Riotinto Mining Research Articles

Pollution au plomb dans la Savoie antique (II–III e s. apr. J.-C.) en relation avec une installation métallurgique de la cité de Vienne

In Lake Anterne (NW French Alps), the Roman period is characterised by a lead contamination more important than that of the 1970s, due to the use of leaded gasoline. The maximum of this contamination period has been varve-dated 220 AD, i.e., during the optimum of Roman civilization in the Alps. Crossing palaeoenvironmental and archaeological evidences points out the economic importance of the town of Passy for the City of Vienne and yields a new example of lead contamination due to local metallurgical activity rather than distant impact of the exploitation of the Spanish Rio Tinto mine. To cite this article: F. Arnaud et al., C. R. Geoscience 338 (2005).

Ferric iron production in packed bed bioreactors: influence of pH, temperature, particle size, bacterial support material and type of air distributor

The biooxidatíon of ferrous iron in solution has industrial applications in the regeneration of ferric iron as a leachíng agent for non-ferrous metallic sulphides and in the treatment of acid mine drainage. The aim of this work was the study of several variables (pH, temperature, particle size, bacterial support material and type of air distributor) for the design of a packed bed bioreactor for ferrous iron biooxidation. The basic criteria of design have been the following. • Maximum residence time of the liquid for a minimum-sized reactor. Flooded packed bed reactors have been used in order to meet this requirement. • The solid material that acts as bacterial support must allow a rapid and permanent biofilm formation and show a good chemical resistance to ferric sulphate and sulphuric acid. • Constant and homogeneous air supply in the whole bed. The bioreactor consisted of a column randomly packed with solid particles, fed with an acidic solution of ferrous sulphate. Air and fresh solution were fed in at the bottom of the column from where they flooded the reactor. The inoculum consisted of a mixed culture of bacteria isolated from Riotinto mines drainage waters, and adapted to pH 1.25 in the laboratory, composed mainly of Thiobacillus ferrooxidans and Leptospirillum ferrooxidans. A methodology for biofilm formation was established. Maximum ferric iron productivity was 11.1 g l −1 h −1. The type of air diffusor has been an important parameter to be taken into account in the design, as the oxygen dissolved in the liquid medium limits the ferrooxidant activity of bacteria.

Cultura del trabajo y culturas de empresa en la Cuenca Minera de Riotinto

I start with a discussion of the terms «work culture» and «company culture», laying emphasis on the different analytical leveis between the two. Then I discuss the impact of the latter on the configuration of «work cultures» and the influence that changes in «company cultures» have on the tranformations of specific «work cultures». As an illustration of this process, I show the evolution of «work cultures» in the Riotinto Mines Region as different companies have succeeded one another to the exploitation of the mines.

4,500-YEAR-OLD MINING POLLUTION IN SOUTHWESTERN SPAIN:LONG-TERM IMPLICATIONS FOR MODERN MINING POLLUTION

The Tinto river drains the Rio Tinto mining district, which comprises the world’s largest known massive sulfide deposits; these orebodies have been mined from the third millenium BC to the present. The Tinto river is strongly acidic (pH, 1.5–2.5); during flood events, it transports a sandy material, including abundant detrital pyrite grains. A core drilled in the Holocene sediments of the Tinto estuary allows for investigation of recent and historical mining pollution. Two anomalous horizons have been recognized (0–1.3 m; 3–4 m). Both are characterized by very high metal content (100 times over the background) and by the presence of abundant clastic pyrite grains. The metal association (Pb, Ba, As, Cu, Zn, Sn, Tl, Cd, Ag, Hg, Au) is typical of that of the Rio Tinto pyritic ore. The upper horizon corresponds to the modern mining activity; the lower horizon has been dated at 2530 BC (14C AMS calibrated age). We show here that active mining occurred early (Copper Age) in the Rio Tinto area, resulting in a watershed-scale metal contamination. We also show that anthropogenic input of metals may be accumulated and immobilized during thousands of years in estuarine sediments.

Age and sources of the ore at Tharsis and Rio Tinto, Iberian Pyrite Belt, from Re-Os isotopes

Re-Os isotopes were used to constrain the source of the ore-forming elements of the Tharsis and Rio Tinto mines of the Iberian Pyrite Belt, and the timing of mineralization. The pyrite from both mines has simila]r Os and Re concentrations, ranging between 0.05–0.7 and 0.6–66 ppb, respectively. 187Re/188Os ratios range from about 14 to 5161. Pyrite-rich ore samples from the massive ore of Tharsis and two samples of stockwork ore from Rio Tinto yield an isochron with an age of 346 ± 26 Ma, and an initial 187Os/188Os ratio of about 0.69. Five samples from Tharsis yield an age of 353 ± 44 Ma with an initial 187Os/188Os ratio of about 0.37. A sample of massive sulfide ore from Tharsis and one from Rio Tinto lie well above both isochrons and could represent Re mobilization after mineralization. The pyrite Re-Os ages agree with the paleontological age of 350 Ma of the black shales in which the ores are disseminated. Our data do not permit us to determine whether the Re-Os isochron yields the original age of ore deposition or the age of the Hercynian metamorphism that affected the ores. However, the reasonable Re-Os age reported here indicates that the complex history of the ores that occurred after the severe metamorphic event that affected the Iberian Pyrite Belt massive sulfide deposits did not fundamentally disturb the Re-Os geochronologic system. The highly radiogenic initial Os isotopic ratio agrees with previous Pb isotopic studies. If the initial ratio is recording the initial and not the metamorphic conditions, then the data indicate that the source of the metals was largely crustal. The continental margin sediments that underlie the deposits (phyllite-quartzite group) or the volcanic rocks (volcanogenic-sedimentary complex) in which the ores occur are plausible sources for the ore-forming metals and should constrain the models for the genesis of these deposits.

