GOLD MINING
DESCRIPTION :
Gold is a chemical component with the symbol Au that springs up from the Latin derivative aurum that means shining dawn and with the atomic number 79. It is a very sought-after valuable metal which, for many centuries, has been utilized as wealth. The metal resembles as nuggets or grain like structures in rocks, subversive "veins" and in alluvial deposits. It is one of the currency metals. Gold is solid, squashy, glossy and the most vulnerable and bendable of the known metals. Chemically, gold charm is a tri-valent and uni-valent changeover metal. Gold does not act in response with the majority of chemicals, but is deteriorated by chlorine, fluorine, aqua regia and cyanide. Gold is the most vulnerable and bendable metal.
* GOLD MINING IN THE UNITED STATES
HOW DOES GOLD FORM ?
The most common natural method of concentration of gold is through the ancient action of hot fluid inside the Earth's crust. Fluids deep in the crust are heated by the Earth's internal heat. As they move towards the surface they cool down. The fluids move through the rocks over a large area and dissolve the gold. When these fluids are cooled or reacted with other rocks, the dissolved gold gets precipitated in cracks or fractures forming veins. If the fluids move over a large enough area, and dissolve the gold for a long enough period of time, gold can be concentrated in amounts in the parts per thousand or even greater. The fluids also carry other dissolved minerals such as quartz. These are known as primary gold deposits and to extract the gold the rock containing the veins of gold has to be mined, crushed and processed. The rocks containing the gold veins have now been exposed on the surface and are eroding away. Here, the gold is further concentrated by the action of water. br/> Because gold is heavier than most of the material moved by a creek or river, it can become concentrated in hollows and trapped in the bed of the river. These are known as secondary gold deposits.
HOW IS GOLD MINED ?
Gold is mined by 4 different methods : Placer mining, hard rock mining, byproduct mining and by processing gold ore.
Each of these categories has its own unique methods of extracting the gold from the surrounding materials.
In placer mining, the gold is retrieved by metal detecting, panning, cradling, sluicing and dredging. Using gravity and water to separate the dense gold from the other materials that surround it, this is the most common gold mining category for amateur gold hunters. Placer mining is an ancient method of using water to excavate, transport, concentrate, and recover heavy minerals from alluvial or placer deposits. Examples of deposits mined by means of this technique are the gold-bearing sands and gravel that settle out from rapidly moving streams and rivers at points where the current slows down. Placer mining takes advantage of gold's high density, which causes it to sink more rapidly from moving water than the lighter siliceous materials with which it is found.
Hard rock mining is the process of using open pit or underground mining tunnels to retrieve the gold from the rock. This method of gold mining is responsible for recovering most of the worlds gold supply. Miners dig a tunnel into the solid rock. They often risked their health, digging with picks and shovels during long shifts in these dark, damp tunnels, building the shafts and carting out the ore.
Byproduct mining is related to hard rock mining in that open pit or underground mining tunnels are used. In byproduct mining, gold is a secondary find. The main purpose of the mining operation is the recovery of Copper, sand, gravel or other products but significant quantities of Gold exist to make byproduct mining a profitable venture. An example of this kind of mining would be the Grasberg mine is Papua, Indonesia, which was developed for extracting Copper from the earth. Though Gold is not the primary product, this mine produces more Gold than any other mine in the world.
The final category of gold mining is the Processing of gold ore. This method is largely becoming deprecated as the yield of Gold is often very low and the environmental impact and costs of the operation are substantial. The Gold ore is finely crushed rock or earth containing trace amounts of Gold which are extracted using a chemical process. The most commonly used chemical for this process is Cyanide.
REFINING OF GOLD :
The final stage of gold mining is the refining which involves removing impurities that remain after the smelting process. Refining companies receive gold bars, as well as scrap gold, and liquefy the metal in a furnace. Workers add borax and soda ash to the molten metal, which separates the pure gold from other precious and less precious metals. A sample is then taken to a lab for tests that measure the gold content. In most cases, the gold is 99.9 percent pure. Workers cast the gold produced during refining into bars. Pure gold is generally too soft for most practical applications, so other metals are nearly always added to it. When gold is combined in this way, it forms an alloy. For example, white gold is made by combining gold with nickel, silver or palladium. Red or pink gold is an alloy of gold and copper. And blue gold is the result of mixing gold with iron.
