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By D. M. MacLean

THE property of Howey Gold Mines, Limited, is situated at Red Lake, Ontario, one hundred and seventy-five miles east of Winnipeg and eighty miles north of the Canadian National railway. The mine has been a continuous producer since April, 1930, and, at present writing, a total of 3,042,690 tons has been hoisted, giving a production of $6,422,858.55, for a grade of $2.32 per ton. From 1,064,477 tons mined during the past two years, however, the yield has been only $1,389,607.03, or $1.41 per ton (gold at $20.67). Present output is at the rate of about 1,470 tons. per day. THE ORE-BODY AND WALL-ROCK: The Howey ore-body is part of a quartz porphyry dyke, which has. intruded an area of greenstone. The dyke strikes north 65° east, and its dip varies from 85° to the south at the surface to practically vertical below the. 1,000-foot horizon. Both along the strike and on the dip, the width of the dyke varies from 25 to 200 feet, the widest portion occurring below the 1,000-foot level. To the east of the ore-body, the dyke increases in width and finally splits into tongues of porphyry enclosed in greenstone, diorite, and congloJ11erate. To the west, it passes into the adjoining property, its width at the boundary being 100 feet. The rock in the ore-body is hard to drill, but, because of numerous horizontal slip-planes, it breaks well when blasted. This characteristic makes it possible to break large breasts or benches with a relatively small number of holes. The ore broken in this manner is consequently quite coarse, a large part of it requiring secondary breaking.

Jan 1, 1938

By H. Hao

This paper outlines the development of a 2-D axisymmetric mathematical model to predict the evolution of temperature during the Direct Chill (DC) casting of AZ31 magnesium billets. Model predictions of temperature have been compared to measurements made on an industrial DC casting machine at Timminco Ltd, in Haley, Ontario. These measurements have been used to fine-tune the thermal boundary conditions employed in the mathematical model, The model, which is based on the commercial finite-element code ABAQUS, has been developed as part of a strategic project aimed at improving the DC casting process for light metals through a reduction in casting related defects and increased productivity.

Jan 1, 2004

By I. A. Cameron, F. Ham, R. Sriram

"Planned increases in electric furnace productivity and higher matte temperatures needed for the Sudbury Smelter's S02 Abatement Plan, require an improved matte tap hole. Since startup in 1978, the matte tap holes have been incrementally improved by the addition of copper cooling blocks around the refractory tap blocks. These improvements provided a tap block life of about 100 taps per campaign.In July 1993, a prototype matte taphole was installed in Number 2 Electric Furnace to develop the technology to increase tap hole service life. The design was based on a heat transfer model of the tapping process to determine candidate refractory materials and cooler arrangements. The prototype tap hole features increased copper cooling, high conductivity refractories and extensive instrumentation. Eight trial campaigns are reviewed outlining the performance of silicon carbide and graphite refractories and typical heat loads during tapping.IntroductionFalconbridge Limited operates two 36 MYA, 6 electrode submerged arc electric furnaces in Falconbridge, Ontario. The furnaces, commissioned in 1978, smelt a partially roasted nickel-copper calcine, to produce matte for converting and slag for discard. Additional details of the smelter are available in the literature(1-4).Each furnace was equipped with two matte tap holes located in the furnace end wall. Early in the campaign, matte tap holes were identified as a weak area in the furnace which could be improved. From 1981 to 1987, incremental improvements were made to the design by the addition of water cooled copper blocks. In 1993, a prototype matte tap hole was designed and installed in Number 2 electric furnace to develop the technology to increase tap hole service life. Improved service life is required to meet planned increases in electric fWl1ace productivity and the higher matte temperature needed for the smelter's S02 Abatement Plan.This paper reviews matte tap hole development since 1978; outlines the prototype matte tap hole design, refractory selection and installation; and details the performance of the prototype tap hole during the first eight campaigns."

