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By F. J. A. van Ruitenbeek, M. Dalm

In the presented study test work was performed with near-infrared hyperspectral imagery (NIR-HI) on 36 ore samples from a South-American epithermal Au-Ag mine. The aim of the test work was to investigate if NIR-HI provides information about the alteration mineralogy of samples that can be used to predict their economic value. Mineral distribution maps were produced from the hyperspectral images by using correlation coefficients between the image pixels and a set of reference spectra. These maps showed that detection of mineralogy with NIR-HI can be used to distinguish; i) ore particles with low Au and Ag grades, ii) ore particles with high carbon contents, iii) ore particles with high sulphur contents.

Jan 1, 2015

By G. Graves, J. A. Walker

"Abstract - The Mount Fronsac North volcanogenic massive sulfide deposit is the most recently discovered massive sulfide body in the Bathurst Mining Camp. The deposit occurs within a sequence of intercalated fine-grained felsic tuff and sedimentary rocks (Little Falls member), at the top of the Nepisiguit Falls Formation. Aphyric to sparsely feldspar-phyric rhyolite and related volcanic rocks of the Flat Landing Brook Formation overlie the host sequence. The massive and semimassive parts of the deposit have a north-south strike length of 525 m and a dip of ~45°E; the deposit is continuous downdip for 600 m, and thickness varies from 2 to 20 m. The deposit contains an estimated geologic resource of 14 Mt of low-grade, semimassive (>60%) to locally massive sulfides, and includes a high-grade zone of 1.26 Mt grading 7.65% Zn, 2.18% Pb, 0.14% Cu, 40.3 g/t Ag, and 0.40 g/t Au. The semimassive to massive sulfide intersections occur in an envelope of quartz-sericite±chlorite schist, which is interpreted to be intensely deformed felsic tuff. This sequence has a maximum thickness of 140 m and contains significant (up to 50%) fine- to coarse-grained disseminated pyrite. The pyritic envelope has a strike length of 900 m and extends over 1000 m downdip. Massive sulfides are found throughout this alteration envelope, but more commonly occur at or near the upper contact. The significance of the discovery of this deposit is that it represents a near surface discovery of a large tonnage sulfide body in a mature mining camp, one in which the possibility of discovery of a new shallow deposit had been all but discounted. This opens the possibility for future discoveries in this part of the Bathurst Mining Camp. Sommaire - Le gîte de sulfures massifs volcanogènes du Mont Fronsac Nord est la découverte de sulfures massifs la plus récente dans le Camp Minier de Bathurst. Le gisement est situé dans une séquence de tufs felsiques à grains fins interlités de roches sédimentaires (membre de Little Falls, au sommet de la Formation de Nepisiguit Falls. La partie massive et la semimassive s’étendent du nord au sud sur 525 m et ont un pendage de ~45°E; le gisement est continu sur 600 m en angle de chute et son épaisseur varie de 2 à 20 m. Le gisement contient une ressource géologique évaluée à 14 Mt de sulfures semimassifs (>60%) localement massifs à basse teneur, incluant une zone à haute teneur de 1.26 Mt titrant 7.65% Zn, 2.18% Pb, 0.14% Cu, 40.3 g/t Ag, et 0.40 g/t Au. Les intersections de sulfures semimassifs à massifs se situent dans une enveloppe de schiste à quartz-sericite ± chlorite interprétée comme un tuf felsique intensément déformé. Cette séquence contient une quantité importante (jusqu’à 50%) de pyrite disséminée dont le grain varie de fin à grossier et son épaisseur maximale est de 140 m. L’enveloppe pyriteuse s’étend latéralement sur 900 m et a été tracée jusqu’à 1000 m en angle de chute. Des sulfures massifs sont trouvés partout à l’intérieur de cette enveloppe d’altération, mais ils sont plus fréquents près du contact supérieur. L’importance de cette découverte tient à ce qu’elle est un exemple d’un gisement à fort tonnage nouvellement découvert à une faible profondeur dans un camp minier mature, i.e., un camp ou l’on ne croyait plus qu’il était possible de trouver un gisement près de la surface. Ceci ouvre la porte à la possibilité d’autres découvertes dans cette partie du Camp Minier de Bathurst."

