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By M. Grenon

"The presence, size, orientation, nature, and persistence of geological discontinuities dictate the behaviour of a rock mass. Block size, which is defined by discontinuity spacing, by the number of joint sets, and by the persistence of the discontinuities delineating potential blocks is an important indicator of the degree of fracturing of a rock mass. Consequently, block size is represented either explicitly or implicitly in all rock mass classification systems employed for analysis and design of surface and underground mining structures. Insitu block size distributions may provide a better means to describe the structural complexity of a rock mass. These are the distributions that would be derived if the in-situ rock mass was separated into its constitutive blocks, delineated by existing discontinuities, and each block measured. This paper presents the results of a field campaign at Louvicourt Mine aiming to characterize the rock mass using different methods for determining block size and block size distributions. IntroductionGeological structural data are used to provide input data for analysis and design methods for surface and underground structures. As the collection of structural data involves considerable investment of time and effort, it is sometimes overlooked, thus denying an important source of information for mine design. What is somewhat surprising, however, is that when structural data are available, they are not used to their full potential. Recent work has shown that data on block size have potential applications in different areas of rock engineering:• Blasting — Hudson (1993) has described the excavation process as the change of a preexisting natural block size distribution to the debris fragment size distribution (Fig. 1). Lizotte and Scoble (1994) have reviewed previous efforts on integrating site specific geological conditions into blast design. Grenon et al. (1997) provide a case study where in-situ block size distributions are compared to photogrammetric studies of blasted rock.• Rock mass classifications — Block size is used in the majority of rock mass classification systems either explicitly, as in the RMi classification system Palmstrøm (1995), or implicitly, such as in the NGI system, Barton et al. (1974)."

Jan 1, 1998

By N. E. Nelson

"The Hidden Creek mine is about l~ miles north of the north end of Granby bay; a nearly landlocked body of water on the west side of Observatory inlet; 90 miles north of Prince Rupert; British Columbia.The main haulage way of the mine at 385 feet above sea-level has been driven north into the somewhat precipitous end of a north-south ridge that rises from the tide flats between the east and west forks of Hidden creek. The outcrops of the principal orebodies, two prominent bluffs of stained rocks and sulphides, were higher on the face of the ridge and extended from about 530 to 850 feet elevation. North from the bluff tops, the ridge comb rose gradually to about 1,200 feet elevation. The name of the discoverer and the date of discovery of the Hidden Creek orebodies are probably unknown, but the discoverer is believed to have been an Indian from one of the reservations along Observatory inlet. The deposit was brought to the attention of John Flewin, Government Agent at Post Simpson, near the beginning of the present century. Mr. M. K. Rodgers, developer of the Nickel Plate mine at Hedley, did the first organized work on the deposits. Next the Hidden Creek Copper Company prospected the property. Rodgers acquired the prospect a second time, did more work, and finally in 1910 optioned the property to the Granby Consolidated Mining, Smelting and Power Company, Limited, at that time operating at Phoenix and Grand Forks in the Boundary district of British Columbia. The optionees stepped up the development work and brought the property to production in 1914. The ores were direct smelted until 1924. In that year a mill was built. From 1930 until the end of the productive life of the properties in 1935, all of the ore was milled and the concentrate smelted. From March 17, 1914, until July 31, 1935, the production from the Hidden Creek mine was, in round numbers, 18,000,000 tons of 1.70 per cent copper ore and 6,000,000 tons of low grade dilution rock. The Hidden Creek mine ""died with its boots on"". During 1934 the average monthly production was 146,377 tons of 1.06 per cent copper ore. For 7 months of 1935 the average was 161,750 tons of 1.03 per cent ore, and for the final month, July 1935, the production was 156,950 tons."

