Search Documents

By J. A. Vezina

The effects of particle size distribution on metal extraction have been determined from pressure leaching Renzy Mines Limited concentrate with oxygen. Using a pulp density of 30 per cent solids, an oxygen pressure of 80 psig, a temperature of 230°F, a grind of 2.5 hours and a retention of 8 hours resulted in the almost complete dissolution of the nickel and the cobalt and the decomposition of over 96 per cent of the chalcopyrite finer than 20 microns. Only 11 per cent of the chalcopyrite coarser than 20 microns was reduced to smaller than 20 microns.

Jan 1, 1973

By B. Dubreuil, J. -M. Lalancette, D. Lemieux, C. Chouinard

The extraction of gold and silver has been examined via the use of mixed halogens: chlorine and bromine. The reaction was performed in a brine of sodium chloride with a small amount of sodium bromide at 40-50°C, in an atmosphere of chlorine, at atmospheric pressure. The process takes advantage of the very high reactivity of bromine towards gold, while the higher oxidation capacity of chlorine leads to gold chloride as end product with recycling of bromine. Fast reaction rates are observed along with gold recovery at the level of 95%. Chlorine-consuming common elements are removed prior to chlorination.

Jan 1, 2011

By R. D. Brown

Ever since British Columbia started the ball rolling in 1974 with the introduction of its now-defunct Mineral Royalties Act, all Canada's resource-based provinces have significantly altered their mining tax systems. The last resource-based province to abandon its pre -1974 mining tax structure is New Brunswick, which introduced a new mining tax regime in the summer of 1977 to take effect from April 1 1977. The new structure, which represents the outcome of considerable study and discussions with industry representatives, contains some intriguing concepts which make Nero Brunswick's new mining tax system unique among the Canadian provinces.

Jan 1, 1977

By David M. R. Stone

Underground mining in the gold industry is gaining popularity in Nevada, and with it the use of cemented rockfill is becoming mainstream. Even with today?s high metal prices, however, mining companies are very sensitive to the margins they realize, and are constantly looking for ways to reduce costs or improve efficiencies. Given that the backfill is one of the largest cost centers in underground mining, mines are constantly under pressure to reduce backfill costs. This paper will present an overview of the factors that impact cemented rockfill quality in Nevada mines based on the authors many years of consulting experience. Cemented rockfill quality can be linked directly to binder consumption, hence programs aimed at improving quality generally result in lower binder costs, better performance in the fill (hence less dilution), and improved safety. The paper will conclude with the key elements of a comprehensive program of backfill quality assessments and backfill QA programs. Comparative laboratory and minesite data from a number of operating and proposed mines will be presented.

May 1, 2007

By X. T. Zeng, X. Z. Ding, W. R. Chen, L. R. Zhao

The effect of deposition defects in metal nitride coatings on erosion behavior is presented. AlCrN, AlTiSiN, TiSiN and TiSiN:MoS2 coatings were fabricated by reactive cathodic arc evaporation and unbalanced magnetron sputtering processes. The microstructure and mechanical properties of the coatings were characterized by X-ray diffraction, scanning electron microscopy and nanoindentation, and the erosion property was assessed by solid particle impingement testing. The erosion characteristics on the coating surface and cross section were analyzed and correlated to the defects, which played an important role by promoting formation of erosion pits.

Jan 1, 2006

By Marc Ruest

A new instrumented cable bolt has been developed by the National Institute for Occupational Safety and Health at the Spokane Research Laboratory in Spokane, WA. Although various instruments are available to measure load distribution and magnitude along a grouted cable, this instrument is innovative in that it uses strain gauges internal to the cable as load-measuring sensors. The instrument has been successfully tested in the field at FMC?s Granger Mine, Meikle Mine, and Getchell Mine. A ?split-pipe? laboratory pull test was performed on each of three cable bolts instrumented with the new device. Each test consisted of grouting a 1.83-m-long cable in two 0.91-m-long sections of schedule 80 pipe. A numerical analysis was then performed in which laboratory boundary conditions were simulated and model properties derived from textbook guidelines. The loads calculated by the model were then compared to the measured loads.