Karatage refers to how much gold is present in an object versus another alloy. A higher karatage indicates a higher proportion of gold in the sample. So, 24-karat gold is 100 percent gold, while 12-karat gold has exactly half as much. The common karatages are shown in the accompanying sidebar. For example, the people of India are partial to 22-karat gold, while Europeans prefer 18-karat gold. In the United States, 14-karat gold, which offers a balance between gold content, hardness and affordability, is by far the most popular.
GOLD MINING IN THE UNITED STATES :
Gold mining in the United States has taken place continually since the discovery of gold at the Reed farm in North Carolina in 1799. The first documented occurrence of gold was in Virginia in 1782.Some minor gold production took place in North Carolina as early as 1793. The discovery on the Reed farm in 1799 which was identified as gold in 1802 and subsequently mined marked the first commercial production. The large scale production of gold started with the California Gold Rush in 1848.
GOLD MINING BY STATE :
* Alabama :
Gold was discovered in Alabama about 1830, shortly following the Georgia Gold Rush. The principal districts were the Arbacoochee district in Cleburne County, mostly from placer deposits, and the Hog Mountain district in Tallapoosa County, which produced 24,000 troy ounces (750 kg) from veins.
* Alaska :
Russian explorers discovered placer gold in the Kenai River in 1848, but no gold was produced. Gold mining started in 1870 from placers southeast of Juneau. Alaska produced a total of 40,300,000 troy ounces (1,250,000 kg) of gold from 1880 through the end of 2007. In 2015 Alaskan mines produced 873,984 troy ounces (27,183.9 kg) of gold, which is about 12.7% of US production. The largest gold producer is the Fort Knox mine, a large open pit and cyanide leaching operation in the Fairbanks mining district. Fort Knox produced 401,553 troy ounces (12,489.7 kg) of gold in 2015. The Pogo mine (283,000 ounces) and Kensington mine (128,865 ounces) gold mines and the Greens Creek polymetallic mine (60,566 ounces) accounted for the remainder of 2015 gold production .
* Arizona :
away by the California Gold Rush. Other gold mining under Spanish and Mexican rule took place in the Oro Blanco district of Santa Cruz County, and the Arivaca district, Pima County. Mountain man Pauline Weaver discovered placer gold on the east side of the Colorado River in 1862. Weaver's discovery started the Colorado River Gold Rush to the now ghost town of La Paz, Arizona and other locations along the river in the ensuing years.. The most prominent of these were those of the San Francisco district, which includes the towns of Oatman, Bullhead City and Katherine in Mohave County was discovered in 1863 or 1864. The district produced 2.0 million ounces of gold through 1959. The gold-bearing quartz veins of the Vulture Mine, southwest of Wickenburg, in Maricopa County were discovered in 1863. The mine produced 366,000 troy ounces (11,400 kg) of gold through 1959.The last gold mine to operate in Arizona was the Gold Road mine at Oatman, which shut down in 1998. Patriot Gold is exploration drilling at the Moss mine at Oatman.In 2006, all of Arizona's gold production came as a byproduct of copper mining.
* Colorado :
Gold was discovered in 1858 during the Pike's Peak Gold Rush in the vicinity of present day Denver in 1858, but the deposits were small. The first important gold discoveries in Colorado were in the Central City-Idaho Springs district in January 1859. Only one Colorado mine continues to produce gold, the Cripple Creek & Victor Gold Mine at Victor near Colorado Springs, an open-pit heap leach operation owned by Newmont Mining Corporation, which produced 350,000 troy ounces (11,000 kg) of gold in 2016.
* Florida :
Small amounts of gold were mined commercially in North Eastern Florida during the late 19th Century. No records are extant on the amount of gold produced, but the find was insufficient to keep the operation running commercially, and the small amount of pay dirt was depleted within a matter of months.
* Georgia :
Georgia is credited with a total historical production of 871,000 troy ounces (27,100 kg) of gold from 1830 through 1959. Although historically important, the state is not currently a gold producer.
* Idaho :
Gold was first discovered in Idaho in 1860, in Pierce at the juncture where Canal Creek meets Orofino Creek. The leading historical gold-producing district is the Boise Basin in Boise County, which was discovered in 1862 and produced 2.9 million troy ounces (90.2 tonnes), mostly from placers. The French Creek-Florence district in Idaho County began in the 1860s, and has produced about 1 million troy ounces (31 tonnes) from placers.The Silver City district in Owyhee County began producing in 1863, and made over 1 million troy ounces (31 tonnes), mostly from lode deposits.The Coeur d'Alene district in Shoshone County has made 44,000 troy ounces (1,400 kg) of gold as byproduct to silver mining.In 2006, active gold mines in Idaho included the Silver Strand mine and the Bond mine.
