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By J. A. Brusset

Introduction I am indebted for most of the information in this paper to Mr. P. S. Lea, Deputy Chief Inspector of Mines of Great Britain, and Mr. A. E. Crook, Engineering Inspector of Mines, Ministry of Fuel and Power. Other coal-mining men in Canada may be as surprised as I was to learn that there are twenty-five Diesel locomotives in service underground in British gassy coal mines. Many more are in use underground in non-gassy coal mines and in metal mines. Approval has been granted for an additional fifty flame-proof locomotives to be used in gassy mines, and these should be in operation by the end of 1946, or as soon as manufacturing facilities permit.

Jan 1, 1946

By P. Bacher, L. Dubourg, M. Jahazi, G. Dezaise

Effect of friction stir welding parameters and natural ageing on weld properties are reported. Using a Taguchi design of experiment, attempt is made to systematically examine the influences of the welding speed, tool rotation speed, forge force, tilt angle and pitch ratio on the weld size and ultimate tensile strength of FSWed joints. One millimetre thick plates of AA7075-T6 were welded in lap joint configuration. Samples were characterized by optical microscopy, hardness and tensile measurements. Trends suggested by the results and directions for further investigation are discussed.

Jan 1, 2006

By R. Howard

"In projects involving resource development and plant optimization, the use of in-mine geophysics can deliver considerable benefit. The value proposition lies in using very high resolution downhole measurements to model process-plant outcomes. The calibration procedure used to convert in-situ physical properties into process engineering parameters is illustrated using two iron ore projects. Data correction was related either to orebody structure or mineral formation. The deliverable from this approach is a series of high-definition sections indicating the variability of ore delivered to a front-end separation plant and parameters for mine scheduling and stockpile design needed for maximum product yield.RÉSUMÉ Dans des projets de développement des ressources et d’optimisation de l’usine, l’utilisation de la géophysique minière peut engendrer des bénéfices considérables. La valeur de la proposition réside dans l’utilisation de diagraphies à très haute résolution afin de modéliser les résultats de l’usine de traitement. La procédure d’étalonnage utilisée pour convertir les propriétés physiques in situ en des paramètres d’ingénierie de procédés est illustrée en se basant sur deux projets de minerai de fer. La correction des données porte sur la structure de la masse minérale ou de la formation minérale. Les livrable attendus de cette approche sont une série de sections à haute définition, signalant la variabilité du minerai livré à une usine de séparation de première ligne, des paramètres pour l’échéancier de la mine et la conception des haldes requis pour une production optimale."

Jan 1, 2016

By T. Grammatikopoulos, K. Gibbs, H. De Souza, C. Gunning

The mineralogy of any ore body is a key factor in defining ore zones and predicting minerals/metals behaviour during processing. The determination of forms of gold, defined as the different chemical states in which gold is encountered in ore deposits, is critical. The most commonly known form is that of gold minerals and alloys, while other forms of gold have been collectively described in the literature as submicroscopic gold (i.e., less than 1 µm in diameter). Gold mining operations generally deal with very low-grade ores, in the order of a few g/t, in which gold displays complex mineralogy. These difficulties complicate the mineralogical studies and pose challenges for processing and recovering the gold. A comprehensive understanding of the chemical forms of gold is necessary to define gold mineralization and optimize gold metallurgy. SGS Canada Inc. has been using QEMSCANTM and a Tescan automated SEM that are automated mineralogical techniques that provide vast amounts of data for microscopic Au. The data in conjunction with other physical and chemical methods provide a comprehensive delineation of the ore composition and behaviour.

