STUDY OF THE POSSIBILITY OF HEAP LEACHING OF GOLD FROM LEAD FLOTATION TAILINGS AT NOVOSHIROKINSK CONCENTRATION PLANT

Abstract

Tailings of lead flotation of the Novoshirokinsk concentration plant is a valuable mineral resource for
gold extraction. The gold content in the tailings of
lead flotation of Novoshirokinsk concentration plant
varies from 7 to 12 ppm. This secondary mineral
raw material contains: 0.47% lead; 0.99 % zinc;
0.29 % copper and 37.69 % iron. The geo-technology of a percolation activated gold leaching was
tested in this study. A direct cyanide leaching provides only 14 % gold extraction. Flotation tailings
contain 70% of –0.071 mm. Preliminary pelletizing
of fine material is necessary to ensure optimal hydrodynamic regime of column leaching. Sodium cyanide solution was added for pelletizing. Electrophoto-activated carbonate-based cyanide solution
saturated with oxygen was used for activated leaching. Direct cyanide leaching provides extraction of
only 14% of gold. Activated leaching by carbonaceous-cyanide solution significantly increases gold
recovery to pregnant solution (more than by 25% in
comparison with standard cyanidation). But it is still
not viable for realization. Roasting of slime tailings
of lead flotation provides liberation of refractory
gold and oxidation of the components causing an
unproductive cyanide consumption. Leaching of
roasted flotation slime provides the high level of
gold recovery (89-95%). This rate of gold recovery
is provided by the activated carbonaceous-cyanide
solution in the mode of high-speed leaching. The
high-speed leaching is implemented as follows: the
activated solution is being added to leaching column
until pellets are flooded. Then the irrigation stops.
The intensive hydrodynamic regime provides the
rapid gold recovery and reduces the “preg-robbing” effect.