GOLD EXTRACTION_proof 19/07/2016 14:55 Page 9
GOLD EXTRACTION
characteristics of the ore and as well as capital
and operating costs. He illustrated this using the
mentioned Barrick Goldstrike operations where a
number of processes have been applied including
the newly developed thiosulphate leaching
technology.
KellGold
The cyanide-free, low-emissions KellGold process
is capable of high recoveries of gold, silver, base
and rare metals from a range of refractory
concentrates and other materials considered to
be problematic, intractable or otherwise poorly
responding to many conventional treatment
routes. The process was developed for the
extraction of platinum group metals (PGMs) and
base metals from sulphidic flotation
concentrates. Pallinghurst Resources is assessing
potential construction of a full-scale Kell plant to
extract base metals and PGMs at its Sedibelo
Platinum Mines subsidiary.
The KellGold process consists of several
commercially proven unit operations and utilises
know-how gained from the processing of PGM
concentrates. The process has been applied
successfully to refractory gold and copper-gold
concentrates and other gold-bearing materials
such as calcine-leach tailings where cyanidation
recoveries are low. Reagent consumers and
valuable byproducts such as S, Cu, Ni and Co are
first selectively removed by use of a pressure
oxidation step during
which the dissolution of
precious metals is
minimised. High
recoveries of gold and
silver are achieved by
subsequent chlorination,
with typically low reagent
consumptions due to
prior removal of reagent
consumers and the use of
efficient lixiviant
recycling. The core steps
within KellGold are
similar to well-proven
conventional unit
operations in common
use elsewhere, as are the
subsequent metal recovery steps to provide
marketable high-purity primary and secondary
end products such as refined metal sponges,
bars or coins. In this way, third-party smelting,
treatment, transportation and refining costs are
removed from the value chain, with saleable
metals being produced on the mine site.
Residues have similar characteristics to flotation
tailings and may be co-disposed. A Kell plant can
be constructed close to the mine site, removing
the often costly transportation and wharfage
costs for shipping concentrate.
The process generally consumes significantly
Kell process
flow chart
less energy, less electricity, and requires lower
capital and operating costs than the equivalent
conventional smelting and refining facilities for
the same duty. Unlike conventional smelters or
bioleaching plants, for example, which lock up
considerable gold and other precious metals in
circuit, the Kell process locks up substantially
less metal inventory and hence, releases
significant working capital early in the project,
sometimes enough to pay for most of the plant
capital costs.
The costs of cyanide detoxification and
management are avoided, as are the risks
2ND INTERNATIONAL
MINING MYANMAR CONFERENCE
14th and 15th October
Myanmar Convention Centre, Yangon
International Mining Events now has great pleasure in
outlining some of the speakers who will be there at our
2nd International Mining Myanmar Conference. The
range includes both the key government ministry and
industry association as well as important names in in-country
players and well as international expertise well placed to
provide technology to Myanmar’s growing mining industry.
KEYNOTE ADDRESSES
Myanmar Ministry of Resources & Environmental
Conservation
Myanmar Federation of Mining Association MFMA
MINING LAW AND DOING BUSINESS IN MYANMAR
Experience of establishing Joint Ventures in the Myanmar
Mining and Minerals industry – Michael Phin, Director,
Valentis Resources
International Capital Raising and Myanmar’s Mining Sector
– Clinton Morrow, Partner, Charltons Law
A Holistic Approach to Mine Development, Operation, and
Closure in a Developing Economy, Mark A Travers, Executive
Vice President for Global Practice Development, Ramboll
76 International Mining | AUGUST 2016
MINING APPROACHES AND EQUIPMENT FOR MYANMAR
Contract Mining options for Myanmar – sharing the risk
with access to global expertise – Steve Coughlan, Managing
Director, Byrnecut Mining
Use of Geosynthetics in the Mining Industry – Jan
Dharmabandu, Manager Projects Development, B2 Gold
Rock Mass Characterisation for Mine Design – Senaka
Welideniya, Specialist Geotechnical Engineer, Curtin
University WASM
Application of Terex Trucks in Myanmar – John Bennett,
Regional Sales Manager APAC, Terex Trucks
More papers will be added in the coming weeks,
those interested in presenting please contact
Event Director Paul Moore at paul@im-mining.com
There are also sponsorship opportunities including
a limited number of booths.
TO REGISTER – go online to
www.im-mining.com/pay-online
and select Mining Myanmar 2016