May 1, 2002

By David O. DeGagné

While mine backfill plants are becoming increasingly more automated and instrumented, especially with paste fill operations, underground backfill distribution systems have hardly changed over the years. While fill properties are appropriately measured in the preparation plants, as backfill enters the mine borehole, the technology for control, data gathering and reporting is somewhat lacking. Mines typically experience problems with borehole and pipeline plugging, pipeline bursting, bulkhead failure and exposed fill sloughing. With adequate instrumentation of the backfill system it is possible to obtain a complete, continuous and detailed picture of the entire filling operation from preparation to post-pour. Good data will, over time, provide the basis for needed improvements of backfill systems and will be essential to safer, more efficient and less costly fill practices. This paper will review the areas of the filling operations where monitoring would prove critical to eliminate failures such as pipelines, bulkheads, fill exposures, stope walls, etc. The types of monitoring systems currently available will be reviewed and potential areas for development will be highlighted.

May 1, 2001

"As mine head grades decline and orebodies become more complex, traditional mineral processing techniques and flowsheets to achieve saleable concentrate become more difficult to design and construct. Mines with lower quality concentrates or concentrates with penalty elements are particular under threat. The economics of these operations are far more susceptible to metal price, concentrate treatment terms and the availability of other, cleaner concentrates. Additional value may be realised for these orebodies through improved recovery by producing a low grade middling concentrate for further processing, in conjunction with a saleable concentrate.The most cost effective way to reduce impurity levels is to do so as early as possible in the mining value chain. Technologies such as fine grinding and fine particle flotation are well established as effective methods for impurity rejection in mineral processing. What is normally overlooked is how a hydrometallurgical process could also be integrated in the overall flowsheet to achieve higher overall recovery at the mill. In the base metals environment, this is mainly because hydrometallurgical processes are associated with production of metal or use of expensive and toxic precipitating agents once the minerals of interest are solubilised. These processes can be very expensive, particularly with rising power costs and poor economies of scale in capital costs associated with low production rates from middling streams.Glencore Technology (GT) has recent experience in the treatment of middling and low grade concentrate streams as well as tailings streams to compliment a concentrator flowsheet in a refractory gold and base metals setting. The value proposition is the isolation of a low grade middlings concentrate from the primary circuit or the tailings stream for upgrading to an intermediate product with an equal or higher grade than the primary concentrate to allow blending for sale. This allows plants to operate on a more favourable part grade-recovery curve while avoiding the expense of metal production. For existing operations this is particularly attractive since it can be added on with no process interruptions.Two case studies are examined showing flowsheets and costings to arrive at the value proposition of the GT low grade treatment flowsheet."

Jan 1, 2017

By W. Geslin

Backward extrusion process is a metal forming process, which limits the manufacturing?s extra thickness when compared with classical die forging technique. Because of a lack of alloy?s mechanical behavior knowledge, the basic strategy of design is as follow: ?Definition of a small scale blank ?Performing experiment in order to get useful process data ?Improvement finite element simulation conditions ?Development of the full scale blank forming process (design of tools,...) using the finite element simulation A comparison between the result of modeling and the experimental data has been done to validate the finite element simulation.