Jan 1, 2006

By A. Brown

IN INTRODUCING the subject of rock pressures, it may safely be assumed that mining men are only too familiar with the physical effects of strata stresses that accompany the extraction of minerals. It may be further assumed that they have, as individuals, arrived at certain conclusions regarding their nature, based upon years spent in observing such phenomena and in learning how to continue mining in spite of them. Such hardly won experience forms the core of what is often referred to as 'pit sense'. This essential type of knowledge is not ?based on theoretical considerations, nor can it be found in text books. It is highly individualistic in nature and almost impossible to pass on from one generation to another in terms of precise rules for guidance. It is this aspect of individual judgment based on practical experience that has led to the significant phrase The Art of Mining.

Jan 1, 1956

By L. R. Bottomer, G. M. Leary

"The Copper Canyon property is located in the Galore Creek area of northwestern British Columbia. Porphyry copper-gold mineralization on the property is notable for its high gold content and close spatial relationship with a distinctive suite of high level syenitic and monzonitic intrusions, and pseudoleucite-bearing volcanic country rocks. The style of alteration and mineralization is similar in many respects to the nearby Galore Creek deposits.The current geological resource of 32.4 million tonnes grading 0.75% Cu, 1.17 g/ t Au and 17.1 g/t Ag is insufficient to support a mining operation, but definition of additional reserves combined with improved transportation infrastructure in the region may change this in the future. The climate, topography and proximity to an active glacier indicate that the most likely production scenario is an underground bulk mining operation, with the ore being milled offsite.IntroductionThe property is located at 57°07' North latitude, 131 °21' West longitude, on NTS sheet 104G/ 3W, approximately 160 km northwest of Stewart and 90 km south of Telegraph Creek (Fig. 1). The Galore Creek camp and airstrip are located 6 km to the west. Current access to the property is via helicopter either from Galore Creek, or from the Bronson Creek airstrip 32 km to the south-southeast.The deposit occurs within the Boundary Ranges of the Coast Mountains, on the north side of the east fork of Galore Creek, which flows northerly into the Scud River and thence westerly to the Stikine River.Topography is rugged. In the deposit area, elevations range from 1130 m to 1750 m. Valley glaciers and permanent snow and ice fields are characteristic of the region at these elevations, and at its southern limit, mineralization is truncated by the East Fork Glacier.The property is entirely above the treeline, and except for areas of moraine cover and talus slopes, outcrop is abundant."

Jan 1, 1995

The tensile test results of as-cast A356.2 grain-refined alloy castings show that the tensile strength can be improved by strontium modification (`SrM'), superheating at 900°C OM, and melt thermal treatment of the Sr-modified alloy melt (`SrMTT'). Both SrM and SrMTT processes can greatly improve the ductility (percent elongation) of the as-cast alloy. During solution heat treatment at 540°C, eutectic Si particles undergo fragmentation, spheroidization, and coarsening, thereby affecting their morphology. The effects of solution heat treatment on the tensile properties of the variously treated A356.2 alloy castings can be summed up as follows: the yield strength of the castings is significantly improved after 8 h solution heat treatment due to the precipitation of Mg2Si, after which it remains more or less the same with the further increase in solution treatment time up to 80 h; the ultimate tensile strength is also greatly improved within the first 8 h of solution heat treatment and then remains at the same level thereafter, up to 80h of solution treatment. The improvement in UTS is attributed to Mg2Si precipitation, dissolution of Si within the aluminum matrix, and changes in the Si particle morphology (spheroidization). The ductility of the as-received grain refined non-modified (`NM'), grain refined and superheated at 900°C (`SH'), and melt thermal-treated grain refined (`MTT') A356.2 alloy castings can be improved considerably with solution heat treatment e.g. from ~6% in the as-cast non-modified casting to ~10% after 80 h solution treatment.