Jan 1, 1954

By G. W. Poling

Sedimentation behaviour of siliceous mill tailings derived from a magnetite-chalcopyrite ore in fresh water, fresh water - sea water mixtures and full-salinity sea waters are compared. Results of batch settling tests are presented in the form of settling curves and solids flux curves. The addition of a few per cent of sea water markedly enhanced the zone sedimentation rate due to particle agglomeration caused by a reduction in zeta potential of the suspended solids. The presence of a small amount of residual, previously magnetized magnetite in the tailings also enhanced agglomeration and sedimentation. The significance of these results to submarine disposal of mill tailings is discussed.

Jan 1, 1973

By G. P. Contractor

Many factors affect the forge ability of steels. One of the major factors is chemical composition.' This article discusses the individual effects of alloying elements and the effect of the resultant modification of microstructure onforgeability. INTRODUCTION T HE use of alloy steels is expanding considerably and the fabrication procedures for such alloys are becoming more complex. An attempt is made in this article to describe the effect of alloying elements on the hot-workability of steels. Most of the data reported here are taken from the studies of Ihrig, Clark and others (Refs. 1-4). Chemical composition is not the only controlling factor. Grain size and surface condition of the material, forging temperature, and speed of deformation are also important. Certain conclusions can be drawn regarding the effect of various alloying elements on the hot-work-ability of forging stock. The results of hot-twist tests are considered useful in this connection as the number of twists to failure has been taken as the level of forgeability at a particular temperature. The peak in the "Number of Twists -Tem--

Jan 1, 1962

By Grant Small, Jessica Kinal, Christopher J. Greet

"The conversion from an electrochemically reactive grinding media (forged steel) to a more electrochemically inert alloy (high chrome white iron) not only reduces the wear rate of the grinding media, but also has an impact on the grinding chemistry. Typically the grinding chemistry becomes more oxidising, with less reducing Eh values and more dissolved oxygen in the pulp. There is also a decrease in the EDTA extractable iron, which is an indication of the change in the media corrosion. These changes are indicative of alterations in the surface chemistry of the minerals that the operator is trying to separate. For porphyry copper ores the changes in the pulp and surface chemistry not only affect the copper sulphide minerals, but also impact the iron sulphides (i.e. pyrite and pyrrhotite). Generally, with more oxidising pulp chemical conditions during grinding there is an increase in the oxidation of the iron sulphides which renders their surfaces hydrophilic, thereby depressing flotation. This leads to improved selectivity for copper sulphides against iron sulphides.INTRODUCTIONPorphyry copper deposits are the dominant source of copper that is mined today to satisfy global demand. These style of deposits typically contain one percent copper mostly as chalcopyrite, but may contain other copper bearing minerals (for example, bornite, chalcocite, azurite, malachite), small quantities of pyrite and quartz. Porphyry copper deposits also contain economically significant quantities of gold, silver and molybdenum. Interestingly, the majority of the world’s porphyry copper deposits are concentrated along tectonic plate boundaries (Figure 1)."

Jan 1, 2016

By Bernhard Schwab

A popular rule in the mining industry is that a property should only be developed if average unit production cost is less than a given proportion of the estimated long-run price of the mineral. This paper provides a comparative analysis of the average cost approach (ACA) with the use of net present value (NPV) as an investment criterion. It is concluded that the ACA is an easily understood and easily applied rule of thumb which may serve as a rough first screening device, for example in the early stages of deposit exploration. Its operational convenience is at the expense of accuracy and validity, and the NPV provides a sounder method of making decisions, especially in the case of marginal deposits.