Jan 1, 1995

By M. Härting, D. T. Britton, M. Nzikou Mamboukou

"Copper containing different types of nanocomposites have been characterized for nanolabelling and ID. Three types of the rare earth nanoparticles were used for this study, the oxide and the sulphur compound of the Eu and Tb. Characterization techniques uses SEM, and Raman for morphology, chemical composition, and optical characterization respectively. It has been shown that it is possible to include the rare earth particle in a copper matrix without damaging its physical properties. INTRODUCTIONThe development of new materials, often involves the addition of new properties without changing the beneficial properties of the original material (Chen et al., 2009; Khana et al., 2007; Patil et al., 2008). Nanocomposites are nanostructured materials, whose structural elements including clusters, crystallites or molecules, of dimensions ranging between 1 to 100 nm (Moriarty, 2001), or a composite material where one of the phases is a one, two or three dimensionally nanostructured material (Nanotechnology, 2006; Wang, 2001). Nanocomposite materials research is a fast growing area due to the high demand for materials for specialized applications (Edelstein & Cammarata, 1998), such as biolabelling, magnetic storage media, solar energy transformation (Jisen et al., 2004), and resistance welding applications (Bessergenev et al., 1997; Kwon et al.,2006).The properties of the nanocomposite materials depend not only on the properties of their individual parent materials, but also on their morphology and the interfacial characteristics. Thus, significant efforts have been focused on the control of the nanoscale structures via innovative synthesis approaches. Therefore, novel materials of unique properties may be obtained by combining properties from the parent constituents into a single material (Balan, 2006; Garcia et al., 2009). Possible effects of nanocomposites in the original material may include changes in the mechanical properties such as hardness , wear resistance (Rafaja et al., 1987), and electrical properties (Britton et al., 2003). The inclusion process may therefore be used to tailor materials to have particular mechanical, electrical and optical properties (Das et al., 2009). However, to fully understand the nanocomposite, it is necessary to study the fundamental properties of both the host matrix and the inclusions (Li, 2008)."

Jan 1, 2012

By D. A. Nelson, Wedding. R. E.

"A planned production increase of 1.25 million tonnes per year at Domtar's salt mine in Goderich, Ontario required an increase in the underground mine ventilation system from 320,000 to 700,000 scfm, The design of the expanded facility included the addition of a 22-foot-diameter shaft to augment the existing production and service shafts.A preliminary review of the ventilation requirement s indicated that in order to pr ovide good economic design for the expanded system, a comprehensive ventilation survey of the existing system was required. The survey was completed in the latter part of 1980, and subsequent engineering design and equipment selection proceeded throughout 1981.This paper presents the methods used to carry out the survey. Particular attention is given to the numerous challenges presented in determining air flows in the large 45-ftwide by 43-ft-high airways. Emphasis is placed on practical field survey techniques.A mathematical model of the ventilation system using a computer program is described, and the application of this program to provide design data and assist in equipment selection is discussed. Economic sizing of airways and fan selection are analyzed considering horsepower and operating costs.IntroductionThe Goderich Mine of Sifto Salt Division, Domtar Inc., is located on the eastern shore of Lake Huron in the town of Goderich, Ontario, and has been operating since November 1959. The salt is extracted by a modified room-and-pillar method, and the workings advance at a rate of 1.5 miles per year by undercutting, drilling and blasting. The surface mine area consists of a 12-acre site in the Goderich harbour, at the mouth of the Maitland River, and the underground property consists of approximately 2,700 acres lying mainly under Lake Huron."

Jan 1, 1983

By F. W. Gray

IN 1922, the writer communicated to the Institute a paper entitled The Development of the Coal Industry in Canada (1), which summarized the considerations set out in a series of papers (2) concerned with coal-mining in Canada which he had presented in 1920 and 1921. This paper contained a forecast by decades, commencing 1920, of Canadian coal production, importation, consumption, and exports, based on anticipated rate of population increase, and continuation of the gradual increase in the per capita rate of coal consumption in Canada that had taken place every year up to 1920. The following comparative statement brings our the differences between the forecast and actual experience:

Jan 1, 1936

By P. M. Chapman

Risks to aquatic receiving environments from uranium mining and milling fall into three categories: physical (habitat change), chemical (e.g., uranium, selenium, total dissolved solids [TDS], metals including vanadium), and radiological. Although all categories of risk need to be managed, chemical risks are the most significant and are typically chronic rather than acute. For instance, selenium toxicity is primarily manifested as reproductive impairment due to maternal transfer, resulting in embryotoxicity and teratogenicity in egg-laying vertebrates. Risk is best assessed using a weight of evidence approach focused on ecosystem services. Risk management should be based on both risk assessment and adaptive monitoring.

