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By H. W. Fleming

In 1955, the results of a regional, geological interpretation of the northern portion of New Brunswick were used as a basis for selecting, for intensive exploration, three areas in which structural and stratigraphic conditions were believed to be favourable. Airborne electromagnetic work, in one of these areas, provided the justification for acquiring the Murray group. Even though the initial results were discouraging, this geological interpretation, combined with the fortuitous discovery of cop• per-bearing float, was sufficient reason for carrying out further work using geochemical methods. This work finally resulted in the discovery of the Murray massive-sulphide deposit, after about eighteen months of coordinated exploration on the property. While this deposit is a typical New Brunswick-type base-metal occurrence, extensive leaching has produced a fossil gossan that rendered it an elusive target for exploration techniques of limited penetration Full credit for localizing the target area is given to the geochemical techniques, but geophysical surveys were needed to provide the necessary

Jan 1, 1961

"Sink-float analysis is often used to obtain yield-ash and density partition curves in the coal industry. These provide a valuable tool for evaluating the performance of a separation process. However, for dense minerals, obtaining complete grade-recovery and density partition curves is more difficult due to the lack of heavy liquids available with the required densities. This paper examines a potential solution to this problem which is to perform batch fractionation of mineral samples in a laboratory-scale REFLUX™ Classifier using high viscosity fluidising liquids. The REFLUX™ Classifier is a gravity separation unit consisting of a system of parallel inclined channels positioned above a vertical fluidised bed. Operated in semi-batch mode, a charge of particles is fluidised from below and particles up to a certain density are elutriated from the top of the system. The fluidisation rate is then increased incrementally to fractionate the sample at progressively increasing densities. Previous work by Hunter et al. (2014) and Iveson et al. (2015) has shown that this method provides excellent agreement with yield-ash and partition curves for coal, especially when glycerol solutions are used as the fluidising liquid. This approach has now been extended to obtain the grade-recovery and density partition curves of high density mineral samples. This method has the potential to provide the minerals industry with an effective tool to evaluate the performance of unit operations separating at cut points higher than the available heavy liquids.INTRODUCTIONMeasuring efficiency and effectiveness is of key importance in the continuous improvement of mineral processing plants. For density based separation, one way the performance of a process can be evaluated is the measurement of density-based partition curves. Currently, this is done in the coal industry using the sink-float method, where heavy liquids are used to fractionate particles into discrete density intervals. However, with high density minerals such as iron ore, liquids of sufficient density are rare, and in most cases also pose serious health and safety concerns to laboratory operators. Most commercial laboratories do not perform sink-float separations above a density of about 4400 kg/m3, the maximum density of Clerici solution without operating at excessive temperatures (Koroznikova, Klutke, McKnight & Hall, 2007; Rosenblum, 1974)."

Jan 1, 2016

By T. Fliß

The protection of natural resources is of essential importance in times of rapidly increasing populations and resulting shortage of agricultural land. Soil and groundwater resources play a central role for the production of food or feed of any kind. The intensive agricultural and environmentally friendly use of these resources must ensure sufficient income and sustainability of life for future generations. Mining projects often represent a particularly deep intervention into ecosystems due to their size as well as the most expensive treatment processes. Conventional mines comprising of shafts and developed mining fields require the stockpiling of waste rock and in particular to potash mining, the discharge of brines from raw salt processing. In contrast, mining operations based on the solution mining method can be operated without major environmental impacts and lower security risks. While the solution mining for the production of rock salt finds application since more than 500 years, exist a procedure to produce potash using solution mining only since the 1980's. For solution mining drill holes are used to exploit the potash, launched from the surface into the deposit. The exploitation of the raw material occurs by the dissolution of the potash injecting solvents and creating so-called brine caverns. Currently, a number of mining projects in Carnallite deposits by the solution mining method are in progress around the world. Often these projects are located in sensitive ecosystems. K-UTEC project and support actual a solution mining operation of a Carnallite deposit for a Chinese customer in South-East Asia. This work comprises a comprehensive geological and geomechanical modeling as well as stability analyses. Furthermore the cavern design and brine field layout as well as the planning of the brine processing and the plant design. The present paper introduces this project as a case study. The application of a special solution mining procedure and processing design ensures an emission-free mining operation (Zero Disposal Plant). The emission-free operation is achieved by utilizing the full extent of the caverns to dispose the liquid solutions from processing. The presentation of principal salt processing and technical equipment will be rounded by information about the geology of the deposit. Since the deposit includes a number of sensitive minerals, such as Tachyhydrite and Bischofite the presentation comprise a lot of interesting items with special view at the brine field operation. K-UTEC designed and delivered a special blanket measuring system and a well cement according the request of the customer. K-UTEC, a research and engineering company with more than 60 years of experience in the sector of potash and rock salt mining, developed the world's first solution mining operation for Carnallite in Germany more than 30 years ago. In recent times K-UTEC served in different solution mining projects worldwide, with special view at the environmental impact, as well as the optimal utilization of the deposits.

