OPERATION FOCUS
Paul Moore visited the Kyzyl gold mine
in East Kazakhstan, based on a deposit
that has had a remarkable change of
fortune under Polymetal thanks to a
robust feasibility process and sound
technical approach
Kazakhstan’s golden phoenix
he Kyzyl gold mine has evolved into a truly
world-class asset, based on a project
acquired by Polymetal in 2014 for a total
of $618.5 million (it acquired Altynalmas Gold,
the holding company, from Sumeru Gold and
Sumeru). Despite naysayers at the time this has
proven to be a very sound investment for
Polymetal with its success based on sound
plant engineering and the selection of the right
process route for what is a difficult refractory
ore. This has turned the fortunes of the
operation around from a very negative period of
press from the 1990s onwards including under
Ivanhoe from 1996 when a combination of its
complex mineralisation and processing issues
caused it to be referred to as cursed (and worse
names) in financial circles. Fast forward to 2019
and the mine is now the largest contributor to
Polymetal’s current success and a flagship of
Kazakhstan’s gold mining industry.
The Kyzyl project is located in north-eastern
Kazakhstan some 750 km east of Astana in a
traditional mining region with good infrastructure
and easy access to grid power and the railway.
Based in the Auezov village, the site is
approximately 750 km east of the capital city of
Nur-Sultan and 75 km west of the mining and
metallurgical industry centre of Ust-Kamenogorsk.
Kyzyl is also in close proximity to the Russian (120
km) and Chinese (330 km) borders. The nearest
railway station is 6 km away in the village of
Chalobai, connecting Ust-Kamenogorsk to Shar,
as well as Russia, China and Europe.
T
Geology and setting
The Kyzyl mine is based on the Bakyrchik (and
will also later include Bolshevik) refractory gold
deposits which are hosted in the Kyzyl Shear
Zone (KSZ), an 11.5 km shear zone dipping 30 to
40 degrees north and ranging in width from 10
to 240 m. It has been traced to depths of 1.5 km
8 International Mining | NOVEMBER 2019
in the west and 3.5 km in the east. The
structural geology is dominated by the large E-
W KSZ fault. The epigenetic mineralisation is
characterised by an irregular shape occurring in
mud shale, siltstone, various grained
sandstone, interstratified rocks and diorite
poryphry. The gold itself is fine grained and
associated with arsenopyrite and to a lesser
extent pyrite. The gold is intimately associated
with these sulphides whose distribution is
related to host rock permeability with coarse
grained sandstone containing the most sulphides
and therefore gold. The host rock averages 3%
carbon of which some 50% is organic.
Kyzyl's open pit utilises a fleet of 136 t BELAZ
trucks for overburden removal
Ownership then passed to Ivanhoe and
extensive metallurgical test work and multiple
scoping studies were undertaken to determine a
potentially viable development approach for
Bakyrchik. A number of options were
considered, including a combination of open pit
and underground mining at several production
rates, as well as rotary kiln or fluidised-bed
roasting processes. Subsequently, a 100,000 t/y
single-stage roaster using a rotary kiln operated
at Bakyrchik between 2009 and 2010, achieving
gold recovery between 30% and 60% at less
than the designed throughput rate.
At Bolshevik, open-pit production
commenced in 1985 and ceased in 2004 with
approximately 1.1 Mt of ore at a 5 g/t grade
produced and sold to smelters as gold-bearing
flux. In addition, a 100,000 t/y pilot plant that
used flotation followed by bioleaching and CIL
operated in 2003-2004 but did not achieve
positive economic results.
No meaningful production activity has taken
place at the Kyzyl Project after 2010. In 2014 the
Kyzyl gold project which comprises the
Bakyrchik and Bolshevik gold deposits was
acquired by Polymetal.
In 2015 the company announced the
successful completion of the Feasibility Study
for the Kyzyl gold project and the updated Ore
Reserve and Mineral Resource estimates. Later
that year the Polymetal Board made a positive
decision to proceed with the Kyzyl construction
and development.
History of Bakyrchik mining
The Kyzyl Shear Zone was discovered in the
early 1950s by surface trenching. Open-pit
production commenced in 1956 at roughly
19,000 t/y at an average Au grade of 9.4 g/t. By
1969, production increased to 165,000 t/y at an
average Au grade of 8.5 g/t and by the time
open-pit production ceased in 1994,
approximately 2.1 Mt of high-grade ore (7.6 g/t)
had been processed.
Underground mining, on the other hand,
commenced in 1963 with production ranging
from 20,000 t/y to 95,000 t/y. As of the
suspension of underground mining in 1997,
approximately 1.7 Mt at 7.4 g/t Au had been
produced. Ore was mostly sold to smelters as
gold-bearing flux. The two headframes are still
visible near the existing mine.
In 1992, an international joint venture was
formed to operate Bakyrchik, and two years
later a provisional processing plant was
constructed with a capacity of 150,000 t/y,
incorporating conventional flotation, nitric-acid
sulphide oxidation (Redox) and CIP. However,
operating results turned out negative and this
option was abandoned in 1996.
Commissioning and start up under
Polymetal
Following the completion of all construction and
commissioning activities, Kyzyl successfully
produced first gold concentrate in June 2018.
Polymetal achieved the start-up of the
concentrator one quarter ahead of the original
schedule, announced in 2014, and one month
earlier than the January 2018 updated plan.
Kyzyl delivered a robust performance in 2018,
exceeding the initial plan on grade, throughput
and production. Full-year gold production came
in at 96,000 oz of gold, significantly beating the
original 2014 guidance of 80,000 oz, while gold
in concentrate amounted to 134,000 oz. Ore
processed was 914,000 t, with average gold
grade in ore processed at 5.7 g/t. Concentrate
of 56,000 t with an average grade of 75 g/t was
produced. Payable gold shipped comprised
89,000 oz. The Amursk POX plant successfully
processed 2,000 t of low-carbon concentrate
from Kyzyl, achieving recovery of 96%, with
7,000 oz of gold produced.
Polymetal reported strong production from
Kyzyl for the second quarter and the six months