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By N. Saeidi

"For a mine section comprising 100 different stoping activities, there are ~10158 different possible stoping sequences to explore in the mine schedule optimization search and this figure is indicative of the challenge posed in maximising profitability through mine schedule optimization. Any viable excavation timetable must satisfy all conditions that will constrain feasible sequences. In general, consideration of additional constraint will tend to reduce profitability. Geomechanical constraints on mine schedules, introduced with the aim of avoiding excavation instabilities, can be established for underground mine schedule optimization processes but, currently, this is done only rather crudely; precedence relations between excavation activities (stoping or development) are encoded to produce particular stope sequence patterns (e.g. ‘chevron’ or pyramidal sequences).The work reported aimed to investigate automated processes for formulation of such geomechanical constraints. The timetable optimization approach to the problem precipitated a fresh look at time dependent, and excavation sequence dependent, deformation. Abundant evidence emerged that supported the notion that any methodology developed that failed to account for such time and sequence dependencies was itself bound to failure. Yet, it was also recognised that any deviation at all from an assumption of linear elasticity for geomechanical numerical modeling, adopted to inform geomechanical constraint formulation, would rapidly lead to impractical levels of computational effort.Thus the approach presented here represents a compromise: the elastic stress fields induced by individual mining activities are computed for each activity, independently considered within a computational domain identical to that of all other activities. These are stored in a database. Instability risk for a specific sequence of mine activities can be assessed through superimposition of stress fields drawn from the pre-computed database. Time stamps allocated to events corresponding to the excavation processes permit the conversion of the sequence of elastic stress fields into a time table of stress fields. For specific locations within the computational domain, the aggregate effect of the sequence of mine activities leads to stress-time histories having a castellated appearance, a result of the near instantaneous response of an elastic medium to the excavation perturbations. Time dependent deformation responses are crudely allowed for through the re-profiling these castellated histories through graphical construction of curved responses, where the curve gradients are related to a viscous parameter. Such curves form the basis for a geomechanical constraint formulation to be adopted for mine schedule optimization."

Jan 1, 2015

By P. C. McLeod

THE GECO OREBODY, located north of lake Superior in the Thunder Bay district of northern' Ontario, was discovered in 1953. Diamond drilling in the following year indicated a 15,000,000-ton ore-body, and production plans were made for the shipment of copper and zinc concentrates in three years. To accomplish this, the Geco Project was initiated. The property was in an undevdoped, inaccessible area, and the project involved the conversion and extension of a logging road to the property, the construction of two railways and seventy miles of hydro transmission line, the erection of a municipality, the building of a plant, and the development of an underground mine to produce 3,300 tons per day. This paper describes some of the methods used in the underground development phase of the Geco Project.

Jan 1, 1958

By H. Kim

"IntroductionThe Hat Creek coal field contains low-grade coal deposits which are the thickest in the world. The diamond drilling and geophysical surveys conducted by B.C. Hydro over the last six years have indicated in excess of 2 billion tonnes of sub-bituminous to lignitic coal. The coal field is in the Interior Plateau Dry Belt, about 240 km northeast of Vancouver, and contains two explored, nearsurface coal deposits amenable to surface mining (Fig. I). The No. I deposit contains approximately 740 million tonnes of coal at 17.71 MJ / kg, or 7,600 Btu/lb, at 34.82% ash and 24% moisture. The No. 2 deposit to the south contains appreciably more coal resources at somewhat lower grade, but it has not been explored so extensively because of its higher stripping ratio. Therefore most of the exploration activities to date have been directed toward the development of the No. I deposit. The No . I coal deposit has been selected as the source of fuel for a proposed thermal powerplant to be built about 5 km east of the deposit. The purpose of this paper is to summarize the data obtained from the diamond drilling and the geophysical logging in the No. I deposit between 1974 and 1979. An attempt is made to explain the depositional environment of the Hat Creek coal measures. Because the understanding of the depositional environment in.a particular basin is essentially an evaluation of all the geologic properties of the area, the available geological information in the No. I deposit has been compiled on the basis of consistent criteria. This includes data on the lithology of the coal measures, thickness and areal distribution of the elastic sediments, and on the changes in the megascopic stratigraphic profile based on geophysical correlation. The palynopetrographic relationship and detailed sedimentological aspects are not examined in this paper. Such studies should provide important information relating the causal vegetal and chemical responses of the coals to -environmental changes. Extensive deposition of surficial materials during de-glaciation left most of the area of the Upper Hat Creek Valley devoid of bedrock exposures. Structural and stratigraphic features are hidden beneath glacial deposits and/or post-Eocene volcanics. As a result, the geological interpretation of the Hat Creek coal basin has been based primarily on drilling and geophysical data. Because of this, any explanation of the depositional environment details is tentative until the deposits are stripped for development."

