At the end ofBlizzard Entertainment celebrated the 10th anniversary of World of Warcraft.
Some early miners also used an early form of hardrock mining, digging solid veins of gold out of rock, where mineralized water had deposited it over thousands of years. Today, gold is extracted in hardrock mines that directly mine the source rock, or "lode" of gold, where it was originally deposited by geochemical processes.
Most ore accessed this way today contains only microscopic grains of gold, and it takes tons of rock to produce ounces of gold. Hardrock mines can be either underground mines or strip mines, and are usually more environmentally destructive than placer mining.
Copyright held by photographer Placer Mining The stereotypical grizzled gold-rush prospector panning for gold was searching for "placer gold", or gold deposited in a waterway.
Placer mining takes a variety of formsincluding panning, "sluice-boxing", hydraulic mining, and dredging. All of these techniques use gravity and water to separate the dense gold from the lighter sand and gravel.
Some modern commercial placer operations are quite large and utilize heavy equipment and river diversions. The sources of all placer gold are "lodes", or veins of gold naturally formed within the rock.
Ongoing weathering and erosion of rock outcrops continuously exposes new fragments of gold that wash downstream. Because gold is far denser than most rock Gold accumulates in such places while other rock and sediment is washed further downstream.
Mine pit at Fort Knox hardrock gold mine Fort Knox hardrock gold mine pit source: Copyright held by photographer Hardrock Lode Mining The vast majority of current gold production comes from commercial hardrock mining operations.
In these mines, the gold is extracted from the rock where it was originally deposited. Some hardrock mines are underground mines.
A tunnel is drilled or blasted to the source of the ore, which is transported out for processing often by truck or rail. A variety of specific techniques can be used for mining the ore, depending on the geology of the area - such as block cavingwhich allows massive strip-mine scale underground excavation, or the more steretypical cut-and-fill and drift-and-fill techniques, where miners dig our out in long horizontal tunnels.
Other hardrock mines are large strip mines that remove the surface dirt and rock and then extract the ore from the resulting open pit. Removal of ore is often accomplished explosives, enormous power shovelsand massive trucks, some capable of carrying tons of rock in one load.
In both kinds of hardrock mining, the ore is then processed in some manner to remove the gold. Usually this entails crushing the rock into powder and using some combination of gravity, centrifugation, and "froth flotation" to perform an initial separation of gold from rock.
In many cases this is followed by some form of cyanide treatment to precipitate out the remaining gold. The remaining ore mud waste is known as "tailings"the disposal of which is one of the largest challenges facing a hardrock mine.
Gold is both highly valuable, and relatively useless. The vast majority of gold mined throughout history is now jewelry, or stored in vaults as an investment This means that governments are in effect lowering the cost of environmentally destructive mining, contributing to demand by hoarding large reserves, and then directly paying for the costs of mine cleanup.
All this in return for no material benefit to taxpayers The primary impacts of placer mining are habitat destruction and sediment release. Habitat destruction occurs as a result of river diversions, and the disruption of riverbanks and river bottoms.
These activities also release large amounts of silt and sediment into downstream waterways, which can severely impact water quality. Modern commercial operations tend to use settling ponds to prevent this discharge. Hardrock mines have a much larger environmental footprint that placer mining, by virtue of their size, the chemistry of the ore deposits, the generation of extremely large volumes of hazardous waste material, and the use of toxic chemicals.
Modern commercial hardrock mines are massive operations, in some cases displacing and processing overtons of gold-bearing ore per day. In addition to the direct ecological disruption of mining on this scale, much of the gold mined this way is found in sulfur-bearing rocks.
In addition, many small mines use mercury for the separation of gold, while large mines instead use cyanide. Gold mining in Alaska Gold mining has a long history in Alaska, beginning with the Klondike Gold Rush at the end of the s.
Even today there exist a variety of placer mining operations ranging from large commercial placer mines to stream panning by tourists.This started with a tweet.
I’m embarrassed how often that happens. Frustrated by a sense of global mispriorities, I blurted out some snarky and mildly regrettable tweets on the lack of attention to climate change in the tech industry (Twitter being a sublime medium for the snarky and regrettable).
Climate change is the problem of our time, it’s everyone’s problem, and most of our problem. Nikola Tesla's article The Problem of Increasing Human Energy which first appeared in the June Century Magazine.
Written shortly after his return from Colorado, this piece contains a comprehensive description of Tesla's . Reconsidering the Value of Gold READ ESSAY Gold is both highly valuable, and relatively useless.
The vast majority of gold mined throughout history is now jewelry, or stored in vaults as an investment. Lifting the Veil: The best ever investigative history of of what's really going on behind the scenes in our world with over links to reliable sources to back up the stunning picture that is painted.
Knowledge is power. The Nationalist's Delusion. Trump’s supporters backed a time-honored American political tradition, disavowing racism while promising to enact a broad agenda of discrimination.
Songs "Classical" Artist Comments- Billboard Rank Subgenre Messiah George Frideric Handel The classic oratorio, especially popular around Christmastime, praises the Son who saved humanity by telling the stories of the Prophets who foretold his coming to earth, the annunciation to the shepherds of Christ's birth, the Passion of Christ, and finally the resurrection of the dead and Christ's.