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By K. Howard Poulsen

Shear zones are tabular tructures which tend to occur either discordantly within, or concordantly along the margins of, competent rock masse uch as plutons, sill or flows. They contain deformed equivalents of their host rock and are common sites for gold mineralization localized in tructure oriented y tematically relative to the shear zones and internal linear fabric. Apan from genetic implications, hear zone analysis proves useful in exploration for this type of deposit because the zones are generally wider and more continuous than associated mineralization and because there is an element of predictability to mineralization geometry (i.e. vein orientation. plunge).

Jan 1, 1986

By J. Gillies

"Those of you who were at last years C.M.P. meeting are aware there was discussion at that meeting concerning the best method of assisting the assayers of metal mines to exchange new ideas and methods of assaying. The opportunity to advise you of what came of that discussion is very much appreciated.There are several societies, including the Chemical Institute of Canada, the Spectroscopy Society and others that could be of some assistance to assayers. However, since these societies cover a rather broad field and not many mine assayers have the opportunity to attend their meetings, it was felt that an organization oriented to the specific needs of the mine assayers would be of more value to them.Several years ago an attempt was made to hold meetings for the benefit of assayers in conjunction with the Conference of Metallurgists held each year by the Metallurgical Society of the C .I.M.M. This did not work because very few of the mine assayers attended the meetings.With the very evident success of the type of meetings the C.M.P. have and the excellent groundwork done by your secretary, Mr. Stevens, in talking about this to mine management and assayers at many mines across the country, it was decided to hold a meeting at Noranda on October 8 to discuss how best we could help ourselves solve our problems.For the initial meeting it was felt that perhaps it would be better to start with a smaller group, so invitations were sent to mines in Ontario and Quebec that were geographically fairly close to Noranda."

Jan 1, 1970

By D. E. Macdonald

"Approximately 2.0 million tonnes of phosphate rock is imported from the U.S. to Alberta annually and is used in the production of agricultural fertilizers. No phosphate rock is presently mined in Canada, although sources of igneous phosphate have been mined in the past. Sedimentary phosphate rock is found in nine geological units within the Cordilleran Foothills and Front Ranges region of Alberta. The Devonian-Mississippian Exshaw Formation, Permo-Pennsylvanian Rocky Mountain Supergroup, and the Jurassic Fernie Formation have the best potential f or future development. Most of the phosphate rock in Alberta is of low grade and lies within restricted land use areas. The best over-all resource potential lies in the Fernie basin area of southeastern British Columbia, in the Fernie Formation. The possibility of deep phosphate rock deposits in the plains region should be examined.Phosphate rock is mined in Idaho, Utah, Montana and Florida, and is shipped to Canadian fertilizer plants for processing. Raw phosphate rock is acidified, usually with sulphuric acid, by a wet process. Varying amounts of ammonia are added, and the fertilizer is pelletized. Future research, in western Canada, is needed in the beneficiating of low-grade ores and in the area of in situ mining. At the present time, phosphate rock sells for around US$50Itonne, and Alberta fertilizer companies probably pay in the range of C$7D-$85Itonne for U.S. phosphate rock delivered to the plant. Environmental concerns about phosphate rock processing are centred around gypsum tailing ponds, and radioactive wastes.U.S. supplies of phosphate rock are secure until the year 2000; however, by this time, the richer deposits in the U.S. may be exhausted. Alternate deposits, such as the ones in Alberta and British Columbia, might then be considered. Phosphate byproducts, such as uranium, vanadium, fluorine and rare earth elements, may help in making the processing of low-grade Canadian phosphates economically feasible."

