3652 XXXI International Mineral Processing Congress 2024 Proceedings/Washington, DC/Sep 29–Oct 3
NON-MERCURY, NON-CYANIDE
PROCESS (ALTERNATIVE)
The process flowsheet for the non-mercury, non-cyanide
gold processing plant used for this study is illustrated in
Figure 2.
The process utilizes a jaw crusher in series with a roll
crusher for the crushing circuit. The grinding circuit con-
sists of a ball mill and hydrocyclone to facilitate size reduc-
tion of the ore particles to the target P80 of 75 microns.
The cyclone overflow is fed to a gravity concentra-
tor where the concentrates are directed to a shaking table
before panning and smelting. The gravity concentrator tail-
ings proceed to the flotation circuit for the recovery of gold-
containing sulfides from the ore. The flotation concentrates
were treated using hypochlorite leaching (Regidor, et al.,
2022) and precipitation using sodium metabisulfite and
ascorbic acid. The recovered gold precipitates were then
collected via filtration for smelting. The tailings from flota-
tion were thickened while the barren solution from precipi-
tation was neutralized before transferring to a settling pond
for disposal.
All the gold recovered from each process was weighed
and the recoveries were calculated.
RESULTS AND DISCUSSION
Analysis of the grab samples from the ore indicated that
5.57% moisture was present in the ore while the head grade
was determined to be 2.41 grams of gold per metric ton.
These values were used in calculating tonnage and recover-
ies per process.
Figure 2. Non-mercury, non-cyanide gold processing method
NON-MERCURY, NON-CYANIDE
PROCESS (ALTERNATIVE)
The process flowsheet for the non-mercury, non-cyanide
gold processing plant used for this study is illustrated in
Figure 2.
The process utilizes a jaw crusher in series with a roll
crusher for the crushing circuit. The grinding circuit con-
sists of a ball mill and hydrocyclone to facilitate size reduc-
tion of the ore particles to the target P80 of 75 microns.
The cyclone overflow is fed to a gravity concentra-
tor where the concentrates are directed to a shaking table
before panning and smelting. The gravity concentrator tail-
ings proceed to the flotation circuit for the recovery of gold-
containing sulfides from the ore. The flotation concentrates
were treated using hypochlorite leaching (Regidor, et al.,
2022) and precipitation using sodium metabisulfite and
ascorbic acid. The recovered gold precipitates were then
collected via filtration for smelting. The tailings from flota-
tion were thickened while the barren solution from precipi-
tation was neutralized before transferring to a settling pond
for disposal.
All the gold recovered from each process was weighed
and the recoveries were calculated.
RESULTS AND DISCUSSION
Analysis of the grab samples from the ore indicated that
5.57% moisture was present in the ore while the head grade
was determined to be 2.41 grams of gold per metric ton.
These values were used in calculating tonnage and recover-
ies per process.
Figure 2. Non-mercury, non-cyanide gold processing method