Modern Gold Mining Techniques

Although gold mining is most often associated with an earlier era as a romantic career for frontiersmen, gold remains a valuable commodity today. While the goal of gold mining remains the same, new technology has given modern gold miners a leg up on their ancestral counterparts.

Panning

Although not suitable for industrial gold mining operations, gold panning remains popular among prospecting hobbyists due to its hands-on nature and its low cost. It is also perhaps the most iconic method of gold mining. Panning is a manual filtering process, where rocks, gravel and sand from riverbeds are put into a wide pan. Water is added to the pan, and the miner shakes the pan back and forth. As gold is much denser than sand or stone, the rocks and sand will be washed out of the pan while pieces of gold will settle to the bottom.

Sluicing

Sluicing takes advantage of the principles of panning, but uses mechanization and a much larger capacity to make it economically viable on a wide scale. Dirt and sand are loaded into the sluice box, which is a long metal slide with ridges on the bottom. Water is then added to the mixture. While the heavier gold will settle into the ridges, the lighter material will get washed out of the sluice box. The gold can then be retrieved.

Underground mining

While more labor intensive and dangerous than other modern gold mining techniques, underground mining is a popular and lucrative technique. Although mining for precious minerals has taken place since before recorded history, it is still a popular form of gold mining today. Mechanized mining equipment and safety regulations make modern underground mining safer and more efficient than in years past.

Gold cyanidation

This process involves adding the poisonous chemical cyanide to rocks that are thought to contain trace amounts of gold. The gold bonds with the cyanide, which can then be separated from the rock it was found in. This combination is called gold cyanide. Zinc is added to the gold cyanide to remove the cyanide, and then sulfuric acid is added to the zinc/cyanide mixture, which removes the zinc. What is left is a paste of pure gold ore.

Metal detection

Modern metal detectors can be used to find gold, but they do not distinguish between gold and other metals. And the fact that a tin can is much larger than the average nugget of gold you're likely to find means that other, less valuable minerals will show up on a metal detector much more often than gold will.

Resources

• Gold Prospectors Association of America