How gold is mined
As soon as it has been decided to explore a site for potential
mining activities, a range of technical actions commence, which
take into account various regulations, requirements and stan-
dards. If sufficiently high grades and amounts of gold are found
in a deposit for it to be considered economically viable, mining
activities can be permitted and then developed. Ore can be
mined from both open pits and underground mine sites. Four
steps will be necessary to mine the ore: drilling, blasting, loading
and hauling. Today’s operations are highly mechanized and
automated and are based on large, efficient, low-energy and
reliable machine and transport systems. Generally, the first pro-
cessing steps are crushing and grinding. Subsequent steps are
depending on the nature of the ore. In many cases, the gold is
associated to a copper mineral, which means the recovery takes
place simultaneously with the recovery of copper, and the pro-
duction of pure gold takes place at the smelter. In many cases,
gold can be recovered using gravity processes such as shaking
tables. In the global perspective, however, most gold is recovered
using cyanidation. Such processes have been used for more than
one hundred years to improve the processing results and to
eliminate the need for mercury amal-gamation. Cyanide is a
substance, which hasthe ability to extract gold and silver from ore
at very low concentrations. The leaching process involves form
ation of complexes of gold and cyanide, and the use of activated
carbon to bind the gold complexes. From the carbon then, the
complexes can be extracted and the metal can be recovered e.g.
by application of a subsequent electrowinning process. Refractory
gold – gold in a form not directly amenable for cyanidation - may
require oxidation, e.g., bio oxidation, in order to liberate the gold
and make it accessible to cyanidation.

After finishing mining, the exhausted mine site will be rehabilita-
ted and given back to nature for further uses such as a wildlife
habitat, recreation or building. This practice is the standard used
in Europe today. According to a reclamation plan put in place and
depending on the properties of the mining waste, the waste de-
posits are decommissioned either by covering with soil or equal material, or by inundation using water. The key parameter is then
to avoid exposure of the pyrite content to air. After covering,
vegetation is established, or measures to secure the water cover
are put in place. The area is then adapted to the most appro-
priate post mining land use, which may vary from caseto case.