|
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 embankments or 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 towards the central pool which is maintained a ... [...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 Australia and overseas to where gold had been discovered. Gold had been found several times before, but the colonial government of New South Wales (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 so destabilise the economy. 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 first gold rush in Australia began in May 1851 after prospector Edward Hargraves claimed to have discovered payable gold near Orange, at a site he called Ophir. Hargraves had been to the Californian goldfields and had learned new gold prospecting techniques such as panning and cradling. H ... [...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 by converting the gold to a water-soluble coordination complex. It is the most commonly used leaching process for gold extraction. Cyanidation is also widely used in the extraction of silver, usually after froth flotation. Production of reagents for mineral processing to recover gold represents more than 70% of cyanide consumption globally. Other metals are recovered from the process include copper, zinc, and silver, but gold is the main driver of this technology. Due to the highly poisonous nature of cyanide, the process is controversial and its use is even banned in some parts of the world. Cyanide can be safely used in the gold mining industry. A key feature for safe use of cyanide is to ensure adequate pH control at an alkaline pH level above 10.5. At industrial scale, pH control is mainly achieved using lime, as an i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oriental Claims
The Oriental Claims are a former gold mining operation, or 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 A$75 million at the 2010 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 mined the area from 1876 to 1904, chiefly working its Oriental Claim. It was established by five shareholders and altogether the company leased two areas containing 43 hectares and rightfully owned another 25 hectar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Mining In Australia
Mining in Australia has long been a significant primary sector industry and contributor to the 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. Production overview 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 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. Australia is the world's largest producer of opal and is one of the largest producers of diamond, ruby, sapphi ... [...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. The pros of surface mining are that it has a lower financial cost and is a lot safer than undergrou ... [...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 an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Hydraulic Sluicing")
