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By A. Taylor, E. Thorn Corthay, R. Storey

In response to requests from its stakeholders, the International Standards Organisation is engaged in development of an international standard for Energy Management Systems (EnMS) which will become "ISO 50001". This new standard will build on the successes of both the EN16001 EnMS standard that has been used by dozens of European companies, as well as the ANSI/MSE 2000:2008 EnMS standard that is currently being used in several pilot projects in the USA and Ontario. This paper provides an overview of the key points of the EnMS standards, and describes how they can be used to drive sustainable energy reductions in the metallurgy industry.

Jan 1, 2010

By W. G. Worcester

IN the presentation of this paper to the Institute, three objects are in the mind of the writer: first, to set forth the close relation which, of necessity, exists between ceramics and the industrial minerals; second, to clarify the apparently hazy understanding which many have of ceramics in general; and lastly, of equal or even more importance, to stimulate a greater interest in the industrial minerals, especially in those used and required by the ceramic industries. While Canada is now producing in large quantities a fairly wide variety of the ceramic industrial minerals, there are some which are not known to occur in the Dominion. Hence it is to be desired that our geologists, prospectors, and others, while on field work, should be on the look out for commercial deposits of such minerals as diaspore, bauxite, ucts of a value in excess of $600,000,000, a figure which places ceramics as kyanite, massive topaz, and sillimanite. A find of any of these in quantity would prove of very great importance and value to the country as a whole. At this point it seems desirable to introduce formally the word ceramic or the plural of it, ceramics. In doing so it may be stated that the origin of the word dates far back in history in that it was derived in part from the Greek word Keramos, 'a potter' or 'pottery', which in turn has been traced back to an older Sanskrit root meaning 'to burn' or 'burned stuff', having reference, no doubt, to burned pottery or other clay wares; and the word was so used until near the close of the last century, when the world's first schools of ceramic engineering were established in the United States. The use of the term ceramics was then expanded to cover a much larger field the entire field of the silicate industries and products. At one time it was suggested by a limited number of ceramists that the term 'ceramic engineering' be changed to 'silicate engineering'. This proposal, however, gained little support and was soon abandoned.

Jan 1, 1945

Uranium mining remains controversial in many parts of the world, especially in a post-Fukushima context, and often in areas with significant uranium resources. Although nuclear proponents point to the relatively low carbon intensity of nuclear power compared to fossil fuels, opponents argue that this will be eroded in the future as ore grades decline and energy and greenhouse gas emissions (GGEs) intensity increases as a result. Invariably both sides fail to make use of the increasingly available data reported by existing uranium mines through sustainability reporting ? allowing a comprehensive assessment of recent trends in the energy and GGEs intensity of uranium production, as well as combining this with reported mineral resources to allow more comprehensive modelling of future energy and GGEs intensity. In this study, detailed data is reported for numerous uranium mines around the world, including production, energy and GGEs intensity and reported mineral resources. An important aspect included ? arguably unique and never before published ? is the relationship between ore grade and recovery, which is crucial in future projections of uranium mining. Overall, the paper shows the importance of continuing to improve reporting by the uranium sector as well as the ability to analyse key trends and future projections in energy and GGEs intensity of uranium production.

Aug 1, 2013

Open pit production planning is a procedure consisting of multiple stages. Although all the planning stages rely on the geostatistical block models, long- to short-term plans each require their appropriate resolutions and levels of details. The main motives behind using different resolutions are the tractability of the models and the practicality of the generated schedules. The current approach in the mining industry is to use nested pits generated by Lerchs-Grossman as the basis for long-term planning and to use manually generated polygons, within those pushbacks, as the units of production control in mid- and short-term planning. However, the nested pits generated by Lerchs-Grossman algorithm and the polygons drawn by mining engineer do not provide control over the value and tonnage of ore and waste inside the planning units and therefore cannot lead to optimum solutions. In this paper, we first present a pushback determination approach which maximizes the profit of the mine with control over the tonnage of ore and waste within each pushback. We then propose a clustering approach with size and shape control that determines aggregates within those pushbacks; and finally, we introduce a mathematical programming model which uses the generated pushbacks and aggregates as the planning basis and generates production schedules that maximize the net present value of the operation and are practical from the operation?s point of view.

