A technical history of the Rio Tinto mines: some notes on exploitation from pre-Phoenician times to the 1950s

121 Pages·1987·26.252 MB·English

by  Leonard Unthank Salkield (auth.), Maurice J. Cahalan (eds.)

A technical history of the Rio Tinto mines:
some notes on exploitation from pre-Phoenician times
to the 1950s
A technical history of the Rio Tinto mines:
some notes on exploitation from pre-Phoenician
times to the 1950s
Leonard Unthank Salkield
Edited by Maurice J. Cahalan
()I I
nrnr;Jrnr;J[
The Institution of
L..:J.JULlJ.JUU
Mining and Metallurgy
I I
Published at the office of
.illl.lil\T he Institution of Mining and Metallurgy
44 Portland Place London WlN 4BR England
© The tnstitution of Mining and Metallurgy 1987
ISBN-13: 978-94-01 0-8017-0 e-ISBN-13: 978-94-009-3377-4
001: 10.1007/978-94-009-3377-4
Contents
page
Editor's note IX 6 Copper production 1849-72 97
7 Formation and corporate evolution of The Rio
Introduction 1 Tinto Company LId 97
Chapter 1 8 Environmental - land. forestry and farming 100
The pre-Roman period 5
9 fundicion Mina - furnace charge 1880-1889 102
Chapter 2
10 The Bessemer smelter and its operations
The Roman period 9 1901-14 102
Chapter 3 11 Pyritic smelting - furnace charge 1913 104
from rediscovery in the sixteenth century until
12 Summary of production and manpower during
the eighteenth century 18
the period of RTC operations. 1874-1954 105
Chapter 4
References 108
The mines under Government control 24
Index lIO
Chapter 5
Private control. 1829-49, the Marquis de
Illustrations
Remisa 27
Plans (folded; inside back cover)
Chapter 6
Reproduction of Rio Tinta Mines general plan of works. 1878
The mines returned to Government control.
Reproduction of RTM plan of works, 1932;
1849-73 32
corrected March 1935
Chapter 7 fi9, 1 Map of part of the Province of Hue!va, Spain 3
Early mining operations of The RIO Tinto
Fig. 2 Proposed workings - Rio Tinto Mines, 1873 4
Company limited 39
Fig. l Niebla - walled Roman town 7
Chapter 8
Early metallurgical operations of RTC 43 Fig. 4 Reconstructed Roman water-lifting whee! 12
Fig. 5 Entrance to Cueva del Lago circd 1880 16
Chapter 9
Infrastructure for the RTC operations 45 Fig. 6 Roman shafts exposed in early operations of
RTC 16
Chapter 10
Mining at San Dionisio and North Lode 51 Fig. 7 Ancient workings at Rio Tinlo Mines 17
Chapter 11 Fig. 8 Blast furnace used by Remisa. 1840s 28
Ore classification and preparation for fi9· 9 Refining furnace. 18405 29
shipment 59
Fig. 10 Opencast operations exposing old workings II
Chapter 12
fi9, II SOuth Lode opencast circd 1890 41
HydrometallurgiCal development 61
Fig. 12 Heap roasting circd 1890 42
Chapter 13
Fig. 13 ·The Rio Tinto Mines in Southern Spain' from
Pyrometallurgical development 68
The lIIustrdted London News 1875 47
Chapter 14
Fig. 14 Rio Tinlo Pueblo, early 19005 50
Sulphur production - the Orkla process 79
fig. 15 Plan of the Rio Tinto orebodies 52
Chapter 15
Fig. 16 Steam shovel - Atalaya opencasl 54
Miscellaneous activities 83
Fig. 17 Train approaching Zarandas Naya from 16th
Appendices floor tunnel. 1950s 60
I Roman activity elsewhere in the Iberian Fig. 18 General plan of leaching grounds 66
Peninsula 88
Fig. 19 Cerda precipitation tanks, 1900 68
2 Translation of report by Diego Delgado 89
fi9·20 Bessemer smelter 70
l Report of 1727 by Robert Sitee 91
fi9. 21 ·Bisbee' converter 71
4 Copper production 1829-1849 94
Fig. 22 Bessemer smelter. Mar asmilla Dam and
5 Commentaries relating to the Remisa era 95 Cerda leaching area 78
vii
Editor's note
leonard Salkield was born in Hoddesdon. To us has fallen the stimulating and challenging
Hertfordshire. in 1901 and graduated Irom the Royal opportunity of editing and presenting the informaUon
School 01 Mines. london. in 1922. He worked at that he collected in a lorm 01 which we hope that he
Enthoven's lead refinery in Rotherhithe and Eastern would have approved. It was never his aim to
Smelting Company's tin smelter in Penang (Malaysia) duplicate the history 01 The Rio Tinto Company
belore joining the Rio Tinto Company In 1928 to work activities so ably presented in David Avery's book. but
at its copper smelter at Port Talbot In Wales. He he lelt that a volume recording important technical
translerred to the Company's Ewell laboratory in 1929 information would be of value and we agree
and to the Rio Tinto Mines in 1930. He returned to wholeheartedly with him on that. This is not intended
England in 1937 during the Spanish Civil War and. as a history in the accepted sense: rather. it is a
after working on a wartime magnesium metal project. volume of technical notes set in a chronological order.
