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By M. Tsesarsky, M. Hazan, E. Gal

"Rock masses comprised of stiff inclusions in softer matrix are common in various geological environments. The heterogeneity and multi-scale nature of these materials make the evaluation of their mechanical properties a challenging task, which cannot be accomplished using conventional laboratory tests and composite mixture rules. We employ the homogenization method to estimate the mechanical properties of geological materials with inclusions. The homogenization method solves the equations of elasticity on the material (microscopic) scale for a unit cell subjected to unit strains under periodic boundary condition. The micro-scale elasticity equations are solved using the Finite Elements Method, and are in turn used to obtain the structure scale (macroscopic) material matrix.In this research, Finite Element models for unit cells with spherical and ellipsoidal inclusions were developed. Using the unit cells, a parametric study of the geometrical and statistical microscopic properties of the material composites was performed. The following parameters were studied: volumetric ratio, Young’s modulus ratio, size-distribution of inclusion and inclination angle of inclusions. The main purpose of the parametric study was to study the deviation from isotropy as a function of the aforementioned parameters.It was found that for volumetric ratio of 5%-40%, the deviation from isotropy increases, as the volumetric ratio of inclusions increases. For spherical inclusions, most of the cases studied exhibit quasiisotropic behaviour; whereas ellipsoidal inclusions exhibit considerable deviation from isotropy. The inclination of the ellipsoidal inclusions enlarges the deviation from isotropy (9% at random orientation and 26% at 0°)."

Jan 1, 2015

By T L. Horsley

This paper deals with the drilling and blasting methods employed at the Cassiar mine, which is located just south of the B.C.-Yukon border. It covers both the "pit" and "peak" mining operations. Specific problems, such as working in frozen ground, are discussed, and the breaking characteristics of the various rock formations are outlined. The paper concludes with a brief mention of the equipment used in the operation, as "~ell as an outline of the breaking costs. Introduction T HE Cassiar asbestos mine is located just south of the British Columbia -Yukon border high on a spur of McDame mountain. Chrysotile asbestos fibre occurs in a faulted enlargement of a serpentine sill lying conformably be-tween a series of sedimentary beds and volcanic flows which dip at 45 degrees into the mountain. One end of the orebody is eroded by a cirque in which a layer of permanently frozen ore and waste talus lies at the end of the mining benches. The topography at the mine is steep, with no flat areas. Roads, dumps, and areas for crushing,

Jan 1, 1965

By J. Groppo, W. Zhang, R. Honaker

"The flotation of monazite is depressed when using hydroxamic acid as a collector in the presence of calcium ions which may exist due to the dissolution of minerals such as calcite. Minor dosages of sodium hexametaphosphate (SHMP) were found to effectively depress calcite, whereas the flotation of monazite was not impaired in single mineral flotation tests. However, in a mixed mineral flotation system, monazite flotation was depressed significantly. The mechanism of hydroxamate adsorption on monazite and calcite, the depression mechanism of calcite on monazite, as well as the depression mechanism of SHMP on calcite and monazite were studied using micro-flotation, electro-kinetic, and adsorption tests. Findings indicate that the adsorption of hydroxamate on monazite was due to chemisorption while adsorption on calcite was a result of physical interaction. SHMP significantly increased the negative charges of calcite surfaces which depressed the adsorption of the hydroxamate anions on the calcite surfaces due to an elevated electrostatic repulsion force. When calcium-rich minerals such as calcite are mixed with monazite, the calcium ions dissolved from the mineral surfaces specifically adsorb onto the phosphate oxygen sites on the monazite mineral surfaces thereby causing depressing effects. The addition of SHMP to suppress collector adsorption on the calcite surfaces interacts with the calcium species that were specifically adsorbed onto the monazite surface, which prevents hydroxamic acid adsorption onto the rare earth oxygen sites due steric hindrance and results in the flotation depression of monazite. INTRODUCTIONAs one of the commercial rare earth ores, monazite has been widely exploited to produce additives for catalysts, batteries, alloys, etc. Because of the complexity and the fine nature of some monazite ores, methods such as gravity, magnetic, and electrostatic separation to treat beach sand monazite fail to produce satisfactory concentrates, suggesting the use of floatation is warranted (Cheng, Holtham, & Tran, 1993). The primary associated minerals of monazite ores include ilmenite, quartz, zircon, rutile, sillimanite (Dixit & Biswas, 1969; Pavez a& Peres, 1994, 1993). Using sodium oleate as collector for monazite has been reported in many studies (Cheng et al., 1993; Dixit & Biswas, 1969; Pavez & Peres, 1994, 1993). Several investigations have reported maximum floatability of monazite occurring at pH values between 8 and 9 (Cheng et al., 1993; Dixit & Biswas, 1969). A study conducted by Pavez and Peres (1994) compared the use of hydroxamate and sodium oleate for the treatment of a monazite ore and found that hydroxamate significantly improved the grade of rougher concentrate."