Aug 1, 2013

By G. M. Ritcey, S. H. Lucas

"On the north shore of the St. Lawrence River, in Quebec, are located orebodies of low-grade titaniferous magnetite. The Quebec Mining Exploration Company (SOQUEM), who have an interest in the deposits, believed that beneficiation of the could generate sufficient revenue to defray the mining costs and the costs of transporting the ore to a steel production facility. A joint research project of SOQUEM and CANMET investigated alkaline roasting of a magnetic concentrate, followed by leaching of the calcine and separation and recovery of Cr and V by solvent extraction. Aluminum was recovered by precipitation.The present paper describes the roast-leach bench-scale and pilot-plant work leading to the development of the optimum conditions f or the integrated process.A plant flowsheet was developed for the treatment of 5 x 106 tons of magnetic concentrate per annum. Estimates of capital and operating costs were made.Based on a recovery of approximately 90% V, 85% Cr and 75% AI, the total hydrometallurgical plant fixed capital costs, including mining, concentration and shipping, are estimated at $1.021 x 109; the operating costs are estimated at $131.92/ton concentrate. Annual revenue from the Na2CrO4.H2O, V2O5 and A12O3 produced is calculated to be $421 x 106.IntroductionThe Quebec Mining Exploration Company (SOQUEM) acquired in 1968 an interest in four titaniferous magnetite orebodies located in Eastern Quebec. 85 miles north of Mingan on the north shore of the St. Lawrence River. The Mingan deposit, with an estimated tonnage of one billion tons, has a reported average grade of 43% Fe, 6.3% Ti , 1.60% Cr, 0.19% V and 6.1% Al with minor amounts of nickel. SOQUEM, on the basis of previous bench-scale data, believed that the recovery of chromium, vanadium and alumina by alkaline roasting would generate sufficient revenue to defray the mining costs and the costs of transporting the ore to a steel production facility on the coast. One of the approaches selected by SOQUEM for beneficiation of the ore consisted of a combination of magnetic concentration followed by alkaline roasting of the calcine."

Jan 1, 1980

By R. Noriega, M. Suazo, V. Murariu

Current AG and SAG mill circuits have continued the trend to larger, fewer mills. These large mills place a significant additional load on the discharge systems and it has become imperative that the designs of these mill discharge systems are evaluated carefully to ensure maximum efficiency and have the capacity to be able to handle the increased mill discharge volumes. The current generation of multiphysics modeling tools allow a detailed analysis of AG and SAG mill discharge performance. The combination of Discrete Element Method modeling and Computational Fluid Dynamics allows the designer to model in detail all aspects of a mill discharge performance. This includes a detailed description of the build-up of solids and slurry in a mill discharge, the recycle of material back into the mill through the grates, the relative wear rates and the occurrence of overloading at the pinch points. These tools allow intelligent decisions to be made regarding the type of discharge arrangement, pan lifter geometry, and discharge cone design, so as to ensure that the discharge is capable of handling the duties required for a specific installation. This paper details the current state of the art in these modeling tools, and provides an overview of some recent applications.