Jan 1, 1978

By L. A. Jameson, J. Awmack, P. J. Lind

"Peñasquito is a polymetallic deposit containing gold, silver, lead, and zinc. The operation is currently the largest producer of gold in Mexico. Over the next few years, the process flowsheet will be expanded beyond the flotation of lead and zinc to include flotation of pyrite from zinc tails and subsequent leaching of the pyrite concentrate. This paper outlines mineralogical leach characterization that has been carried out to improve the understanding of the complex hosting of gold and silver minerals in the ore. Organic carbon that is present in the ore can have an impact on flotation and leaching. Mineralogical techniques used to characterize this deleterious component of the ore are introduced.INTRODUCTION Goldcorp’s Peñasquito operation is located in the Mexican state of Zacatecas, approximately 200 km from the city of Zacatecas as shown in Figure 1. Peñasquito has been in operation since 2009 and is currently Mexico’s largest gold mine. Mining is carried out by open-pit methods, with oxide ore proceeding to a heap leach facility and sulfide ore treated in the sulfide processing plant.The processing capacity of the sulfide plant is 130,000 tonnes of ore per day and in 2016 production amounted to 450,000 ounces of gold, 17.6 million ounces of silver, 109 million lb of contained lead, and 263 million lb of contained zinc in lead and zinc concentrates. GEOLOGY The Peñasquito deposit is hosted in and adjacent to two breccia pipes; Peñasco and Breccia Azul. The two breccia pipes are branches of a larger intrusive-related complex, which is hosted in the sedimentary Caracol formation as illustrated in Figure 2. The regional geology is dominated by Mesozoic sedimentary rocks which comprise a thick series of marine sediments deposited during the Jurassic and Cretaceous periods. A 2 km thick sequence of carbonaceous and calcareous siltstones and interbedded sandstones is underlain by a 1.5 to 2 km thick limestone sequence (Goldcorp Inc., 2015)."

Jan 1, 2017

By Baisheng Nie, Longlong Yang, Tao Yang, Wenjie Jia

"Gas adsorption in coal is an exothermic and physical process. Temperature might change during the dynamical process. In order to get the temperature variation of gas adsorption process, the experiment system which can test the temperature variation and analyze the thermal effect was established. Gas adsorption experiments under different conditions were done by using the test system. The results show that temperature increases during the adsorption process. It is an exothermic reaction process. Also, the temperature variation and the variation gradient increase with the increasing of equilibrium pressure. The temperature variation value is smaller if the experiment temperature is higher. The paper will provide basic experimental data for explaining gas adsorption mechanism better.INTRODUCTIONChina is the largest coal producer in the world while it also has the most serious coal mine disasters. According to the statistics, there are nearly a thousand coal mines in China including more than 110 the key state-owned mines risking to happen coal and gas outburst. Hundreds of coal and gas outburst occur each year which often causes serious casualties and economic losses (State Administration of Work Safety, 2007). With the continuing exploitation of the coal resources, the depth of the Chinese coal mines increases about 100 meters every year which causes the situation of gas accident becoming more and more serious (Xie et al., 2006).At present, the real mechanism of gas adsorption, desorption and the diffusion process in coal and the influence factor of it are not so clear. And because of the limit of prediction method and the technological level caused gas accident prevention theory and technology not so valid."

Jan 1, 2015

By J. Fujioka, Y. F. Gu, C. Cui, D. Ping, A. Sato, H. Harada

"A new kind of cast & wrought (C&W) Ni-Co base superalloys named as ""TMW alloys"" are developed recently for compressor or turbine disks of gas turbine engines in High Temperature Materials 21 Project at National Institute for Materials Science (NIMS) in Japan. These Ni-Co base superalloys combine the characters of two kinds of y- y' two-phase alloys (Ni-base and Co-18at%Ti alloys) and have higher tensile strength and creep resistance than C&W UNDIMET 720Li superalloy."