Jan 1, 2016

By S. Torres, J. Álvarez, R. Castillo, R. Fuentes, C. Sandoval, R. Parra, Myakalwar A. K., M. Velázquez, J. Yáñez, D. Sbarbaro

Rapid analytical assessment in copper mining industry is a limiting factor for operational purposes and for the improvement of processes. The present work aims to review the analytical assessment in the copper industry utilizing emerging spectrochemical techniques such as laser induced breakdown spectroscopy (LIBS) and UV-Vis-IR Hyperspectral Sensing. LIBS is a plasma based spectroscopic method where the sample surface is irradiated by high power laser. The light emitted from the plasma contains atomic -molecular spectral information and can be detected using a simple CCD based spectrometer. UV-Vis-IR Hyperspectral Sensing is produced by the reflection of light from the sample’s rough surface in all directions and it can be collected by using an ellipsoid or paraboloid mirror arrangement. The electromagnetic radiation emitted by the samples in the UV-Vis, NIR and MIR region can be used for molecular characterization. The spectrometer splits different wavelengths through a CCD arrangement in 2D spatial and spectral dimensions, thus a hyperspectral cube of data is generated. Chemometric techniques such as principal component analysis (PCA), K- nearest neighbors (KNN), support vector machine (SVM) among others, can be applied to LIBS and Hyperspectral data for better classification and quantification purposes in copper ores. Real- time determination of elemental and mineral species used for online processing control will help to achieve the copper industry 4.0. INTRODUCTION The demand for copper mineral resources is intensely growing with the increase in population, per capita GDP, the development of new technologies and the increase in global living standard. With the rise in consumption of copper, it is important to optimize mining and metallurgical processes tending to the copper industry 4.0 (Ge, Song, Ding, & Huang, 2017). The real-time analytical assessment in the mining and metallurgical processes is a crucial part for allowing the global improvement in mining industry. The features considered for better analytical assessment are the instrumental automation and interconnection, real time results, low cost, quality in terms of accuracy and precision. Furthermore, improving recovery (extraction), timing and quality of final products avoiding environmental impacts. Some elements such as Cu, Fe, Ag, Au, Mo, S, As, Pb, Zn are important to be determined in the process control. Additionally, rapid mineral identification of few species such as CuFeS2, Cu4FeS5, FeS2, CuS, Cu2S, MoS2, Cu3AsS4, FeAsS, among other can be challenging.

Jan 1, 2019

By Yan Yang

The Jinfeng gold mine is one of the three gold mines that Eldorado Gold has in China and it is the second largest gold mine in China. The mine is located in a relatively remote and mountainous area in the southwestern Guizhou province. The orebody is similar to the Carlin type deposit in Nevada. The mill throughput was designed to treat 3,600 tones per day. The ore comes from open pit mining and underground mining, and is fed to one-stage jaw crushing. The crushed ore is stockpiled, reclaimed and then fed to the SABC grinding circuit. After classification with hydrocylones, the ore is floated, and the resultant concentrate is oxidized biologically in a process known as BIOX®. The oxidized concentrate is then washed in a CCD circuit and finally leached with cyanide in a CIL circuit for gold extraction. Jinfeng produces about 180,000 oz of gold per year. This paper introduces operations and modifications of SABC circuit over the past three years, and then describes some technical characteristic of the SAG mill and other circuits in the processing plant. Major modifications and improvements on the SABC circuit are described in the paper, including: 1. Impacts of grinding ball and mill liner with respect to material selection, quality, hardness, manufacturing methods, and interactions between mill liner and grinding ball. 2. Effect of milling operation parameters on milling efficiency. 3. Impacts of SAG mill scats and modifications of grate size to improve mill throughput. 4. Design and construction of a pebble crushing system, and recycle the crushed scats to the SAG mill to improve mill throughput. With the above-mentioned modifications, 20% increase over the design in mill throughput has been realized over the past three years, and operating cost has been significantly reduced. However, some issues still remain, and thus process modifications and technical innovations are still needed.

