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By Malcolm Scoble, Nick Vagenas, Greg Baiden

Recent advances in underground communications technology have demonstrated the feasibility of teleoperation and automation in underground metal mines. One major challenge lies in the automation of underground mobile machines from surface, with the potential to reduce significantly the need for human involvement in underground operations. This paper reviews the evolution of underground metal mining automation, principally related to the development of teleoperation and automation of mobile mining machines. Examples of prototype systems are given and the associated benefits that have been observed are reviewed.

Jan 1, 1997

By Manqiu Xu, Joe Holmes, Peter Wells, Peter Langlois, Germain Labonté, Jim Barrett

"The flowsheet for the Voisey’s Bay mill had to meet the challenge of processing an ore containing high pentlandite and chalcopyrite values in a largely pyrrhotite/troilite matrix. In the 1994-97 period, circuit development focused on making a high-grade copper concentrate and a relatively low-grade nickel concentrate. However, in 1998 a circuit with copper concentrate, high-grade nickel concentrate and a Ni/Cu middlings concentrate was specified. Following a three year project delay, work resumed on the flowsheet in 2001, and the target for the overall grade of the nickel concentrate was raised from 14% to 20% nickel. To achieve this target triethylamine tetramine (TETA) and sulfite pyrrhotite depressants were used in an all lime circuit. It later became evident that, with appropriate selection of collector and adjustment of the circuit by the addition of a scavenger on the scavenger cleaner, it would be possible to approach the grade of concentrate required without the use of pyrrhotite depressants. The recycle of water and the contained thiosalts was also proven to be instrumental in raising the grade.Construction and commissioning of the mill were fast-tracked with start-up of the mill in September 2005 some six months ahead of the original schedule. Ramp-up of both throughput and metallurgy was faster than any other recent nickel installations with tonnage being limited mainly by concentrate dewatering due to the higher than initially planned ore grades.INTRODUCTIONNickel was discovered in the vicinity of Voisey’s Bay by Chislett and Verbiski working for Diamond Field Resources in 1993 and the Ovoid deposit was delineated in the winter of 1994/95. By the end of 1995 the Ovoid had been well explored and at that time was thought to have a reserve of at least 30 million tonnes with an average grade of 2.83% Ni and 2.0% Cu. Drilling to the east of the Ovoid had indicated the presence of significant mineralization. In June of 1995, Inco Limited bought a 25% share in the Voisey’s Bay Nickel Company (VBNC) which was a subsidiary holding company set up by Diamond Fields. Inco also bought 8% of Diamond Fields and negotiated the right to sell all the nickel produced from VBNC for twenty years as part of this agreement. In April 1996, Inco bought the 75% of VBNC shares that it did not own."

Jan 1, 2007

By Zhiyang Long, Ruiling Xiao

"A mine shaft is one main development method of establishing access in an underground mine. The construction technology of the mine shaft sinking is complicated and large equipment setup on surface and in the mine shaft. The paper briefly reviews a single-line operation method, parallel operation method and mixed operation method as well as the features of the one operation method with the excavation, lining and installation. The special construction technology mainly would include ground freezing methods, full diameter shaft drilling methods, caisson methods, grouting technology and concrete curtain methods as well as other methods. The paper summarizes the shaft sinking numbers and effects by the special construction methods during different periods. The paper states the shaft sinking conditions and the each created record conditions in the coal, metallurgy, non-ferrous metal, hydropower, highway, railway, nonmetallic and other industries. The paper has a prediction on the shaft sinking requirements and development tendency in the future for China.INTRODUCTIONA mine shaft is one main development method of access in an underground mine. In recent years in China the new shaft mines represent 45% of the total number of new mines. With the development of new mining area under construction and the development of deeper mines, the ratio of the mine shaft as access for underground mines will increase. The construction technology of the mine shaft engineering will be complicated, the operation site footprint will be small and the working environment will be more difficult. The mine shaft sinking operation will often be varied by the geological conditions and affected by underground water inflows, seam gas outbursts, geothermal and other natural conditions. The safe construction of the mine shaft sinking will be challenged by all these conditions. Although the mine shaft engineering will only be about 5% of the total mine roadway engineering, the mine shaft construction period often will take over 40% of the total mine construction period. With the progress of modernized mine production technology and the construction of a high production and high efficient mine, the mine transportation roadways mostly would be set in the seam and the engineered amount of the mine rock roadways reduced year by year could cause more prominent long extensions of the mine shaft construction period. Therefore, in order to speed up the construction, to shorten the mine construction period and to realize the investment benefits as early as possible, the technical level of the mine shaft sinking should firstly be improved and the construction speed of the mine shaft engineering and sinking should be speeded up, which would have important significant benefits."