returned to Rio Tinto Mines in 1946 to spend the roughly to the end 01 the Rio Tinto Company
remainder of his professional career there. operations. Even so. there is a conSiderable amount of
relerence lorward and back. especially since places
He became interested in the history of activities at
and areas are frequently identified by names that they
the site soon after first going to Rio Tinto and his work
assumed in recent times.
on the development of metallurgical processes was a
natural complement to his enquiry into the nature of Whereas David Avery drew mainly on records from
the earlier operations. which had lelt so much the old London oflice 01 the Rio Tinto Company In
evidence of smelting on a very large scale. In 1957 he writing his history 01 the Company. leonard Salkield
began to assemble notes for Eric linklater, who had searched through records at the mines and dinering
been invited to write a company history. ThaI project perspectives are given on some episodes. Clerical staff
did not proceed and when David Avery was at the mines kept meticulous operating records. and
commissioned to write a history of the Company· it although it must be said that many 01 the numbers
was natural that the then Chairman of Rio Tinto-linc. contain far fewer significant figures than decimal
Sir Val Duncan. should ask Leonard to assist in points suggest. such records have provided a wealth of
providing inSight into the prehistory of the mines. interesting detail for those technical notes.
This involvement stimulated him to further efforts in The great interest of Rio Tinto to industrial
tracking down information relating to the 4000 or archaeologists has been in unravelling the metallurgy
more years of activities. work by professional employed there and. even in comparatively recent
archaeologists on copper smelting had started at Rio times. metallurgical process development and
Tinto around this time. following earlier dramatic operation has be.n 01 special interest because 01 the
successes in unravelling the ancient technology in the unusual complexity 01 the ores and the novelty 01
Middle East. and leonard collaborated enthusiastically processes to treat them. With his unrivalled insight into
with the various groups that become involved - his metallurgy at Rio Tinlo. Leonard naturally emphasized
unrivalled knowledge 01 the changes made by the metallurgy in his writings. but he also assembled
operations of the past century was of considerable interesting information on mining and infrastructure.
assistance to them.
We have edited the notes to provide a general
In 1962 he received the O.B.E. He continued as a account. albeit slanted towards metallurgical
consultant to Rio Tinto Patino. one of the successor operations. supplemented with more detailed
companies to The Rio Tinto Company. for many years appendices. There are instances where Spanish words
after ·retirement'. living in Spain near Gibraltar and or phrases are not translated because no English
pursuing the collection of information relative to words convey quite the same meaning. or the Spanish
activities at the Rio Tinto mines. When he finally retired is widely used and understood in the mineral industry.
to live in England near his family he embarked on the or for both reasons. For place names for which there is
task 01 preparing his assembled material lor a widely used anglicized version. such as Seville for
publication. With his keen deSire to resolve all possible Sevilla. we have used the anglicized version. Rio Tinto.
ambiguities. access to the British Museum and other literally "fed river", was used as the name of quite
sources of additional information delayed him in this separate townships in the mining area. in referring to
task and. sadly. it was not completed before his death the general area of the mines. and sometimes as an
in 1985. abbreviation lor company names. leonard Salkield
always referred to the stream itself as ·the Tinto river'
and we have also used that convention; other
• Avery D. Not on Queen Victorld·S birthddY the story of the Rio references to Rio Tinto should be clear from their
Tinfo mines (lOndon: Collins. 1974). 464 p. context.
i,
Many of the references listed are not readily For more detailed archaeological information the:
available to the general reader. An exception is David reader is referred to the publications of the Institute for
Avery's Not on Queen Victoria'S birthday; which Archaeo-Metallurgical Studies attached to the
covers much of the subject matter of these notes for UnNersity of London, 31-34 Gordon Square, London
the lay reader and provides an admirable account of WClH OPY, England, and to its volume Studies in
social, political and economic issues concerning ancient mining and metallurgy in South-West Spain.·
operation of the Rio Tinto mines from the sixteenth
Most of the old plans and photographs used to
century, We have not been able to check some of Ihe
illustrate thiS volume have been copied from archives
original documents and Leonard Salkield's translations
in the possession of RTZ Limited and from publications
and deductions from such sources are given verbatim.