Aug 1, 2010

By M. Maldonado

This work details the application of a decentralized control strategy to a pilot flotation column working with a two-phase system (water-air). The process is represented by a multivariable system composed of three inputs and three outputs. The selected control variables are the froth depth, the air hold-up and the bias rate, whereas the corresponding manipulated variables are the set-points of the local flow controllers of tailings, air and wash water. All controlled variables are estimated using electrical conductivity based techniques. In particular, the results of a new method for estimating the bias rate, based on the measurement of the volumetric fraction of wash water under the interface, is presented. This method reduces the coupling problem associated to the bias estimation as a difference between feed and tailing water rates. Moreover, the nominal system transfer matrix can be represented by an upper triangular matrix, in such a way that the closed-loop system stability reduces to the stability of the independent control loops. The experimental results show that the closed-loop system performance, particularly that of the bias rate loop, is strongly dependent on the air flow rate, reaching in some cases the saturation point of the controller.

Jan 1, 2007

By C. E. Cairnes

The Slocan mining camp in Kootenay district; British Columbia; has long been noted for the great number of its silver-bearing deposits; and for the success that has; in many instances; attended their development. The orebearing area lies east of Slocan lake and mainly within a radius of 6 to 8 miles of the mining town of Sandon. Within this limited area 135 or more properties have shipped ore in quantities of from 100 tons or less to more than 500; 000 tons; and with a total value in silver; lead; and zinc ranging from a few hundred dollars to well over $10; 000; 000. Of the three metals; silver has easily ranked first in value; with lead second and zinc third. Zinc production; however; made slow progress in the early years; and with . the exception of the Lucky Jim mine; and a few others where high-grade ore could be readily hand-sorted; was a detriment to the silver-lead ores until improved methods of separation enabled it to take an important place in the mineral production of the Slocan.

Jan 1, 1954

By Peter Bourke, Marc van Olst, Seppo Ronkainen, Natalie Brown

"Since the early days of flotation, process technicians have known that the speed at which the froth is recovered over the lip of the cell has a very direct and consistent influence on the grade and recovery of the circuit. No plant would deny that, even to this day, one of the most important aspects of a process technician’s job is ensuring that the froth is moving at a desired and controlled speed over the lip. Unfortunately, process technicians cannot watch the froth throughout the entire shift, as there are always a lot of other tasks to do.A considerable amount of work has thus been done to develop a “system” that automatically measures the speed of the froth. This measurement would then be used in simple controllers to emulate the steps taken by the process technician in correcting deviations of the froth speed from its desired level. Many of the earlier attempts to measure speed were ineffective, as they were unable to cope with turbulence on the froth surface. The FrothMasterTM instrument makes use of machine vision technologies to measure the speed of the froth over the lip of a cell at a very high sampling rate. This instrument produces an extremely reliable and accurate measurement of the froth speed (as well as other parameters such as bubble size and froth stability). As we will show, the effectiveness of the speed measurement in controlling the performance of the plant is a testimony to its reliability.Three FrothMasterTM units have recently been installed on the Cadia Hills Gold Mine in New South Wales (Australia). The objectives of this installation were:To control the mass-recovery of two Tank Cells in series on the same level where differences in the hydrostatic head between the two cells result in the cells pulling inconsistently with respect to each other.Control of the concentrate grade (%Copper) from the first rougher.Reduction in the frother consumption in the rougher circuit by monitoring the froth speed.A simple controller was designed to react to disturbances in the same way that human operators react. This was done after consultation with the metallurgists and the process technicians at Cadia. The controller had two functions:Stabilisation: The stabilising controller made use of three manipulated variables (level, frother addition rate and aeration rate) to control the froth speed to a setpoint.Optimisation: The optimising controller adjusted the froth speed setpoint based on deviations of the grade (measured in real-time with an OSA) from a setpoint. The plant metallurgist adjusted the grade setpoint based on information about the ore."

Jan 1, 2001

By Kish. L.