Jan 1, 1985

By K. A. Mackinnon

The choice of fan type (axial flow, centrifugal or mixed flow) most suited for a mine ventilation application depends on a number of technical and economic factors. For each project, the relative importance of these factors will vary. It is worthwhile to carry out an assessment on a case by case basis. The paper, by discussing a number of technical and economic factors and their interactions, will provide the ventilation official a methodology to easily and methodically undertake such an assessment.

Aug 1, 2013

By J. R. Giegerich

Purpose It is the purpose of this paper to describe the application of underground conveyor systems to the transportation of ore in the Sullivan mine of The Consolidated Mining and Smelting Company of "Canada, Limited, at Kimberley, British Columbia. General Applications Conveying has been recognized as a means of underground transportation for a great number of years but only during the past fifteen to twenty years has there been any extended application of the method to underground metal-mine operations. Coal miners became conveyor conscious before metal miners. Probably one reason for this is the fact that there are more flat coal seams than flat orebodies. A second reason is that coal is light and is a less abrasive material than most metallic ores. The vast improvements made in belt construction during the past few years, together with improvements in mechanical conveyor equipment, have gone a long way in making this form of transportation attractive to the metal miner. In new mines being opened today, or in major extensions to older mines, the possibilities of conveyor transportation should receive serious consideration. There may not be any widespread application of the belt conveyor as a replacement for the conventional hoisting and locomotive haulage. Where there is an application, tl1e saving in cost can be appreciable and many operating ad-vantages gained because of ease in operation.

Jan 1, 1951

By Ajit K. Sinha

"Abstract - Electromagnetic surveys were conducted over the Yava sandstone-hosted lead deposit in Nova Scotia to evaluate the usefulness of such surveys for detecting and mapping sedimentary­ hosted metallic ore deposits. Both transient and multifrequency systems were used for that purpose. The deposit consists of three zones of disseminated galena which also contain minor amounts of pyrite and sphalerite filling the interstices of the sandstone grains. Each zone overlies a basement depression and is separated from the adjacent zone by an intervening basement high. A conductive shale layer underlies the galena-rich sandstone formation at all three zones.Because the concentration of galena (3% to 4% ) and other sulfides is too low to affect the resistivity of the sandstone formations for detection by ground electromagnetic (EM) methods, the strategy for our survey was to look for areas of basement depressions and the presence of conductive shale in those depressions by EM depth soundings. The presence of the galena-rich sandstone formations could be inferred because of the close association of these two features with the deposits in the Yava area. Both transient and multifrequency EM systems were successful in mapping the basement depressions and detecting conductive shale at the three known mineralized zones. The technique, therefore, seems to offer good prospects for mapping similar stratabound sedimentary-hosted sulfide deposits."

Jan 1, 1993

By M. Gauthier, A. C. Brown

"Monometallic zinc mineralization associated with marbles of the Grenville Supergroup in the Mont-Laurier Basin of Quebec is found to be stratiform and to occur (1) within limited zones of dolomitic marble and (2) more precisely along contacts between these marbles and adjacent metaclastic units. Massive sphalerite with accompanying pyrrhotite and pyrite is the prime exploration target, and commonly gives rise to good geochemical anomalies, but generally weak and ambiguous geophysical responses. Disseminated sphalerite in dolomitic marbles may signal proximity to interesting massive mineralization, although, due to weathering, this broadly disseminated mineralization may not be detected easily on outcrops. It is concluded that the western and possibly the eastern margin of the Mont-Laurier Basin constitute favourable areas for continued exploration.IntroductionThe Grenville Supergroup marbles of Ontario, Quebec and New York State host numerous occurrences of zinc mineralization (Fig. I) , several of which have been periodically mined since the beginning of this century (Fig. 2). The Balmat Edwards district of New York is the giant of this depo sit-type, with the production since 1915 of some 20 million tons of ore grading 10% zinc, and acknowledged current reserves of approximately equal tonnage and grade. At present, there is renewed interest in the potential for similar mineralization throughout the Grenville Supergroup, and this paper outlines some of the geological, geochemical and geophysical guidelines that may be employed in the search for new ore. The geologic guidelines are derived especially from lithologic and stratigraphic features which survived intense, multiphase deformation and metamorphism.Although major portions of the extensive Grenville Supergroup hold potential for zinc mineralization, the present study is confined to a known zone of mineralization in the Mont-Laurier Basin of Quebec. Concurrently, we are compiling information on the regional metallogeny of the basin so that our conclusions can be applied to areas of similar Grenville Supergroup host-rocks elsewhere."

