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"Technological innovation is an extremely complex activity. The author presents his interpretation of innovation and the innovative process. He reviews the strategy used by participants in coal mining innovation in the past and discusses changes required to meet the challenges of the future.Introduction if an industry is to be successful and viable in today's world, the companies active within the industry must remain close to the frontiers of knowledge. The coal mining industry is no exception. Technological problems facing the coal mining industry are basically economic and social. Economic problems are those concerned with the long-term growth and profitability and social problems, with the health and safety of the mine worker and the impact of the mining operation on the environment.Technological innovation can be a key factor in meeting these problems successfully. The general belief is that the information base for technological innovation exists within mining companies and governmental agencies but current industrial and governmental strategies and structures impede the transformation of this knowledge into the mining products and processes required for growth.The purpose of this paper is to determine where Canada is in terms of coal mining on the innovative ladder. The paper as presented: defines innovation and innovative process; gives an historical ""broad brush"" review o f innovation in the industry; and suggests the challenges to be faced in the future."

Jan 1, 1985

By 13409, B. Arjang

"Ground stresses are one of the significant factors in the context of rockbursts and underground instability at some hard rock mines in Canada. Overcoring strain relief measurements using triaxial strain cells were performed at several mine sites to provide stress data for stability evaluations and mine design. Pre-mining stress determinations carried out at depths between 60 m to 1890 m resulted in the following average stress gradients:Maximum horizontal stress, s Hmax = 8.18 + 0.0422 MPa/m depthMinimum horizontal stress, s Hmin = 3.64 + 0.0276 MPa/m depthAverage horizontal stress, s Ha = 5.91 + 0.0349 MPa/m depthVertical stress, a; = 0.0266 ± 0.008 MPa/m depthThe maximum and minimum horizontal compressive stresses, with an average ratio of J.75 ± 0.45, prevail in east-west and northerly directions, respectively. Horizontal compressive stresses in excess of vertical overburden load were determined, indicating large variations in ratios to a depth of about 1000 m with decreasing trend toward depth.From present data, a particular regional zoning for the magnitude and direction of horizontal stress fields cannot be outlined.A common feature at mines with near vertical orebodies is that the maximum horizontal stress acts perpendicular to strike while the minimum horizontal stress is aligned on-strike. The vertical stress components approach the gravitational overburden load."

Jan 1, 1991

By J. W. Matousek

"More copper concentrates are treated in flash smelting furnaces than by any other process, and such furnaces are located in most of the world's major copper producing areas. Except for perhaps two furnaces treating chalcocite-type materials, little difference is seen between the grades of the concentrates being smelted. Within individual smelters, even less variation in feed grades is found. This is both accidental and intended. Many furnaces treat concentrates from captive ores, and these tend to be of relatively constant composition over long periods. Toll smelting operations blend concentrates to ensure delivery of feeds of fixed compositions to their furnaces to avoid upset conditions. Matte grades vary between flash smelting furnaces, but most commonly, these are the result of differences in operating practices rather than because of differences in concentrate grades. This paper reviews an industrial flash smelting test in which the copper content of the furnace feed was intentionally altered over a wide range. IntroductionExcept in a few copper mining regions of the world, the principal copper mineral is chalcopyrite (CuFeSz). This results in the almost universal production of concentrates containing 25070 to 30% copper (and similar amounts of iron and sulphur). Many operators of copper flash furnaces spend their entire metallurgical careers smelting concentrates of essentially fixed grades. This is true both of smelters treating concentrates from captive mines and those processing concentrates on a toll basis. From the production staff's point-of-view, the less variation in grades seen by the furnace, the better. Fixed analyses of concentrates and constant feed rates produce consistent quantities of matte at a consistent grade for processing by the converters. The result is, even in smelters treating a variety of concentrates, efforts are expended in sampling and blending to ensure feeds of relatively uniform compositions being sent to the furnaces."