* Maryland :
Gold was reported in Maryland as early as 1830, but no production resulted. Placer gold was discovered at Great Falls near Washington, DC in 1861 during the American Civil War by Union soldiers from California. After the war a number of mines were opened on gold-bearing quartz veins in Montgomery County. Total production was about 6,000 troy ounces (190 kg).
* Michigan :
Approximately 29,000 troy ounces (900 kg) of gold were produced from the Ropes gold mine northeast of Ishpeming in Marquette County, Michigan. The underground mine, originally operated from 1880 to 1897, and reopened from 1983?1989,[26] extracted gold from quartz veins.
* Montana :
Gold was first discovered in Montana in 1852, but mining did not begin until 1862, when gold placers were discovered at Bannack, Montana in 1862. The resulting gold rush resulted in more placer discoveries, including those at Virginia City in 1863, and at Helena and Butte in 1864. In 1867, the Atlantic Cable Quartz Lode was located.The Butte district, although mined primarily for copper, produced 2.9 million ounces (91 tones) of gold through 1990, almost all as a byproduct of copper production.Current active hardrock gold mines include the Montana Tunnels mine, and the Golden Sunlight mine. Active gold placers include the Browns Gulch placer and the Confederate Gulch placer. Gold is also produced from three platinum mines in the Stillwater igneous complex.
* Nevada :
Nevada is the leading gold-producing state in the nation, in 2015 producing 5,339,659 ounces (166.1 tonnes), representing 78% of US gold and 5.4% of the world's production. Much of the gold in Nevada comes from large open pit mining and with heap leaching recovery. Newmont and Barrick operate the largest mining operations, on the prolific Carlin Trend, one of the world's richest mining districts.
* New Mexico :
Gold was first discovered in New Mexico in 1828 in the "Old Placers" district in the Ortiz Mountains, Santa Fe County, New Mexico.In 1877, two prospectors collected float in the area of the future Opportunity Mine near Hillsboro, New Mexico, which was assayed at $160 per ton in gold and silver. Soon, ore was discovered at the nearby Rattlesnake vein and a placer deposit of gold was found in November at the Rattlesnake and Wicks gulches. Total production prior to 1904 was about $6,750,000
* North Carolina :
North Carolina was the site of the first gold rush in the United States, following the discovery of a 17-pound (7.7 kg) gold nugget by 12-year-old Conrad Reed in a creek at his father's farm in 1799. Gold was produced from 15 districts, almost all in the Piedmont region of the state. Total gold production is estimated at 1.2 million troy ounces (37.3 tonnes).
* Oregon :
Although gold mines are spread over much of Oregon, almost all of the gold produced has ome from two principal areas: the Klamath Mountains in southwest Oregon, including Coos, Curry, Douglas, Jackson and Josephine counties; and the Blue Mountains in northeast Oregon, mostly in Baker and Grant counties.Prospectors from Illinois discovered placer gold in the Klamath Mountains of southwest Oregon in 1850, starting a rush to the area. Lode gold deposits were also discovered.Travelers along the Oregon Trail bound for the Willamette Valley are said to have discovered gold in northeastern Oregon in 1845, but mining in earnest did not begin until 1861.
* Pennsylvania :
About 37,000 troy ounces (1,200 kg) of gold was produced from the Cornwall iron mine five miles south of Lebanon, Lebanon County, Pennsylvania. Although the deposit produced iron since 1742, no gold was reported from the mine until 1878.
* South Carolina :
South Carolina had a number of lode gold mines along the Carolina Slate Belt.The Haile deposit was discovered in Lancaster County in 1827, and at least 257,000 troy ounces (8,000 kg) of gold were extracted intermittently between then and 1942. Beginning in 1951, the deposit was mined for associated sericite, which was used as a white filler. The mine was reopened as an open pit in the 1980s, and operated until 1992. Ocean Gold Corp. restarted mining at the Haile deposit 2016. The company expects to produce an average of 126,700 ounces of gold per year for 13.25 years.The Brewer mine operated from 1828 to 1995, and is now a federal Superfund site.Kennecott Minerals operated the Ridgeway open-pit gold mine from 1988 to 1999, and the land is now being reclaimed by Kennecott.The Barite Hill mine operated from 1990 to 1994.
* South Dakota :
The only operating gold mine in South Dakota is the Wharf mine, at Lead, an open pit heap leach operation operated by Coeur Mining that produced 109,000 ounces of gold in 2016.
