Main Minerals Which Are Carriers of Gold

Some shown examples:

This article concludes about the present tendencies of the treatment of the minerals of gold and the techniques in development (the use of carbon in pulp, in particular by the clay minerals, the use of new reactive of lixiviation as is the case of the thiourea).

From the economical point of view, the mineral which has great predominance is the gold in a metallic or natural state, the same which can revert in a great variety of forms and dimensions in the different beds.

The particles of gold which are more currently found have dimensions which vary between more than ten microns and more than ten millimeters; the masses of gold which weigh between 50 to 100 Kg. have very well been found in the veins of quartz.

The texture of the natural gold varies equally in an important and noticeable manner in function of its origin and of secondary phenomenon (detritus character, metamorphic remobilization or even precipitations with the starting of oxidant, sulphur, chlorides solutions); these different forms are well described by Duan.

The natural gold has a very variable purity (between 45% and 100% Au) that depends in particular of its origin, such as Fisher shows: the silver (average content 10%) is the main impurity found; the copper and iron can equally, have light contents and thus be associated to gold. A particular case is constituted by the natural aleation with the silver, denominated electrum.

The telures constitute the second type of minerals which are carriers of gold in economic importance. These usually contain, besides the silver, the remains of mercury. They are sometimes accompanied by the natural gold (volcanic mineralization of the tertiary or Precambrian mineralization). Markham.

In the lighter contents, one can reach up to one hundredth of ppm, the gold can be found associated to sulphurs like the pyrite and the mispicquel principally, or the pyrrotine, the galena and the blenda, under a non-visible form with the help of the classic instruments of the mineralogy (optical or electronic microscope).

It is generally admitted that gold is present now under the form of submicroscopic inclusions of natural gold, even though some authors believe that this can constitute as a matter of fact in a solid solution in the interior of the sulphurs (Korobushkin).

We finally signal the rarest existence of auriferous compounds in base of bismuth or antimonies (aurostibine).