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By T. S. Smith, C. C. Rennie

"THE LEAD-ZINC and tungsten mines of Canadian Exploration Ltd are on Iron Mountain, 8 miles south of Salmo, B.C., in the Nelson mining division. Relative location of the mines is shown on the general plan.First recorded lead production was in 1908 from surface outcrops. Small amounts of high lead ore were mined intermittently until 1926. No major lead-zinc production occurred until 1949 when outcroppings on the south side of the mountain were mined and diamond drilling began to prove the existence of a large replacement orebody. Lead-zinc ore has been mined continuously from the Jersey orebodies since March 1949, with monthly tonnage as high as 50,000 tons per month, but currently averaging 30,000 tons per month.Schee1ite-bearing tungsten ore was found in 1942 by H. Lakes in an old adit and open cuts at the north end of the Emerald tungsten orebody. The Emerald tungsten mine was developed by the Federal Government as a Wartime Metals project and operated for eight weeks in the fall of 1943, when the poor demand for tungsten closed the mine. Canadian Exploration Ltd. purchased the mine in 1947 and mined in excess of 100,000 tons in 1947-48 until the demand for tungsten dropped again and interest was centred on lead-zinc. The Federal Government repurchased and reopened the Emerald Mine in 195 L and built a new concentrator. The mine and mill were sold back to Canadian Exploration Ltd. in 1952.Regional Geology and IntrusivesThe host rock for both the lead-zinc and tungsten mineralization is the Laib formation of Lower Cambrian age, which consists of 400 feet of crystalline limestone underlain by beds of argillite, and argillaceous limestone locally altered to ""skarn"" or ""tactite"". The Laib limestone is overlain by black argillite and underlain by the Reno quartzite of Pre- cambrian age. Repetition of folded beds has allowed the interpretation of the large isoclinal fold which repeats the limestone (see general cross-section). Dolomitization and the associated lead-zinc ore have been found only in the right-side-up limestone and are not known in the overturned limestone.Two elongated stocks of granite cut the sediments. The Emerald stock outcrops along the east side of the Emerald tungsten mine and again west of the Jersey workings, while the Dodger stock outcrops only at the north end of the Iron Mountain. The shape and attitude of these bodies are believed to have been governed partly by pre-granite faulting and partly by pre-granite folding of the sediments. Although some forceful intrusion may have occurred the detailed granite surface indicates a gentle stoping emplacement."

Jan 1, 1949

By L. Vu, V. Popov, J. Beland, R. Darling

"The Ferderber gold deposit is of Archean age. It consists of a series of gold-bearing quartz lenses within a shear zone that crosscuts the central part of the quartz dioritic Bourlamaque batholith. On average, this zone strikes N70E and dips 65SE. The Ferderber shear zone, which hosts the ore lenses, has been affected by a succession of tectonic events. A possible early period of brittle shear, accompanied by the formation of quartz lenses, resulted from strike slip movement along the zone. These early quartz veins were subsequently folded and boudinaged during reverse movement that accompanied a prolonged period of ductile shear. More quartz veins were emplaced in the shear zone at this time; these were also deformed by the thrusting. The latest tectonic event to affect the shear zone was a period of brittle fracture.Early dextral strike-slip movement on the shear zone is suggested by the local occurrence of Riedel shears, the preferred association of ore with east-northeast oriented segments of the zone, and by the apparent en echelon arrangement of some ore lenses. The most important event, a reverse movement, is indicatedby the attitudesoffoliation, folds, boudins, COS tectonites and slip planes. The late brittle fracturing formed narrow gouge filled faults, locally flanked by brecciazones, whichrun generally within and parallel to the shear zone, and also conjugate fractures that crosscut the zone.The Ferderber and six other adjacent gold deposits were formed in a structural regime dominated by a generally horizontal north-south regional compression. The Y axis of the strain ellipsoid is east-west and varies from horizontal to a plunge of 25 0 w."

