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GOLD
22
MODERN MINING
March 2017
View of the Yanfolila site
(prior to erection of the
tower crane) showing work
on the CIL tank foundations.
economics of Yanfolila have clearly appealed
to the market and last year we were able to
raise US$71 million in equity and US$45 mil-
lion in debt to fully fund the project through
to production. This allowed us to embark on
full-scale construction – as opposed to earlier
preparatory earthworks – in October 2016,
when the first concrete was poured. Our
equity raising, incidentally, was the biggest
by an AIM-listed gold company in the past
four years.”
A key step in the development of Yanfolila
was the appointment in July last year of South
African project house SENET – involved in
the project since the Gold Fields days – as the
EPCM contractor to build the plant and asso-
ciated infrastructure. SENET, of course, boasts
considerable West African experience, hav-
ing worked – amongst others – on Randgold’s
Loulo and Tongon projects in Mali and Côte
d’Ivoire respectively, as well as (more recently)
the Karma gold project in Burkina Faso of True
Gold (now part of Endeavour Mining).
Hummingbird followed up in September
with the appointment of IMAGRI-SARL – a
Malian contractor – as the civil works contrac-
tor (it is now responsible for the SMPP works as
well) and in December announced that African
Mining Services (AMS), a subsidiary of ASX-
listed Ausdrill, had been selected as the mining
contractor.
AMS is highly experienced in West African
gold mining with a track record in the region
going back 25 years. Its contract is for an ini-
tial three-year period and has a total value of
US$112 million. The company will be deploy-
ing a new mining fleet of mainly Caterpillar
equipment worth US$38 million and will
employ in the region of 450 people (mostly
Malians) once it begins operations. Mining is
due to commence in September this year, with
the ore initially being stockpiled in advance of
plant commissioning. At peak production dur-
ing the first three years of mine life, the mining
schedule calls for approximately a million bank
cubic metres to be mined monthly.
The mining will be a conventional drill-and-
blast, load-and-haul operation with the deep
oxide and transitional zones making for an
easy start-up. The first pits to be mined will be
Komana East and Komana West but ultimately
three further pits will be brought into the mix
– Guirin West and Sanioumale West and East.
The Komana East pit has the biggest reserve –
230 koz at a grade of 3,06 g/t.
Recovery of gold will be through a com-
bination of gravimetric means and direct
cyanidation. Gravity concentrate is treated
through an intensive cyanidation process with
the pregnant solution pumped to an indepen-
dent gravity electrowinning circuit. The CIL
circuit consists of seven tanks in series: one
pre-leach tank and six CIL tanks. The plant is
expected to deliver a gold recovery of 92,5 %.
A two-stage crushing circuit is being
installed to treat all ore types. In order to main-
tain mill throughput, a tertiary crushing facility
will be added when the proportion of hard
fresh ore increases. A 12-hour live stockpile
will ensure continuous and consistent feed to
the mill.
Among the companies supplying equipment
for the plant are Metso (crushing circuit equip-
ment), Outotec (ball mill), Afromix (agitators)
and Kemix (screens and carbon regeneration
kiln). To supply power, the mine will need
a 6,5 MW capacity diesel genset facility. It
is anticipated that this will be provided by
an Independent Power Provider (IPP) and
Hummingbird is currently negotiating with
potential partners.
With mine operations not too distant now,
Hummingbird has started appointing the
permanent staff who will run the mine and
in February this year announced that Kevin
Moxham had been employed as General
Manager. He is hugely experienced in min-
ing – in particular gold mining – and was
At peak
production during
the first three
years of mine
life, the mining
schedule calls for
approximately
a million bank
cubic metres to be
mined monthly.