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Les Mines Inmet ? La Division Troilus exploite une mine d?or à ciel ouvert depuis 1996 et produit un concentré de cuivre. La Division Troilus est localisée à 175 KM au nord de la ville de Chibougamau? au 51 parallèle.

Feb 1, 2008

By Galetakis M., Deligiorgis B., Xiroudakis G.

Fragmentation prediction is important in surface mining to optimize downstream processes such as loading, hauling, comminution, and beneficiation processes. Traditional approaches, such as the Kuz-Ram model, image-based fragmentation analysis, and numerical simulations, rely heavily on large datasets acquired after blasting. Moreover, due to the inherent limitations in each method there is an underestimation of fine and coarse fragment sizes, when applying these models without prior knowledge regarding the fragmentation distribution. These drawbacks are restricting their use only in post-blast parameter prediction. In response to these inefficiencies, this study presents a deterministic fragmentation prediction methodology based on a single-blasthole model. The model simulates the formation of the damage zones around a blast hole based on the number of cracks within a distance from the centre of the blast-hole and correlates them with an estimated fragment size in each domain. A fragmentation distribution from the literature is employed to validate the proposed approach and the results are compared with those generated using a modified Kuznetsov model. This approach aims to enhance blast design decisions by enabling pre-blast fragmentation prediction. Based on this, blast designs could be estimated depending on the desired fragmentation before blasting, giving the opportunity for a tailored to local rock properties optimization.

Jan 26, 2026

By Edward W. Ames

"The Jewell tunnel property, situated 3/miles north of Garfield, Chaffee County, Colo., was examined by an engineer3 of the Bureau of Mines in June 1943. Field work began September 16, 1944, but was recessed from December 26, 1944, to gay 15, 1945, because of heavy snows, and was suspended July 12, 1945, when rehabilitation of the New York tunnel workings was completed to the point desired.In its program of exploration of Mineral deposits, the Bureau of Lines has as its promary objective the more effective utilization of our mineral resources, to the end that they make the greatest possible contribution to national security and economy. It is the policy of the Bureau to publish the facts developed by each exploratory project as seen .as practicable after its conclusion. The Mining Branch, Lowell B. Moon, chief, conducts preliminary examinations, performs the actual exploratory work, and prepares the final report. The Metallurgical Branch, R. G. Knickerbocker, chief, analyzes samples of ore and performs beneficiation tests. Both these branches are under the supervision of Dr. R. S. Dean, assistant director.For their supervision of the project and their help in revising the report, particular acknowledgment is due Wm. P. Huleatt, district engineer, Denver, Colo., and Paul T. Allsman, chief, Salt Lake City Division, Mining Branch.The property is situated in secs. 15 and 22, T. 40 N., R. 6 E., N.R.F.M. Salida, the county seat, is on the main line of the Denver & Rio Grande Western Railroad. The property is reached from Salida by following U. S. Highway 50 westward for 18 miles to the village of Garfield, near Monarch Pass, then northward for 3 miles by a very steep mine-access road up Taylor Gulch (fig. 1).The highway to Garfield is accessible throughout the year, but the access road from Garfield is generally impassable from December until June because of snow."

Sep 1, 1946

By Anievas JB, Sevillano AC

This paper describes the acquisition, exploration, development, initial operation and subsequent financing of the Bulawan mine by means of a listing on the Toronto Stock Exchange of a subsidiary of the parent company, Philex Mining Corporation.Located on the island of Negros in the Philippines the property is unique on at least two counts: it is a disseminated gold deposit that occurs in a region of predominantly porphyry copper mineralisation; and it is a gold deposit that is mined by a bulk method of extraction (front and block cave) instead of the normal selective mining methods.

Jan 1, 1997

By Miguel Rutti

El presente trabajo señala la geología, litología y mineralización del yacimiento minero El Tapado del distrito Yanacocha, situado al norte de Cajamarca. Este se encuentra conformado por diferentes depósitos auríferos epitermales de alta sulfuración, los cuales se desarrollan dentro de un vulcanismo calco-alcalino de composición andesítica a dacítica de edad Mioceno y son correlacionables con la Formación Porculla del Grupo Calipuy. La geología del depósito está conformada por rocas porfiríticas (intrusiones) y flujos piroclásticos tales como tufos de cristales, tufos líticos y brechas piroclásticas afectados por eventos eruptivos de brechas freáticas - freatomagmáticas. Todas estas rocas han sufrido posterior alteración hidrotermal con ensambles típicos de sistemas tipo ácido-sulfato. La mineralización económica está controlada por procesos hidrotermales y se encuentra asociada a sílice masiva y sílice vuggy ( 1-10 g/t Au y estructuras de hasta 136 g/t Au ) y en menor grado sílice alunita y sílice granular (moderada a baja ley).