of the Institution of Mining and Metallurgy; exceptions
We have established that Rua Figueroa" is a major
are acknowledged in the text.
source for the detailed information and statistics given
The Institution of Mining and Metallurgy is grateful
in Chapters 3-5.
to RTZ LId for providing the financial support needed
Some of the terminology used at Rio Tinto may
to enable it to undertake publication.
need a little explanation. In mining, levels are
invariably referred to as 'fioars': whether this derives
M J Cahalan
from the Spanish 'piso' or was introduced from United
44 Portland Place
Kingdom coal mining is not clear. The massive pyrites,
London
as mined, is referred to as 'mineral', 'ore:' or 'pyrites'; if
January 1987
of significant copper content. it is called cupreous
mineral or 'cupreous'; low copper pyrites is thus non
cupreous. Country rock enclosing the lodes is
porphyry; in some areas the copper content means
Ihat this is copper ore. Heap leaching of copper from
massive pyrites is known as 'washing', hence 'washed
are' is pyrites recovered from the leaching heaps.
In a preface to his draft Leonard drew attention to
the help that he had received in compiling his notes
from the late Professor David Williams on geology,
Mr Stanley Tong on the Atalaya openeast.
Dr P.T. Craddock on archaeology, the late
Cot. R.F, Lethbridge, Mr John Hunt. Sr D. Eduardo
Figueroa Poyatos and Mr Ivor Herbert, In preparing
the material that he left for publication I have been
greatly assisted by Professor R.F, Tyleeote and
Dr Lynn Willies.
The author's draft includes considerably more
material than has been published here. Some of the
additional material concerns the RTC copper smelting
operations in South Wales, there is mOTe information
on the: ancient slags. a significant section concerning
the developments in sulphuric acid production, and
more sodal history.
In the expectation that publication of this edited
version could stimulate interest in the further
information, a copy of the draft is lodged in the
Institution of Mining and Metallurgy and can be
examined by arrangement with the Head of Library
and Information Services.
• Rothenberg 6. and 6lanOO-Freljelro A. et al. Studies in ancient
mining and metdlfurgy In South-West Spain: exp/OfdtiOnS dnd
• Rua Figueroa RamOn. MindS de RIo Timo: eSludios sobre /d excdvdtlons in the Province of Hue/va (london: lAMS. 1981).
explotdC/on y e/ benefiCIO de sus mlnerdles (Coruna. 1868). 320 p.
x
Introduction
In the south-west of the Iberian Whether the Phoenicians and the
Peninsula there is a vast pyritic Carthaginians ever actually worked
mineral ised zone, known as the the mines, or were merely traders, is
Andevallo, extending from near not certain, but after 205 BC, when
Seville to south of Lisbon, an area they defeated the Carthaginians, the
some 150 kilometres long and 30 Romans brought their own men skilled
kilometres wide. in mining and metallurgy.
The Rio Tinta Mines, which are the The Romans occupied most of the
largest of this "pyrites belt", lie Iberian Peninsula for 600 years,
in the region known as Andalusia, until about 425 AD - the most recent
some 90 kilometres north-west of Roman coins found at Rio Tinto show
Seville and 75 kilometres north-east the head of Honorius who was emperor
of Huelv8. They have a very long from 395 to 423 AD. Mining must
history, dating back to pre-Iberian have declined with the invasion of
times; then came the Iberians, a race Barbarians in the 5th century and the
of North African origin (Turdetarian subsequent entry of the Visigoths who
and Tartessian), the Phoenicians, the were eventually absorbed into the
Carthaginians, the Romans, the Moors, people of Spain. In 711 AD the
the Spaniards and the British. It Moors invaded the Peninsula from
is believed that copper was first North Africa. Little mining was
recovered from the ores in the third done after the departure of the
millenium BC and that silver. was Romans; the Moors probahly recovered
mined in the late Bronze Age, 12th to some copper from acid drainage waters
9th centuries BC onwards. by deposition on iron.
The Phoenicians established a trading The Moors were driven out of Spain in
station at Gades (Cadiz) about 1000 1492 and the first extant report on
BC and found the hinterland rich i n the Rio Tinto mines is dated 1556.
both agriculture and metals - gold, In 1725 a Swede, Liebert Wolters
silver, copper, tin, lead and iron. Sjohjelm, was granted a licence to
Their efforts to dominate the country work five mines in the region, one of
were frustrated by the resistance of which was Rio Tinto - the documented
the Tartessians living to the history of operation of the Rio Tinto
north-west but they apparently traded Mines begins from that date.
successfully and are believed to have
used the fabled port of Tartessos. Over two and a half centuries the
The exact location of Tartessos has mines were worked both directly by
not been identified but jt was Government and by private companies.
probably on the estuary of the Tinto In general, Government operations
and Odiel ri vers near Huelva. were unsuccessful, despite the
outstanding men who served Government
as adminstrators at Rio Tinto. The
In 535 BC, with the decline in power Treasury in Madrid was reluctant to
of the Phoenicians, the Carthaginians supply funds for desirable
conquered southern Spain. They too investment, for example when steam
traded in agricultural produce and power became available it was not
metals and also experienced difficult- installed; miners could not work
ies with the Tartessians. They lower than the Roman adits, yet steam
were responsible for the destruction powered pumps could have resolved
of the port of Tartessos. dewatering problems.