Aug 1, 2013

By Michael S. Moats, Prashant Bagri

"In recent years with increasing concerns about energy consumption in hydrometallurgical processing, there is an ongoing attempt to use Catalytic Titanium Anodes (CTAs) for copper electrowinning. For this work, anodes with IrO2 - Ta2O5 coatings were prepared in the laboratory with the same total coating loading but varying the number of layers by changing the speed of withdrawal in dip coating. A second set of CTAs were fabricated on niobium, Ti Grade 1, Ti Grade 7 and Ti Grade 36 metal substrates. All the anodes prepared in the laboratory were characterized using standard electrochemical techniques and subjected to accelerated life testing. It was found that the coating would not adhere to the niobium substrate, the grade of titanium had a minimal to no effect on the life of the anode, and it is observed that as the coating speed slows, there is an increase in the electrochemically active surface area of the coating which seems to directly contribute to an increase in the Tafel slope of the anodes. There was inconclusive evidence on the effect of coating speed on anode lifetime.INTRODUCTIONLarge scale hydrometallurgical extraction of copper has become widely practiced over the last 40+ years. The hydrometallurgical route entails leaching, solvent extraction and electrowinning. With the increasing desire to process refractory sulphides like enargite and chalcopyrite through the hydrometallurgical route, use of hydro-processing of copper is expected to remain high.In conventional electrowinning, copper is deposited on the cathode and an inert anode is used for oxygen evolution. Presently, the most common anode material is rolled lead-calcium-tin and the cathode is 316L stainless steel (Robinson et al., 2013). This lead alloy is fairly inexpensive and is robust, providing lifetimes typically of 4+ years. The main drawbacks of lead alloys are their relatively high oxygen evolution overpotential, the need for cobalt in the electrolyte to reduce their corrosion, the contamination of cathode product by lead, and the generation of harzardous by-products (Hiskey, 1999)."

Jan 1, 2016

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

The dynamic breakage process of rocks by the impact of a hydraulic hammer is more complex than one normally assumes. It is even more difficult when one has to conduct the breakage under water. In such cases one does not know exactly what the surface topography and composition are at the bottom of the sea or river and, hence, it is more difficult to select the best position of the hammer before starting the hammering. Typically, an industrial hammer has a diameter of about 250 mm, a length of about 1.25 to 1.75 m and a mass of several tons. The hammer frequency can be up to 50 impacts per minute. The general principles of rock hammering can be easily summarized, but this knowledge is not sufficient to adapt adequately the method for less common rock conditions (e.g. less brittle rock, presence of vertical and subvertical fractures, etc.). That is the reason why we initiated a research project, whereby a scale model has been developed to conduct experiments in the laboratory and whereby discrete element simulations are being conducted. Both aim at a better understanding of the basic mechanisms of rock hammering. The scaled experimental model allows varying the impact energy and the static weight independently. Within the experiment, the hammer is in contact with the rock specimen under a certain confining pressure and with a certain contact pressure due to the static weight. A weight falls on the hammer, creating the dynamic action or impact; the height over which the weight falls can be varied. The penetration is recorded after each impact. After a certain penetration the test is stopped and the internal crack patterns are described. Some simulations have been conducted, allowing the modeling of individual fracture initiation and growth during the penetration of the hammer by either a constant displacement rate (using the UDEC-code) or by introducing the dynamic process (using the PFC-code). Some of the observed features in the laboratory experiments can be visualized in the simulations. However, further research is needed to allow the simulations being an adequate tool to well understand the dynamic process in laboratory experiments, as well as the in-situ behavior.