Jan 1, 1993

By A. L. Holloway, N. M. Soonawala, L. S. Collett

"Since the late 1970s, a major R&D program has been under way in Canada to assess the concept of disposing of nuclear fuel wastes in deep plutonic rock. Atomic Energy of Canada Ltd . (AECL), a federally-owned corporation, has been given the responsibility of directing this research (Rummery et al., 1983).The Underground Research Laboratory (URL), constructed in a granite pluton 15 km east of Lac du Bonnet, Manitoba (Fig. 1) is a major component of the Canadian Nuclear Fuel Waste Management Program. A diverse geotechnical experimental program is being carried out during both the construction and operating phases of the URL. This program involves detailed geological mapping, rock mechanics and hydrogeology studies, and geophysical surveying, to characterize the rock mass surrounding the shaft, and it has been described by Simmons et al. (1983). As part of the construction-phase program, ground-penetrating radar (GPR) surveys are being carried out during excavation, in an attempt to delineate fractures both ahead of the excavation and behind the walls of the excavation. This paper presents the results of surveys performed during shaft excavation and describes a procedure for plotting the data.Ulricksen (1982) cites examples of radar surveys to evaluate surficial deposits, such as peat, sands and gravels, and cavity detection in subsurface hard rock. Fowler (1981) used radar for fracture and clay vein detection in coal seams.In Canada, pioneering work in GPR has been done by Annan and Davis since the mid-seventies (Annan and Davies, 1976). Their work concentrated on problems relating to permafrost in the Arctic ."

Jan 1, 1986

By Frédéric Flament, Mary Goldman, Gille Barbery

"Pilot plant testwork on autogenous and semi-autogenous grinding was conducted at the Centre des Recherches Minérales du Québec (CRM) to investigate the effect of ball addition, solids concentration in the feed, specific energy consumption and feed size distribution.A mathematical model that incorporates breakage and surface mechanisms of loss of mass was developed to predict load size distribution of autogenous and semi-autogeneous mills. An empirical model was used to predict product size distribution of autogenous and semi-autogeneous mills.IntroductionAutogenous (AG) and semi-autogenous (SAG) grinding circuits offer potential capital and operating cost savings when compared with conventional grinding. Empirical relationships have been developed to calculate specific power consumption for SAG mills using pilot plant test results (Mular et al., 1989; Barrett and Allan, 1986). Empirical models can be obtained from plant practice data but are applicable only to the particular ore and set of operating conditions used in the model. Grinding mechanisms have to be taken into account in order to develop a model that can be applied to different ores and mills.In AG and SAG, the ore itself acts as grinding media, with the finer sizes being crushed by the coarser ones. Surface mechanisms of loss of mass, in which the inner core of the particle remains intact, also take place. In SAG milling, the effect of balls also has to be taken into account. The role of each one of these mechanisms changes with particle size and the model has to account for such changes."

Jan 1, 1991

By Michel Aubertin

Mining activities can produce large volumes of waste rock, which are typically deposited in piles on the soil surface, above the water table. Such piles can cover areas of several tens of hectares and can reach over a hundred meters in height. For hard rock mines, the waste rock grain size can vary from silty particles to metre-scale blocks. The internal structure of a pile constructed on a relatively flat surface typically includes two main zones. The first zone corresponds to the heart of the pile, and is formed by several sub-horizontal stratifications (with dense and loose layers) due to the heavy mine equipment traffic which induces local compaction and degradation of the waste rock. The second zone corresponds to regions where waste rocks are deposited by push-dumping or end-dumping close to the external flank of the pile, inducing grain size segregation along the slope. Depending on the deposition sequence, grain size distribution and bench height, a gradation may then be observed, with coarser particles (with cobbles and blocks) near the base and finer particles near the crest, together with inclined stratifications due to the advance of the deposition face. These internal features affect the distribution and flow of water (and air) in the pile. To assess the internal distribution of material properties within the pile, a combination of several tools is usually required which can provide information on the hydrogeological and geochemical characteristics of the waste rock. In this regard, geophysical tools are very interesting because they can lead to a threedimensional mapping of property variations. The information gathered from a combination of appropriately selected techniques can be used to construct numerical models to further study unsaturated water flow and reactive transport. Such simulations help better understand the pile response in its actual and future states, which in turn provides input to adjust the deposition sequence, to plan for closure, and to select an in situ groundwater monitoring strategy. The presentation will give an overview of techniques that have been developed to characterise material properties in the laboratory and in the field, and to obtain a general picture of a pile?s internal structure. Additional results on unsaturated reactive transport modelling will also be shown to illustrate how the internal pile structure may influence its hydro-geochemical and environmental response.

