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By Pierre Laliberté

L?utilisation de plusieurs nouvelles technologies et systèmes de contrôle visant des économies d?énergie dans une exploitation minière pourrait laisser croire qu?il suffit d?additionner les économies potentielles de chacune de ces technologies pour en évaluer l?économie totale. Une addition simpliste des pourcentages d?économie pourrait, dans certains cas, dépasser 100%, ce qui est évidemment totalement incohérent. Les LMSM-CANMET sont à réaliser une étude dont les résultats serviront à estimer l?influence de certaines technologies et systèmes de contrôle visant des économies d?énergie et à évaluer l?impact des unes sur les autres. En outre, un modèle de simulation est en cours de création afin d?évaluer les gains incrémentaux liés à l?application d?une série d?innovations dans une exploitation minière. La présentation fera le point sur l'état d'avancement du projet en plus de soumettre quelques exemples.

May 1, 2007

By S. Surapunt, C. M. Nyamai, K. Itagaki

"The use of liquid copper as a medium for zinc extraction has been used in the Warner Process as a method of processing zinc-lead sulphide ore. The recovery of zinc metal is based on the reaction:ZnS(s) + 2Cu(l) = Zn(g) + Cu2S(l)In this method, thermodynamic and phase equilibria investigations of the Cu2S-FeS-ZnS and Cu2S-PbS-ZnS systems are of importance and form the basis for the liquid sulphide phase which appears as a product and is used as a solvent in the Warner Process. Phase relations in the Cu2S-FeS-ZnS and Cu2S-PbS-ZnS ternary systems were determined experimentally at 1473°K to provide a fundamental basis for the new zinc smelting process. The results show that the solid solubility of ZnS in the two systems is very small (2 wt% to 3 wt% ZnS in FeS, 4 wt% ZnS in Cu2S for the Cu2S-FeS-ZnS system; less than 0.5 wt% ZnS in both PbS and Cu2S for the Cu2S-PbS-ZnS system). The Raoultian Activity Coefficient of ZnS in the liquid mixtures and the vapour pressure of zinc over the matte in both systems is relatively large (?° = 7.7 – 15.8, Pzn(atm) = 0.088 – 1.026 for the Cu2S-FeS-ZnS system; ?° = 8.9 – 12.9, PZn(atm) = 0.075 – 0.214 for the Cu2S-PbS-ZnS system). On the FeS-ZnS join, the only phases detected are FeS and iron-rich sphalerite (Zn, Fe)S. The binary join mixture occurs at about 92 wt% FeS-8 wt% ZnS at 1473°K. Electron microprobe examination of the quenched samples indicate about 47 wt% to 48 wt% FeS in sphalerite and about 2 wt% to 3 wt% ZnS in the iron sulphide phase. On the Cu2S-ZnS join, microprobe analysis reveals that the maximum solubility is 4 wt% Zn in liquid Cu2S and 3.6 wt% Cu in solid ZnS. In the Cu2S-PbS-ZnS ternary system, microprobe analysis of the quenched samples indicate on average, 5 wt% ZnS in the liquid phase region. The only phases detected on the PbS- ZnS join are ZnS and PbS. The eutectic phase contains, on average, 13 wt% ZnS. The phase relationships, very low solid solubilities of zinc sulphide in the liquid mixtures of both Cu2S-FeS-ZnS and Cu2S-PbS-ZnS systems, coupled with the high Raoultian Activity Coefficient of ZnS as well as the high vapour pressure of zinc over matte all favour the partitioning of zinc metal into the vapour phase. This new process is cost effective and bypassesthe expensive and tedious conventionaltechnique of zinc production involving oxidationof the sulphide ore by roasting followed bya reduction process to extract the zinc. Theresults indicate that a new zinc smelting technologyusing the Warner Process would bemore efficient and preferable over the traditionalmethods of zinc extraction."