Jan 1, 1988

By J. A. Maritz

"The Hedley and Grant formulation for pillar strength has been widely adopted by the South Africa hard rock mining industry. Today, some forty year later, this formula still provides the foundation for pillar strength calculations when designing for stability and utilising pillars in mine layouts. Various mine specific back analyses were conducted to adjust the equation parameters based on underground observations of failed pillars and comparing to the pillar stresses calculated using numerical models. In all these instances, the influence of shear stresses was ignored. The key to more representative pillar strength estimation is a better understanding of the pillar loading environment.In this paper, special mining cases are evaluated and the existence of shear stresses on the pillar loading environment is illustrated. By revisiting some back analysis data for optimisation of the equation parameters, recommendations were made in respect of the influence of the shear stress component and on how this should be considered in determining the pillar strength.INTRODUCTIONCommon practice on flat dipping, shallow and intermediate depth ore deposits in the South African hard rock and coal mining industry is to exploit the mineral resource using a room-and-pillar layout. The design methodology is mainly based on a Factor of Safety (FoS) approach, where the strength of the pillar is compared to the effective load on the pillar. In these environments, FoS values of 1.6 are applied as it was found to correspond to a probability of failure in coal mines of 0.001. As discussed by Ryder and Jager (2002) page 279: “For lack of anything else more substantial, the figure of 1.6 is generally used in hard rock pillar design in South Africa”. Dependant on the designed purpose of the pillar, the FoS might be selected as high as 2.0 where long term stability is required. The factors directly influencing the FoS include the pillar height (which is linked to the mining height), effective pillar width, a rock-strength factor and extraction ratio."

Jan 1, 2015

By G. Bimpilas, G. N. Anastassakis

"Today, one of the most intense problems in mineral processing systems is referred to the treatment of fine (–100 µm), and even smaller size, particles. Fine mineral particles possess specific properties (small mass, high specific surface area, and high surface energy per unit area) that render their separation inefficient with conventional methods (physical, physicochemical) and equipment. As a result, it is not feasible to obtain a concentrate both of high grade and recovery in mineral value and a considerable amount of mineral fine particles is lost to the tailings. As evidence, we could cite numerous examples from industrial practice with considerable loss of mineral values to the tailings because of the fine particles size, e.g. phosphate, tungsten, tin, etc.The objective of the current paper is to investigate the possibility to separate magnetic gangue minerals and rocks (serpentine, ilmenite, and olivine) from magnesite by co-agglomerating all the gangue components and subsequent magnetic separation of the agglomerates.To meet the target, hydrophobic agglomeration tests were initially carried out on single minerals to define the favorable conditions for selective hydrophobic co-agglomeration of the gangue minerals. In this respect, the effect of the following factors was examined: pH, collector dose, conditioning time, and settling time of the agglomerates. Among the combinations examined, the most favorable proved that with amine in the basic pH region. The use of non-polar oil proved beneficial. The preliminary results were confirmed by tests on mineral mixtures. The application of magnetic separation resulted in the removal of gangue minerals and the recovery of magnesite concentrates of commercial grade (magnesite content 95% approximately) and high yield.The current paper contributes to the development of mineral processing, since it successfully copes with a very important problem of mineral processing, such as the efficient separation of fine particles."

Jan 1, 2016

By F. Y. Grepe

"THE MOST common type of mine hoist is, as is very well known, that in which the a.c. wound rotor motor is the driving medium. The reasons for the use of the wound rotor motor are, of course, economic. This type of equipment has, during the years, proved to be very reliable and reasonably satisfactory. It is, in fact, still being installed and in some places where a very hard and exacting duty cycle is demanded. As an example, a 600 h.p. 2,300-volt job was recently installed at the Caledonia mine (1) at Glace Bay. This is a vertical. hoist in a shaft only 175 feet deep but it is, nevertheless, working hard bringing coal to the surface and in making a trip at a speed somewhat better than every 20 seconds.The control equipment for such installations usually consists of a pair of primary reversing contactors which are interlocked both mechanically and electrically, together with some form of secondary controller. This, in the case of small hoists, can be a drum controller and metallic resistors or, in the case of larger hoists, a magnetic contactor panel and metallic resistors or, alternatively, can be one of the various forms of liquid rheostats which are available. The liquid rheostats, if of the dipper type, may be manually operated or it may be operated by some form of servo motor mechanism. In the weir type of liquid controller, the electrolite is, of course, pumped in and out of the rheostat."