Jan 1, 2019

By Z. G. Tao, Y. Y. Peng, W. L. Gong, M. C. He

"This paper presents an overview of the major landslide hazards in open pit mines in China, the currently used landslide control and monitoring techniques, and development of a new slope control technique incorporating the reinforcement, sliding force monitoring, remote sensing and forecasting in one system in order to constrain the displacement of the sliding blocks in the landslide to minimized the influenced area and provide precise warnings timely for the imminent landslides. For implementation of the new technique, a novel rock cable with large deformation and high resistance (also known as HE cable) was developed, which can elongate as long as 2m. At the same time, the necessary and sufficient condition for initiating a landslide and energy balance equations are formulated. Based on the proposed mathematical models and Beidou satellite system, the software and data transmission hardware for remote sensing and forecasting were developed the new landslide control technique has been applied successfully in 245 landslide sites in 12 provinces across China. In this article, two practical application cases in the open pit mines are reported.INTRODUCTIONChina is one of the countries in the world with the most widely distributed landslides and suffering the heaviest damage. According to the incomplete statistics, landslide hazards have caused death of hundreds of people and direct economic losses of several hundred million RMB each year. The landslide hazards have a great impact on the life and property safety of the people, safety of the infrastructure, as well as the social stability. Thus development of new techniques for forecasting and prediction of the landslides is imperative and of great importance. In general, the forecasting and prediction of the landslides consists of three major aspects, i.e. sliding time forecasting, landslide activity intensity forecasting and landslide hazard degree forecasting. Since a considerable part of the landslide-suspected area are adjacent to the residential areas or important infrastructures, development of the advanced landslide control and monitoring techniques to cope with the sliding time forecasting problem is more important.Over the past one hundred years, the most widely used slope monitoring techniques are based on displacement monitoring (Xu, et al. 2007; Toshitaka, 1998). In the early days owing to the limitation of the technology and equipment, the ground surface displacement and underground water level change were inspected mainly by man power for inferring the possibility of a landslide. In recent several decades, more and more ground surface displacement monitoring devices were brought to the market, such as the automatic total station, theodolite, digital level, borehole inclinometer and GPS based instruments, etc. Based on these modern techniques, some advanced instruments have been developed and applied to the landslide monitoring, for example, the “landslides early warning monitoring system” (Leonardo, et al. 2002), the “In-SAR” technique (Reevea, et al. 2000), the GPS and satellite geodetic survey based technique (Reevea, et al. 2000), and real-time telemetry technology (Xu, et al. 2007). These monitoring approaches have made significant contributions to the landslide disaster monitoring and forecasting. The major limitations for the ground surface displacement monitoring techniques are lie in the inconsistence between the displacement in ground surface and that in the sliding surface for the sliding mass, resulting in low degree of forecasting accuracy."

