OPERATION FOCUS
Outotec TankCells at Kyzyl which are used to
produce both low and high carbon concentrate
ended June 30, 2019. “Excellent results from
Kyzyl drove our production growth while other
operations delivered strong performances,” said
Vitaly Nesis, Group CEO. The operation has
continued to benefit from high-grade softer ore
and has exceeded design specifications on
throughput, grade and production. Half-year
gold production came in at 159,500 oz of gold
with 187,400 oz of gold produced in
concentrate.
The average concentrate recovery rate has
increased to 87.8% despite low mass pulls
achieved to improve transportation economics
and attractiveness of concentrate for Chinese
off-takers. Share of gold in low-carbon
concentrate processed at the Amursk POX plant
exceeded 50%.
The processing plant is now running at a rate
of 2 Mt/y – well above its nameplate capacity of
1.8 Mt/y. Recent performance tests have
demonstrated that further improvement in
throughput can be achieved with a $3 million
investment in hydrocyclones and the
concentrate filtering area. Open-pit mining has
continued at a stable pace. A detailed technical
study is under way to re-optimise the open pit
under updated operational and economic
assumptions with the results, including the
updated Ore Reserves estimate, to be presented
in Q4 2019.
haul road
maintenance.
So far ore
production and plant
throughput (2 Mt/y
instead of 1.8 Mt/y)
have exceeded
design numbers
thanks to softer than
expected ore, small
high-grade ore pods
and positive grade
reconciliation near
surface with group
total cash costs
(TCC) also lower
than predicted at
$407/oz in H1 2019. To maximise this positive
performance Polymetal is now looking to
deepen the open pit the plan for which along
with the reserves update will be announced in
Q4 2019.
The mine has a truck fleet with 26 BELAZ 136
t 75139 trucks used to haul overburden, loaded
by five Russian IZ-Kartez EKG 15M 15 m 3 electric
rope shovels and nine Komatsu 91 t HD785 units
used to haul the gold ore itself, loaded by five
Komatsu hydraulic face shovels: three PC2000,
plus smaller PC1250 and PC300 models.
Ancillary equipment for waste and ore
management includes a large fleet of 10 crawler
dozers including Komatsu D375A-5 models.
Kyzyl has a large maintenance shop to
service its truck fleet. There are two truck
maintenance bays dedicated to BELAZ, two for
Komatsu and one for other OEMs. The hydraulic
excavators for ore loading have their own
maintenance facility but regular servicing is
carried out in the pit itself, with the EKG
machines serviced in-pit. A VIST Karier fleet
management system is used.
Polymetal carries out its own service work for
lubricants/oils, tyres/wheels changeouts as
well as welding steel wear plate to truck bodies
with two contractors conducting more extensive
maintenance for engines, system electronics,
axles etc. There is also an in-house machining
facility for certain spare parts such as hydraulic
cylinders. Currently mainly Michelin radial tyres
are used.
The mine employs truck operators that have
been trained at the technical college in Ust-
Kamenogorsk, where there is also a truck
simulator. Trainees then come to site for an
internship period before becoming full time
employees. The mine operates two 12 hour
shifts with a total of two hours allocated to
maintenance and breaks. Overall the mine has
some 1,140 workers (Polymetal), not including
contractors. The overall remote site
management including catering, housekeeping,
facilities management and support services is
carried out by CAC Kazakhstan, part of the CIS
International Group.
Process plant design
The process plant was designed in-house by
Polymetal Engineering not by a third party
engineering firm. The processing route (see box
for summary) for Kyzyl’s highly carbonaceous
preg-robbing sulphide includes an ex-pit
primary crusher then a Outotec SAG mill for
initial milling and screening using a bank of
Metso inclined screens followed by a bank of
flotation cells for carbon removal, then
intermediate flotation followed by gravity
Simplified flowsheet of Kyzyl plant
Open-pit mining
An open pit cut-off grade of 2 g/t was used in
the pit design with average wall angle of 41-48
degrees and the pit walls monitored using a
Leica slope stability radar. In bulk terms some
75,000 m 3 of material is mined per day with
blasting conducted three to four times a week
by a contractor. The blasthole fleet consists of a
fleet of electric Epiroc PV271 Pit Vipers. Most of
the waste is stockpiled but some 3% is used for
NOVEMBER 2019 | International Mining 9