Jan 1, 2006

By S. Bhattacharjee

"Rock failure process is generally recorded or measured using conventional sensors like strain gauges, seismic, micro-seismic, acoustic, electromagnetic and other techniques. The above sensors are either to be pasted on the surface of the rock sample or placed very near to it to capture the response of the sample with the increment of load. This requires precise tools to cut or polish the locations where sensors are to be placed. Moreover, deformation or acoustic or micro-seismic activities are recorded only at the locations where sensors are pasted.Recent development in Digital Image Correlation (DIC) technique has shown promise to measure deformation / strain at every location of the surface of a sample. In DIC, two images (reference and deformed) are taken within a small time interval of the same object are compared to estimate the change in reflectance as a function of displacement, velocity or rate of strain at each pixel while the object is undergoing through a loading process. In this study, extended digital image correlation (X-DIC) technique has been implemented using 4-noded quadrilateral elements with a discontinuity surface in the deformed image. The continuous and enriched displacements are estimated at each node.The X-DIC method is verified using numerically generated images. The study has been further extended to evaluate the performance of X-DIC method on deformation analysis of experimental samples under uni-axial loading condition. The results of this study show that X-DIC method is an effective tool for determination of displacements of the entire surface of a rock sample having a discrete crack or discontinuity in a non-contact manner. This method demonstrates the applicability to investigate rock failure mechanism for the entire sample in a laboratory set up as well as monitoring of pillar failure mechanism in underground mines."

Jan 1, 2015

By J. Oyunaa, P. Munkhbaatar, A. Sarnai

"The molybdenum mining process used at Mongolia Erdenet Company is a selective flotation of molybdenite from the copper porphyry ores in which the extraction of molybdenum comes as a byproduct of the ongoing copper production.The mineralogical composition of molybdenum concentrate is 99.4% molybdenite (MoS2), 0.09% molybdenum oxide (MoO3), 0.52% powellite (CaMoO4) and wulfenite (PbMoO4) and content 47.76– 47.92% molybdenum, 1.5–2.67% copper, 0.04% renium.From compared solvents sodium and carbonate and ammonia are like extracted molybdenum than hydrochloric acid, which contained 96.23–97.72 p.c. of its total amount. Hence to take into consideration abundance, cheap and suitable for analysis and processing the molybdenum concentrate ammonia is choosing as a basic solvent. By direct evaporation of ammonia extract solution, we obtained ammonium ortomolybdate, which contains 73.47% MoO3. INTRODUCTIONMolybdenum occurs in the earth’s crust in an abundance of about 10–14%, mainly as molybdenite, MoS2. Small quantities are also associated with other metals having similar chemical properties. Thus wulfenite (PbMoO4) is found in oxidized parts of sulfidic lead deposits in many regions of the world; powellite [Ca(Mo,W)O4] is a calcium molybdate usually formed from the modification of molybdenite in deposits containing tungsten as scheelite (CaWO4) and tungsten substitutes for molybdenum up to about 10%. Ferrimolybdite (Fe2Mo3O12·8H2O) is the product of oxidation of molybdenite in the presence of iron (III) compounds. Molybdenite is the primary source of molybdenum. Should demand for molybdenum rise so that additional sources become necessary, wulfenite, powellite, and ferrimolybdite may become commercially significant. Molybdenum ore is mined by underground and open-pit methods. A typical primary molybdenum ore body contains 0.05–0.25% Mo, and secondary ore bodies (copper porphyry ores) average 0.3–1.6% Cu and 0.01–0.05% Mo. Flotation remains the preferred and almost exclusive method of upgrading the molybdenite mineral to an industrial-grade molybdenite concentrate containing 90–95% MoS2, the balance being gangue (Habashi, 1997)."

Jan 1, 2016

By J M. Gibbs

Craigmont Mines Limited mine 50,000 tons of ore and waste per day from the open pit at Merritt, British Columbia. An electric-powered "down-the-hole" drill, a diesel-powered rotary drill and two electric-powered rotary drills have been used. All primary drilling, as a result of cost and operating experience, is now performed with two electric-powered rotary drills. Trials with various loading techniques have increased the amount of AN-FO and decreased the amount of commercially prepared slurries used for primary blasting. Approximately 95 per cent of the primary blasting is accomplished with AN -FO, mixed at the hole. Introduction THE Craigmont mine is located near the village of Merritt, B.C., 240 miles northeast of Vancouver. The concentrator has been in production since September of 1961. Craigmont is a combined open-pit and underground operation. To date, slightly more than 95 per cent of the mill feed has been mined from the open pit. As underground development proceeds, the ore requirements from the open pit will decrease. The average milling rate from September, 1961, to April, 1964, was approximately 4,900 tons per day.