Jan 1, 2011

By Forrest A. Kerr

Northern British Columbia is a term which probably conveys to various individuals quite different meanings. To the average person it signifies an area of indefinite size and indefinite position which may start at Prince Rupert, Stewart, or somewhere else, and end at Alaska or .the Yukon. Many people, in their conception, fail to encompass in their mind's eye that vast tract of land lying ~o the east of the panhandle of Alaska. Few realize that the area north of an east-west line through Stewart represents more than one-third of the Province and is, of course, the part most appropriately designated as northern British Columbia. This section, more especially the northernmost 100,000 square miles, from political, geographic, and economic viewpoints stands isolated perhaps more than any other part of British Columbia. Unlike the rest of the Province, it has no coast line, being cut off from the Pacific ocean by a narrow strip of Alaska. It is bounded on the north by the Yukon, and on the east by Alberta. In the south this northernmost 100,000 square miles is limited by a divide of rugged mountainous country separating the drainage basins of the Stikine and Liard rivers from those to the south.

Jan 1, 1929

By J. D. Christian

WHEN mining development began in the Kirkland Lake camp, twenty-five years ago, there was very little information obtainable from surface showings as to the nature of the ore deposits. A length of almost a mile of the main 'break' lay under the south arm of the lake, and elsewhere most of the outcrops were covered with glacial drift. Shafts were sunk on ore-bodies of uncertain value, either on the outcrop of the veins or-because of the lake to the north-in the south or hanging-wall. In the second year of the camp's development, the Great War broke out and retarded progress for its duration. He would have been a real optimist who, in those early years, could have foreseen mining at depths of more than a mile.

Jan 1, 1939

The Mineral Industry of Canada in 1951 Continuance of the remarkable, successive increases in the value -of Canada's mineral production, chief basis of the nation's post-war expansion, was one of the highlights of Canadian development in 1951, when, according to the preliminary estimate is-sued by the Dominion Bureau of Statistics and reported in the BULLETIN for February, 1952, mineral output for the year reached a new high of $1,228 millions. This marked an increase of 17.5 percent over the previous year, which was the first in which the billion dollar mark had been reached, and an increase of 143.7 per cent over 1946, when production was valued at approximately $503 millions. While higher prices for the principal base metals accounted for a large part of the 1951 increase, quantity gains were made by copper, nickel, zinc, asbestos. lead, cement, and strikingly important. by petroleum, the value of which exceeded for the first time that of coal production. Gold was an exception to the general trend, being lower in both quantity and value than in 1950. For the first time nickel .came within $9 millions of surpassing-gold as the leading mineral product. Metals and Fuels The value of all metals, estimated at $733 millions, was 18.7 per cent more than in the previous year. Nickel advanced 11 per cent in volume and 34 per cent in value. Copper was up 2.4 per cent in quantity and 21 per cent in value, zinc rose 6.6 per cent in quantity and 35 per cent in value, and although the volume of lead produced was lower by 8 per cent, its value increased by 17 per cent. The tonnage of iron ore was 31 per cent higher than in 1950.

Jan 1, 1952

By F. Flores

With the World Summit for Sustainable Development planned for 2002 in mind, nine of the world's largest mining companies decided to initiate a project to examine the role of the minerals sector in contributing to sustainable development, and how that contribution could be increased ? the Mining, Minerals and Sustainable Development Project (MMSD). This project assumed from the start that sustainable development could provide a useful framework to guide the minerals sector which main goal was integrating economic activity with environmental integrity, social concerns, and effective governance systems. The broad steps of MMSD project strategy can be grouped into four major categories: increase understanding of sustainable development; create organizational-level policies and management systems for implementing the principles of sustainable development; collaborate with others with common interests to take joint steps towards sustainable development, and; increase our ability to work towards sustainable development at the local, national, and global levels. In opinion of the article's author, to go ahead with the MMSD strategy and achieving the sustainable development objectives, it is necessary to consider the concept of self-organization, fundamental of the emergent new scientific paradigm, and the consequent epistemology and values that conform a supporting culture for sustainable development.

