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By J. C. Escobedo, J. M. Almanza, A. Flores, Cortés. D. A.

Secondary aluminum dross, which has been exposed for several years to atmospheric conditions, was characterized using chemical analysis, X-ray diffraction, optical and scanning electronic microscopy, and energy-dispersive spectroscopy. Based on the characterization, a method to purify the solids is presented. This method starts with the washing of the dross in boiling water to eliminate the soluble compounds like Na and K, followed by the physical separation of the metallic aluminum by milling and screening. Finally, an acid lixiviation process is applied using three different acid solutions, HCl, HNO3, and H2SO4. The best results were obtained using HCl. The main insoluble components of the dross after lixiviation were Al, SiO2, and Al2O3. MgAl2O4, AlN, Si, and Na2Al22O3·2H20 species were also found. Based on the alumina content, the solid product could be suitable as a raw material in the manufacture of castable refractories or metal matrix composites.

Jan 1, 2005

By J. A. Finch, T. Weber

"Bubble size in flotation is strongly influenced by frother concentration in the pulp liquor. There is no accepted method of judging the dosage and thus how effectively frother is being distributed to control bubble size is not known. This will hamper certain plant test work where constant bubble size (e.g., when comparing reagents) is implicit. Bubble size is not easy to measure in plant and gas holdup is suggested as a surrogate in the development of a proposed “meter” to estimate frother concentration. The meter is calibrated to enable frother concentration to be estimated on samples drawn from any location in the flotation circuit. The meter and its calibration are described.As general background the action of frothers in reducing bubble size by retarding coalescence is discussed and the bubble generation systems for which the effect will be important are considered.INTRODUCTIONBubble size is an important variable in flotation. The flotation rate constant k has been related to mean bubble size Db by k % Db -n with n ranging up to 2 (Ahmed and Jameson, 1989) and even 3 (Yoon, 1993). Recent work has introduced k % Sb, the bubble surface area flux, given by Sb = 6 Jg / Db (where Jg is the superficial gas velocity or volumetric gas rate per unit cell cross-sectional area), i.e., n = 1 (Gorain et al., 1998). Regardless of the exact value of n, the significance of bubble size in flotation remains. In many plant trials it will be implicit that bubble size has not changed and attention will focus on other process variables. The measurement of bubble size, or a surrogate, would be useful addition to any test work.The size of the bubbles is influenced by several variables, gas rate, gas injection system (e.g., impeller design and rotation speed in a mechanical cell) and pulp composition (chemicals added, percent solids), but the most important is frother concentration (Harris, 1976). The frother functions by retarding coalescence (see appendix), which acts to preserve the small bubbles generated in the pulp (and permits a stable froth to form on top of the pulp). The measurement of bubble size is thus related to measuring frother concentration. The distribution of frother and whether sufficient (to control bubble size) is reaching the intended parts of the circuit then become important considerations. At present there is no simple way to judge frother concentration in a plant. In this communication we introduce a possible methodology, a “frother concentration meter”."

Jan 1, 2003

By Pravin Kumar

Goldcorp Inc.?s Red Lake Mine (RLM) is situated in the Red Lake Mining District, a history rich North Western Ontario mining community. Red Lake Mine formerly known as the Dickenson Mine has experienced various degree and type of bursting since the 1960?s. During the 1960?s burst were common in shrinkage stope box hole pillars. After discovering the High Grade Zone (HGZ) between its 30th and 39th levels, the mine has changed its mining method to mechanized cut and fill with cemented paste fill. The rock mass at RLM is mainly massive basalt-ultramafic and behaves in a manner consistent with massive brittle rock. This paper presents the use of empirical and numerical design techniques. The use of the Span versus RMR graph to determine critical stope spans at RLM and the use of numerical design techniques to determine the stability of the sills and post pillars. Selecting of a sill pillar dimension is illustrated using four different failure criteria?s. The four failure criteria are m & s failure criteria, the Pillar Stability Graph, deviatoric stress ???-?3), and induced stress level criteria ?1 /UCS, which are calibrated to RLM?s ground conditions. A wide range of case histories has been studied ranging from stable to highly burst prone ground conditions in order to calibrate the failure criteria to observed conditions and quantified to local micro seismic system.