Jan 1, 2002

By R A. Burwash

In the Yellowknife geologic province, 2,600-million-year-old granites are cut by three sets of diabase or gabbro dyke : (1) large dykes striking 70°E to E-W, (2) rare dykes striking N-S to 30°E and (3) an abundant swarm striking N 10°-300W. Preliminary potassium-argon dating has been carried out on whole-rock samples of the chilled margins and coarse centers of the dykes, and on mineral separates from the dykes and contact aureoles. Data from seventeen dated samples suggest that the dyke sets were intruded during three periods of basaltic magmatism -2,200, 1,500 and 1000 million years ago. The two earlier periods closely follow the time of emplacement of granites in the Yellowknife and Churchill geologic provinces. The latest diabase dykes occurring in the Yellowknife province are temporally related to a widespread basaltic magmatism, for which the term Keweenawan is not appropriate. D DRING the past ten years, methods of physical age determination have been widely applied to date the time of intrusion or metamorphism of Precambrian rock

Jan 1, 1963

By A. Ignatieff

"A practical picture of the effects of stress and of the structural environment in an extraction area in a bedded deposit is described, and the main factors of ground control where principles of rock mechanics can be applied are discussed. Reference is made to early work in Europe, where systematic rock mechanics studies started in coal mines, as well as to the early work in the Canadian coal mines.During the past two decades, considerable theoretical and experimental knowledge, pursued both in the laboratory and in the field, has accumulated throughout the world, but the state of the science still does not permit application of substantiated theory such as is found in the design of above-ground structures, largely because of the complexity of the rocks. The mining engineer, as oppm1ed to the civil engineer, is constantly faced by exposures of new ground that is often subject to unpredictable discontinuities. However, the rationale already developed by rock mechanics principles and experimentation provides concepts and information that may be useful in selecting mining layouts. These concepts and existing measuring techniques can also assist ground control as mining progresses.Many of the bedded deposits, much as coals and evaporites, have pronounced deformation properties, and there are limitations in making stress measurements within short distances of mine openings or extraction areas. On the other hand, the measurement of movement of the hanging wall (roof) and footwall (floor) of roadways and extraction faces, as well as the sides of pillars, provides a most useful tool in assessing ground stability.This paper is to be regarded as a brief progress report with particular reference to Canadian applications of rock mechanics to bedded deposits."

Jan 1, 1968

By C. -G. Berg, J. T. Tuominen

Since the beginning of the 20th century, energy efficiency in copper smelting has been improved by a factor of 30 as a result of adopting autogenous smelting processes with more and more efficient waste heat recovery systems, increasing use of oxygen enrichment and countless smaller improvements. Nevertheless, energy in the form of electricity and fuels continues to be the biggest contributor to smelter operating cost. Metallurgists around the world are under constant pressure to find ways to save those precious megajoules wherever they can. One area that is often neglected is the removal of water contained in concentrates. Copper flotation concentrates, as delivered to a smelter, typically contain some 8–12% moisture. This moisture must be removed and the only way to do this is by evaporation, which consumes a lot of energy. Several studies have shown that the most efficient way of removing this moisture is to use a steam- heated indirect dryer—the least efficient way being the feeding of wet concentrate directly into a smelting furnace. Even in the most efficient smelters that employ modern steam drying, the energy needed to remove the moisture from the concentrates constitutes over 15% of the total energy consumption of a smelter – acid plant complex. The major steps that have been taken in the past to lower the energy consumption of moisture removal are the use of drying in general and the adoption of steam drying. The energy efficiency of concentrate drying has been improved by 25% over the last 20 years. The latest giant leap in this area, the Kumera Heat Recovery Dryer, is the result of Kumera’s long-term development in improving the efficiency of concentrate drying. The Heat Recovery Dryer is a novel application of steam drying that uses the waste heat from dryer exhaust gas for drying concentrates, thus, cutting the energy consumption by a further 30%. This paper discusses energy consumption in copper smelting in general and analyzes the energy consumption of concentrate drying in detail. Different dryer types are compared especially from the perspectives of energy consumption and environmental emissions. Applicability of different energy sources for drying is evaluated and discussed. The principle of the Kumera Heat Recovery Dryer is presented along with results from extensive continuous pilot plant tests. Potential applications and the feasibility of Kumera Heat Recovery Drying technology are discussed.

Jan 1, 2019

By Geology Staff, C. H. Stockwell

"The Flin Flon base metal mine, owned and operated by the Hudson Bay Mining and Smelting Company, is on the Manitoba-Saskatchewan interprovincial boundary at a point 400 miles north of the International boundary. The deposit was discovered in 1914 by Thomas Creighton and the Mosher and Dion brothers. Since production commenced in 1930, 25,000,000 tons of ore have been mined. On January 1st, 1946, reserves were estimated to be 26,000,000 tons, averaging 2.99 per cent copper, 4.i4 per cent zinc, and 0.089 oz. gold and 1.25 oz. silver per ton. In addition to the four metals named, others recovered from the ore include- cadmium, selenium, and tellurium. The mine workings extend to the 3,750-foot level, but little development work has yet been carried on below 3,250 feet.The known ore occurs in six lenticular to irregular bodies within a zone 500 feet wide. These bodies average 900 feet long, 70 feet wide, 1,500 feet in vertical depth, and 2,500 feet in length along the plunge. They were formed by replacement of the country rock and include ore of two types, solid sulphides and disseminated sulphides. Seventy per cent of the total known ore is of the solid sulphide type. This consists essentially of metallic sulphides- chiefly pyrite- with included remnants of the host rock, and additional quartz and carbonate. In places, the ore exhibits banding, inherited from pre-existing structures. The disseminated ore occurs usually on the footwall side, and along the bottom of the plunge, of the solid sulphide bodies."