Jan 1, 2007

By Frederik H. Kriel, John Ralston, Craig Priest

"Stream-based microfluidic solvent extraction offers a novel alternative to bulk-scale mixer-settler operations. However present maximum throughputs are restrictive and there are engineering challenges that need to be overcome before the technology is robust. This is especially the case for mineral processing, where circuits must be able to handle variable feed streams with long retention times and where maintenance should be minimized. This paper highlights research directed at investigating and evaluating these challenges for actual mineral leach solutions of metal ions. Molecular and particulate channel fouling is discussed. Most extraction systems studied to date show no effects that would preclude use of the technology. For rare earth elements (REE) with fast extraction rates, scale-up of volumetric throughput to 100 L/h using suitable arrays of channels, microfluidic chips and modules is shown to be achievable using a small contactor (approx. 2 m3) platform. This requires only 2–3 % of the typical aqueous phase inventory and residence time used in an equivalent mixer-settler. For a circuit with 100 contactors, the overall residence time would be less than 1 h, using an aqueous inventory of 40 L.INTRODUCTIONHydrometallurgy is of pivotal importance in many mineral processing circuits around the world, with liquid-liquid solvent extraction (SX) a key step in the separation of many base metals (e.g. Cu and Ni), radioisotopes, precious metals, and the ‘technology’ metals, such as rare earth elements (REEs) (Ritcey & Ashbrook, 1979). The standard equipment for SX in mineral processing is the mixer-settler, in which liquid dispersions are created, by agitation, to increase the surface-to-bulk ratio and, thus increase the mass transfer rate between the liquid phases. In stream-based microfluidic SX (microSX), these high surface-to-volume ratios are achieved by contacting microscopic streams (Ciceri, Perera, & Stevens, 2014), rather than forming small droplets, so that phase disengagement can be accelerated (essentially instantaneous via branching of the two streams of liquid at a channel junction). MicroSX is profoundly different from bulk mixer-settler SX operations and offers exciting opportunities for processing hydrometallurgy solutions (Kriel, Holzner, Grant, Ash, Woollam, Ralston, & Priest, 2015; Priest, Zhou, Klink, Sedev, & Ralston, 2012). Nonetheless, the advantages of using microfluidic environments are presently balanced by very significant challenges relating to throughput, process control, coupling of stages, flow stability, and fouling. If these challenges can be met using smart chip designs, process control and clever engineering, high-value/low-volume SX processes stand to benefit greatly."

Jan 1, 2016

By E. Brouillette

Difficult operating and mining conditions such as low visibility, difficult roadbeds, fast cycling, small openings, and sharp corners create high demand for LHD manoeuvrability and operator dexterity. Operator experience and patience is especially solicited to fill the bucket rapidly and efficiently and performance can be particularly affected by the skill level of individual operators. Teleoperation and automated loading are viewed as options to improve overall equipment and operation performance in certain mining conditions. Comparative statistical measurements of autoloading performance in different production environments at Noranda demonstrate an increase in bucket filling efficiency and a reduction in filling variance, allowing LHD operation to be more consistent and within manufacturer specifications. Consequential cost savings and productivity increases are demonstrated to be transferable to other mining situations.

May 1, 2003

By Junior Santos

Kinross Paracatu started the operation of the new gold processing plant in the end of 2008, being composed by one SAG mill and two ball mills. During the first year of operation the plant had several problems related to stability and throughput capacity, mainly due to low grinding efficiency of the ball mills. In this period many actions were taken to maximize the throughput rate. Among the actions are reducing the size of balls in the mills, increasing the ball charge in the SAG mill, changing cyclone configuration and return of circulating load to SAG mill. With better stability of the circuit, the second stage of improvements has begun with the objective of increasing throughput rate and also reducing operation costs. Among the actions are the optimization of ball charge in the mills and a better operational control of cyclone parts. After two years of operation was obtained a significant increase in plant capacity, but still requires the addition of a third ball mill in order to maximize the use of SAG mill, which has spare capacity.

