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Mining Sludge
Mining sludge is the waste product of alluvial mining, and in particular hydraulic sluicing. It has been particularly prominent in gold fields in Australia and California in the nineteenth century. In the 1840s in California and 1850s in Australian gold rushes, Australia, methods for extracting alluvial gold were developed which involved washing soil and gravel through sluice boxes using diverted streams and other water sources. The waste or tailings were released into the waterways forming large deposits of highly mobile sediment. This 'sludge' as it was generally termed, blocked the stream channels causing flooding and burial of land downstream. The cyanide process also involved releasing sediment contaminated with cyanide, while other sludge deposits have a variety of contaminants used in the mining process. Large areas of land were affected by sludge, particularly in Victoria, where a Royal Commission was established in 1858-9 to investigate and manage the problem. This resulte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Sluicing
Hydraulic fill is a means of selectively emplacing soil or other materials using a stream of water. It is also a term used to describe the materials thus emplaced. Gravity, coupled with velocity control, is used to effect the selected deposition of the material. Borrow pits containing suitable material are accessible at an elevation such that the earth can be sluiced to the fill after being washed from the bank by high-pressure nozzles. Hydraulic fill is likely to be the most economic method of construction. Even when the source material lacks sufficient elevation, it can be elevated to the sluice by a dredge pump. In the construction of a hydraulic fill dam, the edges of the dam are defined by low Embankment (earthworks), embankments or dyke (construction), dykes which are built upward as the fill progresses. The sluices are carried parallel to, and just inside of, these dykes. The sluices discharge their water-earth mixture at intervals, the water fanning out and flowing tow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australian Gold Rushes
During the Australian gold rushes, starting in 1851, significant numbers of workers moved from elsewhere in History of Australia, Australia and overseas to where gold had been discovered. Gold had been found several times before, but the Colony of New South Wales, colonial government of New South Wales (History of Victoria, Victoria did not become a separate colony until 1 July 1851) had suppressed the news out of the fear that it would reduce the workforce and destabilise the economy. The Australian gold rushes changed the Penal colony, convict colonies into more progressive cities with the Immigration to Australia, influx of free immigrants. After the California Gold Rush began in 1848, many people went there from Australia, so the New South Wales government sought approval from the British Colonial Office for the exploitation of mineral resources, and offered rewards for finding gold. History of discovery The New South Wales gold rush, first gold rush in Australia began i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyanide Process
Gold cyanidation (also known as the cyanide process or the MacArthur–Forrest process) is a hydrometallurgical technique for extracting gold from low-grade ore through conversion to a water-soluble coordination complex. It is the most commonly used leaching process for gold extraction. Cyanidation is also widely used in silver extraction, usually after froth flotation. Production of reagents for mineral processing to recover gold represents 70% of cyanide consumption globally. While other metals, such as copper, zinc, and silver, are also recovered using cyanide, gold remains the primary driver of this technology. The highly toxic nature of cyanide has led to controversy regarding its use in gold mining, with it being banned in some parts of the world. However, when used with appropriate safety measures, cyanide can be safely employed in gold extraction processes. One critical factor in its safe use is maintaining an alkaline pH level above 10.5, which is typically controlled ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Royal Commission
A royal commission is a major ad-hoc formal public inquiry into a defined issue in some monarchies. They have been held in the United Kingdom, Australia, Canada, New Zealand, Norway, Malaysia, Mauritius and Saudi Arabia. In republics an equivalent entity may be termed a commission of inquiry. Such an inquiry has considerable powers, typically equivalent or greater than those of a judge but restricted to the terms of reference for which it was created. These powers may include subpoenaing witnesses, notably video evidences, taking evidence under oath and requesting documents. The commission is created by the head of state (the sovereign, or their representative in the form of a governor-general or governor) on the advice of the government and formally appointed by letters patent. In practice—unlike lesser forms of inquiry—once a commission has started the government cannot stop it. Consequently, governments are usually very careful about framing the terms of reference a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oriental Claims
The Oriental Claims are a former gold mining operation, or Land claim#Mining claim (United States), claim, located 2 km south of Omeo, Victoria, Australia. The Oriental Claims are named in reference to The Oriental Company which mined in the area from 1876 to 1904, and also in memory of the many Chinese miners ('Orientals') that worked the area for over 50 years. During the main years of operation it is estimated that of gold was extracted from the area, which would equate to over Australian dollar, A$75 million at the 2010 Gold as an investment, gold price of over A$1,300 an ounce. The Oriental Claims are currently preserved as a Parks Victoria Historic Area covering about . History The Oriental Company Contrary to the popular belief due to its name that it was an oriental (Asian) company, The Oriental Company was a European company that mining, mined the area from 1876 to 1904, chiefly working its Oriental Claim. It was established by five shareholders and altogether the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Mining In Australia
Mining in Australia has long been a significant primary sector industry (economics), industry and contributor to the economy of Australia, Australian economy by providing export income, royalty payments and employment. Historically, mining booms have also encouraged population growth via immigration to Australia, particularly the gold rushes of the 1850s. Many different ores, gems and minerals have been mined in the past and a wide variety are still mined throughout the country. In 2019, Australia was the world's largest producer of iron ore and bauxite; the second largest of gold, manganese, and lead; the third largest of zinc, cobalt, and uranium; the fifth largest of table salt, salt; the sixth largest of copper and nickel; the eighth largest producer of silver and tin; the fourteenth largest of phosphate; and the fifteenth largest of sulfur. The country is also a major producer of precious stones, being the world's largest producer of opal and is also one of the largest pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surface Mining
Surface mining, including strip mining, open-pit mining and mountaintop removal mining, is a broad category of mining in which soil and rock overlying the mineral deposit (the overburden) are removed, in contrast to underground mining, in which the overlying rock is left in place, and the mineral is removed through shafts or tunnels. In North America, where the majority of surface coal mining occurs, this method began to be used in the mid-16th century and is practiced throughout the world in the mining of many different minerals. In North America, surface mining gained popularity throughout the 20th century, and surface mines now produce most of the coal mined in the United States. In most forms of surface mining, heavy equipment, such as earthmovers, first remove the overburden. Next, large machines, such as dragline excavators or bucket-wheel excavators, extract the mineral. Advantages of surface mining include lower cost and greater safety compared to underground mini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydraulic Engineering
Hydraulic engineering as a sub-discipline of civil engineering is concerned with the flow and conveyance of fluids, principally water and sewage. One feature of these systems is the extensive use of gravity as the motive force to cause the movement of the fluids. This area of civil engineering is intimately related to the design of bridges, dams, channels, canals, and levees, and to both sanitary and environmental engineering. Hydraulic engineering is the application of the principles of fluid mechanics to problems dealing with the collection, storage, control, transport, regulation, measurement, and use of water.Prasuhn, Alan L. ''Fundamentals of Hydraulic Engineering''. Holt, Rinehart, and Winston: New York, 1987. Before beginning a hydraulic engineering project, one must figure out how much water is involved. The hydraulic engineer is concerned with the transport of sediment by the river, the interaction of the water with its alluvial boundary, and the occurrence of scour a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
