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By Miro Mihelich

The mines and prospects in the vicinity of Landlocked Bay, 25 miles southwest of Valdez, Alaska (fig. 1), were examined, mapped, and sampled in July and August 1955 as part of a comprehensive investigation by the Bureau of Mines of ore deposits adjacent to Prince William Sound. The purpose of the investigation is to establish and record the location, nature, extent, and metallurgical characteristics of copper and associated metallization in the Prince William Sound district and to indicate, if possible, those areas in which additional exploration and development may be justified. Of particular interest are the possibly numerous deposits of massive iron sulfides that were neglected during early mining operations. These deposits may constitute important reserves of sulfur and iron. At Landlocked Bay deposits of copper-bearing iron sulfide minerals have been mined or partly explored through mine workings, which are in a zone about 1 mile wide along the western side of a large overthrust fault known as the Landlock Overthrust. Eight of the principal mines along this zone were examined end sampled. Although only three of the mines have a recorded production of shipping-grade copper ore, all have deposits of copper-bearing iron sulfide minerals that are similar in occurrence. The deposits occur as lenticular masses and disseminations of chalcopyrite, pyrite, and pyrrhotite which replace crushed rock or fill cavities along shear zones in greenstones and in sedimentary rocks that are exposed between sea level and an altitude of 2,500 feet. These lenticular masses of sulfide minerals range in size from small pods to ore bodies that have been stoped to maximum widths of 9 feet, strike lengths up to 70 feet, and dip lengths as much as 350 feet. Where accessible for sampling,, the copper content of the deposits ranged from a few hundredths of a percent to over S percent; zinc, gold, and silver are present in negligible amounts. Flotation tests of a sample composited to represent typical mine-run ore indicate that 81 percent of the copper is recoverable in a product assaying 28 percent copper at a concentration ratio of 17.5 : 1. INTRODUCTION Statistical records indicate that approximately 110,000 tons of metallic copper (about 16 percent of total Alaskan production) was produced from mines adjacent to Prince William Sound during the 40-year period ended in 1938. Although the principal production was from a large-scale mining and milling operation on Latouche Island (Kennecott Copper Corp., Beatson mine), a substantial amount of the total copper was derived from direct-shipping ores selectively mined or hand-sorted from numerous other deposits in the district. No production has been made since 1938; many of the claims have long been abandoned, and mine workings are either caved or deteriorating rapidly.

Jan 1, 1957

By Albert Wraith, Thomas Price, Wayne Boyd, Skip (I. E. ) Hills, Cameron Harris

Most Peirce-Smith converters inject air through tuyeres, with nitrogen representing the majority of gas passing through the process. The nitrogen controls the temperature of the vessel by carrying away heat from the reactions, both globally and locally at the tuyere tip. However, nitrogen adds energy to the bath and contributes to splashing and limits the blowing rate. High oxygen smelting has made streams of gas containing high concentrations of sulphur dioxide commonplace, which can be used to substitute SO2 for nitrogen and drastically changes Peirce- Smith converting (and all other smelting/converting processes as well). Less SO2 is required to carry away the same quantity of heat, which allows higher concentrations of oxygen and leads to the possibility of increased production. The paper investigates this substitution, its impact on converter productivity, and on the remainder of the plant. 181

Jan 1, 2009

By A K. B Opitz, M Becker, J L. Broadhurst

"One of the key drivers of geometallurgy is to define the ore characteristics and their variability to build a geometallurgical model. The inclusion of waste rock properties and their variability is just as important, given that the generation of acid rock drainage (ARD) poses one of the most significant environmental challenges facing the mining industry. Formed through the oxidation of sulfide minerals in the presence of oxygen and water, ARD generation is exacerbated through the regeneration of lixiviates by naturally occurring iron- and sulfur-oxidising micro-organisms. In order to manage the potential risk of ARD pollution, timely, accurate, reliable and robust characterisation and prediction of the ARD potential of waste material is critical from an early stage in the mining process.This study demonstrates the use of the biokinetic-accelerated weathering test developed at the University of Cape Town to characterise the ARD potentials of gold waste rock samples under microbial conditions. These tests are performed in conjunction with standard characterisation tests to provide an indication of the potential for ARD generation under both chemical and biological conditions. Results provided information regarding the relative rates of acid neutralisation and acid generation, with the contribution of specific minerals to the observed behaviour considered through use of a detailed mineralogical assessment. Overall, the addition of the biokinetic test to the current geometallurgical characterisation and prediction toolbox will allow for relatively rapid assessment of the bulk kinetics of ARD generation.CITATION:Opitz, A K B, Becker, M, Broadhurst, J L, Bradshaw, D J and Harrison, S T L, 2016. The Biokinetic Test as a Geometallurgical Indicator for Acid Rock Drainage Potentials, in Proceedings The Third AusIMM International Geometallurgy Conference (GeoMet) 2016, pp 183–192 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jun 15, 2016