May 1, 2002

By Tapiwanashe Chenje, David Hewitt, Peter Radziszewski

"Steel media wear is a major cost component in mineral processing. In the case of existing operating mill, steel media wear prediction can be used to help compare the performance of steel media from different suppliers before completing marked ball tests. It can also be used to investigate how ores from different site of a given mine affect steel media wear. In the case of Greenfield cases, steel media wear prediction can be used to estimate the cost of steel media for a given feasibility study.This paper presents a wear testing and prediction methodology that ties together abrasion wear and corrosion wear testing results through the use of a simplified discrete element charge motion model. The experimentation dimension to this methodology takes samples for steel media, mine site ore and water to determine abrasive and corrosive wear parameters of a given media, ore, water set.The test methodology development is illustrated along with a comparison of wear predictions with observed wear rates in some operating mills. A case study is included that illustrates how this methodology was used to estimate steel media wear performance. The paper closes with a discussion on the use of parts of the experimental methodology to investigate other abrasive wear conditions such as liner wear, paste backfill piping and ore breakage as well as avenues for future test development.INTRODUCTIONThe cost of comminution processes represents a significant part of the overall costs of a mining operation. Grinding media/liner wear alone accounts for 15-25% of the total operating cost. The annual steel grinding media consumption is approximately 2.5 mtpa or 0.3% of total world steel production [Smorgon Steel Group, 2005]. Using an estimated grinding media cost of about US$0.75/kg [Halbe and Smolik, 2002], gives a media cost of over US$1.875 billion per annum. Mining continues to shift towards exploitation of lower grade ores as the higher grades get depleted. These low-grade ores require finer grinding for the liberation of the value minerals, and hence it can be assumed that grinding media consumption will also continue to rise.The Bond abrasion test, dating back to 1963, [Weiss, 1985] is still used to estimate the total mill media wear. This is a purely empirical test based on the ore. From Bond abrasion index tests, it is possible to determine a wear rate using the following function:"

Jan 1, 2009

By C. Taschereau, G. A. Vickell, A. R. Laplante

Evidence in support of an iron-gold corrosion cell during the high-temperature/highpressure elution of loaded carbon is presented herein including, but not limited to, its discovery, mode of genesis, and confirmatory laboratory testwork. A discussion of metallurgical and economic impacts, remedial investigations, plant design considerations, and future work including mitigative possibilities is presented.

Jan 1, 2006

By Neil H. Brown

Outline ? Cameco - Cigar Lake ? Cigar Lake Mine Development ? MDS #1 ? MDS #1 Improvements ? MDS #2 ? MDS #2 Improvements Pending ? Acknowledgements Mine Development System ? Mining methods tested and developed over the years ? Construction began officially in 2005 ? Water inflow events in 2006 and 2008 ? Successful dewatering and re-entry in 2010 ? Remediation continues ? Production target is mid-2013

Oct 1, 2010

By Jamie King

This paper describes the use of dynamic scheduling and discrete event control to provide coordinated control of multiple automated vehicles. In the past decade there have been significant advances in the field of robotics for underground mining. As this trend progresses toward a realization of a completely automated underground mine the need for a central control system, capable of providing coordination for multiple vehicles in a semistructured environment, becomes more evident. In the past year general research into multi-robot coordination has been applied to the underground mining scenario and demonstrated in a scaled model underground mine in a laboratory setting. This system shows significant potential to be adopted into a full-scale implementation for mine wide automation.

May 1, 2001

By Robert S. MacPhail, Chilombo Henry, Arnold Kabamba, David Mukelebai, Suresh Thirunagari, Bukali Victor, Yoram Kapai, Chomba Leonard, Kanna Amarasingham