Jan 1, 1987

By S. E. Jackson, L. J. Cabri

Quantitative determination of gold at sub-ppm concentrations in sulphide minerals is an important component of deportment studies for sulphide-gold deposits. Laser Ablation Inductively Coupled Mass Spectrometry (LA-ICP-MS) analysis is preferred for this application because it rapidly and cost-effectively provides spatially resolved (<20 pm), low ppb concentration data for gold and other elements in mineral grains. Recent advances in LA-ICP-MS analysis include the development and application of elemental mapping. Raw signals from multiple line scans or lines-of-spots are deconvoluted and calibrated to generate elemental maps which provide detailed information on spatial variations of gold and other elements within and between grains.

Jan 1, 2011

By John H. Fowler

"Most of the aggregate used in Nova Scotia is produced from numerous glaciofluvial and ice-contact deposits scattered throughout the province. Production from bedrock sources is increasing, with most of the coarse aggregate used in the Halifax-Dartmouth area coming from quarries operating within the metro area.A recently completed provincial sand and gravel inventory mapping program has identified some ""resource-poor"" areas where comprehensive aggregate evaluation programs are underway. Although some areas of the province are experiencing aggregate supply problems, large volumes are exported to markets as far away as Bermuda.IntroductionThe Nova Scotia Department of Mines and Energy has been involved with aggregate resource studies for several years, although sand, gravel and crushed stone are not designated as minerals under the Mineral Resources Act of Nova Scotia. Our role has been to provide the aggregate industry with resource data as well as provide similar information to governmental agencies involved with municipal planning, water resource studies and environmental protection regulations. Several private consulting firms use the information in many of their site development studies.We became involved with aggregates in a rather roundabout way. Several years ago, an outcry from inhabitants of a small coastal community over the removal of sand and gravel from a local beach moved the provincial Department of Lands and Forests to take action to protect provincial beaches. We were asked by the Department to provide information and to suggest alternative sources here operators extracting sand and gravel from beaches could relocate. This request initiated an aggregate inventory survey in southeastern Cape Breton, which was later extended to cover the entire province. The initial provincial sand z and gravel inventory survey provided a series of 1:50,000 maps showing the distribution of sand and gravel deposits in the province."

Jan 1, 1982

By Egbert Burchardt

The challenge of "ore bodies getting steadily harder and lower in grade" was brought to light during the first oil crisis in the 70&apos;s. Shortly afterwards, HPGRs appeared on the scene with the promise of saving energy. This combined with developments in wear protection for the rolls ushered in a period of trade-off studies that considered the HPGR as an option to improve project economics or to even make projects feasible at all. Since then, applications of HPGRs at Cerro Verde (Freeport), PTFI Grasberg (Freeport), Mogalakwena (Anglo Platinum), Tarkwa (Goldfields), Boddington (Newmont), Penasquito (Goldcorp), and others have contributed to the creation of a formidable basket of operating experience. Collected through years of successful operation, this information has been used to validate design criteria, scale-up factors and establishing a clearer picture of what "to do" and what "not to do". This paper compares results from various mining operations using HPGRs in their processing plants. Some of the lessons learnt in different operating environments are reviewed in order to support proper implementation and operation of HPGR&apos;s. Some of the development programs that have been initiated to improve wear life of the tyres and to reduce overall operating costs are reviewed. It is timely to summarize today?s experience and analyse its implications for existing and new operations.

Jan 1, 2012

By B. Tiryaki, M. Ayhan, O. Z. Hekimoglu

Coal shearers are one of the major sources of dust and fines in underground coal mines. Despite considerable research investigations, no comprehensive in situ investigations coupled with extensive laboratory studies on the effects of drum design on generation of dust and fines have been found. It may be for this reason that many major shearer drum manufacturers persistently employ a certain drum-lacing pattern on current coal shearers, which is believed to cause excessive dust and fines in coal mines. This paper shows how respirable dust and fines are minimized under near-identical conditions when the drum lacing pattern was changed from a triple-tracking to a single tracking arrangement. A series of laboratory trials simulating in full scale the practical cutting action of tools was followed by extensive long-term underground trials during production operations in OAL (Cayirhan) Lignite mine in Turkey. The results are presented and discussed, and recommendations for proper drum-lacing in terms of respirable dust and fines are made.

Jan 1, 2002

By R. Pakalnis, H. Miller, Madill. T.