Jan 1, 2011

By P. Marcotte, G. LeBlanc, S. Ouellette, J. Boutin

"To characterize noise and vibration sources of different types of mining equipment used in underground mining, the authors performed a study in eight Quebec mines on 28 pieces of equipment. This paper presents the procedure followed to select the equipment to be evaluated, and the low-cost acquisition system developed to perform multichannel time-domain data acquisition in harsh environments. It also presents the results obtained for the noise level produced by the equipment and for handarm and whole-body vibration exposures.RÉSUMÉ Dans le but de caractériser les sources de bruits et de vibrations de divers équipements miniers utilisés sous terre, les auteurs ont étudié 28 équipements dans huit mines du Québec. L’article présente la procédure suivie pour choisir les équipements à évaluer ainsi qu’un système multicanal à faible coût développé pour acquérir des données dans des environnements difficiles. Il présente aussi les résultats obtenus pour les niveaux de bruit produit par les équipements et pour les expositions main-bras et du corps entier aux vibrations."

Jan 1, 2015

By Deepak Bhadouriya, Saurabh Singh, Aditya Raj Suman

"An experimental study of chemically enhanced filtration and dewatering of fine coal slurry with and without additives was carried out. The experiment involved determination of effect of slurry concentration, additives (cationic, anionic and nonionic), filter area, filtration velocity, particle size and cake resistance on dewatering and filtration using vacuum filtration cell. Finally, the rate of filtration and dewatering and optimum amount of additives used were determined under suitable filtration condition. Overall, it was found that the filtration and dewatering characteristics were enhanced by increased slurry concentration, larger filter area and larger particle size. In addition of additives, the kerosene was found to be best for enhancing the filtration which yielded cake moisture reductions of approximately 17% by weight. At optimum dosages, the final cake moisture contents were reduced by 3.6% and 5.8% by weight using the appropriate surfactant and flocculent, respectively.INTRODUCTIONFor India, it is estimated that coal constitute a principal source of energy for the next several decades. It is majorly used at thermal power plants to generate electricity and also to a great extent in steel and cement industry. It has been observed that its consumption is increasing so as to meet the energy requirements of the country. It has been found that in a coal preparation plant; approximately 20-25 percent coal is of the mined coal of the range below minus 0.5 mm (28 meshes). Generally, this fine fraction is discarded due to its high cost of processing and further utilisatisation is very minimal. But with ongoing research and development for advanced clean coal technology, various new techniques have been evolved to maximize the utilization of available coal. In recent time technologies such as column flotation, cleaning of fine size coal to lower the ash content and low pyretic sulfur is feasible at high recovery value. But in various researches it is found that one of the biggest hurdles in utilization of fine coal cleaning technology by the coal industry is the economic dewatering of the fine clean coal product. Thus, until an economical and practical solution to dewatering of fine clean coal is achieved, the efforts devoted to developing fine clean coal technology will be wasted. In this paper an effort toward enhancing and developing the optimum technique of dewatering and filtration of fine coal slurry has been made."

Jan 1, 2016

By C. J. Simensen, R. Østhus, H. J. Roven, K. G. Skorpen, H. Kalager

"This work encompasses co-extrusion of alloy Al4.5Mg at the core and rapidly solidified Al4.5Mg1Ag forming the surface layer. The goal is to produce a multi-material by co-extrusion having a relatively hard surface as compared to a softer core. At the same time, work hardening in both alloys is expected to be significant due to Mg in solid solution. Precipitation hardening at 160°C is studied by applying solution heat treatments at 560°C. The hardness increased from 80 to 130 VH in the surface material after 236 h. Surprisingly, the Al4.5Mg alloy also shows pronounced aging at this temperature, i.e. from 70 to 90 VH. The relatively high solution heat treatment temperature introduces grain growth in the core, but this is insignificant for the RS surface alloy. Blisters forms at the surface and cracks follows large portions of the interface. However, the tensile ductility is significant in all conditions due to very pronounced work hardening, i.e. for the as co-extruded, T6, under- and over-aged. The elongation at fracture ranges between 40–45% and the tensile strengths 240–275 MPa. The tensile properties increase linearly with the thickness of the RS alloy, i.e. following the rule of mixtures.INTRODUCTION Al-Mg alloys in 5xxx-series are classified as non-heat treatable wrought alloys (Polmear, StJohn, Nie, & Ma, 2017). The formation of the binary ß-Al8Mg5 does not give a substantial increase in the strength of the alloys (Mondolfo, 1976). When a third element like Ag, Cu or Zn are added, G.P.?zones are formed at low temperatures and intermediate, partial coherent phases are nucleated somewhat higher temperatures and finally a ternary, equilibrium phase is formed (Auld, 1968; Cousland & Tate, 1986; Mondolfo, 1976). Both the formation of G.P.?zones and intermediate phases increase the hardness and strength of the materials. An intermediate, hexagonal T´?phase is formed in Al-5 wt%Mg-1wt%Ag, and finally the equilibrium, cubic phase (Al,Ag)9Mg5 is nucleated (Cousland & Tate, 1986; Mondolfo, 1976)."