Jan 1, 2012

By D. R. Schmitt, N. Ong, R. S. Kofman

Shales and mudstones comprise about 75% of all the sedimentary rocks. In, particular, organic rich shales are considered as a petroleum source rock and more recently with the advent of hydraulic fracturing technology to be a reservoir in their own right. In this sense, the aforesaid motivates our work with laboratory measurements of elastic properties of these geologic materials, which are known to be anisotropic. As such, assuming Vertical Transverse Isotropy (VTI) symmetry, the dynamic and static moduli of a series of cores from various geological formations in Alberta, Canada are simultaneously investigated as a function of confining pressure using the ultrasonic pulse transmission method and strain gages. Dynamic moduli were obtained from ultrasonic P- and S-wave velocities measured on a prism cut with faces perpendicular, parallel and oblique to the assumed vertical axis of symmetry. Static moduli were calculated from strain-stress curves obtained along the directions perpendicular and parallel to the assumed axis of symmetry as well. Velocity measurements show that samples are highly anisotropic, but that the pressure-dependent behaviour of the wave speeds differs. VP(90°) and VSH(90°) both with layer parallel propagation and polarizations change little with pressure while VP(0°) and VS(0°) (both with layer perpendicular propagation) display significant nonlinear responses particularly at pressures < 25 MPa. These characters transfer to the derived full set of elastic constants. In order to effect a proper comparison of the dynamic and static moduli, we convert the dynamic elastic constanst to linear compressibilities pependicular (Kdyn1) and parallel (Kdyn3) which are directly comparable to the static tangent compressibiities obtained by differentiation of the observed strains. Both sets highlight the anisotorpic nature of the material but most interestingly Kdyn1 _ Ksta1 but Kdyn3 > Ksta3 by nearly 40% for one of the samples. The other samples measured respond similarly suggesting that conceptually the structure of such materials could be considered to be constructed of alternating stiff or compliant layers. This finding has implications in the response of the formation to stress particularly during hydraulic fracturing and the interpreation of acoustic logs in providing appropriate measures of elastic properties for engineering purposes.

Jan 1, 2015

By R. C. McMurchy

"The Powell mine is in western Quebec about 2 miles northwest of the adjoining towns of Noranda and Rouyn. It is the original discovery of the area, its gold-bearing quartz vein having been discovered in 1922. Considerable work was done on this vein by several companies and discontinued because the grade, when gold was $20 an ounce, was too low for profitable extraction. Between 1922 and 1924 an inclined shaft was sunk to 225 feet and drifts were driven 240 feet on the 100-foot level.In 1929, due to the discovery and development of the Horne mine at Noranda, interest was revived in the property. Sulphide deposits of the disseminated and vein types were explored on the Powell claims. On the B copper 'showing', a vertical shaft, now known as the 'old copper shaft', was sunk to ·a depth of 167 feet and 300 feet of lateral work was carried out on the 150-foot level. As no orebody was discovered this work was discontinued.In 1933 the present company, Powell Rouyn Gold Mines, Limited, was formed and the gold-bearing quartz veins were again tested by drilling and trenching. In 1936, the price of gold having risen to $35 an ounce, operations were resumed. Since then the inclined shaft (No. 1) has been deepened to 500 feet, a second shaft (No. 2, vertical) on the main quartz vein has been sunk to 2,630 feet, and ll; shallow vertical shaft (No. 3) on the same vein but in the south claim has been sunk to 500 feet.Lateral work now approximates 9 miles, and to November 15th, 1946, 1,685,674 tons of ore, which averaged 0.129 oz. gold per ton and 73.6 per cent. Si02, had been extracted."