Aug 1, 2013

By Helge B. Wurst, Michael P. Cipold, Jan F. Bachmann, Claus C. Bachmann

"In washability, the objective is to establish the set of maximum possible separation performance criteria for a given mineral feed. The method of choice for this has been the conventional sink-float analysis. Time, cost and safety aspects of the sink-float method have prompted the search for a new approach for establishing separation performance criteria, especially as performance levels of separator plants can be maximized if reliable information based on an analysis of washability in conjunction with particle size distribution, elemental constituency becomes readily available. The new method to establish washability and associated performance information utilizes at least two measurement technologies concurrently: single energy x-ray transmission and image processing. For porous or very inhomogeneous materials the results can be refined further by using dual energy x-ray transmission and image processing. The value of the collected data increases considerably if the washability data were additionally available in time to be considered in the control of the process plant. The incorporation of an automated washability monitor gives near real-time data that would impinge positively on the profitability of the plant operation. The method was extensively tested with a range of sample with different densities, varying from 1 g/cm³ (coal) to 5 g/cm³ (iron ore).INTRODUCTIONWashability of minerals like coal and iron ore is expressed by a curve or graph showing the results of a series of float-and-sink tests. Several of these curves are drawn to illustrate different conditions or variables, usually on the same axes, thus presenting the information on one sheet of paper. Washability curves are essential not only for the design but also for the operation of preparation plants.In determining the washability analysis, particle density is the underlying feature of all washability curves. Conventionally, the particles are separated into density fractions by immersing them in fluids of a predetermined density followed by skimming of those particles that stay afloat. The particles remaining afloat thus have a density lower than that of the fluid they were subjected to. The particles that remained at the bottom of the fluid container thus had a higher density higher than that of the fluid. By progressively increasing, for example, the density of the fluid and immersing the remaining particles so as to be able to skim the next density fraction, the particles would be fractionated into density groups. The liquids used range from aqueous solutions to organic liquids to suspensions. Unfortunately the liquids used for this separation process are often toxic and expensive. It stands to reason that a new method of determining washability is sought."

Jan 1, 2016

By R. S. Boorman, L. J. Surges

"Ore reserves at Brunswick Mining and Smelting totalled 101(106) tonnes grading 97 grams tonne-1 silver at the end of 1981. Silver is recovered as a byproduct in the copper, lead and bulk concentrates and is lost to the zinc concentrate and plant tailings. Recovery of silver for the year 1981 was 58,5%. The loss of potential revenue is in excess of Cdn $50(106) year-1 at current silver prices and milling rates.Silver is known to occur in solid solution in galena and as tetrshedrite. Evidence indicating the identity and significance of a third silverbearing mineral assemblage is reviewed and the distribution of silver losses is detailed. Characteristics of each the carrier which may be responsible for observed distribution, including size, surface quality, liberation and composition are considered, and the third carrier is shown to have possible implications for improved silver recovery by other Canadian producers as well as by Brunswick Mining.Silver tetrahedrite tailings distributed tailings and losses occur as coarse, free and as very fine unliberated galena in losses of the third carrier are between the zinc concentrate and are concentrated in the finest size fractions. Process alternatives for enhanced silver recovery by physical and chemical means are reviewed."