Jan 1, 1954

By J. Guha, R. Kanwar, G. Archambault, A. Tremblay

The Copper Rand Cu-Au deposit lies within a shear zone which strikes N50-60W and dips steeply southward (50°-55°) and extends over 1. 5 km with a thickness which varies form 350 to 425 metres. Mineralization, inside the shear zone, is structurally controlled by a dilation mechanism which can be explained by a fracture dilatancy model. The principle of this model involves the mechanics of overriding of irregular planes and surfaces of faults and schistosities, These structures are characteristic features of the Copper Rand shear zone. A structural analysis of the shear zone has been carried out to establish relations between the different structures within the shear zone and their evolution with the development of the shear zone. A geomechanical interpretation of the Copper Rand shear zone explains the formation of internal structures such as faults, schistosities and microstructure during the shearing. This interpretation confirms Ramsay's theoretical model on the geomechanical evolutuion of shear zone development, and the experimental work of Morgenstern-Tchalenko on the simulation of shear zones in clay models. The geomechanical interpretation of the shear zone demonstrates that at the onset, subsidiary fracture patterns are developed in second order faults in the following sequence. At peak strength Riedel shears ( R and R') are formed which propagate outside the strength, restraint (P) shears are developed in the thrust attitude within the shear zones. Principal displacement shears (D) develop toward residual strength in the direction of movement. Shear lenses are formed by the interaction of these shear discontinuities and these facilitate the formation of schis tosi ties with the continuation of the shear displacement within the main shear zone. While the main shear zone and the P and D shears within the main shear zone were in continual movement, the Rand R' structures, once formed, retained a simple fracture pattern and moved little outside the shear limits in comparison to the main shear zone. Parts of these structures inside the shear zone were reactivated by subsequent movements and deformed into folds to account for the present attitudes of the HW-1 and HW-2 and HW-3 structures. This geomechanical model for the shear zone with its subsidiary structures (R, R', P and D shears) is also applied on a larger scale to the Dore Lake shear belt and explains the different structures accompanying it. The initial development of the WNW shears (most are ore deposits) was followed by the subsidiary structures of the Dore Lake shear in a north-south stress field and is well defined by the movements characteristic of the different structures. It is concluded that the Dore Lake shear cannot be the prolongation of the McKenzie Narrows shear but it seems that this prolongation relates to the Henderson-Portage shear zone.

Jan 1, 1984

By Kevin Ross

Feasibility Study Team Processing / Engineering?Hatch, Vancouver Mining / Reserves?Australian Mine Consultants, Brisbane Geology / Resources?Roscoe Postle Associates, Vancouver Environmental / Permitting?Rescan, Vancouver Tailings BGC, Kamloops Probable Mine Components Mining tending towards caving methods Underground mine accessed by shaft /conveyor & decline Processing plant producing copper concentrate containing gold Concentrate trucked to rail head for export Non saturated tailings disposal

May 1, 2006

By Staff, G. M. Hogg

"The eastern portion of the Late Precambrian geosynclinal structure known as the Labrador Trough comprises a 16,000-square-mile sulphide-bearing belt of good potential as a base metal exploration area. Hollinger and Hanna mining interests have carried on exploration in the region since 1953, with encouraging results. This program has been considerable in terms of both effort and expenditure, and has resulted in an apparently successful primary evaluation of the entire belt.Much detailed work remains to be done in the area. Exploration to date has been largely of a reconnaissance nature, employing various methods in common use in Canada today. In the course of this work, several deposits of promise, containing near-economic quantities of copper, zinc, nickel and other metals, have been located. A broad classification of these deposits is proposed.Exploration in the sulphide belt was started on the basis of partial control of the area under mineral exploration concessions. This was necessary to justify operations in an area of difficult access and high operating costs. The results of this now-terminated arrangement are regarded as being of benefit to those directly concerned as well as to the mineral industry in general."