Jan 1, 2012

By R. S. Nichols

"During 1973 to 1978, Canadaka Mines Limited, a subsidiary of St. Joseph Explorations Ltd., undertook an extensive exploration and development program in the Cobalt area. This program resulted in the delineation of previously unknown stratigraphic units in the Archean volcanic sequence. During this time period, significant are controls related to area silver deposits were also identified.The Archean geology is comprised of a volcanic pile conformably overlain by sediments. The volcanics contain at least two felsic volcanic centres near the stratigraphic top of the pile. The bulk of the pile consists of mafic flows and interflow sediments. lnterflow sediments around silver are shoots contain mineralized halos of base metal sulphides. The halos exhibit lateral and vertical metal zoning with Cu, Pb and Zn mineralization decreasing away from an are shoot.Silver mineralization controls determined during the Canadaka program agree with the historically well established importance of Coleman sediments as well as Archean contacts for hosting silver deposits. The vertical extent of are shoots is typically 150to 250ft. A strong correlation was found to exist in the Cobalt area between Archean strike and the strike of are veins. Finally, al/ Cobalt area are deposits appear to be associated with a distinct volcanic pile at the top of a sequence of Archean flows."

Jan 1, 1988

By W. R. Bruce, G. W. Hodgson, K. A. Clark

"IntroductionANY PLANT processing mined Athabaska oil •sand for the recovery of oil produces, as a waste material, about one ton of sand for every barrel of oil recovered. A disposal problem of major proportions is thus indicated. For a 100,000-barrel per day plant, provision must be made for moving .about 4,000 tons of sand per hour on a continuous basis to a tailings dump at least several thousand feet removed from the plant site.Of the many known ways of conveying solids on .a large scale, the hydraulic pipeline transfer method is becoming increasingly important because of convenience and economy of operation. It has been in use for many years in mill operations at metalliferrous mines for the disposal of tailings and as such was a natural outgrowth of •hydraulic sluicing (3). Pipeline transportation of mill concentrates has been adopted recently ( 1), wherein high-density solids are moved several miles by hydraulic pipeline. The flotation power of the water suspending the solids may be increased 'by addition of magnetite for the handling of ore in pipelines (8). Low-density solids such as coal have received considerable study for low-cost pipe-lining (2) and a successful operation with coal has been carried out in England with indications of considerable savings over other methods of transportation (9). Dredge operations are based on pipeline transportation for the dredged sol-ids, and the scale of pipelining there .has involved pipe sizes as large as 32-inch (6). However, the tendency has been to regard the pumping of solids in water merely as a simple method of transportation and little consideration has been given in the published literature to study of the most economical modes of operating .a pipeline."

Jan 1, 1952

By David L. Huston, Wouter Bleeker, Bruce E. Taylor, Ron Cook, Bob Stewart, Elizabeth R. Koopman

"Abstract-Detailed oxygen isotope mapping of rhyolites in and around the Kidd Creek mine indicates that the orebodies are associated with relatively low (<12‰) whole rock values that extend up to 200 m laterally from ore. The zone of low d18O values is overlain stratigraphically by a carapace of higher (>13‰) values that extends up to 1.5 km laterally from and 300 m to 500 m above ore. Immediately above the stratigraphically highest orebody this carapace is cut by a zone of lower d18O values extending from the ore zone. Zones of higher d18O values also occur in massive rhyolite bodies that occur in the footwall of the orebodies.The zone of low d18O values partly coincides with a Na2O depletion anomaly associated with hydrothermal alteration, except that the Na2O depletion anomaly has a greater lateral extent, and the low d18O anomaly extends farther into the stratigraphic hanging wall. These data suggest that d18O mapping may detect hanging wall alteration above massive sulfide bodies more effectively than conventional lithogeochemistry. Zones of high d18O values, which define zones through which large quantities of low-temperature hydrothermal fluids have passed, may also have usefulness in exploration.Oxygen isotope variations at Kidd Creek record three stages of a hydrothermal system that evolved in temperature with time, as follows: (1) an early, low-temperature event that produced rocks with high d18O values, (2) a high-temperature event that produced rocks with lower d18O values, and (3) a later, low-temperature event that also produced rocks with high d18O values. The high d18O sig- nature of the massive rhyolite was recorded during early-stage, low-temperature (<200°C) alteration, and was probably preserved owing to decreases in permeability associated with low-temperature silicification. The low d18O signature of cherty breccia and chloritite was recorded during the thermal peak at >300°C. High d18O values in the carapace above the deposit were recorded as the hydrothermal system waned."