"The results of a chemical and mineralogical study of eighteen opaque-oxide occurrences are discussed and the detailed chemical, metallurgical and mining feasibility study of a vanadium-rich magnetite deposit is summarized. A plot of the mol-percentages in the system FeO- Fe2O 3-TiO2 indicates that the deposits fall into two distinct groups: some contain hematite with ilmenite, and some others have magnetite with ilmenite (titaniferous magnetites). The plot also suggests that the two types of deposits were crystallized from liquids of different compositions. Each group has its distinct structural features. Vanadium is present in all of the studied specimens, however concentrations of economic importance have so far been found only in the titaniferous magnetite deposits. The vanadium content of the oxide concentrations of the Dore Lake Complex is the largest among the studied occurrences. Analyses of the concentrates of the drill-core sections show a compositional variation across the orebody; a continuous increase in the tenor of Ti02 and a decrease in the vanadium content upward in the layered sequence is found. Concentration tests on several tons of samples indicate that about 80 per cent of the vanadium is recovered in the magnetite concentrate."

Jan 1, 1972

By P. Mundell, R. Torbin

"There are many physical and operational obstacles in pipelines that make the passage of inspection robots impossible including:•,Small radius bends•,Low operating pressure•,Plug valves•,Large changes in pipe size•,No permanent access to the pipeline.The inspection of unpiggable pipelines requires the marriage of a highly agile robotic platform with NDE sensor technology operating as an integrated system. Foster-Miller and GE/PII are developing a robot that is essentially a battery powered, train-like platform. Both front and rear tractors propel the train in either the downstream or upstream direction. Like a train, the platform includes additional ""cars"" to carry the required payloads. The cars are used for various purposes including the NDE sensor module(s), the power supply, and data acquisition/storage components. The robot is designed with a slender aspect ratio and the ability to change shape as required by the physical obstacle presenting itself. The MFL sensor module must also morph itself through the physical obstacles, and thus, will require some level of segmentation. The segmented MFL magnetizers and transformable sensor module represent a major advance in the science of sensor technology and pipeline inspection."

Jan 1, 2005

By Mark Freberg

"IntroductionThis chapter is intended to provide information on the operation and maintenance of several pieces of equipment used in heavy media separation. Most heavy media separation circuits, particularly those involving bath separators can be considered as high maintenance areas. Because of this the efficient operation and maintenance of these circuits is very important if the cost per ton of material treated is to be kept to an acceptable level.Heavy media separation (HMS), is a process used to separate particles of different specific gravities. Under laboratory conditions the ideal way to separate two types of particles which have different specific gravities is to suspend them in a heavy liquid which has a specific gravity between those of the two types of particles. Those particles with the lower specific gravities will float on top of the liquid while the higher specific gravity material will sink to the bottom. Given enough time and a sufficient volume of heavy liquid this process will be essentially insensitive to the sizes of the particles involved.Heavy media separation circuits make use of the same principles described above. The material to be treated is introduced into a mixture of finely ground solids, called media, and water which takes the place of the heavy liquid; the mixture of solids and water is known as medium. The separating force can be either gravity or centrifugal force. The type of solids used as media varies but it is usually a high specific gravity material such as magnetite, galena or ferrosilicon.Heavy media separation is used extensively in the cleaning of coal and to a lesser extent as a preconcentration step in base metal and iron ore operations."