"FLEX 31 is a chemically enhanced sodium isopropyl xanthate. Developed by Charles Tennant & Co (Canada) Ltd and has shown improved collection properties over SIPX for sulphide minerals flotation. Improvement of recoveries, grades, faster kinetics, lower dosages, high pyrite and pyrrhotite rejection capabilities have all been exhibited by FLEX 31. Recent plant trial carried out in the copper circuit at one of the largest copper mine in Zambia shown over US $ 2.00 Million annual improvement on the bottom line over SIPX at current copper prices. Data produced also showed superior grade and recoveries from rougher concentrates that previously had not been attainable with other reagents effectively. Flex 31 has also shown positive outcomes with zinc, Copper/Zinc, arsenopyrite and copper/molybdenum ores.IntroductionSodium Isopropyl Xanthate (SIPX) is one of the most popular flotation chemicals on the market today. Somewhat more specific than amyl xanthate, SIPX is used in a variety of ores like copper/zinc, lead/zinc, arsenopyrite/pyrite, and many others (Melis et al., 1991). An investigation carried out by the research division of Charles Tennant & Company (Canada) Limited has produced a chemically enhanced SIPX. This product has shown all the advantages of normal SIPX along with improved recoveries of copper and copper activated minerals. The product was named “FLEX 31”."

Jan 1, 2016

By A. Ouchi

This paper presents ground control best practices in weak rock environments including the "Unsupported" Weak Rock Updated Span Design Curve and awareness pertaining to the potentially detrimental effects of using resin grouted rebar in weak rock masses and the false sense of security that the use of resin grouted rebar may instill. Ground support is almost always used in weak rock environments, though the type of support used can vary widely. The development of the Weak Rock Updated Span Design Curve by the addition of 463 case histories of RMR76 values ranging from 25 to 60, has also been calibrated to four different support categories; Category A: Pattern Friction Sets, Category B: Pattern Friction Sets with Spot Bolting of Rebar, Category C: Pattern Friction Sets with Pattern Rebar Bolts and Category D: Cablebolting, Shotcrete, Spiling, Timber Sets or Underhand Cut and Fill. Design of underground man-entry type excavations in North America relies heavily upon empirical analysis. This design requires a higher Factor of Safety than other non-man entry type excavations. A comparison of the calculated ½ span failure Factor of Safety between all the categories is also presented.

May 1, 2009

By Bern Klein

Motivation for Improved Energy Efficiency in Mining ? Canada potentially adopting Greenhouse Gas Emissions and Intensity Legislation in 2013 ? BC -Climate Action Plan and Energy Conservation Agreement in 2008 ? BC Energy Plan 2007 -BC Hydro is mandated to save 50% of new load growth ? TSM Initiative -Energy Management, Energy Reporting, Setting Energy Targets, GHG Management BC MOU for Energy Conservation Agreement -MEMPR, MABC, BC Hydro

May 1, 2010

Geology grads mine heated job market Salaries up 44 per cent in three years ?[Geology student] passed up a $100,000-a-year job at a mining company last December when he finished his degree in geology. The 24-year-old Canadian said he?s confident he?ll get a better offer.? Rob Delaney and Stewart Bailey, Calgary Herald, Published: Saturday, March 15, 2008 Massive shortages across the mining industry > Trades and operators are a large component > Technical people are equally hard to find > Students are in an excellent positions to secure exciting jobs > Experience is at a premium. Why?

May 1, 2008

By Michael J. Kelly

IAMGOLD?s Westwood project is the site for the largest, by volume, bored vent raise in North America. When completed, it will be the fifth largest bored worldwide in a single pass. This paper will review the highest capacity raise drill system ever built (Redbore 100); as well as the technical difficulties in a single pass boring a 2,773 ft x 20 ft to 22 ft diameter raise. The difficult ground conditions and associated problems will be reviewed, as well as the solutions to overcome them. Use of the RVDS drilling tool to achieve .04% accuracy (14.5?) and the Geotube® water filtration system will also be covered.