Jan 1, 2012

"The Australasian Joint Ore Reserves Committee (JORC), which is sponsored by the Australian mining industry and its professional organisations, developed the JORC Code to provide minimum standards for public reporting. JORC was first published in 1989 and later incorporated into the Listing Rules of the Australian and New Zealand Stock Exchanges making compliance mandatory for listing public companies in Australia and New Zealand."

Jan 1, 2003

By S. D. Anitha Kumari, T. G. Sitharam

"The huge urbanisation of the world cities have invariably resulted in enormous requirements of development in transport and other facilities. As the surface space available for the construction of these infrastructural facilities is found to be inadequate, underground space is widely used recently for this purpose. However, to understand the behaviour of these underground structures through experiments under various loading conditions is not practically feasible. Hence numerical methods have widely been used to model these structures and predict their behaviour. The underground structures generally rest on soil or rock. Depending upon the properties of the material surrounding the tunnel, the deformation pattern and the stress contours vary. If the tunnels are placed on soft ground at a shallow depth, the presence of existing structures will add to the stresses and strains developed. In the case of densely populated cities, tunnelling operation may result in huge damages if the settlements are not within the desirable limits. This may in turn lead to the collapse of the tunnel along with adjoining structures. So the determination of stress levels associated with the yield of wall due to excavation is very important and necessary supports and reinforcement should be provided. Numerical simulations using discrete element method (DEM) and finite element method (FEM) have been done to understand the stress variation around single and twin tunnels. Studies are also done to quantify the improvement of stability on the introduction of lining around the tunnels in a weak cemented soil mass like sandstone.INTRODUCTIONMost of the life line facilities which include pipelines for electricity, water, communication, sewage, gas, roads, metro, utility tunnels etc in modern urban areas are underground structures. Infrastructure development is crucial for any city and sustainable development urges for underground constructions. Accordingly, there is already a great demand for tunnels to be constructed in difficult and crowded urban settings. This results in the fact that a large number of risk factors are associated with tunnels in these densely populated urban areas. These constraints pose threats to tunnel construction and also demands for minimal disturbance to the public and to the surrounding utilities. One of the most important factor to be considered while designing an underground structure is its stability with respect to the surrounding medium and adjoining existing structures. In this study, a comprehensive presentation of the numerical modeling of single and twin tunnels adopting two different methods is presented."

Jan 1, 2015

By Seungwoo Park, Whuisu Shim, Roe-Hoan Yoon, Kaiwu Huang

"A comprehensive froth model has been derived from first principles. It is based on predicting the kinetics of film thinning in the presence of particles of varying sizes and surface hydrophobicity. According to the Reynolds lubrication theory, the thinning of a horizontal film is driven by the excess film pressure (p), which is determined by the capillary pressure (pc) and the disjoining pressure (II). In the presence of particles, macroscopic capillary pressure (pc) is affected by the local capillary pressure (pc,local) in the vicinity of a particle and the number of particles in the film (N1,film), which in turn vary with the hydrophobicity and size of the particles. The Reynolds equation corrected for pc,local and N1,film is then used to predict the time (or froth height) at which a film is thinned to a critical rupture thickness (hcr), which in turn can be predicted using the Vrij’s capillary wave model (1966) after a modification to incorporate the contributions from hydrophobic disjoining pressure (IIhp). The model can predict bubble coarsening represented by the bubble size ratio between the top (d2,t) and bottom (d2,b) of a froth as functions of particle size and hydrophobicity, ? -potentials, frother dosages, froth height, gas flow rate, salt concentration, etc. The model predictions have been verified in experiments.INTRODUCTIONFroth flotation is regarded the best available technology today for upgrading minerals and coal fines. In the pulp phase of a flotation cell, air bubbles collect hydrophobic particles dispersed in it and rise to enter the froth phase on the top. Once in a froth phase, the bubbles coalesce with each other and become larger, resulting in a decreased bubble surface area. Under conditions of limited surface area, less hydrophobic particles drop off the bubble surface and return to the pulp phase. Thus, bubble coarsening provides a useful mechanism of increasing product grades. On the other hand, uncontrolled coarsening results in a decrease in bubble carrying capacity and hence throughput."