Jan 1, 1954

By W. A. Parks

Stone that may be applied to purposes of construction is available in nearly all the inhabited parts of Canada, the most important exception being the prairie region, but, even here, the deficiency is overcome in many parts by a wealth of glacial field-stones. In many parts of the country, also, the accessible stone is of a quality so poor that brick is more generally used. There is a great difference, however, between stone that 'may be used' and stone suitable for buildings of a monumental type or even for 'trimmings' on the better class of dwelling in the cities and towns. It is in the latter sense that the expression 'building stone' is commonly used. Thus restricted the term includes varieties of sandstone, limestone, and granite, using the latter word in the custom of the quarryman, not only for the true granite of the geologist but for many other igneous rocks as well. Building stone of high quality grades imperceptibly into stone suitable for monuments, particularly in the case of the granites. The present review will deal with building and monumental stone in this restricted sense and will omit marble, although that material has been used to some extent for building. For instance, the Great West block in Winnipeg is built of marble from British Columbia.

Jan 1, 1925

By Marcin Ziemski

This paper reports on an energy efficiency analysis completed as part of a research project looking at energy reduction opportunities in minerals processing operations. The plant discussed is a gold production facility owned by Newmont Gold in the Tanami region of central Australia. Due to its remote location, lack of nearby gas pipeline or power grid, the operation has been completely dependent on diesel fuel for its electricity generation and transport needs. The mine and processing plant use electrical power at a rate of 12MW to 18MW, resulting in a monthly electricity cost of over US$1.5M. The high cost of diesel combined with an impending power generation capacity shortage drove Newmont to undertake the energy efficiency study. An energy audit of the plant showed opportunities for significant energy savings through the strategic use of waste heat, fuel replacement alternatives and renewable energy sources.

May 1, 2007

By D. Holz

In this work we present a novel level set-based model for the real-time simulation of soil deformations. A level set defined by a signed distance function and sampled in a regular 3D grid represents and tracks the soil volume under deformation. Moving away from classical 2.5D heightfield representations of soil to a full 3D volume representation allows for improved tracking of cutting tool operations and the simulation of near-vertical or vertical soil faces. The proposed level set representation furthermore provides a versatile mathematical platform for modeling additional effects such as soil slip, and does not suffer from the sampling limitations of commonly used heightfields. Cutting forces applied to the tool are simulated via a formulation based on the Fundamental Equation of Earthmoving, modified to support inclined soil surfaces and transient states of tool motion. Discretisation of this 2D cutting force model with respect to the tool surface allows capturing the effects of irregular 3D terrain shapes on blades and buckets. The surcharge created during cutting operations is tracked in the form of particles and included in the soil failure force computation. We make use of an adaptive, hybrid level set-based and particle-based soil deformation scheme, which allows the soil deformation to be simulated in real-time.

Aug 1, 2013

By J. Ga?parík

The optimal selection of machine or machine group for building processes is very important role of building planner during the process of building planning. During this process building planner have to analyze several factors influencing the final effective decision concerning this problem. There are several factors and criteria for effective selection of building machines. In our contribution there are analyzed: ability of machines to realize designed building process (quality aspect), duration of mechanized process (time aspect) and minimizing of energy consumption (cost and environmental aspect). Selected scientific methods and theories of problem solution can be divided into these groups: theory of system (creation of building machine selection method), multi-criteria optimizing method (analysis of mechanized building process from the point of more optimal criteria), queuing theory (application during the mathematical modeling of mechanized soil processes), method of scientific analysis (analysis of factors influencing final decisions), method of scientific synthesis (creation of optimizing method implemented into building processes and possible application in construction sector). Multi-criteria optimizing method were during our research work implemented into soil processes and selected building group machines (excavators and trucks), which are very often used in construction and mining processes. This method can be considered as a multi-level decision making process based on multiple parameters. In our contribution is presented key mathematical models for model example solution and software built in Java, which has been created as a support for method described in this contribution. Application of this method and software will increase the effectiveness of building machine selection from the point of key criteria of optimizing: quality, time and energy consumption.