Jan 1, 2018

By Michael R. Brown

A facilities success or failure of doing well during a regulatory inspection is typically measured by the number and type of citations that result, and financial liability resulting from those citations. The success of a facility during an inspection depends on several factors including, the preparation prior to an inspection, behavior and activities during and inspection, and finally, action taken following the inspection. This paper contains suggestions for improving inspection results and establishing an attitude of compliance at manufacturing and mining facilities.

May 1, 2002

By J. H. McMillan

Most of the recent papers read before the Institute have dealt with purely scientific matters, or with experiences in the various phases of mining operations. Very little, if anything, has been said concerning the part played by the human element in the industry. It is now opportune to consider this vital factor if we are to cope with the complex work of the present-day miner and, at the same time, meet the demands of the executive for greater efficiency. It is time we made an inventory of our knowledge to determine if we are absorbing the information so essential to modern mining practice. We must keep in close touch with all new ideas and developments in our chosen field and keep ourselves up-to-date in regard to everything pertaining to mining operations in general. The man who ceases to study ceases to advance. There are men who on attaining an executive chair give up all study, because they think they have reached the pinnacle of success. Modern industrial business, and coal-mining is no exception, demands that executive officers shall be 'live wires' -- men who are not only well-informed as to their immediate duties, but who are closely in touch with all matters of importance affecting the industry as a whole. We may be graduates of schools and colleges, but the training we receive in these institutions is only the foundation for our later work. Certainly no executive officer can know too much concerning the work he is engaged in, and the more he knows the more pleasure he will get out of his work.

Jan 1, 1925

By H. W. Smith, N. Ichiyen

A convenient method for the calculation of metallurgical balances, based on statistical treatment of all available data, is presented. An error analysis is included. Examples show the advantages of the method, and also that such balances are less precise than might be supposed.

Jan 1, 1973

By V. S. Sastri, M. Elboujdaïni

"Corrosion rates of silicon brasses, highzinc yellow brass, low-zinc yellow brass, leadedtin bronze and silicon bronzes in both permanent-mold and sand-cast conditions were determined in soft water of pH 3, 5 and 8, and hard water of pH 8 at 70°C by electrochemical polarization technique. The alloys in permanent- mold condition showed greater corrosion resistance than sand-cast condition. Corrosion rates obtained from weight loss measurements showed no observable trend of a difference between permanent-mold and sand-cast alloys.The corrosion rates decreased with increasing pH of the medium. Silicon bronze and silicon brass showed high corrosion resistance while leaded-tin bronze showed the least resistance. Addition of small amounts of aluminum improved the corrosion resistance of silicon bronzes and silicon brasses. Alloys in permanent- mold condition showed greater resistance to dezincification than sand-cast alloys when average pit depth parameter is considered."

Jan 1, 1997

By Alain Simard, André Gobeil, Sylvain Lacroix, Maurice Rive, Denis Racicot, Pierre Verpaelst