"This paper describes a methodical approach to the estimation of the orientation and the magnitude of in-situ stresses. The study was performed at the Ruttan Mine, Sherritt Gordon Mines Ltd. , a 6,000 T.P.D. underground operation, located in northern Manitoba, Canada. It involves an initial estimate to be made based upon: structural interpretation • virgin stress measurements conducted in other areas (world wide, regional)The verification of the prevailing stress regime was made by conducting CSIRO hollow inclusion(1) overcoring measurements. The current cost for a virgin stress determination is about $7000 per measurement(2) and the difficulty encountered in attaining a good reading is high. This paper will describe the analytical procedures employed at Ruttan in evaluating the in-situ stress magnitude and orientation based on three overcore tests. It is proposed to perform an additional six measurements in order to verify the following results:Vertical stress = av (MPa) = 0.027 by depth (m)Major principal stress = o! """" 2.5 xav (340°/-20°)*Intermediate principal stress = a2 - 1.2xav (070°/0°)Minor principal stress = a3 """" o.8xov (160°/-70°)IntroductionThe Ruttan Mine of Sherritt Gordon Mines Ltd., a 6,000 T.P.D. underground operation, is located in northern Manitoba, Canada (Fig. I). The Ruttan copper-zinc orebody is a multi-lensed, steeply dipping (70 degrees) en-echelon deposit. Individual lenses have a maximum strike length of 350 m with widths varying from 7 m to 61 m. The mining method is o pen stoping with delayed backfilling and extends from surface to 860 m below surface."

Jan 1, 1985

By Gordon Smith

ABSTRACT Gold-bearing quartz veins in the northeastern Ontario and north western Quebec mining camps are shown to have been mineralized in part by epithermal solutions. The vertical gradient of pressure during this stage of mineralization is calculated, using decrepitation temperatures of quartz and thermoelectric potentials of pyrite. The base of the Cobalt sediments, which lie uncomformably over part of the mining region, may be taken as datum level in calculating the depth of erosion into the basement below that level. The vertical extent of the epithermal gold mineralizaiton in this region is at least 9,000 feet below the datum level. INTRODUCTION IT WOULD have been difficult a few years ago to convince economic geologists that after making a series of measurements in a laboratory in Toronto, the depth of erosion which has taken place below the base of the Cobalt sediments at any place in the Ontario-Quebec mining region can be calculated to the neare.st 500 feet, or that the same series of measurements would also serve to allow a prediction of the minimum vertical depth of probable ore in a producing mine in the same region, with the same degree of certainty. Possibly it is just as difficult today, but the following description of the data and calculations may help to demonstrate the reliability of the method.

Jan 1, 1951

By L. Rosato

In the past decade, as a result of increasing iron loads, Canadian Electrolytic Zinc (CEZinc) has become a pioneer in understanding the critical factors that affect the roasting of concentrates with high pyrite contents as well as those factors governing the effects of high iron loads on the leaching circuit. De-bottlenecking efforts in the roaster and acid plant section of CEZinc have given rise to a better appreciation of the impact of iron on roaster productivity. High standards for impure solution quality, zinc recoveries and residue disposal have all led to an increased comprehension of the limits of the leaching circuit and the optimization potentials with respect to iron and ferrites. In this paper, the impact of iron on the roasting and leaching circuits of CEZinc will be reviewed and special emphasis will be given to some of the more recent process optimization and improvement activities.

Jan 1, 2006

By Norman R. Paterson

"Under certain conditions useful gravity information of a reconnaissance nature can be obtained with-out measuring elevations by spirit level surveys on the ground. Gravity surveys can become part of a practical exploration program where high cost and slow progress previously hindered their utility. The advantages of the new elevation procedures are realized mainly in remote areas, in areas where ground transportation is slow and difficult and on surveys where the station spacing is large in comparison with the distance of the average optimum level shot. To utilize the advantages, transportation by helicopter or light plane is usually necessary. Methods of obtaining elevation control without leveling include: barometric altimeter survey; photogram-metric -APR spot determinations; methods involving the measurement of gravity gradients. The accuracies of these methods have been tested and compared with the normal accuracy of level surveys. It is felt that each method has its place in reconnaissance gravity work, particularly in the open areas of Northern Canada."