Apr 22, 2003

By M. R. Shahan, W. R. Reed, S. Klima, T. W. Beck

"Testing was conducted to determine the ability of foam to maintain roof coverage in a simulated longwall mining environment. Approximately 27% of the respirable coal mine dust can be attributed to longwall shield movement. Developing controls for this dust source has been difficult. The application of foam is a possible dust control method for this source. Laboratory testing of two foam agents was conducted to determine their ability of foam to adhere to a simulated longwall face roof surface. Two different foam generation methods were used; compressed air (CA) and blower air (BA). Using a new imaging technology, image processing and analysis utilizing ImageJ software produced quantifiable results of foam roof coverage. For CA foam in 3.3 m/s (3.3 m/s (650 fpm)) ventilation at 3 minutes after application, 98% of agent A was intact, while 95% of agent B was intact on the roof. At 30 minutes after application 94% of agent A was intact while only 20% of agent B remained. For BA in 3.3 m/s (3.3 m/s (650 fpm)) ventilation, the results were dependent upon nozzle type. Three different nozzles were tested. At 30 minutes after application 74-92% of foam agent A remained, while 3-50% of foam agent B remained. CA foam seems to remain intact for longer durations and is easier to apply than BA foam. However, more water drained from the foam when using CA foam which demonstrates that BA foam retains more water at the roof surface. Agent A seemed to be the better performer as far as roof application is concerned. This testing demonstrates that roof application of foam is feasible and is able withstand a typical face ventilation velocity, establishing this technique’s potential for longwall shield dust control. INTRODUCTION NIOSH personnel have visited many longwall operations at various geographical locations in the U.S., conducting benchmark surveys to characterize current operating practices and dust control measures in use. Sources of respirable dust generated from the longwall face have been identified as: intake (10%), stage loader (20%), shields (27%), and shearer (43%) [1]. Dust generated from the shearer, armored face conveyor, and the stage loader can mainly be controlled by water sprays and increases in ventilation air quantities, however, research has demonstrated limited effective controls for dusts generated by shield movements [2]. One possible approach to mitigating shield dust generation is to apply a layer of water or foam to the shield-roof interface. Once this interface is blanketed with foam or water, dust will be less likely to become airborne and contaminate the airways over the personnel walkways. Though water is an abundant and common dust control measure, roof applications have limited success because water is unable to remain in-place in adequate quantities for the necessary duration between application and shield advance. Past and current testing of foam for material properties has shown that it has longer applicability times, ranging from 10 to 60 minutes [3] and has shown better performance for dust control, ranging from 19-96% improved efficiency over water [4, 5, 6, 7, 8]. The majority of this foam dust control research has focused on dust control efficiency at the longwall shearer or continuous miner cutting drum."

Jan 1, 2017

Effects of High Pressure Grinding Rolls on Platinum-Bearing Ores and the Flotation Response as Compared to the Conventional Ball Mill Three major PGM ore types from the Bushveld Complex of South Africa: Merensky, UG2 and Platreef were comminuted with the use of the high pressure grinding rolls (HPGR). The influence of the feed characteristics and the various operational and design features of the HPGR on energy consumption, throughput, mineral liberation and PGM flotation recovery were investigated. The test work variables included two feed top sizes of 12 mm and 6 mm, specific grinding forces ranging between 3 - 7.5N/ mm2 and zero gaps of 1.5 mm and 3 mm. The results show that the influence of the HPGR operational and design features on energy consumption, throughput, mineral liberation and PGM recovery are ore dependent. The size reduction-specific energy relationships show that the most energy efficient utilisation of the HPGR for Platreef ore was at the lower specific grinding force of 3N/mm2 and the zero gap at 3 mm. For Merensky and UG2 ore on the other hand, the most energy efficient operation was at the higher specific grinding force of 7.5N/mm2 and the zero gap of 1.5 mm. At a specific energy input of 3 kWh/t, reduction ratios (F50/P50) of 6.5, 3.8 and 10 were obtained for Merensky, UG2 and Platreef, respectively for feed top sizes of 12mm. Further application of the HPGR as a pregrinding stage to a ball mill showed a 25 - 30 per cent increase in throughput for Merensky and UG2 ore. Batch flotation tests performed on selected samples appear to indicate that ore comminuted with the ball mill had superior grades compared with that ground with the HPGR. However, Merensky and UG2 ore comminuted at different HPGR operating conditions showed distinctions in PGM recovery. Platreef on the other hand did not appear to show any differences. Therefore, this study highlights the significance of ore type and operating variables in HPGR applications with regards to energy efficiency, throughput and PGM recovery.