Jan 1, 2015

By Colleagues from Process and Operation departments, Guy Chevalier

"QCM's pellet plant, located in Port-Cartier, Quebec, produces up to 8.6 million tons of iron ore pellets annually. Four different types are produced: three for blast furnace operations and one for direct reduction furnaces. The paper presents the scientific approach that led to the installation of new process equipment to improve the reducibility of direct reduction pellets (DR pellet). The findings, the equipment selection and some post start-up modifications are presented.This low silica DR pellet is used in Midrex and HyL shaft furnaces. A good DR pellet has to meet strict chemical, physical and metallurgical specifications. An important metallurgical property is its ability to release oxygen when exposed to reducing gases. Considering that the market for DR pellets is expanding and being aware that reducibility is critical for our clients, a program to improve the latter was undertaken. Test work showed that one factor which has a negative effect on reducibility is the proportion of particles larger than 75 microns. Knowing that the best way to reduce the amount of coarse particles was to close our open grinding circuits, we began evaluating the most suitable classification equipment applicable to our process operations. We settled on hydro-classifiers based on their very sharp cut and their low operating costs. In light of the hydro-classifiers performance it was also decided to replace the hydro-cyclones of an already closed circuit.INTRODUCTIONAt the Québec Cartier Mining pellet plant, continuous improvement programs are aimed at increasing levels of consistency and improved chemical, physical and metallurgical properties. This is being accomplished while still maintaining pellet plant production volumes to satisfy market demands.QCM produces three types of pellets for blast furnace use: acid pellets, designated as ""BHF"", fluxed pellets, designated as ""BAF"", and low silica fluxed pellets, designated as ""BSA"". For direct reduction, a low silica acid pellet or DR pellet, designated as ""BBS"" is produced. This low silica DR pellet is used in Midrex and HyL shaft furnaces.The demand for DR pellets has been increasing during the last few years and is believed to continue so in the future. Wanting to be present in this growing market QCM found that it would be essential to work at improving its DR pellets quality. Efforts have been focused on improvements in three areas: SiO2 reduction, elimination of sticking and increasing reducibility. Improvement programs have begun with laboratory research followed by plant trials and full-scale implementation as a cooperative effort among QCM, COREM, and key customers."

Jan 1, 2002

By Ralph H. Cleland

GENERALLY speaking, the Industry lost ground in 1941 in its accident experience. Though the frequency of compensation accidents was but slightly higher than in the previous year and well below past experience, our fatality rate shot up to that obtaining in 1938, and the average cost per man employed was the highest for some time. The number of fatalities was 56 in 1941 as against 33 in 1940. The average cost of compensation per man employed was $34.25 in 1941 as against $28.43. There was but a slight increase in the number of men employed. Accident prevention efforts were maintained, as shown by our frequency, but our accidents were of a more serious nature. In a period of considerable labour turnover, with many new men entering the Industry, especially the base-metal division, and much mental distraction, we might well have expected a high rate of accidents. That this did not occur is a tribute to managers, supervisors, and workmen alike. We all regret the high fatality rate and one must consider why this occurred. So far as it is possible to determine, there is no apparent explanation. There were no disasters. The accidents occurred to the same class of work-men, both in respect to jobs and age groups, and from the same age-old causes that we all know so well. Luck is a big factor in the seriousness of an accident; the solution lies in preventing accidents, even first-aid cases. Generally speaking, if minor accidents do not occur, major accidents do not occur.

Jan 1, 1942

By Murray Wood, Michael Schaffer, Makat Katom

"An expert system applied to the control of mineral process unit operations is, by its nature, the site best operating practice, having been designed by the local experts in conjunction with consulting metallurgists. The “common sense” layer in a MET (MinnovEX Expert Technology) solution determines an appropriate action for the current operating conditions through a developed heuristic model of the process (expert system). The magnitude of the setpoint change that is made is proportional to the confidence that the system has in its interpretation of the current conditions (fuzzy logic). The solution is always striving to take the process to a constraint and thereby optimise the operation. An accepted limitation of the solution is that the only way the system can determine if a constraint has been reached is to exceed it and then withdraw – essentially “experimenting” with the process. By leveraging a model, which can accurately ""simulate"" the process, this restriction can be circumvented by pre-testing the set point change through a ""what if"" analysis and then modifying the solution as appropriate.At Ok Tedi, the introduction in 1999 of a MET expert system for SAG milling resulted in significant improvement in circuit throughput. Yet, with the additional inclusion of an accurate model of the process there was still more that could be achieved. Hence, in 2002 a MET Neural Network model was developed and deployed to enhance the existing expert system solution. The principal objective of this model was predicting the effect that changes in SAG tonnage and density would have on the power draw of the mill - essentially a power predictor. The results have seen a decrease in process variance with an associated increase in average circuit performance.This paper describes the methodology by which the Neural Network model was implemented, the considerations and limitations when applying this technology and ultimately the results that were achieved."

