Реферат на тему Mining Techniques Essay Research Paper Mining TechniquesThe
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Mining Techniques Essay, Research Paper
Mining TechniquesThe way to discover large amounts of gold, was to have the perfect mining technique. One of the earliest techniques was panning and cradling. This method consisted of a pick, a shovel and a washing dish and people either worked by themselves, or in a small group. First of all, panning was a simple method but required a lot of skill. It worked by loading sediment onto the washing device which had a sieve(strain), and moving the pan to and fro until the heavier gold was separated from the dirt that was collected. Hargraves and his associates used the tin panning dish to separate the gold grains from the sediment, but later on in 1851, the cradle was introduced to speed up the gold mining process by holding larger amounts of dirt to sift through. The cradle consisted of a wooden box that was on rockers, a metal strainer on top and two sloping shelves with thin slats of wood to trap grains of gold with the box. Two men were needed to work the machine. One man shoveled sand and gravel onto the sieve, while a second man, rocked the cradle backwards and forwards with on hand and used a long-handled dipper to pour in water. Sometimes, they worked in a team of four, because often the shelves became coated with mud, and was preventing the gold from being caught. Later on, cradles were replaced by sluice boxes or Long Toms. A number of boxes were placed end to end to create a long channel. When the running water carried the dirt through the boxes, the gold was caught in the slats nailed to the bottom of the boxes.Puddling was used when the clay deposits were heavy. A puddling tub was used to break up the clay before it went into the cradles. The tub was half filled with dirt and then water was added. You then stirred the mixture until the sludge could be poured off. As you can see, the Long Tom was used in the same way the cradling was.Shallow sinking was when they dug in former creek beds to find gold. The diggings were really shallow and were only about 3.6m by 3.6m to each person. All the soil was removed from the shaft before they would search for gold. They would put timber in the shafts so the sides wouldn t cave in on them. Once they dug beneath 4.6m, they could not breath properly, because it was contaminated with rotting vegetation from the former creek beds.
Deep sinking was when they discovered that if they dug deeper, mass quantities of gold was found, although it was an expensive decision and also life endangering. Long rods were driven through the ground and shallow gravel to allow them to dig underground. They soon discovered large quantities of gold beneath the soil, and began to dig deeper. By 1854, shafts were often 48.7m deep and needed eight to twelve men to work in a team.Gold had occasionally been extracted from quartz ( a type of mineral) and because it was so hard to break, miners used sledge hammers or grounded the quartz between stones. Once quartz crushing machinery was developed, this type of mining became very popular. The quartz were crushed by a machine powered by steam, but sometimes a horse was used because the machine used too much water. The horse crushed the quartz by pulling a mill wheel around in a trough. As you can see, these methods of gold mining required mass quantities of water. So during summer, this created a big problem for them, and when the creeks dried up, mud and sludge was left over, so miners often piled heaps of the sludge in a stack and guarded it with care. Edward Hargraves was an Australian who wished to start a gold rush In Australia. He wanted to be the first person to find gold there and present it to the New South Wales government to claim a wealthy reward. John Lister , William, James Tom and Hargraves found specks of gold at Lewis Ponds Creek in February 1851. Hargraves then hastily returned to Sydney to try and get a reward. While he was gone, his companions found four ounces of gold in Fitz Roy Bar, which Hargraves took credit and dismissed his companions. The talk of gold spread worldwide and soon the Australian gold rush had began. A debate soon arose about who should have received the credit and the rewards for discovering gold. Hargraves received rewards of up to 13,000 pounds and a pension of 250 pounds a year. Lister and William Tom fought for recognition as they should also have been rewarded, but Hargraves had dismissed them as being guides.