Oct 1, 2010

By S. W. Stogran

"Chemical and limited biological monitoring of mine and mill effluents are being used by regulatory agencies to monitor and control discharges to the environment. Amendments to the Federal Fisheries Act may make it mandatory for mines to conduct Environmental Effects Monitoring (EEM) which will change the emphasis from monitoring effluents to monitoring impacts on receiving waters. The EEM amendments may expand the scope of present environmental studies to include: effluent mixing zone delineation; inventory and classification of resource, habitat, and historical receiving environment; effluent quality determination; chronic and acute bioassay testing; tissue analysis; benthic invertebrate monitoring; fish population surveying; fish tainting evaluation; and the evaluation of impacts on fish habitat, invertebrate communities and fisheries resources. The requirements for EEM have not yet been worked out by the mining industry and the government committee. Experience at Lakefield Research in conducting biological monitoring studies for the mining industry has shown that biological monitoring may be useful for assessing environmental impacts only if programs are planned and executed to collect relevant data, thus minimizing costs and maximizing effectiveness.IntroductionThe chemical monitoring of effluents and water bodies receiving effluents is common practice in the Canadian mining industry and has been used routinely by regulatory agencies to control discharges to the environment. Biological monitoring has also been used on a limited basis, primarily to augment chemical data collected. A number of regulatory bodies, primarily in Canada and the United States, have been incorporating biological monitoring into environmental regulations.Various forms of biological monitoring techniques have been used in Canada and the United States to help assess the impact of mining operations and effluents on the environment. Biological monitoring includes a wide range of activities, from monitoring metal uptake in individual organisms to examining the population dynamics in ecosystems. The most commonly employed biological monitoring techniques are the chronic lethality toxicity tests. Also becoming widely used are in situ and chronic toxicity tests."

Jan 1, 1994

By R. Grimard, M. Gamache, L. -P. Bigras, P. Cohen

This paper describes a real-time fleet management system for an undergroun mine. Dispatching, routing and scheduling are handled simultaneously, taking into account the mine status, operational constraints and vehicle location information. Each assignment decision takes into account the traffic on the road segments of the mine network, whether road segments are bi-directional or uni-directional, and ensures that each LHD (load-haul-dump) vehicle arrives at loading and dumping points with the correct orientation. Such a system can be used either as a simulation tool for strategic planning or as a real-time managing and optimizing system for operations. In the simulation mode, the system can accurately estimate the impact on productivity of decisions such as the development of waiting areas (bays, sidings), or the addition (elimination) of vehicles to the fleet in operation. When used for real-time dispatching, routing and scheduling of vehicles, the system can optimize production with respect to various assignment criteria such as cycle-time minimization or deviation from a target production plan.

Jan 1, 2004

By E. T. C. Spooner, Ioannou S. E.

"Abstract- The Dixie Zone Au-Ag deposit is a low sulfidation (adularia-sericite) epithermal system located 1.4 km from the producing Ken Snyder mine (7.0 M oz Au equivalent reserve/resource), Midas Mining District, north-central Nevada. This WNW striking, steep south dipping, fault system is hosted by mid-Miocene (17 Ma to 14 Ma) felsic volcanic rocks that were erupted from a vent(s) to the northeast. The system was mineralized by approximately 250 ± 20°C (n = 86), near-neutral pH, ascending fluids of predominantly meteoric origin [volatile corrected salinity = 0.52 ± 0.35 eq.wt% NaCl (n = 86)]. Bulk analytical fluid inclusion gas chromatography identified a mineralizing fluid volatile composition of 99.68 ± 0.18 mole % H2O, 0.16 ± 0.09 mole % CO2, 0.11 ± 0.05 mole percent N2, 0.05 ± 0.04 mole % CH4, and 0.01 ± 0.01 mole % CnHn+i (n = 7). Sulfur species were not analyzed due to absorption within the chromatography system; however, a H2S concentration of 16 ppm to 160 ppm molar is estimated. The volatile content contributes approximately 50% of the microthermometrically measured freezing point depression. Cl- concentrations up to approximately 9000 ppm suggest an additional, probably magmatic, fluid component.Ascending fluids were channelled along approximately NW striking faults related to the same primary extension (17 Ma to 14 Ma) responsible for Nevada basin and range physiography. Boiling induced by CO2 effervescence led to precipitation of Au and Ag over a 150 m vertical interval. At the time, this interval was about 460 m below the water table (approximately 38 bars), but because of erosion, it is now within 90 m of the surface. A Ag:Au ratio of 25:1 has been calculated for the Dixie Zone."