Jan 1, 1983

By A. McLean, X. Men

"With high quality sulphide ores diminishing, nickel production from low-grade oxide ores becomes increasingly important and a major concern is the high sulphur level in the resultant ferro-alloy. So, desulphurization of the ferronickel becomes an important consideration. Red mud is a waste product of alumina industry and causes adverse effects on environment. In the present study, experiments were conducted to determine feasibility of using red mud as a major ingredient of refining fluxes for ferronickel desulphurization. In view of their influence on slag-metal separation, contact angle measurements between ferronickel alloy and molten slag made from red mud were also determined. INTRODUCTIONNickel is a very important metal that finds a variety of applications including consumer products, building, automotive and electronics. There are two kinds of ores containing nickel, namely oxide and sulphide ores. Anthony and Flett [1] reported that about 55% of the world’s nickel production originates from sulphide ores while the balance of new nickel is derived from oxide ores. However, oxide ores count for about 70% of the worldwide reserves. Apparently, oxide ores will play a significant role in the production of nickel in the future. Most of nickel produced using oxide ores is from pyrometallurgical processes namely ferronickel smelting or matte smelting. So, we can draw such a conclusion that using nickel oxide ores to produce ferronickel will become more and more important .Before used to make stainless steel or other materials, the ferronickel need pretreatment to remove impurities especially sulphur and phosphorus that will cause negative influence on the properties of steel product. Red mud is a by-product during alumina production. Usually, about 1 to 1.5 tons of red mud will be produced when we get 1 ton of alumina. About 90 million tones of red mud are produced every year in the world [2].Red mud is deemed as a toxic industrial waste which needs treatment before discharge because of alkalinity and chemical and mineralogical properties. Until now, the main means to deal with red mud are to store it in impoundments or dump it in the sea depending on local environment. Nowadays, how to recycle red mud has become a pretty hot topic around the world. The last 40 years have witnessed a lot of patent applications concerning the ways of red mud utilization. However, a little amount of red mud is consumed until now due to the limitations of recycling red mud."

Jan 1, 2012

By J. ?H. Chen

Remote sensing technologies have been applied to numerous fields and already benefited those in improving efficiency and recognition accuracy. Change of streamflow can be devastating to residents living along riversides. Still it is difficult to detect such deathly change in large area scale by traditional field surveys. The research aims at provision of detecting streamflow change using a mathematic method based on remote sensing technologies. The scope is on remote sensing stream images taken during the invasion by Typhoon Morakot, bringing one of the major catastrophes to Taiwan. An algorithm was adopted to deal with streamflow recognition on RGB images. The algorithm is capable of yielding change measured by meters and illustrates how main streams shift. An practical example for the Baolai area surrounded by Laonong stream shows that the streamflow moved 88 meters (36 pixels) toward the downtown area during the invasion by Typhoon Morakot. In addition, the results highlight all dangerous zones (scouring zones) for residents to prevent further potential damage.

Aug 1, 2013

By Ahmad Ghahremaninezhad, Rebecca Radzinski

Arsenic is a highly toxic compound that is naturally found in the environment and is released through the processing of sulphide minerals. Arsenate (As5+) is less toxic than arsenite (As3+) and is soluble in water but can form insoluble precipitates when metal ions are present. The arsenic removal processes used in industry assume that arsenic is in its pentavalent state. Hydrogen peroxide can be employed to oxidize arsenite; however, it is expensive. It has been shown that activated carbon can be used to catalyze the oxidation of arsenite with oxygen as the only consumed reagent at ambient conditions with an efficiency of 99% in less than 24 hours. The mechanism which oxidizes arsenite is not yet understood; however, this study shows that a strong oxidizing agent is formed in-situ. The species and amount of oxidant formed were determined via iodimetric titration and electrochemical methods. The production of oxidant was optimized by comparing the amount of oxidant formed in-situ to the relative amount of arsenite oxidized.

Jan 1, 2015

By J. A. Ressinger

"The purpose of this paper is to discuss some of the differences between various methods of excavating and loading as they relate to mining operations. The intent is not to provide ""pat"" answers, but instead to raise some questions and set forth some reasonable guidelines.Specifically, the paper deals with the differences and relative merits of power shovels versus rubber-tired front-end loaders - or, carrying this further, comparing what could be called ""stationary"" loading or excavating devices to ""mobile"" types."

Jan 1, 1972

By J. Reinhardt, R. Uken, S. S. Chinnasamy

Au mineralization in the Kilpwal Gold Mine is confined to laminated quartz-carbonate lodes and associated alteration along the Klipwal Shear Zone (KSZ) in the upper Mozaan Group of the Mesoarchaean Pongola Supergroup. The brittle-ductile shear zone is characterized by inner and proximal hydrothermal alteration domains that are comprised of chlorite, epidote, sericite, pyrite, arsenopyrite and gold. Possible sources of gold are: (i) paleo-placer U-Au rich conglomerates from the lower Mozaan Group; (ii) the underlying mafic volcanics of the Nsuze Group; (iii) greenstone belts in the basement to the Pongola basin. Post-Pongola granites probably provided the heat to mobilize auriferous fluids into the KSZ.