Aug 1, 2010

By A. Esterhuizen, S. Essack, H. Joubert, N. Fowler

Tenova Pyromet has developed innovative technologies for copper smelting and electric slag cleaning furnaces. Based on client feedback and requirements, innovative designs have been developed to address key design areas and improve furnace reliability, operability and hygiene. These developments include the NovaLance™ lance system to prevent lance bending on top submerged lance furnaces, the SlagFlo™ slag tapping flow control device to better control bath levels and tapping rate for granulation, and an electrode seal for improved sealing directly onto the electrode casing to allow water-cooled electrode components to be located above the furnace roof. The potential application and benefits of these innovative designs are discussed. INTRODUCTION Tenova Pyromet has a long history in the engineering and supply of innovative electric furnace and related equipment for the base metals and platinum industries. Recently Tenova Pyromet has used its furnace equipment design experience to engineer innovative solutions for top submerged lance (TSL) furnaces, and potentially other furnace technologies. These equipment design solutions are developed to address specific operating challenges and operator requirements. Three of these innovative equipment developments are discussed in this paper. First the NovaLance™ lance technology to prevent lance bending during operation in TSL furnaces, such as used for primary copper smelting, is described. Lance bending has been identified as a significant problem for TSL furnace operators as it causes down time and affects furnace availability. The SlagFlo™ device to control the slag flow rate during tapping has been developed based on specific requirements in the mineral wool industry. The SlagFlo™ device can be used to control slag bath levels in primary smelting, converting and slag cleaning furnaces for base metals including copper. In addition, it can be remotely activated for the safe closing of slag tapholes located upstream from a water granulation system. Finally, Tenova Pyromet developed an electrode seal that seals directly onto an electrode surface. This is a special requirement related to base metals and platinum electric smelting and slag cleaning furnaces where furnace operators prefer to keep the water-cooled electrode equipment above the furnace roof. The seal can be used to seal directly onto the potentially hot and uneven surface of Söderberg, pre-baked and graphite electrodes.

Jan 1, 2019

By T. Joseph, E. Zheng, M. Curley

"Hydraulic transportation efficiency and production optimization are considerations in the surface extraction of Athabasca oil sand deposits. To reduce the dependence on haul trucks, it is possible to extend the hydraulic transport system to production faces using a mobile at-face slurry system (AFSS). The flexible arrangement of connected pipelines transports slurried minerals from the mining face to the processing plant. An experimentally verified mathematical model indicates the friction loss of oil sand slurry associated with the AFSS. Laboratory-scale testing enables extended analyses for examining pipeline slurry transport in an oil sands environment.RÉSUMÉ L’optimisation de l’efficacité du transport hydraulique et de la production sont des considérations importantes dans le domaine de l’exploitation à ciel ouvert des gisements de sables bitumineux de l’Athabasca. Afin de réduire la dépendance envers les camions de transport, on envisage d’étendre le système de transport hydraulique aux fronts de taille à l’aide d’un système mobile de transport des matériaux sous forme de boue à partir du front de taille (AFSS, de l’anglais at-face slurry system). L’organisation flexible des conduites reliées permet le transport de minéraux à l’état de boue du front d’exploitation jusqu’à l’usine de traitement. Un modèle mathématique vérifié de manière expérimentale indique la perte de charge par frottement des schlamms provenant du traitement des sables bitumineux associée à l’utilisation de l’AFSS. Des essais en laboratoire permettent de mener des analyses approfondies portant sur le transport de boues dans des conduites dans un environnement de sables bitumineux. INTRODUCTIONObjectives and scope of studyThe at-face slurry system (AFSS) concept has become a competitive means for materials handling to optimize haulage system efficiency and cost. The mobile and flexible arrangement of the AFSS introduces a unique set of hydraulic transport problems. This paper will focus on developing the mathematical models governing the friction and head losses within the AFSS concept.Background of the problemLarge-capacity shovels and dump trucks are increasingly used for excavation, loading, and hauling in the operation of surface mining. Production cost and efficiency optimization are demanded during the Athabasca oil sands (Alberta, Canada) mining process to secure North America’s energy supply. Increasing haulage distances, rugged terrain, and a constrained mine environment are conditions that will reduce the effectiveness of the shovel-truck haulage system (Frimpong, Szymanski, & Changirwa, 2003). In such conditions, the tire heat index and weight, distance, and time limits for truck haulage can be exceeded, simultaneously creating extreme tire wear and high maintenance costs. In addition to low production cost and equipment effectiveness, a mining environment also requires efficient waste-material recycling and distribution. Waste materials need to be recycled from the processing plant to a new destination such as a tailings dam, or replaced in mined-out areas such as backfill. The Athabasca oil sands configuration and location characteristics result in a mining environment that would benefit from flexible pipelines for constant production and an efficient waste-material recycling process."