By R. H. Roberts

The Environment Weipa is located at 12° south latitude on the west coast of Cape York Peninsula, North Queensland, Australia. The climate is tropical with most of the 1 600 mm. average annual rainfall falling between November and March. During the short winter months (May/ August) the weather is clear and pleasant, with temperatures seldom exceeding 27°C.Throughout the remainder of the year, conditions are frequently oppressive due to consistent high ambient temperatures accompanied by high humidity. The terrain is of low relief, and generally not more than 6 to 10m. above mean sea level adjacent to the coast. The coastline features numerous short estuaries which discharge run-off from the heavy rains collected by creeks and rivers. The whole area is covered by an open forest, the predominant species of which is Eucalyptus tetradonta. These eucalypts have only limited commercial value and are heavily infested with termites. Despite the fact that Weipa is close to the location of the first reported sighting of the Australian coastline by a European (William Janz - 1606), it remains very isolated. There is no developed road or rail connection to centres of population, so that transport of practically all products, personnel and materials to and from Weipa is by sea and air. Cairns (population 49 000) is 580 km. by air and 670 nautical miles by sea; Brisbane, the

Jan 1, 1977

By C. Samson, R. S. Smith, S. W. Hefford

"Abstract - Time-domain electromagnetic systems are most sensitive to highly conductive targets during the transmitter on-time. Data collected during the on-time is highly influenced by the geometric relationship between the transmitter and the receiver. Unless corrections can be applied for these geometric variations, the ability to correctly detect and identify highly conductive targets can not be fully realized. Variables affecting the relative position between the transmitter and receiver include changes in the position of the receiver with respect to the transmitter, variations in transmitter attitude, and transmitter loop deformation. The level of accuracy in the determination of the relative geometry required to permit complete removal of the effects due to geometric variations is different for each of the variables and is dependent on the depth of the target. The most influential geometric variation involves changes in the relative position of the receiver with respect to the transmitter along the direction of flight; this variable, therefore, requires the highest degree of accuracy. The accuracy required for receiver motions along the vertical direction is roughly one order of magnitude less, and in the lateral direction, several orders of magnitude less. The objective of this paper is to relate the sensitivity of the response to transmitter-receiver geometry to the ability of an airborne, time-domain electromagnetic system to resolve a highly conductive vertical target. This is achieved by a detailed analysis of the effect of the individual x, y, and z distances between the transmitter and the receiver, the transmitter attitude (roll, pitch, and yaw), and transmitter deformation.Sommaire - Les systèmes électromagnétiques en domaine temporel sont particulièrement sensibles aux cibles à forte conductivité durant le temps d’excitation. Les données collectées durant l’émission du transmetteur sont fortement affectées par les relations géométriques entre le transmetteur et le récepteur. Si un facteur de correction n’est pas introduit pour tenir compte de ces variations géométriques, la capacité de ces systèmes à détecter et identifier correctement les cibles fortement conductrices ne peut pas être pleinement réalisée. Les facteurs affectant les positions relatives du transmetteur et du récepteur comprennent les changements de position du récepteur relativement au transmetteur, les changements d’altitude du transmetteur et la déformation de la boucle du transmetteur. Le degré de précision requis pour déterminer la configuration nécesaire pour compenser complètement l‘effet des changements géométriques est différent pour chacune des variables et dépend de la profondeur de la cible. Les changements géométriques qui ont le plus d’influence sont ceux qui font varier la position du récepteur relativement au transmetteur dans l’axe de la ligne de vol; c’est donc cette variable qu’il faut contrôler avec le plus de précision. La précision requise pour le suivi des mouvements du récepteur le long de l’axe vertical est moindre d’environ un ordre de grandeur, tandis que selon l’axe latéral elle est diminuée de plusieurs ordres de grandeur. Le but du présent article est d’établir comment la susceptibilité de la réponse à la géométrie transmetteur-récepteur affecte la capacité d’un système électromagnétique en domaine temporel aéroporté à reconnaître une cible verticale fortement conductrice. Cet objectif est atteint par l’analyse détaillée de l’effet individuel des distances x, y, et z entre le transmetteur et le récepteur, l’attitude du transmetteur (lacet, roulis, tangage) et la déformation du transmetteur."

