Some Industrial Examples

Some industrial examples are presented to illustrate in a practical manner the techniques described previously.

• A classic case
• A case of cyanidation in pile
• A case of refractary mineral needing a burning

A classic factory: PINSON Co. (Nevada, USA)

Mineralization Characteristics
Oxidized mineral in silicose and hard gangue (Wi = 20 Kwh/st) containing clay passings.

Content: 4 g/tons.
Capacity Of Treatment: 1,360 TM/day.

Treatment Characteristics
This mentions a cyanidation in tubs, shaken from the mineral after the granulometric reduction; the gold is recuperated by absorption over active carbon.

The mineral after being shredded in two stages, to less than 10 mm., is grinded in a net of 75 micrones in two chain grinders, placed in series and working in closed circuit; the reactives of the cyanidation are added to the first grinder. A thickness allows to separate a thick pulp (40% of solids) of almost half of the recuperable gold which is immediately sent to the columns of absorption above the carbon.

The submitted pulp, afterwards, to a mechanical agitation in 4 reactors of cyanidation, assuring a time of permanence of 24 hours. The gold is immediately recuperated by a circuit of carbon in pulp to five reactors.

The carbon is out of place discontinued during 72 hours at 90°C above atmospheric pressure (Zadra procedure).

In a very classic manner, the gold is deposited by electrolisis in the cathodes in steel wool well refined in an oven at induction for conducing to the gold dossifying 975% Au, 1% Ag, while the active carbon is regenerated in a rotational oven.

The global recuperation is of 86/.