Jan 1, 2011

By Vincent Jourdain

Located in the James Bay Territory of Quebec (figure 1), the Clearwater property is jointly owned by SOQUEM Inc. and Eastmain Resources Inc. Exploration on the property since the early 70's has resulted in the discovery of several gold showings. Exploration work by the joint venture since 1995 has led to the definition of the Eau Claire Zone containing an indicated resource of 540 000 tonnes grading 11.1 g/t Au (8.7 g/t Au cut at 34.28 g/t Au). Hosted by the archean Eastmain Greenstone Belt, the property geology is dominated by mafic volcanics containing thin horizons of felsic volcanics and/or sedimentary rocks (figure 2). The sequence is metamorphosed to the amphibolite facies and contains two small toalitic intrusions. Regionally, the structural trend is oriented E-W but in the area of the Eau Claire Zone a second trend oriented NE-SW is also present. The first exploration work on the property was conducted by SEREM and SDBJ from 1973 to 1976. It consisted of an airborne electromagnetic survey and a ground follow-up program on several grids. This program, comprising geological mapping, geophysics and drilling, led to the discovery of the Natel showing where a drill intersection returned 8.89 g/t Au over 2.65 m. From 1978 to 1985 the area was withdrawn from staking because of the hydroelectric projects of the James Bay. In 1985, Westmin Resources Limited and Eastmain Resources began an exploration program based on a helicopterborne electromagnetic survey. Once again, a ground follow-up program was conducted on several grids. This program included a soil geochemical survey that identified a strong (up to 10 g/t) gold anomaly. Drilling of the anomaly led to the discovery of the Eau Claire Zone where resources were estimated at 270 000 tonnes grading 6.1 g/t Au at the end of 1990. In 1995, SOQUEM Inc. took an option to gain a 50% interest on the property and obtained its interest in 1998. Since 1995, two principal mineralization zones were identified on the property. The "Rosemary Zone" consists of veinlets and disseminations of pyrite and chalcopyrite within a magnetite-rich amphibolite. The mineralized zone was identified by stripping within an area of 1000 by 500 metres. Drilling indicates copper grades up to 0.32 % Cu over 49.2 m. with locally grades of 0.75 % Cu over 5.9 m. The mineralised zone is associated with QFP dykes and corresponds to a strong magnetic anomaly and a strong copper and molybdenum soil anomaly. The "Eau Claire Zone" consists principally of a set of gold bearing quartz-tourmaline veins oriented E-W and dipping at 45-50??to the south (figure 3). More than ten different veins are recognised in the zone and up to eight veins were observed in a single trench (figure 4). The host rock between the veins shows a degree of deformation similar to the regional volcanosedimentary rocks. Each vein is hosted by a unit of actinolite-tourmaline-biotite schist up to one meter thick. The veins and their hosting schist clearly cross-cut the schistosity of the hosting lithologies and the contacts between amphibolites and felsic to intermediate rocks. Usually, the veins are less than a meter thick and are composed of quartz, tourmaline and calcite. The proportion of quartz and tourmaline varies from 0 to 80% within a single vein. The veins commonly show massive, banded or brecciated texture. Sulphides, mainly pyrite, pyrrhotite and chalcopyrite, generally form less than 5% of the vein material.