THE RIO TINTO MINE A VOLUNTEER CLEAN-UP SUCCESS STORY

Underground copper mining at the Rio Tinto mine in northern Nevada commenced in 1932 and continued intermittently for approximately forty years. Since 1975 the site has been essentially inactive. Mine operations included placement of tailings generated from ore processing in the Mill Creek drainage. In 1993, due to concerns about environmental damage to surrounding surface waters, four of the previous owners and operators of the site jointly formed the Rio Tinto Working Group (RTWG) to remediate the site in cooperation with the State of Nevada, Department of Conservation and Natural Resource and the Division of Environmental Protection (NDEP). The Rio Tinto Working Group consists of the Atlantic Richfield Company, Cleveland Cliffs Iron Company, E.I. DuPont de Nemours and Company, and Cominco American Inc., The regulatory and technical approach taken by the RTWG to achieve their objective of proactively implementing remedial measures at the site, rather than following the CERCLA process, are discussed. The steps included preparing an 18-element remedial program to be completed at the site and negotiating an Administrative Order on Consent (AOC) with the State of Nevada, which included a deferral from EPA for listing of the site on the NPL list. By entering into a cooperative relationshipmore » with the NDEP and avoiding the CERCLA process, the Rio Tinto Working Group was able to fast track site investigation and remedial designs, leading to a timely start up of remedial construction activities.« less

Silver-catalysed bioleaching of a chalcopyrite concentrate with mixed cultures of moderately thermophilic microorganisms

Bioleaching of a chalcopyrite concentrate was studied using two mixed cultures of moderately thermophilic microorganisms, one from the drainage of Rio Tinto mines and the other obtained by raising the growth temperature of a mixed culture of mesophilic bacteria. Both cultures were adapted to different concentrations of silver (0.1–0.5 g of silver/kg of concentrate) to test their leaching capacity in the presence of this catalyst. The results showed the important role of silver in the chalcopyrite leaching process carried out at 45°C. Copper yields increased around 3-fold over the control experiment without silver. At 50°C, however, only one of the cultures remained active and the effect of silver was masked by strong jarosite precipitation, which increased with the amount of silver used. The 9K medium played a key role in this respect, and it was clear that more diluted media should be used to avoid this problem. Despite this drawback, the amount of copper extracted using the catalyst was double than that obtained without it.

Study by SEM and EDS of chalcopyrite bioleaching using a new thermophilic bacteria

The main aim of this work is to provide new evidence regarding the interaction of chalcopyrite with an unknown thermophilic bacteria isolated from Rio Tinto mines (Huelva, Spain). This new microorganism gives very high copper recoveries (more than 80%) when a chalcopyrite concentrate is bioleached. Study of the solid massive samples after bioleaching by scanning electron microscopy (SEM) and non-dispersive X-ray microanalysis (EDS) confirmed its ability to attack ore. Chalcopyrite leached in the presence of this bacteria underwent a very strong superficial transformation in comparison with the sample attacked either in the absence of bacteria or in the presence of Fe 3+. The attack started in cracks and genetic defects and finally reached the whole chalcopyrite surface. As a consequence of this, the ore showed deep cracks and a very rough surface. The presence of Fe + to increase the bacteria activity did not improve chalcopyrite bioleaching. These results were similar to those obtained in the absence of bacteria but in the presence of ferric ions. Therefore, the very good capacity o f this new thermophilic microorganism for bacterial leaching and its advantages over conventional chemical leaching were demonstrated.

L. U. Salkield A Technical History of the Rio Tinto Mines: some Notes on Exploitation from Pre-Phoenician Times to the 1950s. London (Institute of Mining and Metallurgy) 1987, x+114 pp., 4 maps. Price £15·99

L. U. Salkield A Technical History of the Rio Tinto Mines: some Notes on Exploitation from Pre-Phoenician Times to the 1950s. London (Institute of Mining and Metallurgy) 1987, x+114 pp., 4 maps. Price £15·99 - Volume 52 Issue 366