Nov 1, 2008

By J. Y. Liu

In Comparison to the application of HPGR (high-pressure grinding rolls) in the cement industry and in iron ore processing, the introduction of this energy-efficient comminution technology to processing of nonferrous base-metal ores has progressed slowly as yet. In the field of minerals industry, challenges lies not only in the large variety of the feed material with respect to particle size, density, hardness, moisture and mineralogy of the material but also in complexity of the processing flowsheet, which need to be addressed from case to case based on result of HPGR comminution test work. Whereas conventional comminution test with HPGR in lab-scale or pilot scale needs quite a large amount of feed material, a compressive stressing test of particle-bed in piston-die device provides an effective way to study interparticle breakage behavior of ore material with much less feed. In the present study the effects of interparticle breakage on comminution of a copper ore has been investigated by compressive stressing of particle bed in a piston-die device. The feeds to the particle-bed stressing tests were four narrow size fractions in the size range of 0.3~3.35 mm and a broad size fraction of 0/3.35 mm. The pressures applied were in the range between 30 and 180 MPa. The results showed that the specific energy consumption increases linearly with the pressure; the product fineness increases also with the pressure, but the magnitude of this increase declines as the pressure goes up. Under the same stressing intensity, the product size distribution curve becomes steeper as the particle size decreases, so there is no self-similarity between product size distributions of different feed sizes. The suitability of a material-characterization model for interparticle breakage was verified for this ore. In addition, the effect of interparticle breakage on comminution of this ore with respect to its influence on the downstream flotation were analyzed in terms of size-metal distribution and mineral liberation.

Jan 1, 2016

By W. J. Mcgaughey, R. G. McCreary, S. C. Maxwell, R. P. Young

"Seismic tomography is a process for obtaining images or maps of seismic velocity or other seismic properties of a rock mass. Seismic velocity images reveal variation in elastic moduli which, in tum, are related to several properties required in the geological or geomechanical assessment of a rock mass. Seismic velocity is sensitive to lithology, discontinuities, and in situ stress. Spatial or temporal variation of these properties may be indirectly assessed. Tomographic measurements are sensitive to volumes of ground, rather than determinations at points, or along lines or surfaces, as in conventional geological or geomechanical measurements or mappings.Tomography surveys are complementary to conventional measurements as they have the capability to interrogate a substantially larger volume of ground. They are thus useful in discerning trends or patterns in regions between or surrounding conventional ""point"" measurements of lithology, rock quality, stress, or other parameters of interest. Seismic velocity images give broad indications of trends in velocity; their spatial resolution of ground properties is typically on the order of five to ten per cent of the nominal survey dimension.Research in seismic tomography has been carried out for several years, and the capabilities and limitations of the technique in mining environments are beginning to be understood. This report reviews the present capabilities of seismic tomography surveys in mining, emphasizing rock mechanics applications. Six case studies are used as examples to demonstrate the capabilities of the method in assessing lithological variation, density and orientation of discontinuities, and the effects of stress."

Jan 1, 1994

By J. H. Nantel, J. F. Archibald

"The presence of radon from uranium-bearing ores, waste and from backfill material introduced underground to provide ground support, work platform and waste disposal functions, requires that ventilation controls be established to maintain safe working level concentrations. One approach has been developed at Queen's University to quantify radon and radon daughter source level s and to estimate ventilation requirements necessary to maintain these safe levels.Knowledge concerning the sources of radioactive contaminants and their production quantities is of value for planning and design stages of ventilation control systems. For any given mine layout, radiation level estimates may be forecast and modified by ventilation network design where excessive production quantities may exist.Behaviour of Radon Gas in MinesRadon gas, produced from the decay of Ra-226 in a host medium, will diffuse through porous media. In areas adjacent to mine workings, radon will be liberated into the mine atmosphere. The rate of radon emanation is proportional to the rate at which radon is produced within the host material (a function of the ore grade of U308) , to the radon concentration gradient in the host pores and to the diffusion properties of the material.The radon source concentration is determined by the rate at which Rn-222 is produced by the decay of Ra-226, and by the emanating coefficient (E), or fraction of the radon which escapes from the source matrix and is free to diffuse through the pore spaces."