Jan 1, 1980

By P. A. Crane, N. Shirley, Aung Moe, H. M. Nicholson, D. Kan

Kazakhstan’s first commercial copper-leach solvent extraction-electrowinning plant, Central Asia Metals’ Kounrad project, was commissioned in April 2012. Exploiting low grade waste stockpiles produced during Soviet era open pit mining, a 10,000 tpa copper cathode plant was designed, constructed and commissioned within 18 months. Overcoming initial challenges with a workforce unfamiliar with the technology and with extensive periods of sub-zero conditions during winter the project has consistently met targets and produced high quality copper cathodes at cash costs of less than US$1/lb. Challenges encountered during the first two years of operation are described and future plans briefly discussed.

Jan 1, 2014

By A. Ignatieff

"Excavation, the principal mining process, 'which hitherto has been based largely on the intuition and logic of mining men, is increasingly receiving the attention of engineers and scientists versed in rock mechanics. The paper intro-duce the principles of this science in simplified form, directed both to underground and open-pit mining. Reference is made to the large annual tonnage from ore and rock excavations, which in 1967 were responsible for 250 million tons of mineral production in Canada.The urge to transform excavation into a continuous instead of an interrupted process is discussed with references to the various types of energies employed or proposed in rock breakage or excavation. Due to the rapid decay of applied energy in the discontinuous and heterogeneous rock environment, large confined blasts proposed for in-situ mining do not give much expectation of success as yet. Raises and ventilating shafts are already bored in reasonably hard rock. Tunnelling machines will be used for drifting and cross-cutting in the future, but continuous mining machines of the cuttmg and shearing type are not 'around the corner' for stoping typical orebodies. On the other hand, bed mining, particularly of coal, has led the way in continuous mining, and Remotely Operated Long-wall Face (ROLF) experiments are progressing in an encouraging way. Some reflections on the mining environment in relation to the human element are made."

Jan 1, 1970

By Ali Hashemi, Anna P. Perry

The PQ Deeps (PQD) is a production zone located at Newmont’s Musselwhite Mine in northern Ontario. Development started for the PQD in late 2017, and the first stopes were mined starting in early 2021. Unlike most historic longitudinal stoping of narrower orebodies at Musselwhite, the PQD is a wider orebody following the plunge of a fold hinge and is extracted primarily by transverse stoping. Some geotechnical challenges were experienced during early stoping efforts, necessitating design changes throughout late 2021 and early 2022 to optimize the stope design. This work describes the mining methods and design changes to transverse PQD stoping based on geotechnical lessons learned during early stoping efforts.

Jan 1, 2023

By C. A. Sosa-Blanco

Minera Sabinas in central Mexico treats a complex sulfide ore containing galena, chalcopyrite, sphalerite and argentite as valuable minerals, and in some cases important amounts of non-magnetic pyrrhotite. For high pyrrhotite ores, results obtained by selective flotation showed good grades and recoveries in the lead-copper circuit, but a commercial zinc concentrate could not be produced due to the high floatability of pyrrhotite. When this is the case, an alternative method was proposed to produce a bulk concentrate by flotation which is then leached to recover copper and zinc from liquor in a SX-EW circuit. Leaching was conducted in an autoclave in order to study the effect of temperature and pressure, but bioleaching tests were also conducted. Leaching lead-silver residues were treated by cyanidation in order to recover silver values. The results obtained by selective flotation and by bulk flotation with leaching of the bulk concentrate showed that the latter alternative increased zinc recovery by 30 % with similar recoveries of the other metals.