Jan 1, 1954

By L. O. Cooper

IN THE operation of most mines, hoisting ropes, made of steel, play a very important part in the conveying of men and material between surface and the underground workings. It is obvious that, in order to maintain a maximum degree of safety, certain restrictions must be placed on the loads that may be carried by hoisting ropes, as well as on other factors that may affect the life of the rope. It is the purpose of this paper to suggest ?a new method of defining the necessary restrictions. The three main stresses in a hoisting rope are the static stress, bending stress, and dynamic stress. Crushing stresses, which are also present, are largely indeterminate and may best be allowed for by proper grooving of drum and sheaves, by adequate inspection of cross-over points, and by limiting the number of layers on the drum. They will, therefore, not be considered in this analysis. In the ?recent Ontario regulations, the limiting conditions for the main stresses are specified separately. The static stress is limited by setting a minimum static safety factor of 5.0 The dynamic stresses are allowed for by specifying a minimum capacity factor of 8.5, which has the effect of increasing the safety factor required at smaller depths in a uniform manner. The bending stresses are limited by calling for a drum-dia./rope-dia. ratio of at least 60 for ropes up to 1 inch in diameter and 80 for ropes greater than 1 inch in diameter. One disadvantage of this method is that the controls are too rigid and do not allow the operator sufficient freedom of action within safe limits.

Jan 1, 1951

By R. K. Collings

Mineral wastes from the mining, metallurgical and chemical processing industries in Canada amount to about 800 million tonnes annually. Such wastes often are largely non-metallic in composition and are of interest for traditional non-metallic mineral uses and applications. Mineral waste disposal and maintenance are costly; furthermore, these wastes may pollute groundwater, rivers and lakes. These factors and an increased appreciation of the potential utility of some mineral wastes have stimulated research in this area.

Jan 1, 1984

By J. Keith Seidler, David R. Lentz, Douglas C. Hall, Nicholas Susak

Abstract - The Ta-Nb-Zr-REE-rich McKeel Lake alkali granite pegmatite-aplite dike swarm is hosted within the late Silurian multiphase alkali granite intrusion (Welsford) near Browns Flats in southwestern New Brunswick. A steep easterly dipping series of pegmatite-aplite dikes trending 170º can be traced 150 m along strike; they are up to 40 cm wide, closely spaced (10-20 cm apart), and interconnected by narrow branching dikelets that generally trend perpendicular to the overall strike direction. The Welsford intrusion has mantle A-type affinities characterized by enrichment of Zr, Ta, Nb, Th, and rare earth elements (REE). Two separate sets of dikes have been identified: (1) an unmineralized fine-grained porphyry, which occurs at depth and seems to be the youngest intrusive phase; and (2) a mineralized pegmatite-aplite dike swarm (419 ± 20 Ma) that crops out at surface. The mineralized pegmatite-aplite dikes likely represent a late magmatic, highly fractionated phase of the Welsford intrusion. XRF and INAA data indicate that the Welsford intrusions and related pegmatite-aplite dikes show elevated levels of Ta (74-220 ppm), Nb (750-3,040 ppm), Zr (1,450-36,000 ppm), Y (540-3,070 ppm), Th (170-870 ppm), U (60-250 ppm), Ce (430-1,950 ppm) and Yb (110-290 ppm). Electron microprobe analysis of two samples identified Ta-Nb- and REE-rich phases: euxenite, fergusonite, aeschynite, (Y)-aeschynite, and a REE carbonate.