Jan 1, 1984

By Gheorghe Vieru

Security and safety due to environmental impact as well as the radiological consequences during the uranium mining operations, tailings management, uranium processing, disposal of waste in conventional landfill sites are matters of great importance. The Uranium National Company (CNU) from Romania is responsible for all aspects belonging to the management of the entire Romanian uranium industry- the uranium ore extraction, transport and processing of uranium ore, concentrates processing, as well as disposal of sterile ore and waste. The paper will presents specific safety problems related to the identification and evaluation of potential environmental risks, as well as possible radiological consequences associated with the disposal of sterile and the uranium processing waste resulting from processing of the uranium ore. Computer codes will be used, such as IAEA INTERTRAN II and RADTRAN 5. It is also to be noted that this paper considers the main results of the scientific research carried out by the main author as CSI (Chief Scientific Investigator) for Romanian Research Contract on NORM concluded with IAEA Vienna.

Aug 1, 2010

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

By A. P. Annan, C. Vaughan, J. L. Davis

"The increase in the price of gold in the last decade has led to a significant increase in placer gold exploration around the world. Placer deposits occur in depressions along ancient river and stream channels. In many instances these channels have been covered with materials from subsequent erosion or glacial activity. Use of high resolution geophysical techniques to map the bedrock and soil strata can improve the probability of finding the placer deposits. The buried bedrock surface is often the factor controlling deposition. Ground probing radar (GPR) and seismic sounding are complementary high resolution techniques which can be used to map bedrock topography and soil stratigraphy. Current radar instrumentation operates best in coarse grained soils. Penetration depths of up to 30 m have been attained, and stratigraphic horizons have been mapped with spatial resolutions of better than 0.5 m. Although its spatial resolution is considerably lower than radar, seismic refraction achieves superior penetration in electrically conductive environments such as clay and silt soils. The seismic refraction method thus proves to be complementary to the radar method. The seismic reflection technique is analogous to the radar method. Current seismic instrumentation and energy sources however, provide limited spatial resolution and do not permit the use of seismic reflection for reflecting horizons lying at depths of less than 20 m to 30 m.This paper discusses the use of both radar and seismic methods for placer exploration. The radar and seismic techniques, the field methods, equipment, and data displays are presented. Field examples illustrate the high resolution mapping capabilities of the techniques. The radar data agree very well with the borehole data, and in fact they sometimes detect subtle soil strata variations associated with changes of permeability that were not initially observed in the borehole logging. The radar method can give a continuous profile of water table and bedrock in sandy soils. Seismic soundings are necessary to differentiate between the bedrock and water table reflections observed by the radar."

Jan 1, 1987

By . A. C. Atenas

Control of arsenic in the Potrerillos' Refinery electrolyte has been obtained by withdrawing a bleed stream of circulating electrolyte and ensuring the ratio of [O]/[As] in the cast anodes is maintained between 0.9 and 1.0. In order to achieve this control the anode oxygen must be adjusted, depending on the arsenic level in the cast anodes. It has been necessary to modify the time of the reduction step in the anode furnace refining process. Control of this ratio has permitted electro refining of anodes with high levels of arsenic, up to 3000 ppm, while minimizing the volume of electrolyte that must be removed for impurity control so as not to affect the copper concentration in the electrolyte. However this control strategy is not useful when the arsenic concentration in the cast anode is too high, because it is limited by the maximum oxygen concentration allowable for a good quality anodic. Costs have been reduced in anode furnace refining because it is no longer necessary to use alkaline flux injection to remove the arsenic in cast anodes.

Jan 1, 2007

By M. C. Bluteau, G. P. Demopoulos

Arsenic reports in the effluents of many non-ferrous metallurgical operations. The production of scorodite, a crystalline ferric arsenate, is considered as an attractive option for the fixation of arsenic from aqueous effluents. However, scorodite solubility and long-term stability in the pH region of interest for tailings disposal have not been thoroughly investigated. In this study the long-term stability of scorodite in the pH 5 to 9 region and the mechanism of scorodite dissolution were studied. Construction of eh-pH diagrams indicated that scorodite stability is highly dependant on the nature (stability) of co-existing iron-hydroxide/oxyhydroxide. It was also found that when scorodite dissolves, a ferrihydrite phase having very small particles size (nano-scale) forms and that the growth and crystallization of this material are delayed by the presence of arsenate even under accelerated (75°C) ageing conditions. Around neutral pH and ambiant temperature (22°C) scorodite seems to reach an equilibrium with ferrihydrite after 48 weeks yielding soluble arsenic concentrations < 5 ppm.