Jan 1, 1965

By W. A. Lang

Introduction That the coal industry has entered a new phase in its development is now evident. Coal, besides being the chief source of heat and power, has become a potential raw material for many industries. Rapid progress has been made in the methods used in the mining and preparation of coal, and in the equipment for the burning of coal. Data of a fundamental nature relating to the composition of coal and to its transformations? during combustion and processing have also been revealed. Research, the key which has opened this new era, has already accomplished much, but it has only begun to show what it may and should be able to do. New developments of coal burning equipment, super-power plants, carbonizing and briquetting plants, hydrogenation and synthetic chemical processes, will undoubtedly have a marked influence in the post-war years on the economic welfare of many coal producing countries. Until comparatively recently, however, there has been in many branches of the coal industry a tendency to regard research as something abstruse and something which had little or no value to those managing such branches. But the fact that coal has suffered as a source of heat and energy through inroads of oil, natural gas, and water power, has made it plain to the industry that, if it is to maintain its present markets in this competitive world, much less increase them, the whole industry must be willing to follow the example of other industries and plan for the future.

Jan 1, 1946

By B. D. Sparks, I. E. Puddington, F. W. Meadus

The continuous separation of bitumen from Athabasca tar sands, with a high clay content, has been demonstrated. Recoveries of 95 per cent or higher have been obtained. Further processing of this product, to produce an accept-able type of crude oil, would require less heat than currently used in the hot-water process. Also, by comparison, substantial savings in equipment and operating costs are indicated.

Jan 1, 1971

By Mike Broczkowski, Laura Dewhirst, Kieran Large, Angelo R. Fernando, Heather Daigneault, Jim Johnson, Randy Wiens

The radioactive isotope radium 226 is a contaminant of potential concern in effluent waters from metal mining operations in Canada. Acceptable release levels of radium 226 are governed by Metal and Diamond Mining Effluent Regulations. Since radium is invariably present as a companion element in uranium ore, monitoring and controlling of radium 226 is a must for uranium mining operations. Measurement of radium 226 is traditionally carried out through a radiochemical technique involving selective co-precipitation of radium with barium sulphate followed by alpha spectroscopy for quantification. As of 2010, Cameco has also been using an ICP-MS based radium analysis method developed in collaboration with a research team at Trent University, Peterborough, Ontario. This method, which is highly automated and requires significantly less sample handling, with improved turn-around-times, is being used by Cameco site laboratories at the McArthur River and Cigar Lake mines as well as the Port Hope Conversion Facility. This paper compares the benefits and drawbacks of this new method, compared to the traditional alpha counting procedure drawing from almost ten years of field experience.

Jan 1, 2020

By Barry J. Turley

With over 700 large electric-drive haulage trucks operating in Canadian mining today and over 3700 in mines worldwide, most aspects of electric drive are well known. Recently, however, extensive application of these trucks to down-hill hauling in mountain mining makes it vitally important that many of us better understand the operation and proper application of the dynamic retarding feature of these vehicles. This paper is an attempt to clear up misunderstandings on this subject, to suggest precautions that mining operators should take in comparing competitive retarding systems and to challenge equipment manufacturers to evolve improvements to the important aspect of system performance.