Jan 1, 2003

By H. Dean

"Mine hoisting machinery, of which wire rope is an essential part, is developing, in Canada as well as in other parts of the North American continent, into highly sophisticated equipment. Heavier payloads are now required to be raised from steadily increasing depths at higher rates of speed and production. These hoisting conditions have, of necessity, brought about a major change in the production of steel roping wires and the wire ropes manufactured from them.Operators and designers of hoisting equipment are requesting a very much more efficient ratio of strength to weight in hoisting ropes, so that heavier loads may be raised from greater depths by ropes which will provide a predeterminable life span on which the operator may depend.The cost of wire rope to the operator is very low indeed, usually less than $0.01 per ton of payload, but the cost of unexpected shutdown periods, due to rope maintenance or change, can be extremely high -particularly in operations where a continuously high rate of production is an absolute necessity. Mine hoist ropes with a higher strength to weight ratio are now being made and used in some areas of Canadian mining, and a general understanding of the performance we may expect from them is required."

Jan 1, 1968

By SangHyeok Han

Selecting the best possible cranes and identifying spatial conflict-free locations on sites can result in productivity and safety improvements for large-scale industrial construction projects. In the current practice, experienced lift engineers select cranes based on the heaviest lift and/or the largest lifting radius of the identified crane. This practice is relatively time-consuming, and optimization of the crane?s use and location is also difficult. There are many factors which need to be considered during the crane selection process, a reality which further complicates the process. This paper presents a framework which aims at developing a decision support system to enhance the crane selection process and collision-free path planning for large-scale construction projects. This paper utilizes an innovative crane selection matrix in order to establish a process for optimized crane selection for construction projects. The study considers more than 40 different factors in order to reduce time and improve safety for crane operations. Following finalization of crane type (mobile crane versus tower crane), a visualization model to simulate crane operation and identify collision-free crane operation paths is proposed. This process can assist project managers to plan the lifting process more effectively and efficiently. A case study-based approach was utilized to demonstrate the proposed methodology. The methodology was tested in the planning and construction process for boiler house structures in Mannheim, Germany. The project entailed numerous challenges: one of the major tasks was to lift a 102-ton load on the top of the boiler structure through crane collaboration; space limitations on site also presented several challenges related to crane selection, location, and operation processes. Based on the project constraints, the proposed crane selection framework, and the visualization models, two tower cranes were selected and successfully implemented in the case study.