"The Abitibi volcano-plutonic belt forms the major portion of the Abitibi lithotectonic subprovince in the Superior Province. The Abitibi belt is composed essentially of"" (1) approximately 2.7 Ga old volcanic and sedimentary rocks; and (2) gabbro, tonalite, granodiorite and syenite intrusions occurring in well-defined prekinematic ( synvolcanic ), synkinematic and post-kinematic plutonic suites. Most of these rocks are metamorphosed to greenschist facies. Regional multi-phase deformation affects the volcano-sedimentary rocks. Deformation was initiated as these rocks were formed, and peaked at the end of the Keno ran orogeny with the emplacement of granitic batholiths.There are 145 former and current mines in the Quebec segment of the belt. To date, more than 420 Mt of ore have been extracted yielding 1,600 tonnesof Au, more than4,000 tonnesof Ag,4,400,000 tonnes of Cu and 5,300,000 tonnes of Zn. Mineral production is concentrated in geologic domains that approximately coincide with the boundaries of lithotectonic domains. We have compared the geology and mineral deposits of different domains to illustrate their distinct metallogenic signature. Certain domains are dominantly gold-producing (Cadillac-Malartic, Val-d'Or, Caopatina), others are base-metal producers (Matagami and Normetal), while others produce both gold and base metals ( Rouyn-Noranda, Chibougamau, Casa-Berardi-Joutel).Gold is extracted from quartz-rich vein deposits (for example, Val-d' Or), sulfide-rich veindeposits(Cadillac or Chibougamau) and from volcanogenic massive sulfide deposits ( Rouyn-Noranda). Base metals are generally mined from volcanogenic massive sulfide( RouynNoranda, Matagami, Normetal), although certain vein deposits yield base metals (Chibougamau) . Certain sectors are dominantly zincrich (Matagami, Normetal)."

Jan 1, 1990

By Alain Simard, Andre Gobeil, Sylvain Lacroix, Maurice Rive, Denis Racicot, Pierre Verpaelst

"The Abitibi volcano-plutonic belt forms the major portion of the Abitibi lithotectonic subprovince in the Superior Province. The Abitibi belt is composed essentially of"" (1) approximately 2.7 Ga old volcanic and sedimentary rocks; and (2) gabbro, tonalite, granodiorite and syenite intrusions occurring in well-defined prekinematic ( synvolcanic ), synkinematic and post-kinematic plutonic suites. Most of these rocks are metamorphosed to greenschist facies. Regional multi-phase deformation affects the volcano-sedimentary rocks. Deformation was initiated as these rocks were formed, and peaked at the end of the Keno ran orogeny with the emplacement of granitic batholiths.There are 145 former and current mines in the Quebec segment of the belt. To date, more than 420 Mt of ore have been extracted yielding 1,600 tonnesof Au, more than4,000 tonnesof Ag,4,400,000 tonnes of Cu and 5,300,000 tonnes of Zn. Mineral production is concentrated in geologic domains that approximately coincide with the boundaries of lithotectonic domains. We have compared the geology and mineral deposits of different domains to illustrate their distinct metallogenic signature. Certain domains are dominantly gold-producing (Cadillac-Malartic, Val-d'Or, Caopatina), others are base-metal producers (Matagami and Normetal), while others produce both gold and base metals ( Rouyn-Noranda, Chibougamau, Casa-Berardi-Joutel).Gold is extracted from quartz-rich vein deposits (for example, Val-d' Or), sulfide-rich veindeposits(Cadillac or Chibougamau) and from volcanogenic massive sulfide deposits ( Rouyn-Noranda). Base metals are generally mined from volcanogenic massive sulfide( RouynNoranda, Matagami, Normetal), although certain vein deposits yield base metals (Chibougamau) . Certain sectors are dominantly zincrich (Matagami, Normetal)."

Jan 1, 1989

By A. Baydusa, K. Barron

A theory for cutter roof failure in coal mines has been developed. It is shown that the key parameters influencing the likelihood of cutter roof failure are the rock strength, the vertical stress (depth) and the horizontal to vertical stress ratio. The support force necessary to prevent the development of this mode of failure is, in most cases, so high as to make it impractical to apply a force of such magnitude. It is, therefore, better to allow the failure to occur and to design a bolting system to support the dead weight load of the failed block. This is probably best achieved by using a yielding bolt system (such as split set bolts) which is anchored well beyond the top of the potential failure block. The maximum potential caving height determined from this theoretical approach compares favourably with field observations reported in the literature.

