AD, the scale of the operation grew; the metal continued to be mined by the eleventh century kings of South India, the Vijayanagara Empire from 1336 to 1560, by Tipu Sultan, the king of Mysore state and the British. It is estimated; the mining of the Hungarian deposit around Kremnica was the largest of the Medieval period in Europe.
During the 19th century, numerous gold rushes in remote regions around the globe caused large migrations of miners, such as the California Gold Rush of 1849, the Victorian Gold Rush, the Klondike Gold Rush. The discovery of gold in the Witwatersrand led to the Second Boer War and the founding of South Africa; the Carlin Trend of Nevada, U. S. was discovered in 1961. Official estimates indicate that total world gold production since the beginning of civilization has been around 6,109,928,000 troy ounces and total gold production in Nevada is 2.5% of that, ranking Nevada as one of the Earth's primary gold producing regions. As of 2017, the world's largest gold producer by far was China with 429.4 tonnes in that year. The second-largest producer, mined 289.0 tonnes in the same year, followed by Russia with 273 tonnes. Despite the decreasing gold content of ores, the production is increasing; this can be achieved with industrial installations, new process, like hydrometallurgy. Placer mining is the technique.
Placer deposits are composed of loose material that makes tunneling difficult, so most means of extracting it involve the use of water or dredging. Gold panning is a manual technique of separating gold from other materials. Wide, shallow pans are filled with gravel that may contain gold; the pan is shaken, sorting the gold from the gravel and other material. As gold is much denser than rock, it settles to the bottom of the pan; the panning material is removed from stream beds at the inside turn in the stream, or from the bedrock shelf of the stream, where the density of gold allows it to concentrate, a type called placer deposits. Gold panning is the easiest and quickest technique for searching for gold, but is not commercially viable for extracting gold from large deposits, except where labor costs are low or gold traces are substantial. Panning is marketed as a tourist attraction on former gold fields. Before large production methods are used, a new source must be identified and panning is useful to identify placer gold deposits to be evaluated for commercial viability.
Using a sluice box to extract gold from placer deposits has long been a common practice in prospecting and small-scale mining. A sluice box is a man made channel with riffles set in the bottom; the riffles are designed to create dead zones in the current to allow gold to drop out of suspension. The box is placed in the stream to channel water flow. Gold-bearing material is placed at the top of the box; the material is carried by the current through the volt where gold and other dense material settles out behind the riffles. Less dense material flows out of the box as tailings. Larger commercial placer mining operations employ screening plants, or trommels, to remove the larger alluvial materials such as boulders and gravel, before concentrating the remainder in a sluice box or jig plant; these operations include diesel powered, earth moving equipment, including excavators, wheel loaders, rock trucks. Although this method has been replaced by modern m
Daisy Milano Gold Mine
The Daisy Milano Gold Mine is a gold mine located 50 km south east of Kalgoorlie at Mount Monger Station, Western Australia. It is owned by Silver Lake Resources. Silver Lake reopened the mine in December 2007. Daisy Milano's ore is processed in the Silver Lake-owned Lakewood gold processing facility, located 5 km south east of Kalgoorlie and capable of processing 300,000 tonnes per annum. Silver Lake purchased the facility in November 2007 for A$2.4 million. While in close proximity to Kalgoorlie, the Mount Monger goldfield had seen no systematic exploration approach in the past. Mining had been carried out in the area from the early 1900s by small mining company's, gold having been found there in 1896. 400,000 ounces have been mined in the Mount Monger area, with old workings in the area reaching a depth of 80 metres. The current Daisy Milano mine has been in operation since 1990, it was an underground operation, with a shaft haulage system, under the ownership of Ridgeview Nominees Pty Limited, a decline was established in 2001.
In May 2002, an underground miner was killed at the facility, having been found unconscious on an underground access road, next to an open electrical switch box. The mine was placed in care and maintenance in March 2007 by then-owner Perilya Limited, with the intention of selling it. Perilya themselves had purchased the operations in January 2005 for A$3.2 million, but suffered from a lack of own production facilities, having to cart its ore long distances to other company’s plants, such as Harmony’s Jubilee or Coolgardie, 100 km away from the mine. Silver Lake, formed in 2004 and listed at the Australian Securities Exchange in 2007, acquired Daisy Milano in November 2007 for A$14.5 million from Perilya. Mining at Daisy Milano resumed in December 2007 and the first gold pour was carried out in April 2008. In the June quarter of 2009, Silver Lake carried out open pit mining 1 km north of the underground operation, at Christmas Flat. Production of the mine: The Australian Mines Handbook: 2003-2004 Edition, Louthean Media Pty Ltd, Editor: Ross Louthean Western Australian Mineral and Petroleum Statistics Digest 2008 Page 34: Principal Mineral and Petroleum Producers - Gold New mining approaches lead to success The Australian Mining Review - Article on the Daisy Milano mine Place Names Search Results - Daisy Milano Geoscience Australia website Silver Lake website - Daisy Milano operation Silver Lake Resources at Google finance
Kimberley (Western Australia)
The Kimberley is the northernmost of the nine regions of Western Australia. It is bordered on the west by the Indian Ocean, on the north by the Timor Sea, on the south by the Great Sandy and Tanami Deserts in the region of Pilbara, on the east by the Northern Territory; the region was named after John Wodehouse, 1st Earl of Kimberley, who served as Secretary of State for the Colonies from 1870 to 1874 and 1880 to 1882. The Kimberley was one of the earliest settled parts of Australia, with the first arrivals landing about 41,000 years ago. In 1837, with support from the Royal Geographical Society, Lieutenants George Grey and Franklin Lushington, 12 men sailed on the schooner Lynher from Cape Town, reaching Hanover Bay on 2 December 1837; the party started inland on 19 January 1838. Leaders and men were inexperienced, progress was delayed by flooded country, many stores were abandoned, the party was split up despite the presence of large numbers of hostile Aboriginals. On 11 February, Grey was speared and became critically ill, but after two weeks, continued the exploration.