Jan 1, 1989

By Eduardo Nunez, Asim Tuzun, Dan Graffi, Glenn MacPherson

"In preparation for the milling of a new nickel and copper mine ore, Nickel Rim South, Xstrata’s Strathcona Mill is undertaking numerous process improvement projects. Within the grinding circuit, several projects are under development and an automated grinding control strategy, consistent with the operating objectives, was identified as a key requirement. The grinding strategy is to maximize the throughput (quantitative objective) while maintaining the cyclone overflow within specifications (qualitative objective).This paper describes the implementation of a robust grinding control strategy using the existing control system. The implemented controls maintain the cyclone overflow density at the desired target, while continually optimising the rod mill feed rate to allow maximum throughput. This approach has the added benefit of improving the stability of the rougher flotation circuit down stream of the grinding and improving energy efficiency of the rod and primary ball mills. This paper discusses the comparison of the before and after the implementation of results.INTRODUCTIONThe grinding process is a size reduction operation used in the mining industry to liberate the valuable minerals from the gangue. Grinding is one of the most important and expensive processes in a concentrator (Xi-song, 2007; Pomerleau 2000; Najim 1995), often accounting for around half of the total operating costs in base metal concentrators (Wills, 1990), which has led to a focus on development and implementation of control and optimisation strategies. The grinding process prepares the ore for the subsequent concentration step, which for sulphide base metal operations, is predominantly flotation. The performance of the concentration (flotation) is very much determined by the feed characteristics of the slurry coming from grinding. The valuable minerals recovery process in flotation is very much influenced by the grinding process and the liberation of the desired minerals from the gangue minerals (McIvor, 1991).The true objective of grinding is to obtain a proper liberation of the minerals as defined by a particle size distribution referenced typically by d80 (80% passing size of product). Besides achieving the desired mineral d80 size, it is clearly desirable to produce as narrow a size distribution as possible to squeeze the maximum amount of the mineral value into the highest recovery region (McIvor, 1991). This is an important criterion for the mill in economically optimizing the grade and recovery for the concentrate product. It is important not to over or under grind, while keeping the specific comminution energy as low as possible (Nunez, 2005) to achieve the target liberation. In other words, maintain an optimal throughput depending on the ore conditions to the capacity of the grinding mills, while providing the flotation process with a constant and narrow size distribution, at a cut size selected to meet the metallurgical requirements (Bascur, 1991)."

Jan 1, 2009

By Mark Sherman, M. Dennis, Raj Rajamani

"The two Alumbrera 36ft (10.97m)dia. SAG mills were sized, using the FDW ""Grindpower 'I program, to treat an average of 1852 tph each. This paper describes how modelling of the shell lifter design, using the Millsoft program, identified milling inefficiencies caused by poor charge motion. This explained the ""as built"" circuit's inability to achieve the throughput rates predcted by the circuit's designer. Use of the Millsoft program to design a new, dramatically different lifter configuration, in conjunction with a different approach to variable speed drive utilization, has resulted in an improved charge motion and a 30% increase in hard ore milling rates. The new lifter design has allowed the designer's predicted average throughput rates to be achieved.IntroductionThe Alumbrera project grinding circuit consists of two 36ft dia. X 17ft EGL, 13 500 kW, variable speed, gearless drive SAG mills coupled to four 20ft dia. X 30ft EGL, 6 000 kW fixed speed, gear driven, ball mills. The circuit is configured as two identical grinding aisles, each consisting of one SAG mill and two ball mills. No pebble crushing circuit was installed due to the expected absence of a critical size fraction in the first years of production. However, the grinding circuit layout does incorporate space for a pebble crushing retrofit. At present, only about 5% - 10% of the new mill feed reports as trommel oversize and is recycled back to each SAG mill using a water cannon.The circuit was designed to be ball mill limited and to treat the four major Alumbrera ore types at rates varying between 68 000 tpd, and 89 750 tpd, depending on ore hardness. Average throughput rate, and hence nominal design rate, for the grinding circuit was 80 000 tpd (1 852tph per line at 90% availability)."

Jan 1, 1999

By Christoph Mueller

Mining operations today are characterized by a high degree of mechanization and single machine automation. However, their potential for cost cuttings and increase of productivity in the future is quite limited. Enabled by newest IT and networking technology, the operation of underground mines more and more can be seen from a process related point of view: Standardized Ethernet and Wireless LAN are the basis for a seamless and unified communication backbones providing an integrated infrastructure for data, telephony and video. All the components are available as off-the-shelf devices leading to an excellent cost efficiency. Basing on this standardized infrastructure, the equipment is able to become part of the infrastructure. To enable machines to be integrated smoothly into IT networks, the machine also has to have enhanced networking capabilities. This results in a new system architecture for the on board machine electronics separating real time control from IT and networking level functionality which can be implemented by a Machine Server. This machine server communicates with all kinds of above ground systems using mainly standardized formats like html or the IREDES standard. This information is made available mainly in 3D mine visualization tools. The paper explains this technology and shows implementations by two working examples.