Jan 1, 2004

By Owen Owens, W. P. Armstrong

The process of arriving at the size and grade of: (a) a newly-discovered body of mineralization, (b) a potential ore resource, (c) an orebody proposed for mining, or (d) the ore reserves in a mine, requires fundamental geological, and geometrical determinations as well as physical and chemical analyses. This paper outlines geological and geometrical features considered critical, in the authors&apos; experience, in realistic reserve determination. These are discussed under the headings "The Four Cs". They include the Character, type or nature of the mineralization; the Continuity of various types of mineralization in the deposit; various key concerns in the Calculation besides the mathematics; and the Classification section which refers to basic considerations in classifying a mineral estimate. It is suggested that the responsibility for the calculation of a Resource or Reserve should be that of a geologist experienced in the ore type under review. Further, it should be the responsibility of the board of directors of the company owning the deposit to ensure that a sufficiently experienced person is chosen to carry out the process.

Jan 1, 1993

A series of small scale tests have been conducted to evaluate the effect of micro-fracture development, imposed by blasting, on the material properties of the rock as well as its resistance to crushing and grinding. The uniaxial compressive strength, tensile strength, Poisson?s ratio, P-wave, Swave velocity, point load test index, crushing and grinding work indices were evaluated for samples without any blasting load and for samples which had received a variety of blast loads ranging from a single impact with low strength detonating cord, to combination of impacts at different times and significant impacts with powder factors close to those used in practical blasts. It was shown that the rock mechanics parameters change even at low impacts, suggesting easier crushing of the rock. Damage values appear to be affected by timing as stress wave superposition affects the damage process. Fragmentation is achieved at higher impact levels while work index modification of the fragments is also observed when high powder factors are used, suggesting improvements in grinding.

May 1, 2003

By G. R. Haiden, E. Henderson

"An LHD teleoperation and guidance system, developed at the Ontario Division of Inco Limited, has been demonstrated in operation at Copper Cliff North Mine (CCNM) since late September, 1993. The tests performed to date have evaluated the feasibility and production viability of multiple LHD operation, from surface by one operator.The systems technology required to accomplish this consists of an electronic monitoring and control package mounted on the LHD; a high bandwidth mining computer network capable of providing radio frequency coverage; and an operator control console which provides an operator workstation for multiple LHD operation.This paper discusses the systems required to accomplish the task of LHD teleoperation and guidance, the benefits of multiple machine operation and future research and development directions. IntroductionSince underground mining began, persolU1el have entered the mine workings to mine ore. Today, however, the rapid advancement of modem telecommunications, computer hardware and software technology has opened the door to remote mining technology that was considered unfeasible a few years ago. This paper discusses the ingredients of remote mining technology that have been developed at Inco Limited.Figure I represents an historical view of the application of electronics to LHD operation at Inco Limited. In 1980, the first radio remote controls for the operation of LI-IDs in large open stopes were tested. The successful application of this technology at Inco went hand-in-hand with the development and application of the Vertical Crater Retreat mining method. The combination of these two advances had a very positive effect on the productivity in the mid-eighties at Inco. In 1991, the Mines Research Department of the Ontario Division advanced remote control technology by developing a high capacity underground mining telecommunications system. This system is capable of moving voice, data and video information throughout the mine workings. The system is based on broadband communication technology found in most automated factories, with the added benefit of providing the information to and from mobile equipment through radio interfaces. The first test of the system consisted of an operator teleoperating a single LHD (on the 3000 ft level) from the surface. The next test on September 13, 1993, demonstrated the first production application of multiple LHDs being run from surface with a single operator."