Sep 13, 2010

By P Breuer, A Simons

The sulfidisation, acidification, recycle and thickening (SART) process is currently being used at NewcrestÆs Telfer Gold Mine to recover cyanide and copper from the cyanidation tails of the pyrite concentrate carbon-in-leach (CIL) process. While the process has been effective at attaining high recoveries of cyanide and copper, the Telfer SART plant has experienced higher than expected sulfide additions to achieve these recoveries. This paper details the results of surveys on the Telfer SART plant, which show that residence time appears to be causing the high sulfide consumptions. The paper also details the results of laboratory scale experiments which confirm the observed residence time impact during the acidified stage of SART.CITATION:Simons, A and Breuer, P, 2013. The impact of residence time on copper recovery in Telfer Gold MineÆs cyanide recycling process, in Proceedings World Gold 2013 , pp 189-196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Sep 26, 2013

In Alaska?s southwest corner, in the Bristol Bay region, 476 holes have been drilled to help define the size of the Pebble Project. The results indicate that the deposit holds close to 32 Mt (72 billion lbs) of copper and 2.9 Gt (94 million oz) of gold. The Pebble Partnership, an Alaskan limited partnership of Anglo American and Northern Dynasty Minerals, owns the project that consists of two world-class mineral deposits. Currently in the prefeasibility and prepermitting stage of development, the Pebble Project is one of the largest and highest profile exploration projects in North America. History The Pebble West Project was originally discovered in 1988 by Cominco (now Teck Cominco). Drilling programs in 1997 defined a near-surface mineral deposit of 1 Gt (1.01 billion st). Minerals found included copper, gold and molybdenum. Northern Dynasty Minerals acquired the property in 2001 and, by 2005, it had confirmed a measured and indicated resource of 4.1 Gt (4.5 billion st) containing 1.2 kt (42.1 million oz) of gold, 11.2 Mt (24.7 billion lbs) of copper and 612 kt (1.35 billion lbs) of molybdenum and additional silver. By September 2005, Pebble East, a deeper, but richer deposit had been found. Drill data by the end of 2005 confirmed a 3.4-Gt (3.7-billion st) inferred resource containing 19 Mt (42.6 billion lbs) of copper, 1.2 Mt (39.6 million oz) of gold and 1.2 Mt (2.7 billion lbs) of molybdenum.

Jan 1, 2009

By S. H. Lorain

This paper briefly describes the principal known commercial and near commercial deposits of gold-bearing gravel end the principal placer mining operations of Idaho County, Idaho. It is one of a series of similar papers on western mining districts. The data used in writing this paper were gathered during the summer of 1937. Information concerning gold-bearing gravels was obtained from prospectors and operators, while operators supplied most of the data on mining operations. No attempt was made actually to test the gravels. The principal object of the examination was to indicate placer areas worthy of further investigation by prospective operators.

Jan 1, 1938

By K. A. Natarajan, S. C. Riemer, I. Iwasaki

The relative significance of corrosive and erosive wear in magnetic taconite grinding is examined. The influence of different types of aeration (nitrogen, air, and oxygen) on ball wear was established for mild steel and high carbon low alloy steel balls. Ball wear data from dry and wet grinding tests are compared with those obtained in the presence of an organic solvent that does not promote electrochemical corrosion. Marked ball grinding tests and electrochemical measurements involving ball material and magnetite electrodes indicate that contribution from oxygen toward wear (corrosive wear) is relatively small, and abrasive wear appears to be significant. Rheological properties of the slurry appear to have an important bearing on the abrasive wear of grinding balls.