Jan 1, 1960

By A. S. Baillie

THE subject of taxes appears to engage our attention altogether too lightly. At least it would seem that, notwithstanding the increase in the cost of government, and its concomitant increased taxation, little constructive work is being done with a view to solving the problem of increased taxes. I believe that the inattention of the public generally to the subject of increased taxation is due largely to the fact that shareholders are not advised of the amount of taxes paid by industry. Were companies to advise their shareholders the amount of monies paid or payable out of each year&apos;s earnings for taxes in one form or another, and were such amounts compared with the amounts available for distribution to shareholders, the effect would be a general demand for more equitable taxation methods. While I am not unmindful of the burdens and inequities in taxation confronting industry generally, I believe that the mining industry in this Province does not fully appreciate the burden represented by the costs of taxation. My reason for this belief is based partly upon1the fact that no serious effort has so far been made to devise some means By which the mining industry in British Columbia might protect itself against the ever-increasing burden of taxation. In addition to this fact the widely diverse nature of mining in British Columbia makes the accumulation of comparable data a problem which, so far as I can ascertain, has never been attempted in a manner which would be authoritative. It should not be necessary to cite the effects of this burden upon any one mining company or upon any branch of the mining industry, such as coal mining, placer mining, base-metal mining, or the precious-metal mines. In my opinion, the operation of our mines by large corporations is conducive to the payment of taxes with much less protest than would be the case were the taxes being taken out of the earnings of just a few partners or a very few shareholders. We appear to be too unmindful of the taxes, paid by mining companies, of a kind that are not so prominently brought to our attention as are the taxes which are calculated upon the taxable income of the company at the end of its fiscal year. British Columbian mining companies pay many other taxes besides those which are calculated upon taxable income. Among these are school taxes, property taxes, gasoline taxes, mineral taxes, coal royalty, to say nothing of fuel-oil tax, sales tax, and excise taxes.

Jan 1, 1935

By A. G. Pentland

PROSPECTING is popularly supposed to be surrounded with an air of romance and adventure. The word &apos;prospecting&apos; brings to mind high mountains, northern lakes, and aeroplanes. A note of urgency has been added to this by the war, particularly in the case of strategic, minerals. Prospecting for strategic minerals in a modern mine in full production, although it may Jack the romance of travel in little-known places, has the advantage of having all the necessary machinery at hand and ready to go into action at a moment&apos;s notice. HISTORY Tin was discovered in the Sullivan ore in 1925, when a white streak was noticed on a pilot table which was being used to check the amount of galena in the tailing. The mineral which made up this streak was identified as cassiterite. The amount of tin in the ore is so small that, while of scientific interest, it was considered to be of very little economic importance. Nevertheless, several attempts were made to learn something of the occurrence during times when other work was nor pressing. These studies were dropped when anything came up that seemed more important.

Jan 1, 1943

By A. Henk, C. M. Aruffo, K. Fischer

"Geomechanical reservoir modeling offers a valuable tool to predict tectonic stresses, in particular the local perturbations in orientation and/or magnitude which occur at lithological boundaries and faults. The paper presents a workflow for building and calibrating such geomechanical models. The numerical simulations are based on the Finite Element method and can range from field-scale models to smaller, highly detailed submodels of specific fault blocks. The approach considers the reservoir-specific characteristics with respect to subsurface geometry (lithostratigraphic boundaries, faults), mechanical properties and ambient stress field. During the subsequent calibration stage calculated stresses are compared to stress data actually observed in borehole data. Poorly constrained input parameters are iteratively modified within reasonable limits until a satisfactory fit between calculated and measured stresses is achieved. This validated model can then be used for stress predictions between wells and in undrilled parts of the reservoir, respectively. The workflow is applied to two case studies - a large gas field in Northern Germany and a CO2 sequestration project in Australia – to test and illustrate its practical value. INTRODUCTIONDetailed knowledge of the tectonic stress field is crucial for the optimal exploration and use not only of conventional and unconventional hydrocarbon reservoirs, but also for deep geothermal reservoirs, carbon capture and storage (CCS) projects as well as underground mining and nuclear waste repositories. Any reliable stress prediction is hindered by the observation that the magnitude and orientation of the stress field can vary significantly – not only in time, but also in space. Such spatial stress variations comprise all scales, i.e., from the scale of lithospheric plates down to the grain-scale. On the reservoir- and fault blockscale, the local stress field can be influenced by faults and different mechanical properties of lithologies (Sassi & Faure, 1997). The resulting variations in stress magnitude and/or stress orientation are commonly referred to as stress perturbations and give rise to a unique, reservoir-specific stress pattern (Yale, 2003). Thereby, local stress fields can deviate by up to 90° in orientation and several tenth of Megapascal (MPa) in magnitude from regional trends."