Aug 1, 2013

By P. Amelunxen

It is well-known that the particle breakage mode that occurs in a semi-autogenous mill is significantly different from that which occurs in a ball mill, enough so to warrant very different lab scale breakage tests and scale-up models. This phenomenon, at the plant scale, leads to changing process constraints depending on the particular properties of the ore. For example, hard or coarse ores might bottleneck the SAG/AG mill throughput, while the ball mills might constrain throughput when milling soft or fine ores. Because the power draw of a ball mill is fairly constant compared to that of a SAG/AG mill, periods of SAG/AG mill bottlenecks lead to increased ball mill circuit specific energy consumption and a finer grinding circuit product size, which together constitute a loss of efficiency of the overall process. Because HPGR circuit throughput is less sensitive to changes in ore hardness, this situation is less common or severe in those circuits. Furthermore, the ball mills are somewhat decoupled from the upstream crushing circuits through the use of surge bins, which also helps to mitigate this effect. As a result, ore hardness variability constitutes a significant cost penalty that should be applied to SAG mill/ball mill/pebble crusher SABC circuits when evaluating the relative economics of different grinding circuit configurations. Nevertheless, the issue is by-and-large ignored, because most current HPGR trade-off studies are based on averaged ore hardness parameters. This paper provides an estimate of the magnitude of this penalty for a typical operation by using Monte Carlo simulation methods and plant data from Freeport-McMoRan?s autogenous, semi-autogenous, and HPGR-based comminution circuits. A case study from an in-house 96K t/d sulphide project is presented to illustrate the concept. It was found that by including variability effects, the trade-off NPV of the HPGR circuit over that of the SAG mill circuit increases to $84 million from negative $33 million, effectively reversing the original decision of selecting a SAG mill circuit for the fixed hardness case.

Jan 1, 2012

By W. Dingley, G. R. Hoey

"Thirteen Canadian sulphide ore mines were surveyed for corrosion control. The mines visited were a small, yet representative, proportion of this segment of the Canadian mining and metallurgical industry. Information on metallic corrosion and methods used to control it in underground workings and mills was gathered (a) by discussing corrosion problems with company personnel, (b) by examining equipment and structures during under-ground and mill tours, (c) by photographing corrosion sites, and (d) by collecting and analyzing mine water samples.The corrosion survey, which is summarized in the re-port, leads to the following general conclusions. Mine environments are corrosive, particularly when the mine w1a-ter is acidic. Because of a lack of good corrosion control measures, excessive deterioration of equipment due to corrosion occurs in mines. Mill environments are also corrosive, but in some cases good preventive measures are being taken to effectively control corrosion losses.Ways to reduce corrosion losses in sulphide ore mines and mills are discussed. The main areas for more corrosion research and development are selection of materials of construction, protective coatings, cathodic protection, inhibitors, equipment design, and mining and milling practices."

Jan 1, 1971

By J. Goyman, K. R. Rawling

"1.1 Location and Transportation ServicesNanisivik Mines Ltd. is located at latitude 73°, 3,200 km north of Montreal and 700 km north of the Arctic circle, on the south side of Strathcona Sound, which is an arm of Admiralty Inlet, in Northern Baffin Island. The orebody and mill site are 4 km distant from Strathcona Sound which provides deep water anchorage for ocean transportation of concentrate to Europe during the short northern shipping season from mid-July to mid-October.The operations and the resident community have direct jet aircraft service from Montreal two days per week, and local nights connect with other Arctic communities in the northern Baffin region. Bulk supplies and general cargo are delivered in the summer shipping season.1.2 HistoryThe Texas Gulf Sulphur Company, now Kidd Creek Mines Limited, staked claims in the Nanisivik area in 1957 and carried out exploration through to 1968. After the Kidd Creek orebody was found, Texas Gulf optioned the property in 1972 to Mineral Resources International Inc. (MRI), which undertook further exploration and completed a feasibility study.Nanisivik Mines Ltd. was formed in 1975, with MRI as the majority shareholder and minority shareholdings held by Metallgesellschaft, Billiton and Texas Gulf. Strathcona Mineral Services Limited was retained to manage the project during both the construction and operational phases."

Jan 1, 1984

By Soumitry J. Ray

Poor visibility of powered industrial vehicles, such as forklifts, used in industry is often the cause of accidents that include pedestrians. Current standards allow up to 20 % non-visible regions for forklifts where measurement of these regions is performed by using lamps. A collaboration of research organizations, including National Institute of Standards and Technology, Georgia Institute of Technology (NIST), and Direct Dimensions, has been evaluating advanced methods for measuring a forklift operator?s visibility. These methods can potentially improve visibility standards. They can also help forklift and sensor manufacturers to determine (1) how visibility-assist sensors and algorithms can be designed and (2) where sensors can be mounted on forklifts. This paper includes explanation of visibility measurement experiments performed and results, associated language suggested to standards organizations, and a prototype design for measuring the visibility of forklifts automatically.