Jan 1, 1985

Calculations of the temperatures of metal, coke, and gas at any level in the cupola furn~ce can be carried out by means of heat balances, using data obtained from experiments with an 18 in. experimental cupola. The results can, to a certain extent, be verified by means of heat transfer calculations.The curves thus obtained, showing the variation of temperature with height in the cupola, provide a valuable picture of the heat transfer processes in a shaft 'furnace.INTRODUCTIONThe Brown Coal Research Laboratory, of the University of Melbourne, has been engaged in recent years on a programme of iron-melting tests in an experimental cupola furnace.Although the ultimate aim of this work is to develop brown coal char as a cupola fuel, most of the experimental work so far has been with conventional coke. The testing programme was designed to provide information on the effect of variables such as blast rate, metal-coke ratio, and coke size on the overall melting process, e.g. melting rate, temperature of metal tapped, and stack gas composition.However, in many cases data were obtained on conditions inside the furnace by measuring temperatures and gas compositions. The aim of the work described in this paper was to qevelop a method for using this data to obtain information on the processes taking place in the cupola.Very little research has been done on the combustion of fuels in shaft furnaces. Early work on this subject, as well as the initial stages of the Brown Coal Research Laboratory's programme, has been discussed by Evans (1959). The use of probes for obtaining information on conditions in the interior of a shaft furnace was pioneered by Belden (1913)...

Jan 1, 1963

By L. O. Bacon, H. R. Joesting, J. H. Getz

"INTRODUCTION For a number of years manganiferous iron ore has been mined on a small scale at Boston Hill, in Grant County, N. Mex. Total production up to 1943 is estimated to be over 793,000 long tons, containing 8 to 35 percent manganese and 26 to 46 percent iron. 4/ During 1941 to 1943 production was estimated to be 206,000 long tons, containing about 13 percent manganese and 37 percent iron. During 1944 daily production was several hundred tons, mostly from a single open pit. Several moderately large deposits have been mined: and many smaller ones have been found.From February to April 1945 geophysical surveys were carried out on Boston Hill by the Division of Geophysical Exploration, in cooperation with District 5, Central Region, Bureau of Mines, to determine if hitherto undiscovered manganiferous iron deposits exist. Field work was interrupted for a total of about 1 month during this period by work on other projects in nearby areas. Previous to the geophysical surveys, a preliminary examination was made by H. R. Joesting to determine if geophysical methods could be utilized in exploring the area. 5/Field measurements were made by L. O. Bacon and J. H. Getz, project geo¬physicists of the Bureau of Mines, under the general supervision of H. R. Joesting. A grid survey of the area, to locate geophysical stations, was made by Paul Russell, Bureau of Mines engineer, who also collected specimens for laboratory tests. Most of the computations and the preliminary magnetic and resistivity maps were made by L. 0. Bacon."

Feb 1, 1948

By G. R. FITT, S. R. B. Cooke, C. W. Davis, V. H. Gottschalk, C. G. Maier, C. E. Wood, R. S. Dean, S. B. THOMAS, John Gross, E. P. Barrett, T. L. Joseph

Lack of funds has prevented publication of much of the metallurgical work of the Bureau of Mines during the past 2 years . The present progress report covers studies in the direct production of iron and steel . The experimental work was carried out in cooperation with the universities of California , Minnesota , and Missouri . Complete reports will be published when funds are available .

May 1, 1934

By P. J. N. Pells

A good thing is becoming a bad thing. Rock mass classification systems, that are so excellent for communications between engineers and geologists, and that can be valuable in categorizing project experience, are emasculating engineering geology and rock mechanics. Some engineering geologists have been sucked into thinking that Q and RMR values are all that is needed for engineering purposes, and seem to have put aside what can be learned from structural geology and geomorphology. Many rock mechanics engineers seem to have forgotten the scientific method. This paper attempts to redress the situation by showing how mechanics can be used in rock engineering to design with a similar rigour to that used in the fields of structural engineering, hydraulics and soil mechanics. It also attempts to remind practitioners of what can be achieved by skilled engineering geology.

Jan 1, 2008

By Ning Shi

This paper suggests an alternative design approach for an innovative shovel dipper, for use in ground conditions where cutting of virgin ground rather than scooping of blasted material is required. Not only does the new design have an optimized dimension ratio (width:height:depth) and attachment arrangement (angle, position), but also a non-linear pro¯le in 2D and 3D. The approach is based on the simulation of a shovel's duty cycle to verify a pilot dipper model. In order to achieve a realistic simulation that could be used to evaluate a dipper design, the model is e®ectively a descriptor of actual shovel activity under soft ground conditions. The shovel geometry, motion and operation, with an emphasis on digging and dumping kinematics and dynamics are the principal elements of the simulation. The simulation considers a fresh face location, repeating tucking, digging and dumping swing motions within the geometric range of the machine, ending when no more face material remaining within reach without re- positioning. The simulation yields digging force, friction force, trajectory, ¯ll time, ¯ll factor, etc, which may be integrated into two basic considerations: power draw (output) and volume delivered (production), as indicators of dipper performance. The simulation has been used as a tool to modify an existing dipper design, prior to looping further simulation cycles. Ultimately, an optimized or totally-new-concept shape is realized. A prototype dipper as a fractional scale model will be built to verity the performance under actual mining conditions.