Jan 1, 2006

By J. Mácsik, J. Lindblom, C. Maurice, Susanne Nigéus

Using non-hazardous industrial residues in mine waste remediation is beneficial not only for the mining industry where substantial amounts of the waste generated have potential to produce acid rock drainage and pollute the environment, but also the providing industry, minimizing the waste landfilled. In this study green liquor dregs (GLD), residue from 15 different paper mills were characterized to valorize it as a potential product as a cover material. In another part of the study, one of the GLDs and a local till were characterized to determine the optimal mixture of GLD amended till to be used in a field application at the closed Näsliden Mine in northern Sweden. The study concluded 10% GLD-amended till to be the optimal recipe and was successfully applied at the Näsliden mine waste dump. However, the great variability in the characteristics of GLD creates challenges if it is to be valorized as a product.

Dec 7, 2023

By G. Meschke

"This paper reports on computational and experimental research, performed at the Collaborative Research Center “Interaction Models for Mechanized Tunneling” at Ruhr-University Bochum, Germany. Research covers a broad spectrum of topics relevant for mechanized tunneling in soft soil conditions. This includes advances exploration methods and models for the characterization of the in-situ ground conditions, the interaction of the face support and the tail gap grouting with the porous soil, multi-scale models for the design of fiber reinforced segmental linings with enhanced robustness, computational methods for the numerical simulation of the tunnel advancement, the soil excavation and the material transport in the pressure chamber, logistics processes and risk analysis in urban tunneling.INTRODUCTIONMechanized Tunneling has proven itself as an economical and flexible construction method that continues to undergo a dynamic evolution process. Shield diameters continue to increase, and the application range of tunnel boring machines is being extended to an ever-increasing variety of geotechnical conditions. In order to maintain economic viability and to ensure an environmentally friendly construction process, realistic and reliable numerical models are required in order to make informed decisions during planning and construction. To provide a reliable numerical prognosis, it is necessary to accurately assess and understand the interactions between the components involved in mechanized tunneling with the surrounding site, the ground, and any pre-existing structures. Heterogeneous geological conditions and often only approximated ground parameters create, in contrast to other engineering projects, special demands. This necessitates new insights to new problems that can only be effectively solved through truly interdisciplinary research. To address these challenges, the German Research Foundation (DFG) has established the Collaborative Research Center “Interaction Models for Mechanized Tunneling” (SFB 837) at the Ruhr-University in Bochum in 2010. Collaborative Research Centers are interdisciplinary scientific research groups in which cooperative research is conducted under the umbrella of a central research theme. With a research budget of ca. 10 Million Euros for the second 4-year funding period, and a research team composed of 13 project leaders along with approximately 35 scientific assistants the SFB 837 is currently one of the largest research groups conducting fundamental research in tunneling related topics worldwide.RESEARCH TOPICSThe research topics of the SFB 837 encompass a number of relevant planning and construction related aspects in mechanized tunneling (Figure 1). These research themes are each supported by computational models and laboratory investigations and are all included in an SFB overarching Tunnel Information Model (TIM). Interaction groups integrate and combine the results of different submodels through prototypical cause-and-effect relationships, and through the analysis of the Wehrhahn metro line (WHL) project in Düsseldorf, which has been adopted as the reference project for the SFB 837."