Aug 1, 2013

By Zhong Zhang, Xijia Wu, Prakash C. Patnaik

"The integrated vehicle health management (IVHM) aims to provide life cycle management decisions for military platforms and their propulsion systems with reduced life cycle cost and increased operational readiness and safety. Among all the issues of IVHM, understanding the physics of failure and predicting lifetimes of the critical components are at the core: the decision makers have to know when and how components may fail in order to plan ahead. The difficulties to tackle failure problems lie in determining the material response to cyclic and dwell loading in a hot and/or corrosive environment, which all combined to induce multiple deformation and damage mechanisms, resulting in mix-mode failures. Decisions on component replacement (material substitution) and mission planning must be based on quantitative knowledge of the failure physics to mitigating the risk. This paper addresses the critical failure issues including creep, low cycle fatigue (LCF), thermomechanical fatigue (TMF); and presents a mechanism-based approach to life prediction. The mechanism-based approach, by its physics, is widely applicable over the entire operational spectrum of both structures and engines, and therefore is suitable for IVHM purposes."

Jan 1, 2015

At the end of a century of mining education in South Africa, it is appropriate to reflect on the past, take stock of the present and ponder the future of mining education. While it is likely that changes in the mining industry will generate an increased demand for mining graduates, the number of suitably qualified applicants to study mining is worryingly small. While good progress has been made in unifying the educational system that previously provided schooling on a racially separate basis, it appears that a decade or more will be required to raise competency levels in mathematics, science and English, and this paper describes the process as it affects mining engineering programs. It also describes the initiatives currently being undertaken by the University of the Witwatersrand and the mining industry to ensure that the South African industry receives an adequate flow of well-qualified mining graduates, despite more than 70% of the intake coming from severely disadvantaged educational backgrounds.

Jan 1, 1999

By Selwyn G. Blaylock

I.-THE HISTORY OF THE SYSTEM TO trace the history of the development of the Co-operative Committee System in The Consolidated Mining and Smelting Company of Canada, Limited, one must look backward about twenty years. In 1915 and 1916, the first years of the W ar to really affect Canadian life, there were sixteen hundred men working in the Trail plant. These men were, on the whole, a splendid body of men and pa trio tic to the core. They were almost one hundred percent organized, ninety-five percent of them be-longing to the Union of the Western Federation of Miners. Most of the tradesmen belonged to their craft unions as well. For example, there were ? local machinist, steel workers', electrician, boiler maker, bricklayer, and carpenter unions. The Company had always maintained an open-shop policy and refused to enforce membership in any union, but recognized the right of every man to belong to unions. The only exceptions have been the I.W.W. and the One Big Union. Both of these organizations have always been fought by the Company. By 1916, membership in the Western Federation being practically 100 per cent, the Company recognized this organization's authority to make agreements, and a wage and hour agreement was drawn up and signed by the Company and the local officials of the Union, and ratified and signed by the Head Office of the Union in Denver, Colorado. This agreement was for the duration of the war.

