What is mining and recovery?
Various mining techniques are employed worldwide to extract this most precious of metals from the earth. The oldest of these methods is called placer mining, more commonly known as panning. As a result of years of erosion the rock containing the gold disintegrated and the gold particles flowed into nearby rivers and streams. As gold resists weathering, pieces ranging from dust-size up to large nuggets were recovered by prospectors as they used their pans to wash through the silt and gravel from the river bottoms. Gold is heavier than sand so the unwanted material could be gently rinsed away leaving the particles of gold behind. Open pit mining is another technique used when the gold is close to the earth’s surface. In Brazil, for example, prospectors (garimpeiros) hand-dig open pits half a mile wide and up to 600 feet deep. After carrying 60-pound sacks of gold-bearing rock up the steep slopes the rock is pulverized and the tiny flecks of gold are separated from the gravel by use of a