Jan 1, 2007

By Yongsheng Song, Yong Chen, Wenjuan Li

"Detailed characterization and improved recovery of a micro-fine, low-grade refractory gold ore from a beneficiation plant in Yunnan Province, China, was investigated. Different analytical techniques, such as videlicet size analysis, scanning electron microscopy, and mineral analysis by a Mineral Liberation Analyser, were used for mineralogical characterization of the ore. This paper describes an experimental study on the effect of the grinding fineness and the use of various flotation reagent regimes involving collectors, depressors, and activators on the flotation behaviour of micro-fine auriferous pyrite. Two-stage flotation resulted in high gold grade (32.71 g/t) and gold recovery (80.02%) of the bulk gold concentrate. This process opens the possibilities of maximizing Au recoveries in a micro-fine low-grade refractory gold ore where low recoveries are common.INTRODUCTIONWith the rapid development of the gold industry, refractory gold ores are becoming increasingly important resources for gold production (O’Connor & Dunne, 1994; Agorhom, Skinner, & Zanin, 2012). Among these refractory gold ores, sulfur and micro-grained native gold ores represent a significant challenge, since they are not amenable to gold recovery by direct cyanidation. The gold contained in this type of ore is very finely disseminated and encapsulated in sulfides, which makes it inaccessible to the cyanide solution during direct cyanidation (Bulatovic, 1997; Allan & Woodcock, 2001). Autoclave pressure oxidation (AC POX) of the sulfide ore and subsequent cyanidation is a common technology used to recover the gold in such types of ore. Flotation is often used as a pre-treatment method to refractory gold ore (Monte Lins, & Oliveira, 1997).As the gold-carrier minerals are usually finely disseminated (sometimes under 10 µm) and intimately associated with gangue minerals, a fine grind is necessary to get a high degree of liberation. At the same time, the fine grind usually causes the production of significant quantities of slimes, which comprise easy-to-float gangue minerals such as mica, dolomite, and calcite. These mineral phases are naturally hydrophobic and float readily, competing with the value minerals in the froth phase and resulting in lower concentrate grades."

Jan 1, 2016

By P. Talonen

Since the last Iron Control in Hydrometallurgy Symposium in Montreal in 1996, the Kokkola zinc plant has increased its capacity from 175,000 t/y to 280,000 t/y by installing an atmospheric concentrate leaching process, which has also affected iron control in the leaching circuit. Major changes have been made at the jarosite residue pond; a subterranean plastic wall reinforced with bentonite and cement has been built around the pond. A new water collecting system that is used for groundwater level control in the pond area was installed. With these two investments in the pond area, it is now possible to prevent any seepage flow from the pond into the surrounding environment. Water pumped from the residue pond is treated in the water treatment plant. This paper describes the behavior of iron in Kokkola's current leaching processes. The treatment of the jarosite, the improvements to the residue pond and the water treatment process are also described.

Jan 1, 2006

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 Namavari. H., M. Ashouri, M. R. Sarhadi, S. H. Mansouri, A. Sarrafi

The splash phenomenon and its effective parameters in metallurgical converters have been studied thoroughly for decades. The detailed studies of processes such as tuyere blockage, wave formation during air injection, entrapped phases, and also processes which control the formation of bubbles in viscous fluids are not feasible yet. In this research, we have used a converter-shaped vessel made of flexi-glass. Water and oil have been used as matte and slag phases respectively. The effective operational factors responsible for creation of splashing have been studied such as air flow rate, tuyere angles, depth of tuyere submergence, tuyere blockage, density and viscosity of liquids, liquids heights, etc. The results have been found as follows: the amount of splashing increases slowly as air flow rate increases. However, as the air flow rate reaches a critical value (depending on the physical specification of converter) the amount of splashing rises sharply, because the flow of air inside the liquid changes from bubbling into a jet stream; and most of the splashed materials are in the form of filaments instead of droplets. Changing tuyere angle from horizontal towards vertical position will increase the turbulence level on the fluid surface and causes an increase in the amount of splashing. The effect of tuyere submergence is related to the converter opening angle. As the converter opening angle is shifted towards the hood position, the amount of tuyere submergence and splashing will increase. As density of the liquid increases, the number of droplets splashing increases with a decrease in drop size. Therefore, the total amount of splashing decreases. However, as viscosity of the liquid increases, the splashing material increases due to the changes in the splashed material from droplet shape into filament form. The height of liquid inside the converter, depending on the relative height of heavy phase and light phase, is an important parameter regarding splashing. As the relative height of heavy phase to light phase increases the splashing will decrease. The tuyere blockage will cause the pressure in the inlet manifold to increase; and in real cases will increase the splashing. Finally, we have development a model based on dimensional analysis to relate the above parameters in order to calculate the amount of splashed material.