Jan 1, 1966

By B. A. Watters, G. A. Parslow, F. H. Mcdougall

Carbonate-rich rocks occur at several localities within the Flin Flon volcanic sequence of the eastern Amisk Lake area. The rocks occur in two areas: as a group of small occurrences on islands within Amisk Lake and as two much larger linear belts running parallel to the regional structure east of Amisk Lake. Mineralogically, the rocks consist of talc and Ca-poor ankerite with occasional graphite. Segregation of these minerals and colour variation impart a well-defined planar fabric to the rocks and where the units are fairly continuous (e.g. Mosher Lake), their trend and attitude suggests a concordant relationship to the volcanics. Major and trace analysis of22 samples confirms the presence of two types, with one type being represented in each of the two areas. Most of the elements studied can be used to characterize the two groups, but three elements in particular give a clear separation: Mg, AI and Ni. Recalculation of the major element analyses, on a water and carbonate-f ree basis, indicates that one group (large concordant bodies with high MgO, high Ni and low AI20.J is altered ultrabasic material of peridotitic or dunitic composition. Because no relict igneous material is observed, and the contacts are apparently very sharp, it is possible that the hydration-carbonization process occurred simultaneously with intrusion, .in a closed system. The other group (small occurrences with relatively low MgO, low Ni and high AI203J represents alteration of basaltic rocks. AIthough some analyses suggest the introduction of calcium, as carbonate, along with the volatiles, the major oxides have remained remarkably stable during the alteration process(es).

Jan 1, 1981

By J. Guha, D. Racicot, S. Peloquin, F. Lange-Brard, S. Bureau, A. Tremblay

The Devlin copper deposit consists of a flat-lying vein and a network of steeply dipping mineralized veinlets hosted by leucotonalite of the Chibougamau Pluton. Most of the vein is enclosed in a hydrothermal breccia zone which has been superimposed on a primary igneous breccia formed during the emplacement of the leucotonalite unit. This igneous breccia contains cognate fragments as well as fragments of the Dore Lake Complex, host rock to the pluton, set in a leucotonalite matrix. The hydrothermal breccia is formed of fragments of leucotonalite and the earlier breccia set in a matrix of finely comminuted rock variously altered in a roughly zonal arrangement. The major ore-bearing structure is the tabular flat-lying vein, varying in thickness from 10 centimetres to 1 metre, with a slight dip to the northeast. Well developed fracture planes, in four major orientations, contain both sulphides and gangue minerals. These appear to be displaced by the flat-lying vein. Late movements affecting the deposit include minor vertical displacements and an east-west shear truncating the southern edge of the vein. Widespread selective alteration of the leucotonalite, followed by multiple alteration veining stages characterize the deposit. Fluid inclusions associated with the mineralization indicate low temperatures, variable salinities with a variety of daughter minerals, and a vapour dominated phase. The fluid shows evidences of boiling at shallow depths. The sequence of events envisaged for the Devlin deposit is a primary brecciation during emplacement of the leucotonalite unit with widespread selective alteration possibly during the cooling stages followed by hydrothermal brecciation and late stage fract uring producing the vertical fractures and the flat-lying vein. From the alteration characteristics and the fluid data it is inferred that the Devlin deposit is the near-surface expression of a porphyry system.

Jan 1, 1984

By P. C. Lightfoot, J. M. Duke, A. J. Naldrett

"The segregation of magmatic sulphides from mafic and ultramafic silicate magmas, in many circumstances, leaves the magma with a lower-than-normal Ni/MgO ratio, which is characteristic of both lavas erupted from the magma chamber and olivine crystallizing within it. Two end members of the segregation process are discussed; i) batch segregation and ii) fractional segregation.In the former, the critical factor is the magma/sulphide ratio. Computer modelling suggests that where this ratio has been less than 1000, the magma will be recognizable as anomalously low in Ni, due to sulphide segregation, and thus a good target for exploration. In fractional segregation, the critical factors are the proportion of sulphide to silicate being segregated and the degree of fractionation.Samples believed to represent the liquid portion of komatiitic lava f lows from a series of unmineralized sequences in the Abitibi greenstone belt, Canada. Belingwe belt, Zimbabwe, and Barberton Mountainland, South Africa coincide with the sulphide-free fractionation model. They are in marked contrast to samples from the ore-bearing districts of Kambalda and Scotia. Western Australia in which distinct Ni depletion, corresponding to fractionation of olivine plus sulphide in a ratio of between 100 and 200:1 is recognizable. Ni-depleted olivines also mark the sulphide-bearing Dumont intrusion of the Abitibi belt.The Moxie intrusion of northern Maine has distinctly Nidepleted olivines, as does the nearby and petrologically related Katahdin body. In both of these intrusions, the composition of the olivine allows reasonable predictions to be made of the Ni tenors of sulphide showings within them. At Katahdin, the Ni depletion is so widespread that little hope is help out for the presence of economic concentrations of sulphide. At Moxie. the olivine compositions suggest that the best chance of economic sulphides lies in the southern lobe of the intrusion.Ni-depleted olivines also characterize certain rock units within intrusions of the Insizwa complex, Transkei, Southern Africa. Many millions of tonnes of Ni have apparently been removed by sulphides from these rock units, many more than are contained within the single mineralized occurrence so far identified at Waterfall Gorge."

