1
25-102
Synergistic Effects of the Jetti Chalcopyrite Leach Catalyst and
Biooxidation—A Bioreactor Example
Candice Simms
Jetti Resources, Vancouver, CA
Monserrat Rebolledo
Jetti Resources, Vancouver, CA
John L. Uhrie
Jetti Resources, Boulder, CO
ABSTRACT
Jetti Resources has developed a catalyst which overcomes
the passivation of primary sulfides, enhancing the heap
leach recovery of copper from chalcopyrite. It is important
to emphasize that heap leaching of copper sulfides, whether
with or without the Jetti catalyst, is a biooxidative process.
We have demonstrated the efficacy of Jetti’s technology in
bioreactors, with a chalcopyrite-dominant porphyry ore. In
the presence of Jetti’s technology, optimal bioleaching con-
ditions significantly increase copper extraction by 2.6 times
that of the baseline.
INTRODUCTION
The world’s largest source of copper is contained in the
hypogene zone of porphyry ore bodies, dominantly pres-
ent as the mineral chalcopyrite (CuFeS2) (Schlesinger et. al,
2011). The conventional method to produce copper from
chalcopyrite involves bulk mining, fine grinding, flotation,
dewatering, and finally smelting and electrorefining.
A lesser but still significant percentage of the world’s
copper is produced from the oxide and supergene zones of
copper porphyry ore bodies (ICSG, 2022). Copper from
these minerals is economically recovered using the proven
industrial hydrometallurgical process of heap leaching.
Heap leaching involves using bulk mining methods, but
instead of using conventional milling and smelting, these
ores are stacked into large stockpile or heaps (with or with-
out crushing) and irrigated with an acid-ferric sulfate to
leach copper into solution. The now-aqueous copper is
then concentrated and recovered using conventional sol-
vent extraction- electrowinning (SXEW) techniques.
Chalcopyrite leaching is slowed due to the presence of
an iron depleted, copper rich layer which rapidly forms on
the mineral surface under typical bioleaching conditions.
This surface passivation layer is a p-type semiconductor
which while in contact with a n- type semiconductor of
unleached chalcopyrite forms an electrical diode (Ren et
al., 2022). Diodes are one-way electrical gates which will in
turn effectively halt leaching reactions.
Jetti Resources has invested nearly 10 years and millions
of dollars into developing a leach alternative that allows the
recovery of copper from chalcopyrite ores. This patented
technology requires little to no environmental permitting,
is fully compatible with existing heap leach SXEW process-
ing, has very low capital intensity, is relatively inexpensive,
and is stable under acidic conditions. The Jetti catalyst
reacts with the chalcopyrite surface and overcomes the pas-
sivation layer, allowing economic hydrometallurgical recov-
ery of copper from low-grade chalcopyrite dominant ores.
EXPERIMENTAL
A series of bioleach reactors were operated at the SGS
Burnaby laboratories using inoculum and mine site raf-
finate as lixiviant. A general description of the analytical
procedure is summarized in the following sections.
Materials
A chalcopyrite dominant ore sample from a “typical” cop-
per porphyry deposit was used for the test work. The sam-
ple copper grade is below mill-cutoff and contains 0.08%
Cu and 2.4% Fe as determined by multi- element analysis
by ICP and shown in Table 1.
25-102
Synergistic Effects of the Jetti Chalcopyrite Leach Catalyst and
Biooxidation—A Bioreactor Example
Candice Simms
Jetti Resources, Vancouver, CA
Monserrat Rebolledo
Jetti Resources, Vancouver, CA
John L. Uhrie
Jetti Resources, Boulder, CO
ABSTRACT
Jetti Resources has developed a catalyst which overcomes
the passivation of primary sulfides, enhancing the heap
leach recovery of copper from chalcopyrite. It is important
to emphasize that heap leaching of copper sulfides, whether
with or without the Jetti catalyst, is a biooxidative process.
We have demonstrated the efficacy of Jetti’s technology in
bioreactors, with a chalcopyrite-dominant porphyry ore. In
the presence of Jetti’s technology, optimal bioleaching con-
ditions significantly increase copper extraction by 2.6 times
that of the baseline.
INTRODUCTION
The world’s largest source of copper is contained in the
hypogene zone of porphyry ore bodies, dominantly pres-
ent as the mineral chalcopyrite (CuFeS2) (Schlesinger et. al,
2011). The conventional method to produce copper from
chalcopyrite involves bulk mining, fine grinding, flotation,
dewatering, and finally smelting and electrorefining.
A lesser but still significant percentage of the world’s
copper is produced from the oxide and supergene zones of
copper porphyry ore bodies (ICSG, 2022). Copper from
these minerals is economically recovered using the proven
industrial hydrometallurgical process of heap leaching.
Heap leaching involves using bulk mining methods, but
instead of using conventional milling and smelting, these
ores are stacked into large stockpile or heaps (with or with-
out crushing) and irrigated with an acid-ferric sulfate to
leach copper into solution. The now-aqueous copper is
then concentrated and recovered using conventional sol-
vent extraction- electrowinning (SXEW) techniques.
Chalcopyrite leaching is slowed due to the presence of
an iron depleted, copper rich layer which rapidly forms on
the mineral surface under typical bioleaching conditions.
This surface passivation layer is a p-type semiconductor
which while in contact with a n- type semiconductor of
unleached chalcopyrite forms an electrical diode (Ren et
al., 2022). Diodes are one-way electrical gates which will in
turn effectively halt leaching reactions.
Jetti Resources has invested nearly 10 years and millions
of dollars into developing a leach alternative that allows the
recovery of copper from chalcopyrite ores. This patented
technology requires little to no environmental permitting,
is fully compatible with existing heap leach SXEW process-
ing, has very low capital intensity, is relatively inexpensive,
and is stable under acidic conditions. The Jetti catalyst
reacts with the chalcopyrite surface and overcomes the pas-
sivation layer, allowing economic hydrometallurgical recov-
ery of copper from low-grade chalcopyrite dominant ores.
EXPERIMENTAL
A series of bioleach reactors were operated at the SGS
Burnaby laboratories using inoculum and mine site raf-
finate as lixiviant. A general description of the analytical
procedure is summarized in the following sections.
Materials
A chalcopyrite dominant ore sample from a “typical” cop-
per porphyry deposit was used for the test work. The sam-
ple copper grade is below mill-cutoff and contains 0.08%
Cu and 2.4% Fe as determined by multi- element analysis
by ICP and shown in Table 1.