Jan 1, 2005

By John (Jack) D. Young, Frank M. Wheeler

Metallurgical plants are typically large, complex facilities. Their design is a multidisciplinary activity with a wide range of inputs, based on: the business case; metallurgical and process requirements; and the main processing equipment selection. Many constraints limit what can be achieved. Appropriate phasing of the design and development, and clear go/no-go decision criteria, are critical to successful implementation of a plant design project. Risk management concepts are used as a framework for successful project development, working from the business case, through project development, to implementation and startup, paying constant attention to technology, safe design, and sustainability. 1.1 INTRODUCTION The subject of “Metallurgical Plant Design” is the design of metallurgical plant facilities in the broadest sense. Plant design represents the culmination of many multidisciplinary activities: knowledge of process metallurgy is applied to design facilities to manufacture useful, economical, metal-based products. In the field of metallurgy, plant design is often overlooked, and its unique requirements are commonly not well understood, let alone appreciated. This book is a contribution to remedying this situation. The focus is the specifics of the metals industries, because an extensive literature already exists on the general topic of plant design.

Jan 1, 2015

By Q. Li, X. -L. Lei

Accompanying global energy shortage and high energy prices, shale gas has been the focus of exploration and it has attracted great attention from both academia and industry. The combination of horizontal drilling and hydraulic fracturing enables the extraction of huge quantities of shale gas from impermeable shale formations. During the process of hydraulic fracturing, great amounts of water, sand and chemicals must be injected into the shale formation at a high pressure, which may trigger seismicity. Such events could occur due to the presence of faults or the reactivation of these potential faults. Shale is the main component of source rock in the Sichuan Basin, China, and has the greatest contribution to the natural gas of the basin. In order to investigate the fracturing mechanism of shale in the Sichuan Basin, China, a series of rock fracture tests under triaxial compression were carried out in the laboratory in order to investigate the hydraulic fracturing behavior in relation to the seismicity. Based on the high multichannel waveform recording system, the detailed spatio-temporal distribution of acoustic emission due to micro-cracking was used to examine the deformation and fracture behavior of shale. In addition, the effects of confining pressure on the deformation and fracture in shale under triaxial compression by acoustic emission monitoring and X-ray computed tomography were discussed in the paper. The experimental results indicate that the shale samples demonstrate brittle fracture behavior. The confining pressure has a great effect on the complexity of the fracture planes and the spatial distribution of acoustic emissions, but few contributions to the location of the major hydraulic fracturing plane. The foliation of shale plays a dominant role in the rupture process and the geometry of the major hydraulic fracturing plane. The high confining pressure increases the strength and restrains the deformation of shale during compression process. These results shed some light on the understanding of onset of hydraulic fracture initiation not only for shale gas exploration and production, but also for CO2 geological storage and underground energy storage.

Jan 1, 2015

By T. G. Phillips

"This paper gives an inside look at a bulk terminal and describes the preparations that must be made by a company in developing such a terminal and its position in today's traffic pattern. The following headings cover the subject material: (a) Traffic pressures, their detection and measurement, (b) position in the traffic flow -selection of site, (c) transportation connections -present and possible future routes, (d) engineering studies and costs, (e) contracts, the basic material for insured traffic, (f) financing, (g) budgetary control, (h) development of new techniques, (i) growth into new cargoes or cargo-handling methods and (j) consolidation."

Jan 1, 1968

By J. D. Galloway

The mining industry of British Columbia continues to grow steadily in importance. The gross value of the production in 1925, sixty-two and a half million dollars, was a record, and ali indications point to the 1926 output registering a still higher figure. In an industry such as mining, where production means the depletion of known ore reserves, the discovery and development of new &apos;ore-deposits is of the utmost importance. To maintain and increase production, steady development is essential. In this respect, the record of the last three years in British Columbia mining is most satisfactory, as in this period more real development has been carried on than in any similar period in the history of mining in the Province. Prospecting, or the search for new ore-bodies, has also been fairly active, but comparatively few important new discoveries have been reported in the past few years. The mineral output of British Columbia consists of Iode minerals, coat and coke, and building materials. In 1925 the value of the output of these three classes of products was, respectively, about 46, 13, and 3 million dollars. The industry as a whole embraces the mining of these materials, and the treatment and manufacturing processes involved in preparing the various products for the market.

Jan 1, 1926

By J. R. Perumareddi, V. S. Sastri, M. Elboujdaini

It is well known that high strength steels used in aerospace industry, are generally susceptible to hydrogen embrittlement during surface treatment such as electroplating with zinc on cadmium. Hydrogen embrittlement reduces ductility and results in brittle fracture rather than failure by plastic deformation. Hydrogen embrittlement of high strength steels is mitigated by surface treatment such as plating with other metals. Data on the hydrogen contents of steels before and after surface treatment by hot extraction-thermal conductivity, secondary ion mass spectrometry (SIMS) and UV-visible spectroscopy along with the mechanism are presented.