Jan 1, 1984

Commercial SOFC systems will likely utilize hydrocarbons or hydrogen produced from hydrocarbon fuels and therefore will likely be exposed to sulfur impurities. Conducting-Atomic Force Microscopy (C-AFM) is a scanning probe microscopy technique which maps both sample topography and conductivity with tens of nanometers resolution. In Ni-YSZ, C-AFM measures the resistance of the metallic network at scanned locations, with the ability to differentiate between interconnected and isolated metallic particles. We have applied C-AFM to Ni-YSZ SOFC anode materials, with the goal of monitoring changes in the conductivity of the Ni anode network resulting from SOFC degradation processes, such as H2S poisoning.

Jan 1, 2005

By Janet E. Halliwell

In keeping with the traditions of the Science Council of Canada - an independent and forward looking agency that applies broad and multidisciplinary analyses to the various issues it examines the author indulges in a holistic approach to the integration of the environmental, scientific, economic, and cultural concerns. This paper will characterize the changing conditions which the mining industry is facing. It will then explore the changing expectations of society with respect to environmental sustainability and how those attitudes in turn, must influence the strategic directions and attitudes of the industry, and within that, the role of science and technology.

Jan 1, 1991

By Cale J. Dubois

At Cameco Corporations' Cigar Lake Project, large excavations are developed on the 480 Level and 500 Level must remain stable for at least 15 years to host underground processing infrastructure. Following the successful dewatering of the mine in October 2009, subsequent internal rockmechanics investigations augmented by third party technical investigations; determined that to keep the back of the Water Flush Crusher/Run-of-Mine (WFC/ROMs) excavation stable; required a rehabilitation strategy to mitigate deterioration/deformation of the WFC walls and intersection pillars. The mechanism of failure propagating the movement of the excavation walls is understood to be controlled by the presence of a dominant E-W striking and steeply dipping foliation within a relatively weak and mildly altered rockmass sub-parallel in strike with 14 meters high walls and an intersection span approaching 15 meters. The application of open and resourceful communications between site mining engineers, geologists, contract mining staff, construction management experts, corporate mining and civil engineers, and third party technical experts resulted in a multi-faceted short-term ground support strategy consisting of standard bolting and screening, deep-seated modified-strand cable bolts coupled with heavy gauge mesh straps, rockmass reconditioning using low-pressure grout injection, and horizontal cable-lacing for the intersection pillars applied in lifts using a top-down methodology. The intention of the short-term strategy was to stabilize the excavation so that a long-term structural steel support installation - consisting of composite concrete walls, and arch support applied to the side walls and crown of the back - could be constructed safely. This paper summarizes the evolution of the short and long-term ground support strategy and criteria for the WFC/ROMs excavation developed using elements of civil, mining and hydrogeologic design.

Nov 1, 2011

By Peter Hood

Data on world-wide geophysical activity in mining exploration programs are collected annually by the Society of Exploration Geophysicists' Geo-physical Activity Committee as part of a continuing service to the industry. The data are obtained by sending out questionnaires to all organizations which are known to be carrying out mining geophysical work; the organizations canvassed include mining companies, contractors, government departments and universities. The questionnaire is divided into three sections; namely, ground methods, airborne methods and research. The data compiled from the questionnaires show that world-wide utilization of mining geophysical methods reached a new high in 1967 with total expenditures of (U .S.) $32,323,240. This was divided as follows: ground methods, $18,106,785; airborne methods, $10,-123,405; and research, $4,093,050. For the ground methods, most money was spent on the induced polarization technique ($5,681,780); electromagne-tic methods were second in reported expenditures ($2,010,900). The total reported geophysical line mileage flown was 1,275,072 line miles, with aeromagnetic surveying being the most popular airborne method. The total amount spent on aeromagnetic surveys was $5,832,564 for 895,420 line miles. This gives an average cost of (U.S.)$6.50 per line mile.