- I -
In April 1867 a Royal Commission made depressions, until 20 June 1954 when
recommendations to develop the mines two-thirds of its Spanish assets were
but the Treasury as ever, sold to a Spanish group of bankers
~as,
reluctant to fund the recommended and the company was renamed "Campania
programme and the Government decided Espanola de las Minas de Rio Tinto".
to sell the mines. During a period
of great political turmoil, an Few mines have such a history as Rio
authorising law was passed by the Tinto. These notes concentrate on
Cortes in June 1870 and bids were technical aspects of mining and
invited in the following year. An metallurgical activities using
offer by a consortium of British and information obtained from a wide
German bankers was accepted and The variety of sources, some well
Rio Tinto Company Limited was documented, some anecdotal. There
registered in London in March 1873. is inevitably a degree of speculation
The events leading to the purchase by about many aspects but, on the whole,
this new company have been chronicled we can deduce a fairly convincing
in detail in David Avery's "Not on picture of the activities which have
Queen Victoria's Birthday"(I). taken place over more than 4,000
years.
The purchase price for the mines, in
the form of the freehold of an area It will simplify later references to
of some 1,900 hectares, was locations to give at this stage some
£3,600,000 equal to 92,800,000 general description of the mining
pesetas. This was a huge sum at area as it has taken shape in recent,
that time and, although slightly recorded history. Figures 1 and 2,
below the Spanish Government's taken from the prospectus for the
valuation, was regarded by others who sale of Rio Tinto Company shares to
had contemplated purchase as the public, give details of the local
excessive. geography.
The Chairman of the Rio Tinto The Rio Tinto Mines (Minas de Rio
Company, Mr Hugh Matheson, clearly Tinto) are situated in the western
had great faith in the reports he foothills of the Sierra Morena, in an
received on the mines from Dr Roemar, area sometimes referred to as the
a German mineralogist, Mr David Sierra de Aracena, with the main
Forbes, a British mining engineer, lodes divided by a ridge which
and Messrs Sundheim and Doetsch, contained four peaks - Colorado,
general merchants operating from Salomon, Retamar and San Dionisio.
Huelva with interests in mining. Between Retamar and San Dionisio is a
Doetsch was the catalyst who brought pass called Puerto Rubio. The
German finance to join Matheson's highest peak. Cerro Colorado, was 534
marketing and management experience. metres above sea level but has now
been lost through opencast mining.
It certainly did not appear to be a The most impressive peak was Cerro
propitious time to make such a Salomon, 515 metres, but this too
massive investment in Spain - the will soon be mined away. Earlier
State was bankrupt, a Republic had writers about the area thought that
just been declared and the country the name Salomon came from the
was in a state of virtual anarchy. biblical King Solomon who came to the
However there was a rapidly growing throne of David about 970 BC; however
demand for pyrites for sulphuric acid the earliest recorded reference to
production in Europe for the Cerro Salomon comes from the 17th
expanding chemical industry. century.
The Rio Tinto Company continued The British company began its
mining and smelting in Spain, through operations in 1873 with opencast
two world wars and a civil war, mining of the South Lode, followed by
economic booms but more long lasting underground mining at South Lode and
- 2 -
San Dionisio in 1880. In 1883 a
start was made on opencast working of Mining from 1873 relied on rail
North Lode and three further opencast transport to and from the port of
mines came into operation at the Huelva, and for mineral, waste and
beginning of this century - Lago in supplies movement in the mining area.
1903, Dehesa in 1906 and Atalaya in Installation of the railway was a
1909. Since Campania Espanola de major commitment for the new company
las Minas de Rio Tinto took over in and, seen in retrospect, railway
1954 major opencast mining of gas sans development added to the opportun
for gold and porphyry for copper has ities to uncover early mining and
transformed the landscape. metallurgical activity.
MAP OF PART or THE PROYINCE OF HUElVA, SPAIN, SHOWING POSITION, ETC, OF THE
RIO TINTO COMP...,.'Y'S PROPERTY, MID OF THE RAILWAY TO THE PORT Of HUELVA
Figure 1
- 3 -