Jan 1, 2016

By Al Gagnon

Since start-up in 1972, many circuit problems have been encountered, most of which were related to the abundance of fines (-28 mesh), which the circuit had not been designed to treat. The major problems associated with the original circuit included excessive loss of magnetite, reduced throughput during periods of a high proportion of fine coal in the plant feed and low yield in the fine coal circuit. This paper outlines the coal processing circuit at Fording Coal Limited as it exists today, with emphasis on the changes to the original fine coal treatment circuit.

Jan 1, 1978

By Clement K. Chase

Although flotation is the generally accepted process employed to recover gold and silver as well as copper, lead, and zinc from primary sulfide ores, the metallurgical requirements for the treatment of massive sulfide ore deposits differ markedly in many respects from those employed for the more common disseminated porphyry deposits. In Arizona, some properties classified as other then massive sulfide deposits because of mining and geological characteristics have produced mill-feeds similar to those from massive deposits. Several such occurrences are noted. The process requirements for massive sulfide deposits and unique mill-design implications are discussed in the perspective of world-wide economic considerations and the individual regional metallurgical and economic constraints in the United States.

Jan 1, 1986

By G. J. Feng

Based on detailed theoretical analysis of coarse floatation and three-phase froth, a laboratory system which contains a new type of froth floatation equipment is established. Through water experiment, the relationship among floatation dynamics parameters of the equipment is studied and the best work parameters are educed too. Based on all of above, Slurry test is carried out in a copper concentration plant. Granule between 0.28~0.45mm can be reclaimed successfully. The slurry test proves that to separate coarse minerals in froth floatation equipment is a kind of effective method, it is well worth to make a further study.

Jan 1, 2014

By C. W. Smith

The Bureau of Mines conducted laboratory-scale beneficiation tests on a sample of corundum gneiss from Montana to devise a method for beneficiating corundum for use as a substitute for refractory-grade bauxite. A flotation process utilizing petroleum sulfonate as the collector in an acid circuit was devised. Results showed that two flotation schemes each produced a concentrate exceeding the national stockpile specifications for calcined bauxite. From a feed containing 28 pct corundum concentrates containing up to 92.5 pct alumina (A1203) were produced with a corundum recovery of 78.5 pct.

Jan 1, 1987

By Charles E. Locke

PROSPERITY of the gold miner has continued with attendant construction of numerous plants, many of them small but some of good size. Many new mills have been erected in Canada and in the Philippines, end one should mention the new mill at Cripple Creek, Colo., a custom plant allowing a choice of flotation, cyaniding, or roasting and cyaniding. Flotation is a feature of many of the new plants and some existing mills have been remodeled to use flotation in place of amalgamation and cyaniding. The Utah Copper Co. has re- opened its Arthur mill and operations are being resumed in the big Ray, Chino, and Inspiration copper mills. Examples of new construction are the Mountain City 300-ton copper flotation mill in northern Elko County, Nevada; the Star zinc mill and one or two other mills in the Coeur d'Alene district of Idaho; and the 500-ton mill for the Buena Vista mine at Stewart, B. C. The last-named is to be installed underground, following the example of the zinc mill at Gilman, Colo., and he small Doyle jigging plant in the Wisconsin zinc fields.

Jan 1, 1937

By Marcilio do Carmo Silva

O circuito de flotação de Fábrica Nova é composto por três colunas de quatro metros de diâmetro e quinze de altura, equipadas com sparger’s tipo retrofit (misturadores), utilizando uma mistura de ar e polpa para geração de bolhas. As colunas operam em paralelo constituindo o estágio rougher. Os produtos gerados neste estágio são tratados em células convencionais (cleaner e scavenger). Com o empobrecimento do ROM proveniente da Mina de Fábrica Nova e conseqüente aumento de SiO2 na alimentação da flotação, fez-se necessário ajuste no circuito com o intuito de garantirmos qualidade competitiva do pellet feed de Fábrica Nova. Foram feitas alterações de rota do rejeito do estágio rougher, direcionando o mesmo para o rejeito final (no circuito padrão o mesmo alimentava o estágio scavenger). O rejeito do rougher e o rejeito do scavenger compõem o rejeito final da flotação. Um ajuste no percentual de sólidos da alimentação da flotação foi necessário para favorecer a coleta da sílica (saindo da ordem de 58-60% para 53-54%). Com esta manobra conseguimos retirar o excesso de SiO2 do circuito de flotação, possibilitando a geração de pellet feed com qualidade dentro dos padrões VALE.