Jan 1, 1999

By P. K. Kaiser, D. D. Tannant

"A support system for large ground convergence conditions or burst-prone ground must contain holding elements (rockbolts, cable bolts, etc.) that are strong yet capable of sustaining large deformations, i.e., they must absorb as much energy as possible. Steel wire rope anchored in a borehole by a friction bolt provides these desired yield characteristics if the frictional anchorage is placed deep enough into the rockmass, i.e., in non-yielding rock or beyond the expected depth of rock ejected during a rockburst. Pull-out tests were conducted on wire ropes anchored by inflated Swellex bolts to assess the feasibility of this support concept. The test results demonstrate that a Swellex bolt generates a frictional anchorage that allows the wire rope to slide at high loads and to absorb significantly more energy than either a Swellex bolt alone, or a cement-grouted cable.The rope/friction bolt combination can be engineered to provide the desired energy absorption and allowable deformation by varying the installed lengths of the friction bolt and the rope. For yielding rope support, the contact length between the rope and Swellex bolt must be short enough to ensure that the rope can slip well before its tensile capacity is reached. A safe maximum overlap length is about one metre for the wire rope used in this testing. When used as support in the backs of drifts, a swaged button on the ropes end must be used to ultimately mobilize the full rope capacity thereby protecting against gravity-driven falls of ground."

Jan 1, 1995

By J. P. Harrison, N. Bozorgzadeh, M. Dolowy-Busch

"It is common in rock engineering practice to characterize the triaxial strength of intact rock by using only data samples of small size. Practical guidelines such as ASTM support such sample sizes. In this paper, we investigate the reliability of the Hoek-Brown strength criterion estimated from such samples. For this purpose, we use an unusually large published set of triaxial strength data to randomly select a large number of data samples of small size to simulate the situation that frequently encounters in practice. The samples are generated with different arrangements with regards to the confining pressure. We fit the Hoek-Brown criterion to each of these samples, obtain estimates of strength parameters and compare them to those obtained from the complete data set. Our analysis suggests that estimates based on small samples are not reliable and can lead to both over- and under-estimation of strength.Additionally, we use these small samples to investigate the statistical methods for obtaining design values of strength as suggested by limit state design standards such as Eurocode 7. We show that, if used in conjunction with small samples, these methods do not guarantee a safe estimate of strength and in many cases lead to highly over-conservative estimates.We present a potential solution to this problem by augmenting the small data sets with Bayesian informative priors to give much more reliable estimates of strength. We conclude with suggestions for the development of informative prior distributions."

Jan 1, 2015

By Dave Shook

A Mineral Processing facility in Montreal has recently implemented a leading-edge intranet solution for monitoring the performance of plant operations, and providing condition-based maintenance. This innovative multi-faceted software implementation incorporates: web-delivered plant information systems; area-wide control loop performance assessment (using sophisticated algorithms to evaluate poorly performing controllers); and integrated alarm management functions. The system has enabled a project to improve plant operations through better process control. Maintenance technicians, engineers, supervisors and managers all can see the performance of the controllers, and the performance of the plant itself, through webdelivered graphics and reports. Information is combined from many sources, real-time, historical, relational and analytical, to provide a complete picture of plant operation. The web-based solution centralizes the administration of user access, and simplifies the deployment of several different kinds of information to many desktops. It is an extensible system that allows users to create and share their own web pages and data views. The paper will discuss the solution architecture and the improvements the I.T., operations, maintenance, and engineering groups have experienced, and overall benefits to the facility.

May 1, 2002

By A. A. McDonald

Anode casting has been in operation for two years in Hudson Bay Mining and Smelting's Flin Flon smelter. The new plant allows all casting to be done on one shift and so achieves considerable labour savings. The equipment and operations are described. Some important features are as follows: very consistent anode weights by the use of the load-cell controlled casting ladle; excellent mould life ; very low reject rate; and trouble-free take -off tower. Some of the start-up problems are described and an outline is given of the main operator functions. Data on labour, propane and maintenance costs are presented.

Jan 1, 1977

By Jun Deng

The aim of this paper is to study the scientificity and reliability of three coal gas indices used to predict coal fire disasters, namely Graham?s ratio, CO/CO2 ratio, Litton ratio and their different characteristics and service conditions. Data from a programmed temperature experiment were applied to check their veracity and accuracy. Each index performed well in detecting the level of a fire. We conclude that it is better to redefine the definition through experimentation before applying a given index. Integrated analysis of the results can provide reliable reference data for predicting spontaneous combustion of coal.

Aug 1, 2013