Jan 1, 2000

By Jason Clarke, André R. Laplante

"The gravity-recoverable gold (GRG) ore characterization test was developed 15 years ago and has been applied to hundreds of ore samples. The test accurately determines the size distribution of GRG, at which grind it is recoverable, and the extent of its liberation above 150 µm. This contribution shows how the test can be simplified, what are the likely problems to occur, and what information is then lost. Two simplified versions of the test are presented, of which the simplest, grinding a 20-kg sample to a P80 of 75 µm, is retained as the best one. A database of 18 comparative tests is presented. The choice of the full GRG test vs. the simple test is discussed, as is the deportment of the GRG recovered in the standard test but not in the simplest test.INTRODUCTIONThe GRG test was developed in 1990 to characterize the progressive liberation of gold in representative samples of ores, with the primary objective of generating data for a gold gravity recovery model (Woodcock and Laplante, 1993; Laplante et al., 2000). Characterization includes the size distribution of GRG as well as the grind size at which it becomes recoverable. This is achieved in a 3-stage protocol of liberation and recovery using a laboratory centrifuge unit, a Laboratory Knelson Concentrator 3 inches in diameter (KC MD3). This protocol is shown in Figure 1. The first stage takes place at a F100 of 850 ?m (F80 of ~550 ?m), the second at F80 of 180 ?m, and the third at a P80 of 75 ?m. The rationale for the three cycles is the desire to preserve the original size distribution of the gold grains in the ore and to obtain a recovery grind size curve. The feed is a representative sample of ore that can be extracted from ore samples (e.g. drill core reject) or stream products of the grinding circuit other than circulating loads or product having undergone hydraulic classification (e.g. rod mill discharge or SAG screen undersize). Ideally the samples should weigh between 60 and 100 kg, depending on feed grade and gold top size. It is beyond the scope of this paper to fully discuss measures of representativity in the ore sample, for example Gy’s minimum sample mass model (Gy, 1979). However, further work in this regard may be an opportunity. The large initial weight facilitates representativity and minimizes weight and sulphide recovery to the concentrate (since concentrate weight is relatively constant at ~100 g), which limits the recovery of gold in nonsulphide gangue or gold carriers (i.e. sulphides). Thus, the 100 g concentrate carries principally discrete gold species, such as electrum, and native gold. The concentrate and a 600-g representative sample of gangue of each stage are screened down to 20 ?m and each size class is fire assayed (the concentrates to extinction, the tails up to 30 g per size class). The five coarsest size fractions of stage-1 concentrate are individually upgraded using a hydrosizer and the concentrates examined with an optical microscope to assess the degree of liberation of the gold phase. Scanning electron microscope work has established that the GRG has an excellent degree of liberation below 150 ?m in stage 1 and generally a good degree of liberation in stages 2 and 3 (Guerney et al., 2003); as a result the size distribution of the GRG has been found to approach closely that of gold grains (Nesset et al. 2005)."

Jan 1, 2006

By G. B. Bell

"INTRODUCTION On February 1, 1962, after five years of exploration and research, Jones & Laughlin Steel Corporation announced that they would develop the Adams Mine. Plant construction began immediately and in December of 1964 the first shipment of pellets arrived at J & L's blast furnaces in Pittsburgh. J & L continued to operate the property through its wholly owned subsidiary, Jones & Laughlin Mining Company, Ltd., until August of 1971 when it was sold to Dominion Foundries and Steel, Limited of Hamilton. Dofasco engaged Cliffs of Canada, a subsidiary of Cleveland Cliffs Iron Company, to manage the operation of the property.SUMMARY:The Adams Mine is a one million tons per year iron ore pellet operation located in the Boston Township Iron Range, approximately seven miles southeast of Kirkland Lake, Ontario. The property includes 5,300 acres in which eight areas suitable for open pit mining have been outlined. It was estimated that the reserves in these out lined areas are sufficient to produce 30 million tons of high grade iron ore pellets.The ore 'consists of fine grained magnetite with alternating layers of chert and is mined by conventional open pit methods. This extremely hard and abrasive ore averages about 20 percent magnetic iron, and has a ratio of concentration of 3. 9 /1. Presently, mining operations are confined to two pits with a third one being developed for operations to begin in 1973.The run-of-mine ore is crushed and ground and then concentrated by magnetic separation and flotation to a concentrate grade of 68 percent magnetic iron. The concentrate is agglomerated by a grate-kiln pelletizing process and shipped by rail to Dofasco's blast furnaces in Hamilton and to Jones & Laughlin's furnaces in Pittsburgh."