Aug 1, 2013

By R. D. Corrans

"Abstract - Africa is endowed with a number of the world's giant ore deposits which have contributed significantly to the development of their host countries. Mineral exploration has a long history in the continent, but mining on an unprecedented scale took off during the latter part of the 19th century, accompanied by the development of lines of communication and other infrastructure to service the major mining centres .The ""Winds of Change"" which swept Africa in the 1950s and 1960s brought in new styles of government and economic management to a number of regions, often with demise of economic viability and infrastructure. ln recent years, with the end of the cold war, collapse of communism and changes in South Africa, new opportunities for mineral exploration are opening up rapidly in Africa. However, due to the large cost, long lead-in time, and high risk of developing new mineral ventures in the continent, it is necessary for the host countries to draft realistic and favorable mineral laws and fiscal codes in order to attract, and not deter, potential mineral investors.There will be an on-going role in mineral exploration throughout Africa for the artisanal miner, the smaller entrepreneurs and mining companies, exploration aid programs funded by the developed countries through African governments, as well as the major mining houses who have the resources to develop larger viable mineral deposits."

Jan 1, 1994

By N. Saracoglu, J. P. Golightly, R. H. Wallis, J. J. Brummer

"The McClean uranium deposits are located 11 km west northwest of the Rabbit Lake Mine. Their average grade is 1.8 % U3O8 , and they contain 6. 350 tonnes of uranium oxide in seven pods of variable grade and mineral assemblage. They are hosted by both basal Athabasca Group and the regolith developed on the underlying crystalline basement. The major mineral facies are: sulphide, arsenide, 'bleached', and hematite, with the important uranium minerals being coffinite, uraninite and pitchblende. Abundances of carbon and sulphur isotopes are consistent with their derivation from pyritic graphite in basement gneisses. Isotopes of oxygen and hydrogen suggest equilibration at temperatures of about 200°C. Ar39/ Ar40 age determination of illite associated with ore suggest mineralization began about 1300 m.y. ago and that significant alteration had ceased by about 1170 m.y. ago though Pb/ U data suggest the deposits continued to evolve into the Mesozoic.IntroductionThe McClean deposits lie on the eastern side of the Athabasca Basin of northern Saskatchewan where they are part of a cluster of uranium deposits lying west of Wollaston Lake (Fig. 1). The general stratigraphy is schematically portrayed in Figure 2 which emphasizes that mineralization is hosted by both the Athabasca Group and the underlying regolith and also that the deposits are preserved at depth and have not suffered from preand post-Pleistocene weathering and erosion. This circumstance, combined with their simple shape and the presence of seven separate zones of mineralization (pods) allows a description, based on over 450 fully cored drill holes, to be made of the wide variation in chemistry, grade, alteration patterns and position relative to the sub-Athabasca Group unconformity. Ar39 / Ar40 age determinations have been made of illites associated with regolith, Athabasca Group and mineralization and studies are in progress on C, S, 0 and H isotopes of mineralized material and host rocks. Only some of these data have been published; Brummer et al., (1981); Golightly et al., (1982); Bray et al., (1982); and Saracoglu et al., (1983). The only other published data on McClean geology are by Tremblay (1982, 1983)."

Jan 1, 1986

By D. M. Baird

"Enormous deposits of gypsum of exceptionally high grade are readily accessible in southwestern Newfoundland. Coming large-scale production from one of these is resulting in renewed interest in deposits which have been known for more than a hundred and twenty years. General stratigraphy and structure of the Carboniferous rocks in which the gypsum occurs are de-scribed. The stratigraphic position of the basal gypsum-anhydrite zone is described. This massive evaporite horizon, which reaches a thickness of about 1,0001 feet, appears at Fishels-Heatherton, where it is largely undeveloped, and again on the nose of an anticline east of Flat bay, where a present production of 20,000 to 40,000 tons per annum is soon to be expanded to make it one of Canada's major producers. Detailed descriptions are given of the several types of gypsum, the relation of the gypsum and anhydrite, and the distribution of sodium chloride in the evaporite beds, and the bearing of all these on the origin of the gypsum are discussed. Brief reference is made to relation to world markets, mining and transportation, grade, and reserves."