May 1, 2004

By Met B. E

During the operation of the Parkes process of desilverising, and in the earlier days of the continuous process, gold and silver were removed separately from softened lead bullion. Gold was removed in the Parkes process by a selective zincing, and -in the continuous process by treatment with zinc in a special de-golding kettle, in each case a crust being obtained carrying the gold and a small portion of the silver. Actually the process could have been more correctly termed a de-copperising process, on accountof the relatively large amount of this metal present, and its affinity for zinc, which caused it to enter the crusts produced.The crust was treated in reverberatory furnaces, where the bulk of the copper and zinc was removed in by-products, and the resulting "gold bullion" cupelled to give adore bullion containing approximately 2,000 ounces gold per ton.For the purpose of parting this dore, a small Balbach-Thum plant of 11 cells was used, and once each six months a short campaign was conducted on the accumulated metal.With the development of the process of de-copperising smelter bullion by means of sulphur, when a bullion averaging about .004% copper was constantly available for refining, the need for a separate de-golding process disappeared.The de-golding kettle of the Continuous Process...

Jan 1, 1937

Although the Diamond that is cut and polished and made up into an article of jewellery, is so well known, there are, comparatively speaking, very few outside the industry who know this beautiful crystal in the crude state, as turned out ofNature's laboratory, and the means employed in winning this precious stone.This article is written with the endeavour to give the reader some idea of the geological formations in which the Diamond occurs, and as it is reported that Diamonds have been found in Western Australia, as well as in other parts of the Australian Colonies, a few hints as to the means employed in working the ground in South Africa may be of use to those intending to prqsecute the search in this country. The general geological formation of the South African Diamond Fields is Lacustrine shales and sandstones, intersected by dykes of various eruptive rocks, varying considerably in their character. and in places vesicular in texture, the vesicules being more or less filled in with zeolites by permeating waters.

By R. C. Troxell

Alternative methods of analyzing data acquired by the Morenci copper concentrator process control instrument-computer system are presented. Experimental measures of ore characteristics, for proposed feed forward control, are introduced. These include on-line indexes of ore hardness, ore density, ore dusting, and ore color. Comparison of metallurgical results before and after computerized process control implementation, allowing for differing ore grades, oxidation, hardness, and fineness of grind, also is described.

Jan 1, 1979

By Graham Davey

"Low speed stirred milling has been employed for many years in the metalliferous and industrial minerals industries. High speed stirred milling is a relatively new method of grinding in the metalliferous process industries. However it has been it has been in wide spread use in the industrial mineral field for over 30 years for various minerals. Many existing metallurgical operations are looking to maximize economic return from existing deposits, requiring new thinking and technologies. By combining low speed and high-speed milling fine and ultrafine grinding efficiency and operating costs can be improved.The correct selection of different fine grinding technologies is covered, when each mill is applicable and when a combination of the VERTIMILL® Grinding Mill and SMD provides the best economic solution.INTRODUCTIONUltra-fine grinding of minerals has been in wide spread use in the industrial mineral field for over 30 years. Within the last 10 years the metalliferous industry has shown interest in the ability to produce ultrafine particles, as chemical, physio-chemical and physical separation processes have advanced to be able to treat ultrafine metalliferous particles. Also as the primary mineral deposits, around the world are depleted, new more difficult deposits must be mined. Existing operations are also looking to maximize economic return from existing deposits, requiring new thinking and technologies.The traditional approach for gold containing refractory material has been to liberate the locked gold by chemically destroying the pyrite through oxidation. Roasting, pressure oxidation, and bacterial oxidation all employ various degrees of temperature, pressure and catalysis to react the pyrite with oxygen to produce iron oxide and sulfur by-products. However all of these methods are economically impacted due to specific operational added requirements and emissions controls. Pressure and bacterial oxidation have very high capital and operating costs."

Jan 1, 2006