Jan 1, 2016

In most instances, the preferred mining methods in steeply dipping narrow vein deposits are selective methods such as cut and fill or shrinkage. The main advantage of these methods lies in the higher degree of control over dilution that can be achieved. However, where ore body geometry lends itself to it, high yield bulk methods can also be attractive. Higher productivity (and the associated lower costs) and lower worker exposure are some of the significant advantages that have made such methods so popular. The Lapa gold mine located in North-Western Quebec uses the long hole mining method (with cemented rock fill) very successfully despite challenging ground conditions. This paper focuses on the experience of the mine with regards to drilling and blasting practices. Firstly, the reasons that prompted the selection of this mining method at Lapa are examined. Secondly, the challenges that the difficult ground conditions found at Lapa pose to drilling and blasting are discussed. Finally, the results of trials of different drilling and blasting strategies that were performed at the mine are presented with particular emphasis on the lessons learned.

Aug 1, 2013

By B. K. Gorain

"The Air-Metabisulfite (AMBS) process has been developed to treat complex copper, molybdenum and precious metals (gold, silver) bearing ores using brackish and sea water. This process was able to produce significantly better copper concentrate grades and higher recovery than possible using conventional lime and/or cyanide based processes for certain complex ores with high sulphide gangue minerals. The AMBS technology in now used commercially following a rigorous evaluation process emanating from laboratory curiosity to plant applications. In addition, many projects have embraced this technology at a feasibility level involving various complex ore bodies.This paper presents a summary of the findings from testing the AMBS technology on various ores types. Experiences gained from this successful development from bench to piloting and then to plant applications are also presented in this paper.INTRODUCTIONProcessing of sulphide copper, molybdenum and precious metal ores typically involves flotation of copper bearing minerals while depressing non-sulphide and other non-copper sulphide minerals such as pyrite, pyrrhotite and sometimes arsenopyrite. Though in many precious metal ores, the values are in these sulphide minerals as well. The conventional method employed in the industry to produce a saleable copper concentrate requires depression of these non-copper sulphide minerals using an alkaline pH above 9.5, though 10.5 to 11.5 is more common. Alkalinity is controlled by the addition of a pH modifier. Lime is normally employed as a pH modifier due to its relatively low cost; however, the costs associated with adding lime can be significant and the effectiveness of lime as a depressant could be drastically reduced when the process water supplied to the flotation circuit contains high level of dissolved salts. In some cases, a small amount of cyanide is used along with lime to depress non-copper sulphide minerals especially when its proportion to copper sulphide minerals in the ore is higher than three."

Jan 1, 2016

By D. R. Pyke, R. S. Middleton

"Three main types of base metal sulphide mineralization are present in the Timmins area:(1) -Massive and stringer-type copper-zinc deposits occurring mainly in pyroclastic rocks, as typified by the mines of Kam-Kotia, Jameland and Canadian Jamieson, or within or close to possible breccia pipes as shown by the Genex and Kidd Creek mines. With the exception of the Kidd Creek mine, all of these orebodies occur northwest of Timmins (Kamiskotia area) and appear to lie within or close to a major center of volcanic activity characterized by a thick accumulation of felsic pyroclastic rocks and subordinate epizonal intrusions. The margins of the rhyolitic pile are interfingered with mafic volcanics; overlying sedi-ments mark the termination of a vol-canic cycle. The copper-zinc deposits in the Kamiskotia area are confined to a particular stratigraphic unit. Ore-bearing solutions were probably derived from the intrusive complex of the volcanic pile.(2) -Porphyry copper deposit of the Mcintyre mine. The deposit occurs in a quarz porphyry intrusion related to the volcanism in the area (Hurst, 1936). Mineralization was probably introduced at the time of intrusion, and subsequently redistributed within the porphyry during deformation. (3) -Massive and disseminated nickel mineralization, associated with serpentinized alpine-type ultramafic intrusions, as shown by the Alexo, McWatters, Hart, Inco and Texmont deposits. The nickel mineralization occurs at or near contacts of the serpentinites with felsic or mafic volcanics, or sulphide-bearing iron formations. The nickel deposits south of Timmins are confined to a particular stratigraphic unit along the margins of domical-shaped structures which appear to outline former volcanic centers. Sulphurization as pro-posed by Naldrett (1966) appears to be a workable hypothesis for the formation of some of the deposits."