Jan 1, 2007

By Roy S. Celland, K. H. Singh

The introduction of 'post' pillar mining at the Strathcona mine represents a new approach to ground support in cut-and-fill applications. The method has also shown significant economic advantages. It is believed that the development of this concept is one of the few examples where rock mechanics principles have successfully been applied in the development of a stoping method. The paper describes the evolution of this method and contains discussions on the theoretical analysis of the technical, operational and economics aspects of the system. Pillar design procedures and field observations on the practical application of theoretical analysis are also outlined.

Jan 1, 1973

By Robert J. Mitchell

A general approach to mine backfill design, including laboratory testing procedures, is outlined in this paper. Relationships between certain design parameters are developed and the effect of other factors is discussed. It is concluded that the inclusion of backfill design calculations at an early stage of mine design can often produce over-all design economies. Not only are the data needed for backfill plant and tailings disposal area design, but also the pillar recovery method and over-all mine stability are dependent on the attainable fill properties.

Jan 1, 1979

By R. C. Rowe

THIS paper is an endeavour to analyse the ideal and practical functions of government technical mining services, and their relationship to the National Domain, as well as to one another. its spirit is not critical, even though at times it may appear to besoin fact. It is a serious effort to divert a trend in public thought which delights in calling itself practical whereas it is really merely short-sighted. The author refers particularly to the idea that governmental research is a luxury which should be curtailed in the interests of economy, and turned over to private enterprise or the provinces. In order that we obtain the proper perspective of the question, it is advisable to indulge in a little history. In the year 1842, the Geological Survey of Canada was formed under the guidance of William (later Sir William) Edmund Logan. The literature on the founding and history of the Geological Survey of Canada is extensive, and therefore it is unnecessary to go into detail here regarding it. It might be mentioned, however, that the Geological Survey of Canada is only seven years younger than the Geological Survey of Great Britain (founded in 1835), and is only exceeded in age on the American continent by the State Geological Surveys of New York, Pennsylvania, Massachusetts, and Michigan, which were founded between 1833 and 1836. In 1877, the Geological Survey became a permanent government institution as a branch of the Department of the Interior. It should be noted, however, that the Director of the Survey ranked as a Deputy Minister and reported direct to the Minister. This continued until 1907. In 1886, the Mineral Resources and Statistics Division of the Geological Survey was formed. Some years later, the Canadian Institute of Mining and Metallurgy (then the Canadian Mining Institute), backed by the mining press, began to agitate for the establishment of a Dominion Department of Mines, and in 1907 such a department was founded by the Geology and Mines Act of that year, with a separate Cabinet portfolio for the position of Minister of Mines.

Jan 1, 1939

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 A. Montera, M. Loken

"The process of blending consistent and predictable feed for the roasters is critical for optimizing product quality and controlling production costs. To assist in this process, online PGNAA slurry analyzers have been installed and evaluated at a Sudbury Ontario smelter. They are used to measure 100 % of the full process stream to obtain elemental composition data in real time. This paper explains the application details at Sudbury and the benefits achieved from their full stream, elemental slurry analyzers.INTRODUCTIONSudbury Integrated Nickel Operations (Sudbury INO), a Glencore Company, consists of two underground nickel/copper mines in Sudbury, Nickel Rim South and, Fraser, along with the Strathcona mill and the Sudbury smelter. The facilities are spread throughout the 60 kilometer-long, oval-shaped geological formation known as the Sudbury Basin (Figure 1). The company has been mining nickel-copper ores in the Sudbury area since 1929. Nickel and copper are the primary focus of operations at Nickel Rim South and Fraser. Other base metals such as cobalt and precious metals are also produced.The Strathcona Mill receives ore from Nickel Rim South, Fraser, and third-party miners to produce two concentrate streams. One is a nickel-copper concentrate for use by the Sudbury Smelter; the other is a copper concentrate which goes to other Glencore operations for smelting and refining. The Sudbury Smelter converts the mineral concentrate into a high grade matte containing nickel, copper, cobalt and platinum group metals. This matte product is shipped to Glencore's Nikkelverk refinery in Norway for further processing. In 2015, the Sudbury INO Smelter completed the first phase of the Process Gas Project (PGP); a series of process changes and capital investments designed to reduce sulphur dioxide (SO2) emissions in accordance with Ontario Regulation 194. A critical element of the planned emissions reduction was the elimination of a higher percentage of sulphur contained in input concentrate streams, which can then be captured and converted to sulphuric acid."

Jan 1, 2017