Jan 1, 1995

By K. Barbetti, J. Avraamides

"The processing of gold ores with high silver contents can provide operational challenges, such as high cyanide consumption, retardation of gold leaching and competition during adsorption stages of carbon-in-pulp/leach/column (CIP/CIL/CIC) circuits. In particular, the silver, which is about 1.5% of the value of gold, competes with gold during carbon adsorption due to its higher concentration in many Ag-Au ores, potentially leading to gold solution losses. Fresh and partially fouled (barren and regenerated) activated carbons were evaluated at various Ag:Au ratios and total metal concentrations with regard to the adsorption kinetics and equilibrium loadings. Conventional Freundlich isotherms were found to be highly inaccurate for predicting equilibrium loadings in the competitive adsorption environment. An integrated model, which incorporates competitive adsorption kinetics with a modified competitive adsorption isotherm model has been developed and validated using plant and laboratory data. The model performance and some of its salient features will be discussed.INTRODUCTIONThe processing of gold ores with high silver contents can present a range of operational challenges, such as high cyanide consumption, retardation of gold leaching and competition in carbon adsorption circuits. Silver is often present at significantly higher concentrations than gold in many gold-silver ores and competes with gold in carbon adsorption circuits, limiting the gold loading rate and capacity, resulting in gold solution losses and reduced gold recovery.Curtin University’s Gold Technology Group has evaluated fresh and partially fouled (barren and regenerated) activated carbons at various Ag:Au ratios and total metal concentrations to determine the adsorption kinetics and equilibrium loadings for gold and silver. Conventional Freundlich isotherms were found to be highly inaccurate for predicting equilibrium loadings in the presence of both gold and silver.An integrated model, which incorporates competitive adsorption kinetics with a modified competitive adsorption isotherm model has been developed and validated using plant and laboratory data. This paper describes the model performance and some of its salient features."

Jan 1, 2016

By Stanley G. Butcher

Predictions of coal cleaning plant performance from the washability data are traditionally used at the conceptual design stage of a coal preparation plant to confirm process selection. The development of computer programs which simulate the operation of a plant facilitates the optimization of product yield and quality, and ultimately proceeds. It is shown that the optimum is sensitive to changes in mine operations and market price structure. A computerized review of operations is thus recommended as an on-going activity .

Jan 1, 1979

By D. Mu

A method is presented for evaluating the effective gas diffusion coefficient of porous media. A series of random-distributed porous solids with different porosity are generated, a solution of the gas diffusion equations inside the porous media is obtained using the finite element method (FEM), and then the effective gas diffusivities are computed. The results show that there is a percolation threshold sp, and this percolation threshold decreases with an increase in the connectivity of the pore network; the relationship between the effective diffusivity and the porosity is strongly nonlinear when the porosity £ is less than about 0.2; and is quasi linear for higher porosities. The threshold decreases with increasing the connectivity of the pore network. A formula relating the effective diffusion coefficient with porosity is proposed.

Jan 1, 2005

By A. Sutherland Brown

"The ProblemMany science activities receive substantial funding from governments without much direct economic benefit accruing to state or individuals. In contrast, the search for knowledge has never been an acceptable so le justification of geoscience activity, perhaps because of its utility right from its inception. William Smith&apos;s geological activities were embraced because of their usefulness in building canals. Utility has been expected ever since.For decades it has been accepted at senior level s of government, without much understanding of the process, that geological surveys are necessary as a basis of resource evaluation and utilization. Recently, government treasury board s, staffed with economist s, have questioned these near axioms and in many cases the budget s of geological surveys have reflected their stone y-eyed appraisal s. Are government surveys necessary? Can their functions be reduced? Can some or all of their functions be privatized?Government geologists have been muted in trumpeting their successes outside their own ranks. Companies have been reluctant to give specific public feedback on the work of government surveys that have truly aided or guided them toward discovery. Lack of acknowledged linkages between survey work and discovery has dogged survey managers in budget reviews. Impoverished surveys cannot perform adequately so the circle is completed and the doubters&apos; prophecy fulfilled. This is the genera l problem; British Columbia is the archetypical province."