Jan 1, 1978

By David R. Lentz

Abstract -At True Hill in southwestern New Brunswick, low-grade porphyry-style Bi-Sn-Mo greisen mineralization is associated with the cupola of an epizonal granite porphyry (granite) that also exhibits three episodes of brecciation. The first episode of brecciation is an in situ, 8 m to 10 m wide transitional zone of net-veined to coarse-grained "blocky" endogranitic mesobreccia that is chloritized and greisenized and hosts weak disseminated mineralization. ln a zone doser to the host rock­ granite contact, angular fine- to coarse-grained endogranitic mesobreccia with greisenized matrix is superimposed on the earlier transitional breccia. The latest episode is fault-controlled and consists of quartz- and chalcedony-hosted subangular to rounded fine-grained "pebble" mesobreccias that crosscut and brecciate the other breccia types, as well as the adjacent altered metasedimentary country rocks. The first two episodes of brecciation are magrnatic-hydrothermal in origin related to hydrofracturing of the granite carapace and are accompanied by greisenization and mineralization, whereas the post-mineralization, silica-hosted, "pebble" mesobreccias related to hydromagrnatic, low­ temperature fluid circulation and/or boiling along faults near the contact. These magmatic­ hydrothermal and hydromagmatic mesobreccias are similar to those associated with W-Mo-Bi porphyry-greisen mineralization at the Mount Pleasant deposit.

Jan 1, 1994

By M. Dupuis, V. Bojarevics

It is well known that horizontal current density in the metal pad contributes greatly to the generation of MHD driven bath-metal interface wave. It is possible to compute very accurately the metal pad current density using a very detailed finite element model [1], but a MHD model must be compatible to this level of mesh refinement and to recalculate the current distribution at each time step, including the full busbar supply system. The accuracy of the instability prediction of the cell depends on the accuracy of the metal pad current density calculation. This study presents the comparison of the metal pad current density calculation of the detailed finite element model and the MHD-Valdis model for different metal pad heights and ledge thickness. It also presents the corresponding cell MHD stability predictions.

Jan 1, 2006

By J. D. Aitken

"DEFINITION OF THE REGIONTHE REGION considered in this paper is bounded on the south by the 60th parallel, on the north by the Beau-fort Sea and Amundsen Gulf, on the east by Archean rocks or by highly deformed Proterozoic rocks of the Canadian Shield (certain weakly deformed Proterozoic strata being regarded as belonging to the Great Plains), and on the west mainly by the Mackenzie and Richardson Mountains.Only the unmetamorphosed strata of the region are considered; that is, the geology of the crystalline basement is ignored.SIGNIFICANCE OF THE REGIONThe region is significant from three points of view -namely, the economic, the scientific and the social. It constitutes 46 per cent of the area of the Western Canada Sedimentary Basin."

Jan 1, 1970

By R. A. Rabnett, G. Paget, Patrick Walsh

"Tumbler Ridge, Canada's newest resource community, has been developed differently than have been other resource communities.Since its conceptualization, emphasis has been placed on the establishment of a traditional municipal government at early a stage as possible.Planning f or the community goes back to 1977. By then, extensive study by provincial agencies had shown a new resource town would be required to exploit north east coal. The Ministry of Municipal Affairs, in conjunction with a consultant named R.A. Rabnett began the extensive Tumbler Ridge conceptual plan.The results of the conceptual plan are evident in the organizational and planning goals of Tumbler Ridge. In every aspect from the election of officials to some financial matters, the town functions as a normal municipality. With the resource companies of the North East Coal Development within its municipal boundaries. Tumbler Ridge has been able to debenture its capital projects against its municipal tax base.The town's ability to function as a normal municipality is enhanced by its control over Crown land it has purchased from the province. This gives it further control over the development of the community and helps in establishing agreements with the resource companies and the provincial government to ensure that housing and service needs are met. While resource company representatives sit on certain municipal committees, their roles are advisory in nature.The community continues to move toward full municipal status and will have a fully elected Council by 1986.BackgroundPlanning for the development of northeast British Columbia coal resources began in 1976 under the aegis of the provincial Cabinet Committee on Coal Development. A series of subcommittees were established including a Townsite/Community Development subcommittee. The Ministry of Municipal Affairs chaired this subcommittee and continued as the lead agency for the provincial settlement planning effort over the period 1976 to 1981."

Jan 1, 1983