Aug 8, 2018

By R. J. Corfield

MODERNIZATION of the entire electrical system and improvement of Rotation process efficiency is the twofold goal of the improvement program underway at the Arthur and Magna concentrators of the Utah Copper Div., Kennecott Copper Corp. Copper ore from the Bingham pit goes to these two concentrators where an interlocking program calls for complete electrical modernization and increased flotation process efficiency through additional capacity and flow scheme revisions. Flotation plants at the two mills are essentially duplicates, and while this article deals with the changes at the Arthur mill similiar improvements are being made at the Magna mill.

Jan 3, 1953

By James J. Meadows, Jason D. Pampena, Emanuele G. Cauda, Lauren G. Chubb

Respirable crystalline silica (RCS) found in dust generated by various mining processes is an important occupational hazard in the underground coal-mining industry. Exposure can lead to disabling and incurable diseases, including coal workers’ pneumoconiosis (CWP), silicosis and lung cancer [1,2]. Clusters of rapidly progressive CWP have been observed in the Appalachian regions of eastern Kentucky and southwestern Virginia, and recent cases have been generally more severe and showing more rapid progression. CWP is approximately four times as common among long-tenured underground coal miners in central Appalachia than long-tenured underground miners in the rest of the United States, and 20.6 percent of long-tenured underground miners in central Appalachia were suffering from the disease as of 2017.

By James McMaster

The Kamyr Countercurrent Tower Leaching Process is intended to combine, in a single tower, thickening, leaching, separation and clarification of pregnant solution, and washing of leaching chemicals from the tailing pulp. For a gold or silver metallurgical plant, the flowsheet would consist of crushing and grinding, cyclones for size control and partial thickening, the Kamyr tower, and a gold or silver recovery system of either carbon in solution, zinc precipitation, or direct electrowinning. Ancillary systems for the Kamyr metallurgical plant would include cyanide preparation, fiber preparation and recovery, and flocculant preparation.

Jan 1, 1990

By J. S. McAlpine, J. Matousek, W. Muir, P. Downey, K. Major

The Golden Bear refractory gold ore roasting operation is located at Huddy Lake, in northwestern British Columbia, about BO km northwest of Telegraph Creek (see Figure 1). The mine access road, used for supplies delivery, was developed by Golden Bear and consists of a radio controlled 155 km gravel road originating at Highway 114. Hine operations are based on a two week in, two week out rotating shift schedule with personnel transport by chartered aircraft from Vancouver, Whitehorse or the 3 Talthan conmunities. The site runway Is located adjacent to the tailings impoundment.

Jan 1, 1992

By Michael Botz, Craig McKenzie

Recovery of cyanide from mill tailings can be conducted to lower the overall cost of precious metals extraction, while lowering cyanide concentrations in mill discharges and potentially eliminating the need to chemically destroy cyanide. Recent applications of cyanide recovery based on acidification­volatilization-reneutralization (A VR) technology have elimi­nated the need for cyanide destruction and substantially increased the profitability at several gold and silver operations. Recent developments in the technology permits processing of scale-prone and high percent solids pulps while generally affecting cyanide recoveries in excess of 70% to 90%.

Jan 1, 1997

By Paul Doherty

The offshore wind sector is booming on a global scale, with the U.S. becoming a front runner in this highly progressive market. The Global Wind Energy Council has highlighted the exponential growth in both fixed bottom and floating projects in the years ahead, with global installed capacity set to exceed 300 GW by 2030. This growth in installed capacity is primarily related to fixed bottom projects, which have dominated the market for the past 20 years. However by the tail end of this decade, floating projects are likely to become

Oct 1, 2022

By D. J. Adams, R. G. Gürtunca

This paper describes the results obtained from a rock-engineering monitoring programme carried out at West Driefontein gold mine, where dewatered and classified tailings have been used as backfils for local and regional support. The in situ behaviour of these backfils and the surounding rockmass were determined, and it was found that the backfil used on this mine has provided significant regional support. The underground observations also showed less rockburst damage in backfiled panels than in unfiled panels, provided the backfil had been placed properly in the stopes.

Jan 1, 1991