Jan 1, 1973

By Arthur L. Holloway, James C. Mugford

"The Underground Research Laboratory (URL) is located in southeastern Manitoba, in the Lac du Bonnet granite batholith of the Canadian Shield. It was constructed by Atomic Energy of Canada Limited (AECL) to conduct geotechnical research for the Canadian Nuclear Fuel Waste Management Program, assessing the concept of permanent disposal of nuclear fuel waste deep in plutonic rock.One of the primary objectives of the research program at the URL is to develop a nondestructive rock mass characterization method that can be used during siting, design and construction of a used fu el waste disposal vault. An experimental program was established to assess radar reflection profiling as a technique for fracture characterization in granite. The highly resistive, homogeneous nature of the Lac du Bonnet granite is ideal for the propagation of electromagnetic energy at the radar range of frequencies and water-filled fracture zones act as excellent reflectors because of their contrasting electrical properties.Radar reflection profiling was undertaken to characterize a major fracture zone located between 5 m and 10 m below Room 211 on the 240 m level of the URL. The profiling was done at a frequency of 120 MHz, on a 1m grid laid out on the bare rock floor of the room. Reflectors identified in the analog data were correlated between the profile lines, digitized, and a three-dimensional surf ace for each recognizable reflector was constructed. These surf aces were then compared with data obtained from the examination of numerous cores from adjacent boreholes intersecting the fracture zone. A very good correlation was found between the major radar reflectors and the most intensely fractured regions of the zone. Modelling studies also showed that a series of prominent shallow radar reflectors were caused by a borehole drilled close to Room 211."

Jan 1, 1990

Material scheduling, sequencing planning and execution are the core tactical mine plan for achieving production targets that maximize the objective function of any mine production entity. This objective function is constrained by several exogenous and endogenous constraints including geological, operating, technological, marketing, financial, political, social and local field constraints. Linear and dynamic programming techniques have been used to formulate algorithms to solve the problems associated with scheduling and sequencing operations. These algorithms possess the mathematical rigor for dealing with the fundamental problems but they fail to provide adequate answers to random and dynamic process problems. Materials scheduling and sequencing are carried out within the bounds of random and dynamic fields. The functional relations between the output and dependent variables are random, and thus, current algorithms are limited in their abilities to address the problems arising from these random field processes. In this study a production simulator is developed to capture the random field process associated with materials scheduling and sequencing in an open pit environment. The algorithm incorporates a geometric pit evolution model, using solid geometry of an ellipsoidal frustum to capture material displacement dynamics. Taylor series expansion about the dimensions of the initial frustum is used to provide numerical solutions to the resulting partial differential equations governing the pushback dynamics. A production simulator, derived from the stochastic and dynamic models, is developed, validated and used to simulate the changes in the pit volume resulting from periodic incremental pushbacks and the random field process. The hybrid stochastic-optimization algorithm provides a powerful tool for addressing the random field and dynamic process problems. Combined with a hybrid stochastic-optimization dispatch system, tactical production planning and execution will be efficient and economic for achieving desired.

May 1, 2004

By Lam. E. K., J. W. Jarvi, B. P. Bharadwaj

"The Rabbit Lake Operation is located in Northern Saskatchewan on the western shore of Wollaston Lake approximately 800 km north of Saskatoon, Saskatchewan.The Operation is owned by a joint venture of Cameco Corporation and Uranerz Exploration and Mining Limited. Cameco is the operator.The Mill started production in June 1975 under the ownership of Gulf Minerals Canada Limited and over the past twenty years has increased the rated production capacity to over twice the original design.The Mill was originally designed to process 485,000 tonnes per year of ore with an annual production of 2.0 million kg of U308 (yellowcake). During the past ten years changes in ore sources and process modifications have led to increased milling capacity and production targets. The Mill has treated a total of 8.6 million tonnes of ore and produced over 40 million kg of U308 in the twenty year period, despite the shutdown and cutbacks in operating time since 1989.The 1995 tonnage throughput was 206,000 tonnes per year. Annual production though has risen to 3.6 million kg of yellowcake despite the departure from full-time to half-time operation in 1991 (7 up-7 down). The forecast for the coming years will see tonnage rising from 300,000 to 570,000 tonnes, production of 4.5 to 5.4 million kg of yellowcake and an anticipated return in the year 1998 to full time operation.This paper will give a brief history of the Mill and focus on the present flowsheet and recent improvements to the process."

Jan 1, 1996