Jan 1, 2015

By D. Runnels, A. Allaire, J. Torrealba-Vargas

Data mining and modelling of operational data involves the discovery of patterns in large datasets for future use in benchmarking and plant optimization. The modern pattern of discovery in large data sets involves statistical techniques, machine learning and new visualization tools. Former examples of data mining are revisited and presented in this document. INTRODUCTION A network of enthusiastic and active professionals is currently developing and maintaining several open source statistical software tools (packages) for data analysis (example Rstudio, Orange, Spyder, etc.). The advantages of the open source software philosophy are the fast development and testing of the solutions presented to the community. Books and support are available for each software application. Since each modern work activity generates massive amounts of data, it is attractive to learn and test those available tools considering that we are at the door of the new work revolution coined as “Mine 4.0”. Data mining involves collecting large datasets, the preparation and cleaning of a dataset (term named data wrangling), the uploading of the data to a database program capable of handling big datasets, the development of prediction models and the presentation of the results. Machine learning techniques help to develop mathematical models and algorithms that could be used to improve the performance on a specific task. Mine operations are producing an incredible amount of data each day and the need to analyze those results seems to be impossible due to the lack of time, as well as the lack of skills to investigate the data collected. If we add to this the traditional habit of working in silos, an additional challenge is to consolidate databases from different departments in search of trends that could help to optimize production.

Jan 1, 2019

By The Staff

Introduction In this paper it is proposed to discuss briefly some of the problems confronting the management of a gold mine in choosing a method of milling to recover the gold from various classes of ore. In order to simplify the discussion, the more common types of gold ores are classified from a metallurgical point of view as follows: Class 1?A: Free-milling ores which require only relatively coarse crushing. B: Free-milling ores which require finer grinding to release the gold. Class 2?A: Gold ores which contain the gold partly in the flee state and partly associated with a small amount of iron sulphide, and which do not require fine grinding. B: Gold ores similar to 2A, but which require fine grinding. Class 3?A: Gold ores containing copper in quantities insufficient to interfere to a serious extent with cyanidation. Gold ores containing copper in sufficient quantity to interfere with cyanidation but in which a large proportion of the gold is in the free state, the remainder being chiefly associated with the copper mineral, chalcopyrite. Gold ores containing copper and other sulphides, such as pyrite, etc., in which the gold is principally associated with these sulphides.

Jan 1, 1931

By Marie-Eve Boucher

The slag in iron ore pellets allows wet sintering during firing and leads to suitable bounding. The process of slag formation differs whether it takes place in the core or in the external zone of a pellet. In the core, hematite can be reduced to secondary hematite, depending on the temperature and on the carbon monoxide/dioxide partial pressure ratio. The reaction rim that appears at the outskirts of a silica particle in contact with the FeO bearing magnetite is considered as the slag precursor in the core of the pellet. By contrast, in the external zone of a pellet, where O2 is available and CO partial pressure is very low, the first step towards slag formation is flux decomposition, mainly dolomite and limestone. The CaO liberated through this reaction will be available to react with hematite by solid diffusion to form calcioferrites, which play an active part in the slag evolution process. These two slag formation paths will be explained.

May 1, 2007

By P. Condori

Palabora Mining Copper (PMC) has two autogenous mills that have been in operation since 1976. The mills were originally designed to treat 30 000 t/d of open cast copper ore in a closed circuit with cyclones. As the ore body went deeper the open cast method of mining was changed to block caving, a consequence of this was the dolerite content (hardest barren material) increased significantly, increasing the production rate of pebbles and thus reducing the milling capacity. In order to cope with the increased ore hardness and to increase mill capacity, a second ball milling stage and pebble crushing were incorporated to the circuit. The above actions created new challenges to the circuit operation and bottlenecks in different areas of the milling circuit. This paper reports the holistic work performed on the Palabora autogenous milling circuit including the implementation of a mill constraint control scheme, the implementation of a pebble removal system from the circuit and a new circuit configuration. The achieved plant stability and increment of ore throughput are also reported in this paper.