May 1, 2006

By George P. Demopoulos, Nima Parsi Benehkohal, Marianna Uceda

Lithium-ion batteries (LIBs) find wide range of applications from portable electronics to electric cars and stationary storage or renewable energy. LIB electrode fabrication is done through mixing the active material (Li-ion host) with carbon (conductive component) and polyvinylidene fluoride (PVDF), which acts as a binder. These components are dissolved in N-methyl-2-pyrrolidone (NMP) to form a paste which is then doctor bladed onto the aluminum current collector. NMP is a toxic chemical and the overall fabrication process remains costly. Efforts are made of eliminating NMP by (1) replacing the binder and (2) using a new fabrication method. Of particular interest among these new methods is electrophoretic deposition (EPD). Via the application of DC potential, particles in suspension can be electrophoretically deposited on different conductive substrates in a relatively fast rate rendering EPD feasible for industrial application. A key aspect for successful application of EPD is the formulation of a stable suspension. Within the McGill HydroMET group, we explore the potential of EPD in fabricating LIB electrodes having demonstrated its effectiveness in the case of P25 nanotitania/carbon anodes. The performance of EPD fabricated TiO2/C electrodes is compared to standard PVDF-based electrodes and shown to have comparable charge capacity. This method is now being extended to other electrode materials. In this paper an introduction to the EPD method will be made and subsequently its use in fabricating LIB electrodes will be described. The performance of the fabricated batteries is evaluated via galvanostatic charging/discharging and cycling tests.

Jan 1, 2016

"3.1. IntroductionAmong the six platinum-group elements (POE), four have identical cubic symmetry, two identical hexagonal symmetry (Table 3.1). Despite crystallographic differences, there is a clear relationship expressed in the chemistries of the POE: they tend to be mutually soluble in one another and can frequently substitute for one another in compounds with other elements. This chapter consolidates the data on phase relations of the POE and the compounds they form with elements selected for their known or potentially important mineralogical significance- As, Bi, Cu, Fe, Hg, In, Ni, Pb, S, Sb, Se, Sn and Te-together with selected data for the occurrence of POE in certain elements such as Au and Ag, and compounds such as FeS. Resources used to compile the data are those available from the chemical, mineralogical and metallurgical literature. First each element is discussed, with composition limits of solid solutions drawn from binary phase diagrams. Single element data are followed by a discussion of the relevant binary systems and a tabulation of data for binary compounds found in those systems (Table 3.2). Tables and diagrams for the ternary and quaternary systems for which information is available follow, and finally the very limited information on the solubility of POE in mineralogically important elements and compounds is presented.The chemical, mineralogical and metallurgical literature on the unary and binary systems is extensive and widely scattered in many languages and publications; fortunately, most of the data needed to compile this chapter can be found in reliable compendia. The most useful and most recent of these works is by Moffatt (1979), because it provides a ready index to all material relating to binary systems listed in previous compendia; furthermore, the Moffatt compendium will reportably be kept up to date by annual supplements."

Jan 1, 1979

By Steve Piercey

Introduction ? VMS Deposits: The Target ? Key points for every belt: heat flow and extension. ? Good felsic rocks ? Good mafic rocks. ? Petrochemical assemblages. ? Summary Key Points Throughout ? Common themes: ? Heat ? driver of the hydrothermal system ? Extensional geodynamic setting ? conduits to focus fluid flux ? (e.g., Lesher et al., 1986; Swinden et al., 1991; Barrie et al., 1993; Lentz, 1998; Syme et al., 1999; Piercey et al., 2001, etc.) ? We must identify rocks, belts and tectonic environments that encompass these two criteria (among others but?) ? e.g., forearc rifts, intracontinental rifts, arc rifts, and back-arc basins.

Apr 1, 2005

By D J. Murray

This paper outlines the principles of friction hoisting and the components involved, and gives a description of a specific mine hoist. Friction hoisting is compared with conventional drum hoisting, and the depth of shaft at which friction hoists become more economical than drum hoists, with respect to power consumption, is determined. Introduction T HE purpose of this paper is to outline the principles of friction hoisting, to describe the components and to show the advantages of multi-rope friction hoisting. Some calculations are made to show that the power requirements and the initial costs of friction hoists are less than those of conventional drum hoists, once a certain depth of shaft has been reached. The use of multi-rope friction hoists is gradually superseding the employment of the conventional drum hoist in many parts of the world. It results in heavier payloads from deeper levels, an increase in shaft safe-ty and a more compact installation for protection against adverse weather conditions. It was observed that where drums and friction sheaves exceeded 30 feet in diameter, a number of mechanical disadvantages were being experienced;

Jan 1, 1965