* Tennessee :
Placer gold was discovered on Coker Creek in Monroe County, Tennessee in 1827. The district produced about 9,000 troy ounces (280 kg).About 15,000 troy ounces (470 kg) of gold was recovered from the massive sulfide copper ores at Ducktown, Tennessee.
* Texas :
Some prospects have been excavated for gold on the Llano Uplift of central Texas. Gold prospects include the Heath mine and the Baby head district, both in Llano County, and the Central Texas mine in Gillespie County. Gold production, if any, is not known. Historically, the Lost Nigger Gold Mine may be in Texas.
* Utah :
Most gold produced in Utah today is a byproduct of the huge Bingham Canyon copper mine, southwest of Salt Lake City. In 2013, the Bingham Canyon mine produced 192,300 troy ounces (5,980 kg) of gold. Over its life, Bingham Canyon has produced more than 23 million ounces (715 tonnes) of gold, making it one of the largest gold producers in the US.The Barneys Canyon mine in Salt Lake County, the last primary gold mine to operate in Utah. Utah gold production was 460,000 troy ounces (14,000 kg) in 2006.
* Washington :
Gold was first discovered in Washington in 1853, as placer deposits in the Yakima Valley. Production from the state never exceeded 50,000 troy ounces per year until the mid-1930s, when large hard rock deposits were developed near the Chelan Lake and Wenatchee deposits in Chelan County, and the Republic deposit in Ferry County. Production through 1965 is estimated to be 2.3 million ounces.
* Wyoming :
Gold was discovered at the South Pass-Atlantic City-Sweetwater district in present Fremont County in 1842. The placers were worked intermittently until 1867, when the first important gold vein was discovered, and prospectors and miners rushed to the area.. The towns of South Pass City, Atlantic City, and Miner's Delight catered to the miners. The district was nearly deserted by 1875, and was worked only intermittently afterward. Total gold production was about 300,000 troy ounces (9,300 kg). In 1962, the district became the site of a major iron mine.
* Moraine gold :
Several states (e.g., Illinois, Indiana, Ohio, Pennsylvania) have placer gold deposits, despite having no hard rock gold deposits. This placer gold is found north of, or near the terminus of, Pleistocene, or earlier, moraines left by Ice Age glaciers that pushed gold-rich dirt down from Canada, where hard rock gold deposits do exist, and which were scoured by glaciers. Small commercial operations have existed at various times, to mine this gold, with various degrees of limited success. The southernmost limit of these moraines, Pleistocene and older, is approximately at the Ohio River for Illinois, Indiana, and Ohio. The moraines in Pennsylvania are in the northwestern and northeastern portions of the Commonwealth.
CALIFORNIA GOLD RUSH :
California gold rush was a rapid rush of fortune seekers in California that began after gold was found at Sutter's Mill in early 1848 and reached its peak in 1852. According to estimates, more than 300,000 people came to the territory during the Gold Rush.
In 1848 John Sutter was having a water-powered sawmill built along the American River in Coloma, California. On January 24 his carpenter, James W. Marshall, found flakes of gold in a streambed. Sutter and Marshall agreed to become partners and tried to keep their find a secret. The discovery, however, soon spread, and they were surrounded by thousands of fortune seekers. From the East, prospectors sailed around Cape Horn or risked disease hiking across the Isthmus of Panama. By August 1848, 4,000 gold miners were in the area, and within a year about 80,000 had arrived at the California goldfields. By 1853 their numbers had grown to 250,000. Although it was estimated that some $2 billion in gold was extracted, few of the prospectors struck it rich. The work was hard, prices were high, and living conditions were primitive. The Gold Rush loosen as the most-workable deposits were exhausted and organized capital and machinery replaced the efforts of individual miner-adventurers with more efficient and business like operations. Likewise, the lawless and violent mining camps gave way to permanent settlements with organized government and law enforcement. Those settlements that lacked other viable economic activities soon became ghost towns after the gold was exhausted. The California Gold Rush peaked in 1852, and by the end of the decade, it was over. The Gold Rush had a profound impact on California, dramatically changing its census. Before the discovery of gold, the territory's population was approximately 160,000, the vast majority of whom were Native Americans. By about 1855, more than 300,000 people had arrived. Most were Americans, though a number of settlers also came from China, Europe, and South America. The massive rush gave rise to numerous cities and towns, with San Francisco gaining particular prominence. The Gold Rush was credited with hastening statehood for California in 1850.
