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By David G. Adam

Introduction Syncrude Canada Ltd. is the operating company for a consortium of industry and government participants that produce synthetic crude oil from their leases in the Athabasca Oil Sands. Production from the $2.3 billion (1978) integrated mining, extraction, and bitumen upgrading and utility complex started in September 1978. Production is currently about 6.4 Mm3/a (40 million bbl per year) of high quality synthetic crude oil. This is done by upgrading the extracted bitumen from the oil sands mined. Plans are to increase the production to 8 Mm3/a (50 million bbl pier year) by 1989. At that time, the mining operation will be required to deliver 100 Mt/a (110 million stpy) of oil sand (ore) to the extraction plants, and handle quantities of waste ranging from 50 to 75 Mt/a (55 to 83 million stpy). The Syncrude plant is located at Mildred Lake, 40 km (25 miles) north of Fort McMurray and 480 km (300 miles) north of Edmonton, Alberta. Climate, particularly winter, is therefore a major factor affecting the design and operation of all the Syncrude production facilities. Bitumen production, consisting of overburden removal, oil/sand mining, bitumen extraction, and tailings disposal, account for about half the total SCO production costs. Considerable research and development, therefore, continues to be applied to improve both material handling and bitumen recovery methods. Potential applications for feeder breakers were identified in the material handling aspects of both overburden and oil sand mining to reduce cost and to attain planned production increments. Overburden removal Overburden materials on the leases comprise thin Pleistocene sands, gravel and fill, and sands, silts and clays of the thicker Clearwater Formation with the silt to clay components predominating. The latter contains multiple leases of hard siltstone with unconfined compressive strengths up to 148 MPa and thicknesses up 0.1 to 0.9 m (1 to 3ft). Characteristics of the overburden as well as the climatic environment and scale of operation present unique problems for the efficient removal of the material. In a bucketwheel/conveyor system, the weak silty clay formations require relatively flat working slopes for safe operation, while the siltstone lenses and frozen overburden require blasting or selective removal by other equipment. These factors, combined with the normal bucketwheel/conveyor design parameters, lead to high capital investment and relatively inefficient use of that capital. Hydraulic mining alternatives, including dredging, are constrained by severe clay settling problems in the waste disposal

Jan 6, 1986

A review of historic mining information and geological literature pertaining to the Alpine Mine, Lyell Goldfield has been completed. As a result of this work the Alpine reef is inferred to be associated with an upright anticline with a sub-horizontal axis. Structural profiles prepared from limited underground data indicate that the reef is subparallel to the eastern limb of the anticline and cuts across the western limb. Reassessment of structural mapping completed by the New Zealand Geological Survey indicates that Greenland Group metasediments within the Lyell Goldfield are folded into a series of opposed assymetic folds with sub-horizontal axes. It is suggested that the anticline which harbours the Alpine Reef is located on the axis of a synclinorium. Along the western limb of the synclinorium the subsidiary folds have steep west dipping limbs and shallow east dipping limbs (western sense of assymmetry) whereas shallow west dips and steep east dips are typical of the eastern limb. The notion of quartz mineralisation occupying the axis of a synclinorium is contrary to the situation in the Reefton Goldfield where quartz mineralisation is affiliated with folds associated with an anticlinorium. Historic mine data reveals that below No.4 Level the quartz-gold mineralisation, in the Alpine Mine, occupied a steeply dipping ore channel. The strike of the channel was to the northwest and within this structure the are shoots plunged to the north at approximately 40¦. Archival mine plans show that two quartz bodies, the North and South Blocks, were present at No. 4 Level. Although the North Block was followed down to No 14 Level (530 m vertically below the surface outcrop) the South Block was only mined as far as No 7 Level. Sampling on No 7 Level together with the results of trial mining suggest that the grade of quartz underfoot in South Block is low. Information from the Mines Statements and mapping undertaken by the Gold Prospecting Scheme reveals that faulting had a profound influence on the intregity and extent of the Alpine Reef. The reef occupies a Inajor shear zone but little is known about it. It is also apparent that below No 7 Level the reef was progressively shattered by faulting and this may be the chief reason for the decrease in grade in the lower levels of the mine. No substantive facts are available about wall rock alteration effects adjacent to the Alpine Reef Still this is not surprising considering that comments on the mineralised pug envelope and breccias adjacent to the mined quartz shoots at the Globe - Progress Prospect were omitted from contemporary publications. In spite of this the existance of sulphide bearing reef casing lithologies cannot be completely dismissed since 9.15 m of 'reef track' has been reported in Reids No 2 Level.