Jan 1, 2017

By J. Álvarez, J. Mesías, C. O. Gómez

"Operations routinely run flotation tests in laboratory mechanical cells to determine adjustments to plant operation based on feed flotation response or the effect of new reagents and dosages. The metallurgical results of these tests are certainly affected by changes in bubble size, which simultaneously impact the recoveries of the collection and froth zones. It is known that bubble size depends on the characteristics and operation of the machine in use, particularly on the gas flow rate delivered to the unit and the selected frother type and dosage. Although flotation rate constants have been related to bubble size, bubble surface area flux seems to be a more fitting variable to correlate flotation kinetics and cell performance, as it integrates bubble size and superficial gas velocity effects. However, although some evidence has been provided, a categorical relationship between cell recovery and bubble surface area flux has not been established. Our interest is to demonstrate this relationship to use it as a basis for developing soft sensors to track on-line collection zone recovery in cells. Flotation tests were designed to produce Cu concentrates for a range of bubble surface area flux values, obtained through changes in frother concentration at a constant gas flow rate, and by increasing gas flow rate at the same frother concentration. The tests were run on samples prepared from an ore batch supplied by a local operation, following strict grinding and flotation procedures, with a shallow froth to approximate cell recovery to that in the collection zone. Bubble sizes were determined using the sampling-for-imaging technique developed at McGill. The results unequivocally showed a consistent positive correlation between cell recovery and bubble surface area flux, and significant variations in performance when frother addition and gas flow rate were changed.INTRODUCTIONMineral flotation is a separation process to produce concentrates of valuable minerals by selective attachment of particles to the surface of bubbles. The process is carried out in machines where air is injected through a mineral pulp to form bubbles, and operated to create two zones: a bottom one (collection zone) where bubbles are continuously generated under conditions adequate to form bubble-particle aggregates by collision of the rising bubbles with suspended particles; and a top one (froth zone) where bubbles and bubble-particle aggregates continue to rise while concentrating and forming a froth layer for water and entrained particles to drain back to the collection zone, before overflowing as a concentrate stream. The phenomena occurring in these zones are complex and, in many cases, interactive, as they simultaneously affect stages of the particle separation sequence occurring in both zones. Although there have been significant advances in instrumentation to characterize particle and bubble populations, these have not resulted in knowledge to explain or models to describe phenomena from fundamental principles. Measurements continue to be limited to the development of empirical models for predicting the effect of operating variables on performance."

Jan 1, 2016

By Nicole Peter

When introducing digital training technology a practical approach helps address cultural concerns.  Solutions to help create acceptance are discussed.  Resistance to change may be deeply rooted in traditional mine training personnel.  Traditional training staff members may consider themselves less digitally-savvy and resist technological methods available to them. A transitional approach intended to help mitigate or resolve resistance is presented as a continuous improvement pathway toward full adoption.  This presentation contends every mine should welcome the benefit of a digitally connected critical enabler.  The adoption of a digitally savvy learning centre is often viewed a disrupter to existing practice.  Given a commitment-driven learning centre model, technology offers the opportunity to transition from a compliance-based training model to one of competence.  Learning and Development practitioners should welcome the latest advances in neuroscience, Bloom’s taxonomy of learning model, and principles which guide mine safety training as outlined by the Lowell Institute for Mineral Resources at the University of Arizona. By employing digital applications to include animation, game-based simulations and immersive Virtual Reality (VR) these technologies create a viable digitally-savvy learning centre. We will outline the ingredients of a digitally enabled, or VR, Learning Centre to offer some observed benefits, successes, and potential short-comings. Much excitement in the industry surrounds implementation of simulation and/or VR headset training.  Given fair consideration of these as a ‘fit-for-purpose’ solution we examine the paradigm shift required to create real results for on-the-job learning.  Interim steps may be needed to meet the cultural transformation.   Simpler forms of VR, in the form of 3D models and VR environments as displayed on a large interactive touch screen, can serve to bridge this challenge and address a group learning environment. Features of the interactive 3D technology and ease of adoption are presented.  Usage of the touch screen is similar to that of a smart phone. It may be implemented as an obvious transitional tool.  To help describe merits of the interactive touch screen the presentation points out these sample underground and surface mine training applications. There are 3-D simulations such as ventilation, emergency response, support installation, and mine cycle and activity scheduling programs. These applications offer the ability to conduct entry examinations, complete digital pre-use checklists, and perform planned task observations in the virtual world of work. The tool may be used to teach the flow of hydraulics and do fault-finding on machinery such as loaders and dump trucks. Learners may navigate in a virtual mining environment to identify hazards, detect and assess abnormal ground conditions, address poor design features, and alleviate traffic constraints. It is possible to use connected physical controls to navigate machinery in the virtual environment. We conclude the presentation with a “compare and contrast” approach to cite potential cultural benefits by adopting a transitional method. 