Jan 1, 1968

By John G. Ayttes

"The following is a review of the advance of raise boring and its current position. The viewpoint presented is that the mining industry, through its worldwide acceptance of raise boring, has acknowledged the success of the method in general. Acceptance, however, does not imply complete satisfaction with either the equipment or current operating costs. Therefore, a brief review of how boring costs are being r educed is presented, citing examples. Recent raise borer applications of special interest are presented to show adaptability of current equipment, and some special projects in the planning stage are highlighted."

Jan 1, 1972

By O. Worku, J. H. Masliyah, Z. A. Zhou

ABSTRACT The viscosity of concentrated kaolinite or illite clay in aqueous suspensions was measured in the presence and absence of a small amount of montmorillonite (<1 wt%). To avoid solids settling and to increase the sensitivity of the suspension viscosity measurements, solids concentrations higher than 38 wt% were used. The pH of the suspensions and the concentration of calcium and bicarbonate ions were found to significantly impact the viscosity of the clay suspensions. The results showed a significant increase in the viscosity of kaolinite suspensions with the addition of as low as 0.25 wt% of montmorillonite on a solids weight basis. In addition to illustrating the role of water chemistry in modifying slurry rheological properties, our study demonstrated that viscosity measurement could be a simple, yet sensitive technique for determining the content of smectite clays, such as montmorillonite, in a complex mix of various types of clay.

Jan 1, 2012

By J. M. Ortiz, J. P. Bertini

"In mineral resource and ore reserve estimation, several sources of information are generally available, such as diamond drillholes, reversed-circulation drillholes, and blastholes, and originate from one or more sampling campaigns and are analyzed by one or more laboratories. In such a situation, the grade measurements may not have the same precision and one should distinguish between hard and imprecise data.This work aims at studying the impact of data imprecision in resource/reserve evaluation through two case studies on simulated deposits: a porphyry copper deposit conditioned to real exploration and production data, and a gold deposit simulated without any conditioning data. Several geostatistical techniques are used to estimate the grades of selective mining units from exploration samples, including kriging, cokriging, lognormal and indicator kriging. Two types of imprecision are examined— measurements with multiplicative errors and measurements defined as intervals. The results are compared to the simulated grades of the selective mining units from a statistical and economic viewpoint.The study concludes that imprecise measurements should never be discarded because they help to improve the estimates, and that simple methods such as kriging are as efficient as more sophisticated ones for resource/reserve assessment. Finally, a few indications on how to diagnose and model the data imprecision are given."

Jan 1, 2005

By Richard P. Taylor, Rod Henham

Abstract - Newly discovered pegmatites distributed throughout the sub-surface environs of the Musselwhite Archean gold deposit occur as narrow dikes that intrude most of the major lithological units. The mineralogy and textures of the pegmatite dikes are characteristic of granitic pegmatites of the "Rare-Element Class"; more specifically, they closely resemble varieties of the "Complex-type" granitic pegmatites that are commonly associated with zones of tantalum mineralization. The essential minerals in the dikes comprise albite, quartz, and K-feldspar, together with lesser amounts of mica (including lepidolite), spessartine, tourmaline, and locally, spodumene. Fine-grained (30 µm to 300 µm), tantalum-bearing minerals occur in the quartzo-feldspathic matrix of the dikes as disseminations, in interstices, and in small vugs. The nature of the tantalum-bearing mineral assemblage present in individual pegmatite dikes varies from a simple mineral assemblage composed of ferrocolumbite (with around 39 wt% Ta2O5) in the most northerly dike, to more complex assemblages comprised of manganotantalite (with up to 75 wt% Ta2O5), ferrotapiolite (with up to 79 wt% Ta2O5), and microlite (with up to 76 wt% Ta2O5) that are present in dikes located several kilometers to the south and southwest. The compositional characteristics and textural relationships of the tantalum-bearing minerals in the dikes provide evidence of igneous fractionation trends that are typical of rare-element granitic pegmatites. Such trends suggest that the newly discovered pegmatites represent part of a more extensive group of cogenetic, tantalum-mineralized dikes.

Jan 1, 2001