2018
METALLURGY
Jack Holmes
or his massive contribution to the large-
scale commercialisation of solvent
extraction of copper, in Zambia and
worldwide, Jack Anthony Holmes, formerly
Technical Director of Anglo American Corp
(AAC), has been inducted.
F
In 1970, Jack, after a year of private study and
calculation, persuaded the understandably
apprehensive Board of Anglo American Central
Africa Ltd to abandon convention and rather
invest upwards of $150 million in some
innovative technology to recover 100,000 t/y of
residual acid-soluble copper from current and
accumulated flotation tailings at Nchanga mine:
that technology was solvent extraction (coupled
with electro-winning). This bold proposal was
made at a time when SX of copper was in its
mere infancy, having been installed in only
Arizona at very small scale, in specifically
Ranchers Bluebird (5,000 t/y copper) and
Bagdad (7,000 t/y copper). The recommended
venture represented considerable (albeit much-
investigated, by JAH himself ) technical and
financial risk to Nchanga mine; and it was a
major vote of confidence in Jack’s capabilities,
for a positive decision to have been taken by the
board, at that time. The Zambian project
accordingly went ahead and the plant was
commissioned in 1973. The operation’s early
and obvious success generated universal
confidence in the technology and heralded the
subsequent world-wide acceptance of SX-EW as
a reliable and preferred technology for recovery
of leached copper (and later zinc and cobalt).
Although a succession of other plants of
substantial size soon emulated the Nchanga
project, the latter remained the biggest in the
world for a decade or more.
Recovery of the material from the tailings
dams was done by hydraulic monitoring, as
used at English China Clays but only slightly in
the metals mining industry eg Umgababa
Minerals, Natal, where Jack was involved in
1962. Leached tailings were dewatered in the
biggest horizontal-belt-filter installation in the
world; and indeed, the filters were developed
and modified, especially for the project.
It was an inspired decision of Jack’s, before
final plant design, to seek permission from
Bagdad Copper Company, to ‘borrow’ sections
of its 7,000 t/y commercial plant, for his
metallurgists to use as a pilot plant, in which
newer technologies and optimising techniques
could be researched and developed. One piece
of Anglo knowledge that was disclosed
gratuitously to Bagdad and allowed to become
HoF 12 International Mining | JUNE 2019 Supplement
The Nchanga tailings leach plant (TLP) circa
2004
JAH eventually
transferred to the Anglo
American Head Office in
Johannesburg, as Deputy
Technical Director to the
then biggest miner of
minerals in the world. In
this role he enhanced
metallurgical disciplines and project
participation throughout AAC’s operations,
globally. He remained, though, an unflinching
advocate for continuing investment in the
Central African copper mining industry, which is
now once again a thriving business – further
evidence of Jack’s tenacity and vision.
public, was the use of dissolved cobalt (in
electrolyte) to stabilise lead anodes when
operating at increased levels of acidity and
current density. This modus operandi is now
standard practice, throughout the industry.
Additionally, Jack was involved in and very
supportive of the setting up – (by jointly ICI Ltd,
UK, and Pinkney and Atmore of AAC,
Johannesburg) – of ACORGA Ltd, UK, a company
that soon introduced the enormously successful
alternative range of modified aldoxime SX
reagents for copper.
Jack’s higher education began at Kings
College, London, from which establishment he
emerged in 1953 with graduate qualifications in
both chemistry and chemical engineering. He
was eventually to be professionally qualified as
FIMM, FIChem.E and FSAIMM. In 1978 he was appointed Technical and
Executive Director of AAC, assuming managerial
responsibility for also the engineering, mining
and geological service departments; and he had
technical oversight of AAC operations
worldwide, including projects and exploration.
He started his illustrious industrial career at
the Harwell division of the United Kingdom
Atomic Energy Authority, where he stayed for
over three years before joining Anglo American’s
mining operations in Northern Rhodesia. His
first assignment was in R&D where, working for
Denis Kelsall, he helped develop and patent the
cyclowash system for improving classification
efficiency of hydro-cyclones. They also
developed a new flow-sheet for the Nchanga
concentrator operations. He stepped down voluntarily in 1992 but was
retained for a further eight years, working in the
Chairman’s Office, with a range of managerial
responsibilities, including negotiation of the re-
privatisation of the Zambian Copper Mines,
developing and controlling a high-tech Venture-
Capital Company in Israel, and directing a long-
running AIDS research project based in America.
Jack, in his career, had been a Director of no less
than 11 mining companies.
Jack moved rapidly through the Anglo-
Rhokana-Nchanga divisions, working in various
concentrators, including presiding over the
building of a new satellite mill and the re-
structuring of the concentrator, both at
Nchanga. He assisted at the cobalt plant and
managed both the electro- and fire-refineries, at
Rhokana: and he went also to Johannesburg,
becoming involved in projects and operations in
vanadium, monazite, and other minerals. He
became Metallurgical Manager at Nchanga in
1968: and it was from this position that his bold
solvent extraction recommendation was made.
Jack then progressed to become Consulting
Metallurgist for the entire Zambian operations
of the Anglo Group.
To combat AIDS, Virginia van der Vliet
reported in Optima, Healthy Profits, April 2011,
pp06-10: “Anglo American assembled a
heavyweight in-house ‘brains trust’ to examine
ways of tackling HIV/AIDS, which was rapidly
becoming a pandemic. The incipient team
included Technical Services Director Jack
Holmes, Chairman’s Fund Director Michael
O’Dowd, Industrial Relations Consultant Bobby
Godsell, Scenario-Planning Expert Clem Sunter,
and medical consultants Drs John Laing, Ian
Potgieter and Charles Thomas.”
There are but few metallurgical technologies
in the mining world that have not been
influenced by Jack Holmes; and many
figureheads in the industry owe gratitude to him
for their successful careers.