Jan 1, 2006

By B. K. Mishra, P. Patnaik, B. C. Tripathy, I. N. Bhattacharya

Cobalt is an essential metal considering its numerous industrial applications. The demand for the metal is increasing due to its wide range of use in, for example, rechargeable batteries and as an alloying element in super alloys. Cost effective production of Co is critical. Electrowinning from aqueous sulphate solutions is the preferred technology available for the production of Co. Attempts are being made to produce uniform, smooth and bright deposits of cobalt metal. Use of organic additives in the electrolytic bath improves current efficiency and deposit morphology of the metal. We investigated the effect of quaternary amines TEABr, TPABr and TBABr during cobalt electrowinning from aqueous sulphate solutions. Among the additives studied, TEABr yielded the best results. Smooth and bright deposits of cobalt were obtained at low concentration of TEABr (10 mg/L) maintaining a very high current efficiency of 99.6%. X-ray crystallography indicated that (100) is the most preferred plane of crystal growth.

Jan 1, 2014

By A. -M. Cadieux

During the geological synthesis of the Réservoir Pipmuacan area (NTS 22E) by the Ministère des Ressources naturelles (Québec), several ilmenite-apatite occurrences, some well-known and some recently discovered, have been examined. These occurrences are hosted in the Lac-Saint-Jean and Labrieville AMCG anorthositic suites. The Lac-Saint-Jean Anorthositic Suite (1160-1140 Ma), composed of multiple intrusions covering an extensive surface area, is characterized by labradorite plagioclase. The Labrieville Anorthositic Suite (1010-1008 Ma) is characterized by andesine plagioclase. It was previously known as the Labrieville Anorthosite, which was composed of a small isolated pluton located east of the Lac-Saint-Jean Anorthositic Suite. However, new geochronological data and field observations indicate that the Labrieville Anorthositic Suite in fact includes several intrusive bodies, namely the La Hache Monzonite and the Mattawa Anorthosite. A series of major structures (Saint-Fulgence, Pipmuacan, and Chute-des-Passes deformation zones) and their conjugate faults played an important role in the emplacement of the Lac-Saint-Jean Anorthositic Suite. The Saint-Fulgence deformation zone appears to have been involved in the emplacement of the Labrieville Anorthositic Suite. Oxide mineralizations are abundant in both anorthositic suites. Ilmenite, magnetite (± titaniferous), and apatite assemblages are found mostly in the labradorite-type anorthosites, while hemo-ilmenite, magnetite and apatite assemblages are associated only with the andesine-type anorthosites. Field works has revealed ilmenite-apatite mineralizations in a variety of settings, with grades reaching 48% TiO2, 16.2% P2O5, and 71.7% Fe2O3 (tot). Numerous oxide-bearing gabbronorites, often accompanied by or located near massive apatite-oxide accumulations (nelsonites), were discovered. Among these oxide-rich zones, breccia zones with anorthosite enclaves in an oxide matrix (ilmenite-magnetiteapatite) have been observed. Locally, ilmenite-apatite mineralization occurs as cumulate concentrations in ultramafic rocks. Evidence has been observed for immiscible magmas, for magmas differentiated from a mangerite or jotunite parent, and even for late magmas differentiated from the anorthosite magma itself (apatite-bearing anorthosite). Finally, the northern part of the Lac-Saint-Jean Anorthositic Suite hosts sulfide and vanadium mineralizations associated with ilmenite-apatite enriched zones, with grades reaching 1.48% Cu, 1.22% Ni, 1.6% Cr2O5, 0.25% Co, and 0.52% V2O5.