GOLD MINING IN INDIA :
India's been the number one source of global gold demand for decades importing close to a 1,000 tonnes in good years.But, following the closure of the iconic Kolar Gold Field in 2001 after more than 120 years and 800 tonnes or 26 million troy ounces of production, India is home to a single gold mine.The Hutti Gold Mine in the southwestern state of Karnataka is also an historic mine where the production started in 1902, is located in the same greenstone belt as Kolar.Hutti produced some 45,000 ounces in 2015 and even after adding gold produced as a byproduct of copper mining on the subcontinent, India's gold output is little more than 60,000 ounces. The rate of production is also the lowest since at least 1970.
GOLD MINING IN AUSTRALIA :
Gold mining in Western Australia is the fourth largest commodity sector in Western Australia, behind iron ore, crude oil, with a value of A$10 billion.Gold mining in Western Australia dates back to the 1880s but became a significant industry in the 1890s, following gold discoveries at Coolgardie in 1892 and Kalgoorlie in 1893. It reached an early peak in 1903, experienced a revival in the 1930s and a further revival in the 1980s. Between, the industry declined a number of times, such as during the two world wars, experiencing an absolute low point in 1976.
CURRENT SITUATION :
Western Australia produced over 50% ($69.5 billion) of all Australian mineral and petroleum sales, which made up 88% of the state's merchandise exports in 2015-16. In 2015-16, gold was ranked third in the list of resources exported by Western Australia with regard to value, behind iron ore and petroleum, with a value of A$10 billion. The state produced 6.27 million troy ounces of gold, or 195 tonnes, 6% of world production. During 2014-15 the Western Australian gold mining industry directly employed 19,175 people.By 2008-09, gold had jumped into fourth spot in regards to export value with a value of A$5.2 billion, overtaking alumina. The average gold price was US$874 per ounce in 2008?09, or A$1,171 per ounce, which was 28 per cent higher than the previous year. While the value of sales increased by 25%, the gold output of the state decreased by 4%, to 4.4 million ounces. Western Australia accounted for 62% of Australia's gold production in 2008-09.In 2008-09, 41% of Western Australia's gold exports went to the United Kingdom, followed by India with 34%. Thailand and the United Arab Emirates hold third spot jointly, with an 8% share.The Golden Mile, producing 20 tonnes of gold, was Western Australia's top-producing mine in 2008-09, followed by the Telfer with 18.1 tonnes and St Ives with 13.4 tonnes. With a project cost of US$2.9 billion, the Boddington Gold Mine is by far the biggest gold project to commence production in the state in 2009, being capable to produce 900,000 ounces of gold per annum.The number of people employed in the Western Australian gold mining industry rose to 15,572 in 2008-09.
WORLD PRODUCTION :
USES :
Gold is extremely malleable, conducts electricity, doesn't tarnish, alloys well with other metals and is easy to work into wires or sheets. Not to mention, gold is unrivaled in its natural brilliant luster and glossy shine. Because of these unique properties, gold makes its ways into almost every sphere of modern life in some way or the other.
Here are the 6 most common uses for gold in the world today:
? Jewelry :
About 78% of gold consumed each year is made into jewelry. Jewelry is the most common way gold reaches consumers, and has been a primary use for the metal in various cultures. Because of its beautiful and durable properties, gold jewelry is an adornment that is both ethereal and revered.
? Finances and Investing :
Because gold is so rare and highly valued, this precious metal makes a natural currency. The U.S. used to hold all its monetary currency to a gold standard. In an uncertain economy, gold has emerged as a possible financial staple. One of the most common ways to hold or invest in gold is in gold coins, gold bars, also gold bullion.
? Electronics and Computers :
Gold is a highly efficient conductor that is able to carry tiny electrical charges, and because of this property a small amount is found in almost all electronic devices, including cell phones, televisions, GPS units and more. Because gold is such an efficient conductor of electrical charges, it is also often found in desktop and laptop computers to transfer information quickly.
? Dentistry and Medicine :
Gold makes for the best fillings, crowns, bridges and orthodontic appliances because the metal is chemically inert, easy to insert and nonallergenic. Gold has been used in dentistry since 700 B.C. In the medical field, small amounts of gold isotopes are used in certain radiation treatments and diagnosis.
? Aerospace :
In the aerospace industry where reliable and effective technologies are key to survival, gold plays an essential role. Gold is used to lubricate mechanical parts, conduct electricity and coat the insides of space vehicles to protect people inside from infrared radiation and heat.
? Medals and Awards :
As a highly esteemed precious metal, gold makes a natural appearance in crowns, awards and religious statues. In everything from Academy Awards to Olympic medals, gold is recognized for its admirable qualities and it holds a permanent place of value in humanity's eyes.
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