Jan 1, 1996

By B. P. Watson

The Bushveld platinum group metal deposits are two distinct, shallow-dipping stratiform tabular orebodies and strike for many hundreds of kilometres. Mining is extensive, with depths ranging from close-to-surface to 2 000 m. The mining method is a variation of planar open stoping. Pillars are widely used to support the openstopes. Little work has been done in the past to determine pillar strength and pillars have been designed using experience and formulae developed for other hard-rock mines. This has led to oversize pillars with consequential loss of ore or undersize pillars resulting in potential collapses or pillar bursts. This paper describes a back-analysis of pillar failures at Impala Platinum, just north of Rustenburg, and provides insights into pillar behaviour. Strength formulae are presented for Merensky Reef pillars at Impala. These formulae may be used cautiously on other platinum mines with similar geotechnical and geomechanical conditions.

Jan 1, 2008

Enhancement of Energy Efficiency in Fine Grinding of Copper Sulfide Minerals Using a Pilot-Scale Stirred Media Mill - IsaMill The mineral liberation size of run of mine ores has dramatically reduced over recent years. As a result, the demand for fine grinding which is the most energy-intensive form of grinding has markedly increased in the minerals industry. Furthermore, the fine grinding costs increase exponentially with decreasing product particle size. As a result of the increased energy requirement for fine grinding, it is desirable to optimise fine grinding processes such as stirred media milling (ie IsaMill) to enhance energy efficiency, throughput and the product fineness. In the present study, the influence of slurry rheology, grinding media type and grinding media-to-feed size ratio on energy efficiency in a pilot-scale IsaMill was investigated under certain industrially relevant pulp processing conditions. It was shown that a critical rheological state existed, below which the energy required to achieve an 80 per cent passing (ie P80) 20 ¦m product size was unaffected by shear rheology (ie apparent viscosity and shear yield stress) whilst above which the grinding energy required increased dramatically with increasing shear rheology. Colorado River sand (3.35 mm) showed higher energy efficiency than MT1 ceramic media (2.5 mm) for a target P80 of 20 ¦m in the solids concentration range of 38 to 55 per cent by weight, but the former experienced more than four times the wear rate of the later. The high wear rate of the Colorado River sand may be due to its much lower hardness. For feeds with an 80 per cent passing (ie F80) 70 to 110 ¦m, 2.0 or 2.5 mm MT1 media appeared to be more energy efficient than 3.5 mm MT1 media whilst a media-to-feed size ratio of 41 to 53 is applicable for ~50 ¦m (ie F80) feeds for efficient grinding.

Sep 13, 2010

By Harold J. Miller

Loading and haulage of run-of-mine ore is frequently the highest cost in underground mining operations. These costs can be significantly reduced by use of belt conveyors, a common practice in coal and similar soft miner ii mines. This is particularly true if oversize ore and rock can he eliminated prior to conveying; thus producing a demand for crushers near the production areas. Portable feeder-breakers are extensively used in conveyorized mines, but no suitable, equivalent equipment, is available to provide these benefits to hard rock mines of low to medium headroom. A hard rock crusher capable of easy movement and readily disassembled would allow use to belt conveyors and could improve the general safety and productivity of any underground ore hauling system. This report summarizes proposals and findings made in conjunction with the newly designed M-44 Low Head Portable Crusher which is believed well capable of meeting the requirements of a "portable, underground, hard rock" machine as previously defined in earlier reports. Data gathered by use of the 1/4 Scale Model of the M-44 has substantiated and verified the concept sufficiently to justify construction of a full-size machine for further testing under actual mine conditions.