May 1, 2001

By M. Al Mukhtar, D. Hoxha, X. Brunetaud, D. P. Do, C. Auvray, L. Michel

"Mechanical behavior of rock joints is often the key factor governing the response of complex structures constructed in fractured rock masses such as underground openings or of objects assembling various stones blocks such as historical building walls or damaged marble statues. This paper aims at developing a theoretical model to describe the behavior of fresh joints based on the description of their morphology. The main idea of the model is to establish a link between the effective contact surface of joints and the frictional coefficient. Beginning from a chosen level of joint surface description where a joint is considered as “smooth”, the model describes the added friction with respect to the increase of the contact surface of the joints and the distribution of stress in these contacts. The model developed initially for asperities with regular geometry is firstly compared with existing models and then applied on fresh artificial joints. For that, healthy artificial joints have been characterised using in one hand classical CNL shearing tests and in another hand the morphology of joints. The joints surfaces are digitized before testing using a high resolution laser scanner (Konica Minelota Vivid 910) allowing to obtain a precision up to 10µm. From these scanned surfaces the morphology of joints is characterised on the profiles running in the direction of shearing and a mean value of friction is calculated using the developed model. This calculated value is then compared with that obtained from CNL shearing test and a good approximation is notedINTRODUCTIONThe role of the mechanical behavior of rock joints on the overall response of fractured rock masses is well established in many fields of engineering activity going from the stability of underground constructions (Souley M, Hoxha D, Homand F 1999), rock slope stability (Einstein H.H. Veneziano D., Baecher GB., O’Reilly K.J, 1983, Jaeger 1971), various rehabilitation of masonry construction, damaged stone artworks restoration (Michel L., Do D.P, Coignard B, Hoxha, 2014) and so on. In the same time the characterisation of the behavior of joints and their modeling is nowadays a dynamic field of research or/and investigations and many alternative approaches have been proposed (Barton, N.R. and Choubey, V. 1977, Tatone, S.A. Bryan, Grasselli Giovanni 2010, William C E. 2007). While empirical relations of shear strength with various parameters of the joint morphology are the most used in practice because of their simplicity (Barton. and Choubey, 1977, Barton 1973, Bandis S., Lumsden A. C. and Barton N. R. 1983) many other models of joint strength are developed based on mechanistic considerations (Haberfield CM, Johnston IW. 1994), multiscale approaches (Yang Z.Y., Di C.C., Yen K.C. 2001, Fardin N., O. Stephansson, Lanru Jing 2001) or micromechanical ones (A. Serrano, C. Olalla, R.A. Galindo 2014) to mention just a few of research trends on rock joints modeling."

Jan 1, 2015

By Ernest A. Hodgson

A SERIOUS hazard which must be faced in some mines, though quite absent in others, is that of rockbursts. Bursts cannot be wholly avoided in such mines, but the hazard would largely disappear if they could be predicted. The problem of prediction resolves itself into that of measuring pressure in the mine and determining when that pressure nears a critical value. The geophysical approach to the problem lies in discovering some physical property of the rock, which varies with pressure, which can be measured for rock in place, and for which the indication of critical conditions is sufficiently definite and open scale. A physical property, suggested first in connection with earthquake pre-diction, is that of sub-audible snapping. It was argued that, as the pressure grows, the rock probably yields microscopically and that minute snapping occurs which is so faint as to be inaudible to the unaided ear. Experience has proved this to be the case. Following other earlier work begun early in 1939, experiments with this method were initiated at Lake Shore Mines in 1941, and equipment was slowly being developed in practice when, fortunately, it was found possible to by-pass this tedious development programme. Experiments with sub-audible snapping in mine rocks had been carried out by Dr. L. A. Obert of the U.S. Bureau of Mines and his associates over a period of about four years. An amplifier and a recorder were developed, each reasonably satisfactory in practice. Lake Shore Mines offers a tempting field for rockburst research. Dr. Obert was invited to test his equipment in this and other mines in Ontario and did so. As a result, he and the administrative personnel of the Bureau became interested in the Lake Shore experiments co the extent of most generously arranging for the manufacture of sets of their own designed equipment for use in this programme. The first three sets of recorders were ordered at once and were delivered in May, 1942. A second group of three sets, incorporating various improvements indicated by experience both in the United States and in Canada, reached Kirkland Lake in April, 1943. The pick-up devices, known as geophones, were made in the electronics laboratory at Lake Shore by Mr. Zack Gibbs, who has had charge of all the instrument development in this re-search.