Jan 1, 1994

By Robert B. Parsons

"The pendulum in Ottawa has swung dramatically from fiscal policy to monetary policy over the last several years. International trends indicate that the pendulum has to start its swing the other way, if Canada&apos;s mining industry is to maintain its preeminent position in the global mining arena. This article, which is based on a paper presented by the author at the 37th Annual Meeting of the Newfoundland Branch of CIM, identifies these trends and how they could interact with Canadian policy.IntroductionThe title of this paper is not a very imaginative or catchy one, but it states the topic quite succinctly, if not tersely. This paper looks into a crystal ball to see what might be in store for mine financing over the balance of the current decade.In the event that the reader feels some trepidation about the prospect that such a paper could seek to be the definitive work on the subject, it should be made clear at the outset that this is not the case. The author is, after all, not an economist, a scholar, a financial analyst, or a soothsayer, but is rather a simple accountant who has been closely involved with the mining industry, and the financing thereof, for some twenty years.The paper recognizes that, while a mine may be born when production begins, the mine is conceived when exploration starts. As this act of conception is obviously an essential part of mining, the financing of exploration is also covered in this paper. To attain a focus, this paper approaches the topic of mine financing in the nineties as follows: first, the major emerging forces in the industry are identified: and, second, the implications of each of these forces on financing are considered."

Jan 1, 1991

By X. Cao, X. -G. Chen, K. Liu

As is well known, the standard Al-Cu 206 cast alloys have extremely low iron contents, usually less than 0.15 wt. %. Recently it is found that the iron contents of the 206 cast alloys can be extended up to 0.5 wt. % through the precise control of the iron-rich intermetallic phases. In the present work, the tensile fracture surfaces of the 206 cast alloys with various iron contents are systematically analyzed to understand the failure mechanisms. Results show that higher iron contents can reduce the tensile properties (especially the ductility) of the alloys mainly due to the increasing volume percent and size of the iron-rich intermetallics. Tensile failure mainly occurs at the iron-rich intermetallics/matrix interfaces for the platelet ß-Fe, but by the self-disassociation for the Chinese script a-Fe and Alm(FeMn). Cracking is easier to initiate and propagate along the longitudinal axis of the platelet intermetallics, but it can be deflected along the branches/arms of the Chinese script iron-rich phases, making the alloy more resistant to the propagation of the cracks, and thus the Chinese script iron-rich intermetallics are less harmful than platelet ß-Fe. In addition, it was also found that the Chinese script a-Fe has even a less damaging effect compared to the Chinese script Alm(FeMn) due to the relatively small size and compact morphology.

Jan 1, 2014

By Julian Baldry

"This paper begins by describing the parameters of high-speed underground tracked drifting operations and the mucking cycle, and-discusses their variations. The railbound Haggloader 8HR is then described, as well as the Hagglund shuttle trains, outlining the advantages and disadvantages of the system. A comparison with conventional mucking operations is then given.IntroductionDrift and tunnel rounds are mucked by one of two major methods, either trackless with diesel loaders and trucks or with track loaders and cars. The aim of this paper is to compare the conventional tracked mucking cycle with the Hagglunds system alternatives.For many years, the traditional method of attacking the mucking cycle has been with a rocker shovel loader, a string of cars and a locomotive. The rocker shovel loads the first car and when full it is taken to a side drift, cherry picker or some other transfer point and is exchanged for an empty one. This empty car is then pushed back into the face and the loading continues until all cars are full . Then the whole train is taken out to a dump point where the cars are emptied. Normally the train&apos;s capacity is less than the volume of the muckpile, so the cars go back to the face. This loading cycle is repeated until all muck is removed from the heading. The last train out from the heading usually takes the loader and parks it in a side drift before continuing on to the dump where the cars are emptied.This simplified version of the traditional loading cycle excludes the ancillary work elements such as track laying and so on, but does point out that the cars must be transferred when full and that the whole train normally makes at least two round trips from the dump to the face. The prime aim in drifting is to cycle a round whithin a working shift which necessitates that no one part absorbs so much time as to prevent the completion of the cycle.Mucking, drilling and loading and the ancillary work such as rock bolting, vent and service pipe hanging typically each take one-third of the available work time. Drilling or mucking can and often do, because of various factors, take nearly half of the total cycle time. Once any segment of the operation starts to take this portion of the shift, the likelihood of missed rounds becomes increasingly greater."

Jan 1, 1981