Jan 1, 1978

By Hong Yong Sohn

Keywords: Barium sulfate, Barium sulfide, Environment, Kinetics, Pollutants, Sulfur dioxide conversion, Thermodynamics Nonferrous smelters and coal gasification processes generate sulfur dioxide streams, most of which are treated to produce sulfuric acid with the accompanying problems of market shortage and transportation difficulties. While the conversion of sulfur dioxide to elemental sulfur has many environmental advantages, no processes exist that are environmentally acceptable and economically viable. A method for converting sulfur dioxide to elemental sulfur by a cyclic process involving calcium or barium sulfide and calcium or barium sulfate without generating solid wastes has been developed. In this process, the sulfate, as the starting raw material, is reduced by a suitable reducing agent such as hydrogen to produce the sulfide, which is used to reduce sulfur dioxide producing elemental sulfur vapor and regenerating the sulfate. The latter is then reduced to reproduce the sulfide. This paper describes work on the BaS/BaSO4 system. Thermodynamic analysis and experimental results indicated that the BaS-SO2 reaction produces mainly sulfur vapor and solid barium sulfate and that the gaseous product from the BaSO4-H2 reaction is mainly water vapor. The rates of the two reactions are reasonably rapid in the temperature range 700-1050°C.

Jan 1, 2005

By R. G. Hall

WHEN we want to interpret some problem which faces us at the present, if that problem be a social or political movement, we turn to the pages of history for 'information. If the problem be one of science or of industry we turn to the library of the subject and endeavor to translate the present from the experience of the past. I wonder if you would bear with me for a few minutes as I look back to the time when I was going through mining school and looking forward with hope, it is true and with confidence also, but still with some trepidation and an occasional qualm, to the month of June when the class of 1897 would be hunting jobs. Those were the years 1893 to 1897. Those years saw the Treasury of the United States so empty of gold that the President had to appeal to financiers to accept the country's promises to pay in return for $100,000,000 in gold. And the invectives that were hurled at both their heads for such a betrayal of the people sound strangely similar to those you read today being daily written and screamed at another President for taking us into the League of Nations or for not issuing bonds in huge amounts for unemployment relief, or for not adopting somebody else's particular specific for the relief of hard times.

Jan 1, 1931

By Christopher Bambridge

The Washington State Department of Transportation (WSDOT) is constructing a new tunneled route under Seattle to replace the existing State Route 99, Alaskan Way Viaduct (AWV), which follows the historic waterfront for several miles. The viaduct separates the businesses that rely upon the tourist trade from the down-town area. The reconnection of the city to the waterfront areas will occur following the completion of the SR99 Re-placement program that replaces the aging structure that was severely impacted by the 2001 Nisqually earthquake, with a state-of-the-art, twin-deck highway with a world record-breaking 17.4-m (57.3-ft) bored tunnel. Constructed in the 1950s, the double-tiered viaduct is nearly 3.2 km (2 miles) long and runs parallel to city?s waterfront. The viaduct, which is partially supported by the seawall, is a vital local and regional transportation link and carries about 110,000 vehicles each day. The seawall, built from concrete and timber in the 1930s, extends along Seattle?s waterfront and supports the soil behind it. Studies in the 1990s showed that the viaduct was nearing the end of its useful life, apparent by its exposed rebar and weakened columns. The 2001 Nisqually earth-quake further damaged the viaduct, forcing WSDOT to temporarily close it for inspection and limited repairs. The viaduct and nearby seawall are vulnerable to an-other earthquake and continue to show signs of age and deterioration. Following a collaborative process, WSDOT developed the following guiding principles to the viaduct replace-ment:

Sep 1, 2013

By W. Jilowa, C. Nguni, M. Simukoko, C. Nampungwe

The upsurge in cobalt price and demand is propelled by high demand from the electronics and electric vehicle industry. Konkola Copper Mines has cobalt occurring with copper in the ratio 1:10 in ore. The ore is treated in the concentrator and recovered at the smelter as an alloy (Cu 70%, Co 4%–7%, 15% Fe). Subsequent processing of the cobalt alloy is challenging, with very few plants able to treat it, leading to marketing challenges. Konkola Copper Mines sought to improve the cobalt alloy by producing a slag that is easier to handle and process in subsequent processes. Cobalt alloy (3.60% Co, 85.4% Cu) was re-melted in a copper bath four times the mass of the alloy. Silica and lime were added for phase separation and fire refining commenced. Following completion of fire refining and after holding the temperature at 1200°C, cobalt-rich slag was skimmed and blister copper was cast into anodes for electrorefining

Jan 1, 2023

By Doug Harding

The Niagara Tunnel Project (NTP) is a 10.4 km (6.5 mi) long, 14.4 m (47.5 ft)bored tunnel that will run under the City of Niagara Falls from the Upper Niagara River to the Sir Adam Beck Power Station. The completed project will enhance the capacity of the Sir Adam Beck Power Station by adding 500 m3 (17,657 ft3) of water per second through the tunnel. The paper describes the project in which the world’s largest hard rock TBM at14.4 m (47.5 ft) in diameter is being used to excavate the tunnel. Features of the project include the use of a High Performance (HP) Main Beam TBM, state-of-the-art ground support and tunnel logistics systems. A continuous conveyor is used for muck transport from the TBM to the disposal area. The paper will also discuss the optimization of the TBM system as the tunnel advances through the varying geology. In June 2004 the Ontario Government announced that Ontario Power Generation(OPG) had been given approval to proceed with the third tunnel under the city of Niagara Falls—the first two tunnels were constructed in the 1950s using drill and blast techniques. The third tunnel, appropriately named The Niagara Tunnel Project (NTP), consists of a 10.4 km (6.5 mi) long TBM-bored, concrete-lined tunnel with a finished diameter of 12.5 m (41.1 ft). In August 2005, OPG announced the selection of Strabag AG of Austria, one of the largest construction companies in Europe, as the contractor to build the NTP Project at a price of CAN $600 million. In September 2005, Strabag A.G. selected The Robbins Company of Solon, Ohio to design, manufacture and deliver a new 14.4 m (47.5 ft) diameter High Performance state-of-the-art Main Beam Hard Rock TBM to be used in the excavation of the tunnel. In order to meet the aggressive construction schedule as requested by OPG/Strabag, the TBM needed to be supplied as “ready to bore” within a 12 month period after the contract was awarded to Robbins.

Jan 1, 2007

The nature of the specialty glass and ceramic business magnifies the dependency of the ultimate product on the unique properties of their raw materials used to make them. This dependency has implications in the management of risk in the supply process which requires a special procurement organization and program commitment to be successful. The Coming system of managing critical materials and factors in development of alternate new suppliers and products is discussed.

Jan 1, 1989

By Ádria Rocha Corrêa

Durante a solidificação de ligas metálicas, o produto fundido se contrai, o qual provoca o surgimento de espaçamentos vazios na interface metal/molde chamados de “gaps”. Estes gaps causam o aumento da resistência térmica influenciando em toda a cinética da solidificação. A transferência de calor durante a solidificação depende do conhecido parâmetro chamado de coeficiente global de transferência de calor ( hg). Este parâmetro é representado pela equação do tipo: hg =C.t-n, a qual indica que a eficiência térmica na interface metal/molde decai com o tempo. Muitos parâmetros podem influenciar o coeficiente global de transferência de calor (hg), neste estudo, os percentuais de Sn em ligas do sistema Al-Sn são analisados (10,20,30 e 40%Sn). Portanto, o principal objetivo deste estudo é propor uma relação matemática que descreva, para o sistema Al-Sn, a evolução hg em função do teor de Sn. A relação matemática foi obtida através do método dos mínimos quadrados