Jan 1, 1959

By Mario Gerards, Axel Wellendorf, Arulnesan Rajesh

"In times of increasing energy cost and global demand for improved machine technology, the optimization of industrial mineral processes in terms of efficiency and production cost is an important factor when choosing industrial equipment suppliers. Of course this applies for screening machines, feeders and distributers as well!Besides of the ability of a screening machine for being adjustable to changing requirements during the production process itself, it becomes more and more important to choose the correct screening machine type, peripheral equipment for arising screening tasks and to optimize the overall design of the screening machine starting at a very early stage.The different types of screening machines bring many advantages and disadvantages with them. The selection of the correct type of screening machine can improve the flow rate, energy, efficiency, yield, quality, output, availability and decrease the maintenance costs and structural steel work.The machine optimization has to be a consecutive process in which at any time results of simulation and “real-life measurement” are compared and the findings are implemented in machine development and design. As an example, it is possible to reduce machine weight and reinforce the steel structure of a screening machine at the same time, which enables the manufacturer to use smaller drives for the screen.This paper will present the methods ANSYS and 3D Solid Works used at RHEWUM GmbH for this way of optimizing machine design and construction and examples for results gained from this continuous improvement process."

Jan 1, 2016

By M. R. Hegge

The Jabiluka One and Two uranium deposits occur in Lower Proterozoic metasediments of the Cahill Formation, which is part of the Pine Creek Geosyncline in the East Alligator River area, Nothern Territory. The Jabiluka One deposit coincides with a "window" through unconformably overlying Middle Proterozoic sandstone of the Kombolgie Formation; Jabiluka Two is completely covered by that sandstone. The observed part of the Cahill Formation exhibits four horizons which are favourable hosts for uranium mineralization. These have been folded into an east-southeast-striking, gently plunging, open asymmetric syncline-anticline structure. The host rocks are mainly chlorite and/or graphite schists and their brecciated equivalents which have undergone initial regional prograde metamorphism to the amphibolite facies, then retrograde metamorphism to the greenschist facies. Mineralization consists of pitchblende, mainly filling open spaces and to a lesser extent in disseminated form. Chlorite, pyrite and quartz are commonly associated with the uranium mineralization. A portion of the Jabiluka Two deposit contains economic concentrations of gold. Structural preparation with low-pressure conditions at these sites appears to be the most significant ore control. Genetic hypotheses favour initial deposition in Lower Proterozoic sediments, followed by remobilization during later orogenic events. The deposits bear a marked similarity to some pitchblende deposits in central Canada.

Jan 1, 1977

By S. V. Ulianov, A. Y. Senchenko, E. M. Kurchevskaya

"A process sample of old copper-containing tailings (-2.0+0 mm) from an iron-ore plant was tested in TOMS institute in order to develop a process for copper concentrate production. The study of tailings material composition indicated that -0.2+0 mm fraction was efficient and contained 97.26% of copper. Copper is predominantly concentrated in chalcopyrite which is present both in free form and in intergrowth with ore and rock-forming minerals. Study of chalcopyrite using an optical microscope and Qemscan SEM determined that the most grains surface was covered with oxide films. Additionally, a lot of grains had micropores on their surfaces that indicated a partial mineral leaching. The oxide films did not make it possible to float copper minerals from head material. It was recommended to apply an attrition operation to restore chalcopyrite floatability. In order to increase selectivity a regrinding stage for a primary copper concentrate was introduced to obtain P80 26 um. Taking these recommendations into account a flotation flowsheet was developed to process the old Cu-containing tailings. The flowsheet allowed us to obtain a concentrate with 23.5% Cu content at 71.5% recovery.INTRODUCTIONStudy of material composition is an important prerequisite for development of a minerals processing technology. Mineralogical study contributes to search for an efficient technology to recover valuables and for prospective methods of minerals processing.The use of such up-to-date analysis methods and equipment as Qemscan and Mineral-C7 allows one to determine minerals size, liberation degree, and mineral associations. Mineralogical data can reveal reasons for hard processing of minerals prior to development of the process.The advanced process mineralogical methods used to study Cu-bearing pond tailings indicated several factors that influenced development of the process. The first one is a barren size fraction which is to be removed from the process in order to considerably reduce the costs connected with grinding. The second is the presence of films on chalcopyrite surface; in this context, a preliminary attrition of the material was recommended. The third factor is finely disseminated Cu minerals in sulphide and in the rock, which predetermined selection of particle size for flotation. All these data led to significant decrease in time required to develop the process technology. The developed process flowsheet based on the obtained mineralogical data is present in Figure 1."