May 4, 2025

By Y. Mudryk, D. Paudyal, K. A. Gschneidner, V. K. Pecharsky, M. Khan

"Rare earth intermetallic compounds are utilized commercially as magnetic and battery materials, electron gun electrodes, etc. Several of these intermetallics will be briefly discussed. There are many other rare earth intermetallic compounds which are not utilized industrially but have unusual properties which are of fundamental interest and may have future technological applications. Several of these materials are discussed as well.INTRODUCTIONTens of thousands of rare earth intermetallic compounds exist, but physical properties (primarily their magnetic behaviors), other than their crystal structures have been measured for only a small percentage of these materials. Among these are the commercially important compounds: Nd2Fe14B, and the SmCo5 – Sm2Co17 family – well known high strength permanent magnets; (Tb0.3Dy0.7)Fe2, Terfenol-D, a giant magnetostrictive material; LaNi5Hx a critical component of the rechargeable Ni metal hydride batteries; and LaB6 an electron emitter. There are, however, many other intermetallic compounds which are not utilized industrially, but none-the-less, exhibit interesting, and sometimes, exotic physical properties which are of fundamental interest and may have some future technological significance. These include: the giant magnetocaloric effect compounds Gd5Si2Ge2 and La(Fe13-xSix)Hy; the RCu and RAg families of ductile intermetallics; the mixed intra-lanthanide (R,R')Al2 compounds in which magnetic transitions disappear and reappear as one R is substituted for by R'; and GdNi which exhibits large dilations along two crystallographic directions and a larger contraction in the third direction at the Curie temperature resulting in zero volume change as GdNi orders magnetically via a second order phase transition.COMMERCIALLY IMPORTANT INTERMETALLICSNdFeB Permanent MagnetsThe Nd2Fe14B permanent magnets were discovered in 1984 independently in the USA and Japan. It is a ferromagnet and with proper heat treatment and processing Nd2Fe14B is the strongest near room temperature permanent magnetic material known today. This intermetallic compound is utilized as a permanent magnet in many applications, such as electric motors (e.g. the modern automobile contains up to 35 electric motors), spindles for computer hard disc drives, microphones and speaker magnets for cell phones and other audio equipment, direct drive wind turbines, actuators, and Magnetic Resonance Imaging (MRI) units. There are two kinds of NdFeB permanent magnets – bonded and sintered. The bonded magnets have a lower magnetic strength than the sintered magnet. The highest strength magnets are obtained by small substitutions of Dy (up to a maximum of 10%) for Nd, because Dy can significantly increase the coercivity and thus the energy product (a measure of the magnetic strength or hardness). The bonded magnets account for about 12% of the NdFeB market (~82 metric kt per year, containing ~20 kt/a of Nd). The NdFeB permanent magnet market is growing at a rate of about 15% per year. (Burzo & Kirchmayr, 1989; Kobayashi & Hirosawa, 2001; Coey, 2011)."