A technical history of the Rio Tinto mines

A technical history of the Rio Tinto mines

Charles Enrique Dent, 25 August 1911 - 19 September 1976

Charles Dent was born in Burgos, Spain, on 25 August 1911. His paternal grandfather, who was a Church of England parson in Coverdale, a Cambridge M.A., and reputed to be a good Greek scholar, died under the age of 40. Charles’s father was Dr Frankland Dent, who studied chemistry in Leeds and, as was not unusual before World War I, went afterwards to Munich to acquire a Ph.D. He then joined the Rio Tinto Mining Company and worked in Spain, where he met his wife and married her in 1903. Charles’s mother was Carmen Colsa de Miray Perceval, who came from a well established Spanish family. She had been orphaned early in her life and was educated in a convent. She died in 1976 only a short time before Charles, in her hundredth year. Soon after his marriage, Dr Frankland Dent accepted a post in Singapore, which at that time was part of the Straits Settlement. Dr Frankland Dent was the government chemist and analyst, responsible for a territory which is now Malaysia and Singapore. The two eldest children were born in Singapore, but Charles’s mother decided to return to Spain for the birth of her third child. After about a year in Burgos, the family returned to Singapore and stayed there until the outbreak of war in 1914. Mrs Dent then decided to come to England with her children, but travelling across the Continent at that time was not easy, and the family spent some time near Marseilles before finally settling in Bedford in 1915, where Charles received his early education. He attended Bedford School for a few years where he did well at games, but showed no particular interest in academic subjects. This worried Charles’s father, and a change of school was considered desirable.

Electrochemical nucleation and growth of copper on iron and aluminum: A TEM study of industrial copper cementation

Georgius Agricola in 1556 in his classical book, “De Re Metallica”, mentioned a strange water drawn from a mine shaft near Schmölnitz in Hungary that eroded iron and turned it into copper. This precipitation (or cementation) of copper on iron was employed as a commercial technique for producing copper at the Rio Tinto Mines in Spain in the 16th Century, and it continues today to account for as much as 15 percent of the copper produced by several U.S. copper companies.In addition to the Cu/Fe system, many other similar heterogeneous, electrochemical reactions can occur where ions from solution are reduced to metal on a more electropositive metal surface. In the case of copper precipitation from solution, aluminum is also an interesting system because of economic, environmental (ecological) and energy considerations. In studies of copper cementation on aluminum as an alternative to the historical Cu/Fe system, it was noticed that the two systems (Cu/Fe and Cu/Al) were kinetically very different, and that this difference was due in large part to differences in the structure of the residual, cement-copper deposit.

Treating blind river uranium ores by leaching ion exchange precipitation

From one of the world’s most important uranium producing areas, here is the story of how uranium precipitates are produced. This is a description of techniques used in the seven mills of Rio Tinto Mining Co. of Canada.

Fausto de Elhuyar (1755–1833), A Spanish Mining Geologist

AbstractElhuyar, born in Spain in 1755, received a thorough training in mining geology at several of the leading European mining schools. He was appointed to an important post in New Spain (Mexico), where he arrived in 1788. There he devoted himself to reorganizing the administration of the mining industry and then to founding a School of Mines in Mexico City. This was opened in 1792, and in 1811 moved into the magnificent new building known as El Palacio de Minería, which now houses the Engineering School of the University. When an independent government was set up in Mexico in 1821, Elhuyar returned to Spain, where he continued to work for the government as a mining consultant. He prepared a report on the Rio Tinto mines and was responsible for the planning of the School of Mining Engineering in Madrid.

Origin of the Rio Tinto Ore Bodies

AFTER a year's intensive study of the surface and underground conditions at the Rio Tinto Mines in the Province of Huelva, Spain, I have been led to a theory as to the origin of the great ore bodies in this region. As this theory or working hypothesis has already borne fruit, inasmuch as it has led directly to the finding of several new ore masses, it is deemed worthy of brief mention here in advance of the full discussion which will appear later.

On the Geology of the Rio-Tinto Mines, with some General Remarks on the Pyritic Region of the Sierra Morena

The pyrites deposits of the Andevallo, as the mineral zone of the south-western branch of the Sierra Morena is called, are certainly the most extensive ever yet discovered. In addition to the world-famous mines of Rio Tinto and Tharsis in Spain, and of San Domingos in Portugal, they include many others of very considerable extent and importance, yielding in the aggregate, at the present time, upwards of two and a half millions of tons of ore per annum. The deposits in question are included within a band of country about 140 miles long and 30 miles wide, consisting for the most part of Palæozoic schists, now known to be principally, if not entirely, of Upper Devonian age, but which are often very highly metamorphosed locally into jasper, talc-schists, chiastolite-schists, &c., and are associated with quartz- and felspar-porphyries, diabase, quartz-syenite, and granite. The mineral strata to the northward abut against or rest upon the highly crystalline schists and gneissose rocks of the Sierra Alta, which have been assigned to the Huronian and even to the Laurentian period, while to the southward they are overlain by Tertiary limestones and sandstones. The chief mineral riches of this region consist of masses of cupriferous pyrites, such as those so largely worked at the above-mentioned mines; but there are, in addition, numerous veins of manganeseore, as well as of lead, copper, and zinc ores, some of which have been worked occasionally to considerble advantage, while a very large number of them could be so worked