Gold has been important as precious metal since early times. The extraction and recovery of gold ores has experimented a special interest each time that the international price takes a high value. Then, techniques of extraction and treatment trend to improve gold recovery each time more and more. Process selection is an iterative procedure which usually starts as soon as exploration has established the presence of gold mineralization in sufficient grade and tonnage for the orebody to be considered a potentially economic reserve. The effort devoted to process selection is related to the degree of certainly of the grade and reserve estimations and their absolute values, such as attractiveness of the deposit.
The risk associated with the development of gold projects can be minimized planning a good work metallurgical program, and considering aspects that have been considered in the project: capital, profitability, risk and environmental factors. It is essential in the evaluation of a gold deposit to have, as accurately as possible, a model of the mineralized zone geometry, shape, size, quality, variability, and limits. Physical, chemical and geological characteristics may vary greatly within a single deposit and from deposit to deposit. Critical data can be collected in a variety of ways, including drilling, surface and/or underground mapping, geophysical or geochemical surveys, or studies of rock mechanics properties, mineralogical types and relations.