May 1, 2003

By R. Loney, M. Militzer

There is a significant demand for new high strength steels with fine grain sizes for structural applications. One approach in this regard is to develop hot-rolled HSLA steels where refining the microstructure leads to increased strength levels, e.g. 700 MPa yield strength, that can be attained by suitable modifications of chemistry and processing. Here, an HSLA steel is investigated that contains 0.05wt%C-1.65wt%Mn-0.20wt%Mo¬0.07wt%Nb-0.02wt%Ti and approaches the above strength class. The ability to control and predict the mechanical properties of hot rolled steel depends strongly on the thermomechanical processes, which the steel undergoes. The final microstructure and, thus, the properties of the hot-rolled steel are a function of the austenite decomposition obtained during accelerated cooling on the run-out table and precipitation during coiling. The austenite-to-ferrite phase transformation under run-out table conditions has been investigated using a Gleeble 3500 thermomechanical simulator equipped with a dilatometer. The effects of cooling rate and initial austenite microstructure including the degree of work hardening on austenite decomposition kinetics and ferrite grain refinement have been quantified. Results show that grain refinement can be optimized by the presence of work hardened austenite and accelerated cooling. Based on the experimental results, a model is proposed to predict the transformation start temperature and the resulting ferrite grain size for run-out table cooling conditions.

Jan 1, 2004

By F. Mercier-Langevin

ABSTRACT; Agnico-Eagle’s LaRonde mine is one of the deepest mines in Canada. Ground conditions in the deeper levels can be very challenging, ranging from hard and brittle to soft and squeezing. As a result, rock mechanics and ground control practices have had to evolve considerably to accommodate progressively deeper mining activities. This paper focuses on the deeper levels of mines and how the difficult ground conditions encountered there have influenced the mining strategy. The first section examines ground control practices and support systems in highly stressed, poor quality rock. The evolution of level layout is also presented. Finally, improvements in stope sequencing are reviewed.

Jan 1, 2010

By Claude Hubert, Alex C. Brown, Michel Richard, Rejean Sirois

"The Pierre Beauchemin gold deposit, situated 15 km NW of Rouyn-Noranda, produces an average of 1050 tonnes of ore a day. Reserves are 1.2 Mt grading 5.6 g/t Au. The deposit, located in a shear zone within the Flavrianpluton, in the Blake River Group, is hosted by four major rock types: meta-trondhjemite, meta-tonalite, hybrid rocks and meta-diorite (the prefu; ""meta-"" is omitted thereafter). The trondhjemite, tonalite, and metamorphic hybrid rocks are spatially distributed as a series of sub-horizontal tabular sills that form a genetically related group. Early fractures that permitted either the emplacement of pre-diorite felsic dikes or the formation of a visible alteration caused by early fluid circulation might have been developed in response to initial strain created during regional deformation. These fractures were precursors to the emplacement of diorite and the development of major shear planes. Sub-horizontal north-trending en échelon diorite lenses are observed at the mine. Together, these diorite lenses constitute larger scale diorite zones which are observed at the scale of the pluton. The diorite zones are interpreted as evidence of an episode of sub-vertical extension sustained by the layered trondhjemite, tonalite and hybrid system. The anisotropy created by the less competent sub-horizontal en échelon diorite was an important factor. In shear zone development and subsequent mineralization. The tonalite and diorite accommodated further defomation and developed the main N030°/40° ESE shears along with the spatially associated N060°/50°-60° SSE, and the N000°/10°-40° E shear zones. The N000° shears are interpreted as refracted or deflected equivalents of the N030° shears. The combined shears compose the Eldrich shear system which trends approximately N030°/40° ESE and has had a general reverse movement with a minor sinistral component.Gold mineralization occurs in all four major rock types as en échelon sigmoidal shaped lenses associated with the major N030° deformation system. The distribution of ore lenses can be divided into two categories: The first category occupies sub-horizontal diorite zones. The lenses trend N-S, dip 100 40° E, and are associated with shear zones, sub-horizontal fractures or tonalite-diorite contact planes. The second category of lenses is found in felsic granitic rocks; the lenses trend either N0300!40°ESE or N060°/50°-60° SSE. Local hydraulic breccia zones are observed near ore zones occupying felsic granitic rocks. These breccias may have resulted from high fluid pressures brought upon by confinement as a result of impermeable zones in an anisotropic tonalite-diorite system."

Jan 1, 1990