Jan 1, 2016

By A. E. Moss

"IntroductionTHE WORLD-WIDE search for iron ore has been vastly accelerated during the past fifteen years .and Canada is playing a most prominent role in this prospecting boom. During this period, the search for .and development of iron ore deposits in Canada bas proven eminently successful and there is every indication that exploration will continue to be active for many years.This paper has been prepared primarily for the information of those who have bad little or no experience in iron ore exploration. For convenience, it is divided into three parts: ( 1) a brief discussion of the marketing of iron ores, with special reference to Canadian production; (2) a summary of the main features to be considered when prospecting for or evaluating a potential iron ore deposit; and (3) an outline of the methods and procedures used in the search for the direct-shipping iron ores in the Quebec•-Labrador iron ore field.The Iron Ore MarketDue to the tremendous tonnages of high-grade direct-shipping iron ore indicated in the iron ore fields of the Quebec-Labrador and Steep •Rock areas, it might be assumed that there would have been a sharp decline in iron ore prospecting in this country. On the contrary, the development of these two major fields, which must be classed among the world's greatest, has been responsible for much of the current activity. The search for high and medium grade magnetite deposits is being• conducted in many parts of the country and a number of these have reached the development stage. Production is being expanded from the known fields, such as Wabana in Newfoundland and Michipicoten in Ontario."

Jan 1, 1955

By W. W. Cummings

Canada's only current tungsten producer started up in 1962 with a small open-pit mine on the Flat River , 180 air miles north of Watson Lake, Yukon Territory. The orebody was in a contact-metamorphic skarn zone and contained about 1.5 million tons of ore grading an estimated 2.47% W03 and 0.5% copper. Near the end of the open pit , a new zone was discovered on the lower limb of the same structure, and the decision to go underground was made in 1972. The new "E Zone" contains over 4 million tons of ore grading an estimated 1.6% W03 and 0.28% Cu , and has been supplying the concentrator at about 175,0 00 tons/ year since late 1974. A continuing program of change and up-grading is necessary in the conversion from a seasonal open-pit mine with limited life to an underground operation with twenty years of reserves. Changes are necessary in plant and services as well as the mine. Also, environmental protection requirements have changed from rudimentary to rigorous over the life of the operation. This paper sums up the changes in the operation since 1971 and outlines the changes yet to come.

Jan 1, 1977

By D. Krippner, C. Nexhip, D. George-Kennedy, P. Gebski, R. Kaur, W. L. Ying

ABSTRACT Water-Cooled Tapblocks Are Essential Components Of Modern Smelting Furnaces. Uninterrupted Operation Of A Tapblock Is Critical For The Optimal Operation Of A Furnace. This Critical Function, Together With Exposure To Extreme Conditions, Drives The Need For An Efficient And Reliable Means For Tapblock Monitoring. The Main Objective Of Tapblock Monitoring Is To Help Optimize The Life Of The Tapblocks By Better Scheduling Inner Refractory Relining And Protecting Operators By Preventing Sudden Deterioration Of The Tapblock. A Taphole Acoustic Monitoring (TAM) System Was Developed To Meet The Above Requirements. This Paper Describes The Principles Of The TAM System And Selected Case Studies.

Jan 1, 2013

By T. W. Wlodek

"AbstractSatisfactory mine drilling operations depend on the good performance of the drilling machine, and of what may be called the drill set, i.e., the following four elements: bit, attachment, drill rod, and shank end. The field performances of these four elements in the drill set are analysed and their service lives are compared. The most .common causes of service failure are reviewed and possibilities of increasing service life are discussed.The laboratory methods now employed for the simulated service testing of tungsten carbide bits, conical push-on and threaded .types of attachments, drill rods, and shank ends are described, and some results are discussed. The objectives of the research programme now being carried out •on the above mentioned elements are outlined.A number of mines in British Columbia, northern Ontario, and northern Quebec have been visited, and, with the co-operation of the C.I.M. Branches in these areas, meetings with representatives of the mining and steel industries concerned have been held. In this paper, the mechanical-metallurgical problems most frequently encountered and discussed during these visits and meetings are described and .analysed.IntroductionSUCCESSFUL mine drill operations depend to a great extent on• the satisfactory field performance of the four elements which form the mining drill set, shown diagrammatically in Figure 1.These important elements are:1. -The bit, which may be one of the following types:(a) Detachable tungsten carbide bit( b) Inserted rod bit, so called chisel bit( c) Detachable steel bit( d) Solid rod bit"

Jan 1, 1952