Here are opinions and answers from FAQ Farmers:
The first method would be for testing if there is gold present, the second is the basis of extraction used in a crushing mill. NOTE: gold is not wetted by water, so no parts of a crushing mill are lubricated by petroleum compounds because the fine gold would float away in the oil. Usually molasses is used as a lubricant around gold machinery.
An additional method involves the above mentioned property of gold not being wetted by water. A slurry of finely crushed gold ore is fed into a tank where fine bubbles are used to rapidly stir the slurry. These bubbles will suspend fine gold which is skimmed from the froth.
Another method is to use Mercury to combine with the gold as an amalgam. This makes a lump of gold that is then heat refined and the mercury condensed for reuse. NOTE: mercury fumes are very dangerous and can lead to brain damage. This is not used much anymore mostly due to the expense of mercury and its hazards.
The most common beneficiation method used in commercial ores that consist of finely dispersed particles of gold, is the cyanide leaching process. This is where a fine slurry of gold ore is mixed with sodium cyanide, this solution has the rare ability to dissolve gold. The gold is then recovered by passing the liquid over zinc shavings and heating the zinc thus melting gold plated on the shavings. Huge piles of low grade ore are treated this way.
Since most gold mined actually comes from silver mines as a part of a solid solution series between gold and silver, nitric acid is used to remove the silver from the gold, with the silver then removed from the silver nitrate solution.
Aqua Regia (a mixture of concentrated nitric and hydrochloric acids) can be used to dissolve gold, which can then be precipitated out using a selective reducing agent.
the rock is hader
what is difference in a gold ring and rock salt
Gold is an element.
Classic Rock Gold was created on 2005-04-26.
Southern Rock Gold was created on 2005-10-11.
Neither its a precious metal
Gold is an elemental metallic mineral, and therefore is not a rock as described in the metamorphic, sedimentary, and igneous rock cycle.
it is found in a rock
Gold is usually found in metamorphic rock but can also be found in sedimentary rock. In deep mines, quartz rock is found in association with gold.
by chipping the rock of the gold
gold does not form in a rock. however it does forms along igneous rock and quarts veins. For gold to be present one of these two rocks will more then likely be there as well. (In some large gold nuggets, pieces of quarts will be stuck to the gold)
California has more earthquakes and the type of rock where gold is. In Illinois, we have mostly sedimentary rock so we don't have gold deposits.