Aug 17, 2017

By Vaughan J. P

The Pegmont deposit is a stratiform Pb-Zn sulphide body occurring in a thin, iron-rich metasedimentary unit situated near the top of the Kuridala Formation, a part of the Mary Kathleen Group of the Middle Proterozoic"Eastern Geosyncline" succession of the Mount Isa-Cloncurry district. The deposit appears to have developed in a shallow basin or depression on a sea or lake floor.Detailed chemical and mineralogical study of seven diamond drill cores through the ore horizon shows that in addition to galena and sphalerite the orebody contains a large range of iron-rich silicates and aluminosilicates.Further, five drill cores selected to represent a section from basin centre to basin edge exhibit clear and systematic chemical and mineralogical changes in the ore horizon in both a vertical and, most importantly, ill a lateral sense.Reconstruction of the sedimentary environment of the ore horizon as a whole shows this to be a silicate facies of a phosphatic, manganiferous iron formation or, more accurately, of "ironstone" in the sense of James (1966, U.S. Geol. Surv. Prof. Paper 440, chapter W).On the basis of both mineralogy and chemistry this silicate facies may be subdivided into three microfacies according to the dominant iron silicates characteristic of each: a fayalite microfacies, a hornblende-clinopyroxenemicrofacies, and a garnet microfacies. Significant Pb-Zn sulphide concentrations are confined almost entirely to the fayalite microfacies.

Jan 1, 1979

By D. D. Blue

To insure domestic production of aluminium for, essential civilian and defense uses, the Government, under authority of the Defense Production Act of 1950, programed and promoted an aluminum-expansion program that will more than double the primary production capacity that existed in 1949. In view of this vastly increased production, the raw materials, with respect to both quantity and sources, are reviewed. The raw-material consumption pattern, the requirements during an expansion period when excess quantities of materials for starting up new facilities are consumed, and the probable requirements for production of 1.7 million tons per year of primary aluminum are discussed. The raw materials that presented the most difficult supply problems were bauxite, electrical power, and fluoride salts, and the supply pattern for these materials probably will undergo changes. A major part of the electrical energy for the increased capacity was to come from thermal generation, Jamaica-was to become a major source of bauxite, and synthetic fluoride salts were replacing natural cryolite in increasing quantities. Other raw-material requirements discussed are: Soda ash; lime, and limestone; starch; filter cloth; fuel; alumina; the carbonaceous materials, green and calcined petroleum coke, high-and low-temperature pitch and coke or anthracite; cryolite; aluminum fluoride; the materials going into production of synthetic fluorides, acid-grade fluorspar, and sulfuric acid; and labor. INTRODUCTION The raw materials for the aluminum industry that have received the most publicity are bauxite, the ore that supplies elemental aluminum, and electrical energy, the means by which aluminum oxide is reduced to metal. A number of other important materials are, however, required in large quantities in the production of primary aluminum metal.

Jan 1, 1954

By Jerry Ran

Stope back caving in a mine using open stope mining interrupts the planned mining sequence and causes oversize muck and dilution with adverse economic implications. As many underground mines are mining or have plans to mine at depth, stope back caving could have significant impact on the mine sustainability. Therefore understanding the caving mechanism is important in preventing future occurrence and improving the mine economic performance. Falconbridge Ltd Kidd Mine is an underground mine using open stope method producing more than 2 million tonnes per year. Its current lowest mining level is approximately 2070m below surface and the lower portion of the orebody is being developed. In years of 2002 and 2003 the back of three stopes of approximately 1900m and 2040m below surface caved and caused substantial mining difficulties at the mine. As these caved stopes are subject to stress concentration, seismic activities and near major geological structures, the caving mechanism is much more complex than that of stopes near surface. In addition to the recorded caving history by site observations, the mine carried out cavity surveys and test drilling to define the caved profiles. The mine seismic monitoring database provided information at these stopes. Stress modeling work conducted by an external consultant provided the stress patterns at the caved stopes. Based on the field collected data and stress and seismic information, this paper presents details of the stope caving process and cavity surveyed profiles, reviews the predictability of the stability graph approach for these cases, discusses the caving mechanism and proposes preventive measures to stabilize the stope back.

