SOME ELEMENTS OF INTEREST
GOLD
There are four basic methods of gold recovery depending on the deposits. Placer mining where panning, sluicing or dredging is used to separate the dense gold from other materials; Either open pit or underground mining to retrieve gold from hard rock; Secondary recovery from the spoil produced as a byproduct of mining for other elements such as copper; gold ore mining, again open pit or underground, however this method tends to produce a very low yield.
SILVER
Silver ore mining, open pit or underground, but in general silver ores contain very low quantities of silver together with much higher concentrations of minerals such as copper and lead. It is therefore most often a secondary product recovered from mines dedicated to other elements.
COPPER
Copper, along with by-products such as zinc, silver, gold and molybdenum, is predominantly mined from open cast pits.
LITHIUM
There are two main ways to extract lithium from the ground. Generally, in South America the lithium is recovered from salt flats (salars). The brine is pumped from the earth and placed in pools where the water evaporates leaving behind lithium and other elements.
Predominantly in Australia a lithium rich mineral, spodumene is mined in open pits.
RARE EARTHS
The Lanthanides or Rare Earths are generally extracted from open cast mines or in situ by passing solvents through the rock to leach the REE elements.