The party discovered and named the Gairdner River, the Glenelg River, the Stephen and Whately ranges and Mount Lyell before returning to Hanover Bay in April. There they were taken to Mauritius to recuperate. In 1879, Alexander Forrest trekked across from the western coast to the Northern Territory. Forrest named the Kimberley district, discovered the Margaret and Ord Rivers, the King Leopold Ranges, the fertile area between the Fitzroy and Ord River, he subsequently set himself up as a land agent specialising in the Kimberley and was thus instrumental in the leasing of over 21,000,000 hectares of land in the region during 1883. In 1881, Philip Saunders and Adam Johns, in the face of great difficulties and dangers, found gold in various parts of the Kimberley. Early in 1881, the first five graziers, who called themselves the Murray Squatting Company, took up 49,000 hectares behind Beagle Bay and named it Yeeda Station, they became the first men to shear sheep in the southern Kimberley in 1883.
There was further European settlement in 1885, when cattle were driven across Australia from the eastern states in search of good pasture lands. Many other Europeans arrived soon after. In the 1890s, the area was the site of an armed insurrection of indigenous people under the leadership of Jandamarra, a Bunuba warrior; the only Japanese force to land in Australia during World War II was a small reconnaissance party that landed in the Kimberley on 19 January 1944 to investigate reports that the Allies were building large bases in the region. The party consisted of four Japanese officers on board a small fishing boat, it investigated the York Sound region for a day and a night before returning to Kupang in Timor on 20 January. Upon returning to Japan in February, the junior officer who commanded the party suggested using 200 Japanese prison inmates to launch a guerrilla campaign in Australia. Nothing came of this and the officer was posted to other duties; the 2011 estimated permanent population of the Kimberley was 34,794 but it rises during winter.
On Census night in 2011, it was 50,113. The population is evenly distributed, with only three towns having populations in excess of 2,000: Broome and Kununurra. 40% of the region's population is of Aboriginal descent. At federal level, the Kimberley is represented by the member for Durack. At state level, the Kimberley electorate takes in all of its towns; the Kimberley region consists of the local government areas of Broome, Derby-West Kimberley, Halls Creek and Wyndham-East Kimberley. The Kimberley is an area of 423,517 square kilometres, about three times the size of England, twice the size of Victoria, or just smaller than California; the Kimberley consists of the ancient, steep-sided mountain ranges of northwestern Australia cut through with sandstone and limestone gorges and steep ridges, from which the extreme monsoonal climate has removed much of the soil. The southern end of the Kimberley beyond the Dampier Peninsula is flatter with dry tropical grassland and is used for cattle ranching.
In parts of the Kimberley, such as the valleys of the Ord and Fitzroy Rivers in the south, the soils are usable cracking clays, whilst elsewhere they are lateritic Orthents. Although none of the mountains reach 1,000 metres, there is so much steep land as to make much of the region difficult to traverse during the wet season, when sealed roads are flooded; the coast is steep cliffs in the north but flatter in the south, all subject to high tides. The Kimberley has a tropical monsoon climate; the region receives about 90% of its rainfall during the short wet season, from November to April, when cyclones are common and the rivers flood. The annual rainfall is highest in the northwest, where Kalumburu and the Mitchell Plateau average 1,270 millimetres per year, lowest in the southeast where it is around 520 millimetres. In the dry season, from May to October, south easterly breezes bring cool nights. Climate change since 1967 has led to large increases of as much as 250 millimetres per year in annual rainfall over the whole region.
Recent studies suggest Asian pollution and not global warming as the cause of this increased rainfall. In 1997 and 2000, the region received heavy rains, leading to record flooding of the Fitzroy and other rivers; the Kimberley is one of the hottest parts of Australia, with the average annual mean temperature around 27 °C, with mean maximu