Jan 1, 1943

By Juan Asalgado

The JORC and NI43-101 codes impose that mineralized material has a reasonable prospect of economical extraction to be classified as Mineral Resource. For deposits close to surface and amenable to open pit mining, it is easy to show reasonable prospect of economic extraction running a Lerch-Grossman optimization. The Lerch-Grossman pit provides a transparent and repeatable way of separating the Mineral Resource (within the pit) from the remainder of the mineral inventory (outside the pit). Deposits amenable to underground mining are more challenging because of the variety of the underground methods. AMEC developed a stand-alone software package that outlines the material which has reasonable prospect of economic extraction for open stoping, block caving, sublevel caving and room and pillar. The software takes a block model file in ASCII and exports a 3D surface outlining the part of the mineralization that has a reasonable prospect of economic extraction, and which the Qualified Person can smooth out manually if required.

Oct 1, 2009

By H. Warren Newcomen, Dennis C. Martin

"This paper describes the investigation of a large, progressive slope failure on the southeast wall of the east pit at Highmont Mine, British Columbia Geotechnical investigation s consisted of geological and structural mapping, assessment of blasthole drilling records, review of rock core information, slope movement monitoring and back analysis of various possible failure modes. Climate records and mining history were also assessed to determine their relationship to slope movement .Analysis of movement monitoring records and geotechnical information indicates that the failure is deep seated. The upper portion of the failure surf ace occurs along clay filled discontinuities. The lower portion of the failure surf ace appears to occur through the highly altered rock mass. High groundwater pressures and mining at the toe of the slope are documented to have had a major influence on stability at various times during the failure. Stability analyses results are presented and possible remedial measures are discussed.IntroductionHighmont Mine is located near Logan Lake in the Highland Valley approximately 50 km southwest of Karnloops, British Columbia (Fig. I). Mining of the porphyry copper and molydenum ore bodies began in 1980. In May, 1983, when mining in the east pit had progressed to a depth of about 60 m (200 feet) , a failure (designated the Southeast Failure) began to develop in the southeast corner of the east pit. Subsequent mining to a depth of 110m (360 feet) was accompanied by frequent and substantial slope movements involving between 500000 and I 000 000 m3 of rock . The slope was monitored extensively to assess short-term movement trends for operational safety. Geological mapping, core logging and rock mechanics testing were used in conjunction with the long-term monitoring information to determine the failure mechanism, conduct stability analyses, assess the effects of instability on pit design and enable design and installation of remedial measures."

Jan 1, 1988

By E. A. Davies, Trevor T. Jones

"Aspects of materials, design and operation of suspension equipment is dealt with, hazard, fatigue and special metallurgical properties of certain steels to resist are described, as is the effect of temperature in service modifying the properties of some steels to resist stress concentration and propagation of cracks.The influence of steady impact and fatigue loading and its results are described. Control of manufacture including nondestructive testing is outlined and acceptance parameters and strength calculations are given. Quality requirements and control in manufacture are outlined. A short description of the overwind detaching hook, together with illustrations of the operation of detachment are presented.MaterialsWinding engine ratings of 8000 h .p. and large capacity shafts 2000 m in depth (4000 m depths have already been reached and it may be necessary to go to 6000 m) and up to ten conveyances are not uncommon today. Loads of 100 or even 200 tons hoisted at low speeds are possible within the near future. Some of these appliances are designed to protect lives and installations in hazardous conditions when, due to human or mechanical fault, a malfunction occurs in the system. In addition, such equipment includes suspension gear of various kinds designed to anchor and apply high mechanical tensions to numerous steel ropes installed in shafts necessary either for the safe passage of conveyances or for balancing purposes when heavy loads are in motion.No unique metallurgical problems are presented in underground mining operations, but they have two special characteristics that influence the metallurgical aspects of the de sign of suspension gear and other equipment concerned in the transport of men and materials. (1) Any uncontrolled release of energy caused by the unexpected failure of a component is more likely to injure personnel and cause costly damage to installations in the narrow confines of an underground mine shaft. (2) Some mechanical equipment in mines, tends to be overloaded in service and suffer plastic distortion."

Jan 1, 1987