Jan 1, 1986

By Brian Mattie

Overview ?Overview of the mining area ?Description of the mining phases ?Risk assessment ?Design criteria and description for freeze drifts ?Freeze wall design ?Raisebore mining Four Main Phases: 1.Development of freeze drifts on the 520 and 590 levels 2.Freeze drilling and ground freezing to isolate the Zone 4 North ore body from water bearing sandstone. 3.Develop raisebore and extraction chambers including access drifts and ramps under freeze protection. 4.Start raisebore production mining of the Zone 4 North area.

Nov 1, 2011

By J. Stachulak, M. Scobie

"This paper addresses the occurrence and indicated causes of conveyor fires in North American and European underground mines. Some significant convey or fires which have been experienced in recent years in Canadian hardrock mines are then reviewed. The nature of existing conveyor monitoring technology is considered in the context of such fire hazards. Experiences with new monitoring technology recently installed at several conveyor sites at Inca Ltd. mines are then reviewed.IntroductionFires associated with conveyors have long been recognized as a serious hazard in underground coal mines. Recently, however, there have been some significant conveyor fires in Canadian underground hardrock mines. These offer important evidence as to the nature and causes of potential hardrock mine fifes. They also warrant attention with a view to improving over-all mine design, ventilation and emergency preparedness.In addition, a new era in mine communications and monitoring technology has been entered which should offer improved capability to protect against such fires. This paper was motivated by the need to understand the causes and mechanisms of conveyor fires in order to improve their safety. This should be possible through implementing more effective monitoring systems, as well as improving conveyor design. Underground mines are becoming more intensively mechanized, with less human surveillance of equipment and a greater dependency on remote monitoring systems."

Jan 1, 1992

By A. Osouli, B. Moradi Bajestani

"Increase in permeability of rock mass is vital for both petroleum and geothermal applications. Hydraulic fracturing is a common method to create and increase the permeability for production. Due to the complexity of fracture propagation in a naturally fractured medium, understanding the interaction between hydraulic fracture (HF) and natural fracture (NF) is of great importance to optimize the fracturing process. The possibility of interaction between HF and NF is partly a function of orientation. Various scenarios are predictable for hydraulic fracture regarding the intersection with NF such as being arrested by NF, crossing NF or crossing the fissure while injecting water into it. Different parameters such as geomechanical and geometrical properties of surrounding rock mass, the operational parameters such as injection rate and the angle between created hydraulic fracture and natural fracture (approach angle) can affect the result of hydraulic fracture and natural fracture intersection. In this paper, using a series of flow-coupled Distinct Fracture Network (DFN) simulations, hydraulic fractures were analyzed to investigate the influence of the aforementioned parameters on the hydraulic fracture propagating. Results show that the most significant parameters affecting the interaction of natural and hydraulic fracture are orientation of the intersection as well as injection rate. The interaction and fracture propagation in NF and HF intersections are also studied and discussed in detail.INTRODUCTIONThe hydraulic fracture technology has substantially changed the oil, gas and geothermal industries. With the help of this technology, extraction of fossil resources from tight shale reservoirs will be economical, feasible and sustainable. Due to presence of massive oil and gas trapped in these reservoirs, this technology has been the center of attention for the past 40 years (King, 2012). Hydraulic fracturing is the process in which high pressure water is pumped into shale unconventional reservoirs with low to ultralow permeabilities. With this process paths are created in these mediums for delivering oil and gas to horizontal wellbore and increase the surrounding rock medium permeability. Economical and sustainable stimulation of these tight reservoirs is highly dependable on our understanding in regard to fracture propagation in the highly complex rock medium. Hydraulic fracturing process in rock mediums with preexisting natural fractures is more complex because of the high possibility of Hydraulic Fracture (HF) being arrested or deviated by Natural Fracture (NF). Also, HF and NF intersection can influence the required pumping pressure, injection rate, the outcome of horizontal wellbore and the affected geological underground zones. Since the 1950s, numerous studies have been conducted to predict and plan fracture propagation with the help of modeling and simulation methods. Having a thorough and accurate prediction of fracturing process will not only prevent stimulation of unwanted geological zones or pollution of aquifers, but also will improve the efficiency of the fracturing process. Previously, several studies have been conducted in order to investigate and analyze the interaction of hydraulic fracture and natural fracture (Cottrell, Hosseinpour, & Dershowitz, 2013; Doe, Lacazette, Dershowitz, & Knitter, 2013; Shakib, 2013; Zhang & Jeffrey, 2006)."