Jan 1, 2012

By Dale Lens, W. S. (Wayne) Cusitar

"The use of continuous loading and conveying technology for mining is currently practiced in relatively few mining environments and, even in these cases, on a non-exclusive basis. For the most part, and particularly in hard rock mining, appropriate equipment technology has only recently been developed for continuous loaders, mobile low profile crushers and flexible face conveyors. Mining R&D work by Inco Limited has promoted the development and proving of a loader suited to hard rock conditions and capable of sustained loading rates of500 tonnes per hour. Current R&D work at Inco will test the production capabilities of a low profile mobile crusher by CMS/Eagle and a flexible/ mobile face conveyor system by DME. This follows successful production testing of the Belt Bender concepts in potash mining in Saskatchewan and the development of enhanced extensible conveyor equipment features by DME. Numerous applications are seen for variations of the LCC technology in soft rock, hard rock and surface mining environments. Introduction In some respects, this paper is an announcement of new technology which has the potential to bring revolutionary change to the mining industry. It is also the story of technology transfer, in which mining concepts that have developed independently in underground soft rock and hard rock mines and in surface mining operations are being brought together for a common benefit. It is also the story of key developments in equipment technology which 'complete the cycle' of cooperating technical capabilities to enable the revolution to begin. The phrase ""technological revolution"" requires some defmition: an equipment innovation, or invention, or improvement, will only be revolutionary if its use gives rise to a significant new mining practice."

Jan 1, 1987

By Rowena Anderson

Mining companies are now looking for more effective ways to engage the community in public participation. Consensus-based approaches are becoming the most popularly applied way of achieving meaningful public participation. This paper introduces the principles surrounding consensus-building approaches and the processes for getting them started. The Healthy Communities Movement is one such consensus-based approach that offers a well-established holistic model for conceptualizing a healthy sustainable community. It also highlights the importance of public participation as an essential component of achieving a sustainable community. The paper concludes by illustrating how current company-community relations programs can utilize these models.

May 1, 2002

By Ernest Baafi

A simulation model RoadSIM using the ARENA modelling system has been developed to evaluate roadway development options for a given development panel configuration. The RoadSIM simulation system has provisions for variability/randomness in operations including cutting and loading at the face, tramming and discharge of coal to the boot end and availability of equipment. The modelling system provides a means for assessing the operational limitations of roadway development practices at a particular coalmine. It is a ?what if? tool that allows a range of equipment, configurations and operating practices to be assessed in terms of achievable advance rates and equipment utilisation. Output from the system is in the form of a dynamic visualisation as well as summary reports and detailed logs of operations over time.

Oct 1, 2009

By F. Malek

At Creighton Mine, magnitude events are a regular occurrence due to depth and major seismically-active structures. Over the last ten years, major advances have been made in research and development to develop strategies for the management of these major events. Today, the number of rockbursts has been drastically reduced at the mine and damage due to seismic events, when they occur, is often minimal. This paper describes the evolution and implementation of appropriate geomechanics strategies, designs, and practical ground control measures undertaken for the management of seismicity at Vale Inco?s Creighton Mine. A description of the research and development approach, implementation, and ground control strategy is provided for placement of enhanced support systems to manage the consequences of magnitude events at Creighton

May 1, 2009

By Yoshitaka Mitsuda, Masao Miyake, Masafumi Maeda

A leaching treatment was investigated to recover metals including rare earths from the mixtures of hydrogen storage alloys and nickel hydroxide. A potential-pH diagram of the La-Ni-H20 system including the domain of stability of LaNi5 was drawn to find appropriate leaching conditions. Alkaline solutions containing ligands that form complexes with nickel ions were supposed to be available to separate hydrogen storage alloys from the mixture. When the mixture was leached with ammoniacal alkaline aqueous solutions, the nickel hydroxide was dissolved and the hydrogen storage alloy was recovered as its original alloy.

Jan 1, 2004

By Brian Putland, Fred Kock, Leigh Siddall

Single stage semi-autogenous / autogenous (S/AG) milling has become a common design for a variety of ore types with the advantages of being comparatively low capital cost and flexible for future expansion. The single stage SAG/AG milling option is ideal for starter projects with significant exploration and expansion potential. Currently a number of the largest SAG mills designed are installed in single stage configuration. This paper discusses the challenges associated with the process design of single stage SAG/AG milling circuits, the design flexibility required to ensure a robust circuit and the operating techniques adopted at successful installations.

Jan 1, 2012