Jan 1, 2012

By Lawrence Devon Smith

The selection of the production rate is one of the most crucial decisions to be made in the development of a mineral property. However, it is not uncommon for the production rate to be decided arbitrarily, before any technical evaluations begin, and it is often not reconsidered when better data becomes available. A number of methods are used in the mineral industry to select the production rate for a project. There is general agreement that the size of the ore reserve has a strong influence on this decision, but what other factors are involved? Is there a way to identify an optimum rate? This paper examines the factors that influence the selection of a production rate from the perspective of project economics. The NPV maximum value should be viewed as a “failure” point. The “two times capital” maximum is proposed as a lower limit. A practical check is suggested to confirm that a selected rate is in an optimum range. Production rate assumptions are much more likely to be reviewed for marginal projects, but they should also be reviewed for viable projects.

Jan 1, 1997

By K. Ogawa, T. Yokoyama

Hydraulic fracturing technique, an applied technique to cause tensile fractures to rock by injecting water pressure to a certain closed section of the borehole, is a measurement method of in-situ rock stress. This technique has the highest track record for techniques used in sub 1000 meter. A feature of this technique is comparatively simple and easy for in-situ stress measurement, because the measurement is applicable when a drilled borehole is available. The predominant advantage of this method is that elastic constants such as Young’s modulus and Poisson’s ratio are not required for determining the value and direction of initial stress. The factors to determine the stress state are the water pressures of re-opening and shut-in of fractures around the borehole wall and its directions. With conventional methods, however, the accuracy of the derived stress states from the observation equations was often adversely affected by the lack of consideration of the remaining water pressure in fractures and insufficient stiffness of the pressurization system. We have developed a new hydraulic fracturing system based on a new test method concept overcoming these defects, and applied to a 300 meter deep borehole in granite. The most important improvement of the new system is an employment of a syringe pump which enables an accurate flow control of fluid with less than 1ml/min in the pressure of 30MPa. Therefore the new test system has a quick response for pressurising in the interval zone, and the measured data was confirmed extremely accurate.

Jan 1, 2015

By S. S. Rahman, A. Gholami, M. A. Aghighi

"This paper provides a foundation for studying the growth of fractures in presence of other discontinuities and different anisotropies of low permeable hydrocarbon formations and helps to improve the design strategies for multistage fracturing.The multistage fracturing technology has recently been used to exploit low permeable hydrocarbon reservoirs. However, the mechanism of hydraulic fractures interaction and the impact of local heterogeneities on ultimate trajectory of the growing hydraulic fractures are not yet understood in depth. A fully coupled poroelastic Finite Element based model is developed to investigate the mixed mode propagation behaviour of growing hydraulic fractures. This model takes advantage of an explicit representation of the fracture which enables us to take the effects of rock and fluid related parameters into account. Moreover, impact of fracture geometry and leak-off phenomenon is investigated. The refined mesh around the crack provides the added advantage of more detailed stress distribution, pore pressure change and back stress in the vicinity of the fracture and in particular at the fracture tip. The potential deviation propensity of the fractures is evaluated based on the fundamental rule that fractures propagate perpendicular to the direction of the minimum horizontal stress.This study shows that pressurization of transverse hydraulic fractures results in the reorientation of local principal stresses, particularly in vicinity of fracture tips. Variation of flow patterns clearly influences the evolution of shear stress around the fracture tips which will potentially lead to mixed-mode I and II fracturing and consequently, fracture deviation. The presence of local heterogeneities such as preexisting fissures and/or fractures is a main source of such pore pressure induced stress redistribution and reorientation and potential deviation of hydraulic fractures.Most existing models ignore or simplify the effect of pore pressure/stress coupling as well as the fracture geometry and fluid flow within the fracture. Also, the fluid leak-off from the hydraulic fracture into the formation, which is a controlling factor in fracture growth, is often considered using analytical models. Taking advantage of a fully coupled porelastic model along with an explicitly discretized fracture, this study provides a more realistic insight into the complex fracture propagation processes of multistage fracturing operations particularly in presence of reservoir geo-mechanical complexities."

Jan 1, 2015