Jan 1, 2015

By X. Cao, X. -G. Chen, K. Liu

As is well known, the standard Al-Cu 206 cast alloys have extremely low iron contents, usually less than 0.15 wt. %. Recently it is found that the iron contents of the 206 cast alloys can be extended up to 0.5 wt. % through the precise control of the iron-rich intermetallic phases. In the present work, the tensile fracture surfaces of the 206 cast alloys with various iron contents are systematically analyzed to understand the failure mechanisms. Results show that higher iron contents can reduce the tensile properties (especially the ductility) of the alloys mainly due to the increasing volume percent and size of the iron-rich intermetallics. Tensile failure mainly occurs at the iron-rich intermetallics/matrix interfaces for the platelet ß-Fe, but by the self-disassociation for the Chinese script a-Fe and Alm(FeMn). Cracking is easier to initiate and propagate along the longitudinal axis of the platelet intermetallics, but it can be deflected along the branches/arms of the Chinese script iron-rich phases, making the alloy more resistant to the propagation of the cracks, and thus the Chinese script iron-rich intermetallics are less harmful than platelet ß-Fe. In addition, it was also found that the Chinese script a-Fe has even a less damaging effect compared to the Chinese script Alm(FeMn) due to the relatively small size and compact morphology.

Jan 1, 2014

By Z. F. Lodhi, J. H. W. De Wit, H. A. Terry

Zinc and its alloys have been extensively used as replacements for Cadmium coatings in aeronautical and automobile industries. Zn alloys with low Co or Fe have been highly investigated but coatings with higher amount of Co are very difficult to achieve due to anomalism associated with these coatings. Anomalous Zn-Co-Fe alloy is a relatively recent addition to the family of Zn alloys. It is found that the addition of Fe in the electrolyte assist in overcoming the anomalism. In this research Zn-Co-Fe alloys especially with higher amount of Co (>15%) and Fe (~1%) are investigated, after overcoming the anomalism associated with its deposition, and the corrosion resistance is compared with pure Zn and Cd. It is found that an increase in Co to higher than 25 % accounts for a shift in the OCP to a level near Cd yet keeps it electronegative to steel. The coating shows superior corrosion resistance, in terms of its sacrificial and barrier properties in 3.5% NaC1 as compared to Zn and Cd.