May 1, 2004

By R. J. Gochin, G. D. Schena, R. Spencer

The impact of a mineral project in a developing country is evaluated in the broad context of its economy using input-output models. Minimum economic theory is used to develop simple numerical models. Sets of technical coefficients are exploited in the development of linear models of the productive element of an economy. The analysis allows assessment of the overall economic consequences of a mineral development in which issues broader in scope than financial objectives need to be incorporated in the evaluation. In part 1, the framework for the development of the input-output model is presented. The model is refined to incorporate country-specific behaviour. The increased flexibility of the enhanced semi-input-output model permits a more confident investigation of the economy-wide effects associated with a new project in the mineral sector of a developing country. The relevance of the models is illustrated using an example from Namibia

Sep 1, 1991

By John E. Wiegand

This study will discuss the AMAX Coal Co., Penndiana Pipeline Project, which was conducted in conjunction with the following parties: AMAX Coal Industries, (U.S.B.O.M.) United States Bureau of Mines, (I.D.O.R.) Indiana Division of Reclamation, Ohio Valley Pipeline, Inc., New Mexico Tech, and ourselves, VIBRONICS, INC., Evansville, Indiana. The purpose of this study was to find a safe vibration level for active gas transmission pipelines near surface coal operations.

Jan 1, 1994

By Kurt RP Petersen, Hendriena van der Walt

With the decline in fine diamond production from the Argyle mine in Australia, there is a greater emphasis on efficiently treating the finer size fractions through a DMS circuit. Although it is generally well understood that smaller diameter cyclones are more appropriate for this application, practical results do not necessarily meet this expectation. In this paper the operational performance of particular sized cyclones throughout the group was compared. Based on the results there is evidence that under certain practical operating conditions, small cyclones are not necessarily best for fine size particle treatment, particularly given the production pressures faced by all mines. However, there seems to be considerable merit in using larger sized cyclones, which tend to exhibit less performance variability, irrespective of operation conditions.

Jan 1, 2006

By R J. Holmes

The procedures and equipment used for sampling iron ore process streams have generally improved in recent years. However, there are a number of areas where significant issues still commonly occur, including sampling high capacity streams, sample cutter design and operation, division of primary increments at the secondary sampling stage, the performance of crushers installed to reduce the particle size prior to sample division, and the sample mass that is retained at each sampling stage. These issues of non-conformance with correct sampling principles are caused by factors such as increasing the speed and loading of conveyor belts to increase throughput, which changes the trajectory of the ore stream and may result in an inability of the sample cutter to handle the increased flow rate without sample loss. Failure to sample the entire primary increment stream at the secondary sampling stage is also a common issue as well as failure of crushers to provide crushed products of the required particle size due to ongoing maintenance and/or adjustment issues. These common pitfalls can all be addressed through careful attention to detail.CITATION:Holmes, R J, 2017. Common pitfalls in sampling iron ore, in Proceedings Eighth World Conference on Sampling and Blending , pp 261–264 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By Mark P. Meyer

During 1991 through 1993, the U.S. Bureau of Mines (Bureau) -Alaska Field Operations Center (AFOC) in cooperation with the Bureau of Land Management (BLM) -Arctic District Office and the State of Alaska, Division of Geological and Geophysical Surveys (ADGGS), conducted exploration, geological, geochemical, geophysical, mineral resource, and mineral potential investigations in the 6.7 million hectare Colville Mining District (CMD) study area. This mining district study area, located in northern Alaska, includes the Colville River drainage basin as well as 0.35 million hectares of the southern part of the National Petroleum Reserve in Alaska (NPRA). This investigation was conducted as part of the Bureau's continuing Mineral Land Assessment (MLA) mining district program. The Bureau's MLA mining district program is designed to provide reliable and comprehensive mineral resource information that supports mineral resource policy and land use decisions made by Congress and Federal land management agencies.

Jan 1, 2011