Jan 1, 1971

By G. H. Agnew

When water floods are initiated after gas-oil ratios have increased, the transition period from the start of injection until" the gas-oil ratios are returned to the solution gas-oil ratio may be important for either economic or technical reasons. The transition period is longest, and consequently most critical in water floods where injection is equal to withdrawals. This paper describes a theoretical basis for predicting the behavior of such a system and outlines a procedure for making the necessary calculations. The calculation procedure is illustrated for two actual cases: a line drive water flood and a five spot water flood. In each case there is a reasonable similarity between the actual and calculated performance.

Jan 1, 1960

By J. B. Hadaway

The operation at Phu Kham commenced design and construction in early 2006 and was commissioned in May 2008. This paper will examine and discuss the project from the inception of flow sheet development and equipment selection, equipment design and manufacture, construction, commissioning and ramp up to full production. The paper will touch on the strategies employed to achieve a short schedule and the efficient use of capital, but with the main emphasis on the grinding circuit. Various challenges during the early years of operation will be discussed including the effect of ore characteristics, including competency, on the performance of the grinding circuit. Actions to overcome these challenges and to enhance performance will also be discussed. Finally, current and future plans to improve the performance of the grinding circuit and the overall plant will be summarised.

Jan 1, 2012

By P. Karimi, G. Mollataheri, A. Amini, H. Abdollahi, A. Mirzaeian

"Chah-Palang tungsten deposit is one of the two tungsten indexes in Iran. Based on ore characterization techniques (including optical mineralogy and XRD analysis), quartz, chlorite, atacamite, azurite, malachite, ferberite, illite, goethite and calcite were distinguished as major minerals. The representative sample was analyzed qualitatively by using X-ray fluorescence and chemical assay. Results showed that grade of tungsten oxide and copper were 1.76 and 7%, respectively. Also precious metals such as gold with grade of 1 ppm was reported in the sample. By using the mineralogical studies on the prepared sample, the liberation degree of tungsten minerals in –0.6 mm size fraction was obtained 80%. Several tabling tests were carried out on the original sample which at the optimum conditions and as a result, the grade and recovery of tungsten in concentrate reached to proximately 23 and 59%, respectively. To increase the grade of tungsten in the final concentrate, acidic leaching were performed on the tabling concentrate and its appropriate results indicated that the grade of tungsten increased to 27%. Also more than 90% of copper was extracted as a byproduct in the fallowed process.INTRODUCTIONTungsten, a unique hard, heavy heat-resistant metal, is distributed erratically in economic concentrations throughout most continents, occurring mostly as small irregular deposits that are not readily adaptable to large-scale, low-cost mining methods. The diverse physical characteristics and mineral composition of tungsten ores also present problems in beneficiation, requiring complex hydro- and pyrometallurgical treatment to yield high-purity concentrates suitable for the production of ferro alloys, carbides and super alloys in the steel industry (Hausen, 1989; Kholmogorov & Kononova, 2005). Tungsten is most frequently used as tungsten monocarbide, which has hardness close to diamond, in cemented carbides. The most well-known use of tungsten is in lighting filaments, and other important applications include improving steel properties and use in tungsten alloys, electronics, and chemical products (Hausen, 1989; Kholmogorov & Kononova, 2005)."

Jan 1, 2016