Jan 1, 2006

By A. A. Rogozhin, E. G. Likhnikevich, S. I. Anufrieva, A. V. Kurkov

The Beloziminskoe deposit in Siberia is a large, potentially productive deposit of rare metals contained in ochreous apatite pyrochlore ores formed by weathering of a carbonatite. The ores are composed of pyrochlore, columbitized pyrochlore, monazite, apatite, magnetite, ferric and manganese hydroxide, titanic iron ore, zircon, hydromica, quartz, feldspar, and carbonates. A gravity-flotation enrichment flowsheet with application of cationic and anionic collectors has been developed. This flowsheet allows for obtaining a pyrochlore concentrate containing 44.3% Nb2O5 and 1.89% P2O5 with recovery of 55.83% Nb2O5 as well as an apatite concentrate containing 39.2% P2O5 and 1.05% TR2O3 with recovery of 62% P2O5 and 43.23% TR2O3 from ores containing 0.92% Nb2O5, 16.9% P2O5 and 0.6% TR2O3. Rare-earth concentrate containing 40% TR2O3 with recovery of approximately 10% TR2O3 was obtained at the same time. Major losses of valuable elements are related to slimes, which make up more than 50% of the ground ore. The niobium concentrate does not meet the phosphorus and radionuclide concentrations needed for the production of ferro-niobium. Acid leaching and sulfatization provided a high level of phosphorous and radionuclide removal. Conditions include hydrochloric acid pre-leaching at 75- 80°C with an 18% HCl solution for four hours and low-temperature sulfatization of acid-leached concentrate at 160-180°C for one hour followed by water leaching of the residue. The apatite concentrate could potentially be processed using nitric acid leaching. This technology is based on decomposition of apatite concentrate with 55-57% strength nitric acid with transfer of rare-earth metals into solution in the form of ammonium phosphate. This technology recovers a rare-earth concentrate containing 95% TR2O3 with extraction of 86%, and highly concentrated polynutrient fertilizer (ammophos) with phosphorus extraction of 95%. The completed research shows how complex multicomponent ores of residual soil may be processed for the extraction of niobium, phosphorus, and rare-earth products.

Jan 1, 2016

By Neda Zangeneh

Production efficiency from low permeability gas shales require techniques to optimize hydraulic fracture completions. One completion strategy involves the simultaneous or near simultaneous hydraulic fracturing of multiple horizontal wells to maximize the fracture network area and stimulated reservoir volume. However, changes to the in-situ stress field caused by an earlier hydrofrac on subsequent hydraulic fractures are not accounted for in traditional hydrofrac design calculations. Presented here are the results from a set of transient, coupled hydro-mechanical simulations of a rock mass containing two wellbores using the discontinuum-based distinct-element method. The results demonstrate the influence of stress-shadows generated by a hydraulic fracture on the development of subsequent hydrofracs from an adjacent well. It is shown here that these interactions have the potential to change the size and effectiveness of the hydraulic fracture stimulation by changing the extent of the hydraulic fracture around the secondary well.

Jun 1, 2012

By A. Liard, H. Sommelet, G. Sauriol

"Description des études qui ant conduit à la conception spécifique du système de drainage de la mine à ciel ouvert. Les approches différentes sont examinées ainsi que la valeur du système recommande.IntroductionLa Division Mines Gaspé de Mines Noranda Ltée exploite un gisement de cuivre par mine souterraine et mine à ciel ouvert à Murdochville, Québec. L&apos;exploitation par mine aciel ouvert a commencé en 1965 avec une operation à flanc de montagne. Elle se poursuit actuellement sous Ie niveau de la vallée dans une fosse dont Ie diamètre est de I&apos;ordre de 800 m (2,600 pi), et la profondeur de 150 m (500 pi) sou s Ie fond de la vallee. Elle doit atteindre une profondeur de 360 m (l, 180 pi) sous Ie fond de la vallee , avec des murs hauts de 360 à 490 m et des pentes moyenne de 44°. Le rythrne d&apos;extraction est actuellement de 85,000 tonnes par jour.Dans Ie cadre des etudes entreprises par les Services Techniques de la Division Mines Gaspé, la compagnie Géomines Ltée a été consultée pour étudier les conditions hydrogéologiques et hydrologiques locales et participer a la conception d&apos;un système de drainage superficiel et souterr ain. Un tel systerne de drainage visait: a éviter les importantes venues d&apos;eau qu i affectent I&apos;exploitation en periode de crue; amaintenir les pressions hydrostatiques au sein des parois de la fosse dans les limites imposees par les etudes de stabilite des pentes réalisees par la Mine.Les principales étapes de cette etude ont porté sur: la collecte et la compilation des données sur la géologie, l&apos;hydrologie et l&apos;hydrogeologie du site; . la détermination des caractéristiques hydrauliques du milieu rocheux à partir d&apos;études structurales et de test s de perméabilité;"

Jan 1, 1981