Jan 1, 1936

By Y. Sasseville

"Niobec has been using vibrating screens and screw classifiers as a double stage classification in its grinding circuit since the very beginning of its operation in St-Honoré. Most of the other mineral processing plants around the world uses cyclones as the classification device in their grinding circuit. The difference between these two methods are well known in terms of capital cost and grinding efficiency but the differences in terms of the impact on the downstream processing stages are a lot harder to predict and are case specific. In the interest of lowering the capital cost of a future expansion project, Niobec decided to test the cyclones in its actual grinding circuit and evaluate their impact on the recovery of the downstream processing stages as well as the operating cost of the mill. We switched between cyclones and screens for 8 month in 2013 and early 2014 and we are now operating only with cyclones since march 2014.INTRODUCTIONThe Niobec mine and concentrator were built in the mid 70’s and at that time, the mill was processing 1 500 tons per day. Over the years, many expansion projects have brought the plant to 7 000 tons per day. Throughout the initial concentrator design and commissioning, screens have been chosen over cyclones because of their higher classification efficiency which is known to reduce variability and limit the fine generation especially due to a high undersize classification efficiency. Just like many other plants, fine particle generation is a major problem at Niobec because of its negative effect on downstream processing stages. In the interest of lowering the capital cost of a future expansion project, Niobec’s engineering team decided, 35 years later, to test the cyclones in its actual grinding circuit and evaluate their actual impact on the final recovery and the operating cost of the mill.The grinding circuit is separated in two lines which will be called Circuit #1 and Circuit #2 along this paper. Circuit #1 is, as you can see in Figure 1, composed of a rod mill and two parallel ball mills in closed circuit with screens and screw classifiers. The screens oversize are sent to the screw classifiers while the undersize are sent to the next processing stage. The screw classifiers overflow are both sent back to the pump box while their oversize streams return in their corresponding ball mills for further grinding. Circuit #2 is, as you can see in Figure 1, quite the same as Circuit #1 except it has only one set of screw classifier and ball mill. Figure 1 also shows the modification in arrangement each circuits went through to integrate the new cyclones. One of the ball mills in Circuit #1 now appears dotted because it can still be used but is not now"

Jan 1, 2015

By J. W. Reynolds

Introduction The Sullivan mine, at Kimberley, B.C., is the principal source of ore for the Consolidated Mining and Smelting Company of Canada, Limited. Current production amounts to about 2,500,000 tons of lead-zinc ore a year. With approximately 1,600,000 feet of percussion drilling and 700,000 feet of diamond drilling being carried on each year, any improvements in drilling practice are important. Testing of new equipment and drill bits is a major function of the Testing Department at the mine. Tungsten carbide bits have been the subject of many tests since 1947 and have been used in operations since 1948. This paper details with the methods of testing and gives comparative data on performance and costs for tungsten carbide bits as compared to steel bits. Operational use of tungsten carbide bits started in April, 1948, and the extent of application has increased considerably since that time. The scale of employment is illustrated in Table I, which also shows other statistics on the use of carbide bits. Up to the present time eighteen types of carbide bits or tipped steel, as made by six different manufacturers, have been tested. In general, one supplier's bits have been used in operations, but some large-scale operational tests have been carried out with other types. The types tried are shown in Table II. To date they have been, the subject of 33 tests, covering the destruction of 804 bits over an observed footage of 42,586 feet.

Jan 1, 1951

By K. Musgrave

"The ISO 9000 Quality Management System Standards have become internationally accepted as the way to manage quality assurance. The author has developed a Maintenance Management System Standard using ISO 9001as a model and is working with a major basemetal mining company to implement this. This paper describes the structure of the standard and the steps required for its implementation.Using a management standard ensures that a system is maintained, reviewed by internal audit, and when instances of failing to follow the procedures (nonconformances) occur, that corrective action is taken. It also ensures that regular reviews are made and that the sys-tem is continuously improved.The Standard is designed so that if an organization decides to register to an ISO 9000standard, the Maintenance Management System will be in a format that is compatible and can be incorporated with little effort into the Quality System.IntroductionIn reviewing maintenance operations at many mining companies, and often seeing those same organizations some years later, two recurring issues have been noticed..The first issue is how dependent effective maintenance is upon individual supervisors and crews. In one situation, a mine that had an excellent maintenance system in the 1980s. Now, with new supervisors and crews, it is starting to develop a system that will bring it back to where it once was. No written procedures remain from the earlier excellent system.The second issue is that most operations feel that maintenance is the sole responsibility of the maintenance supervisors and crews. Nothing could be further from the truth. Maintenance, like safety, is everyone’s responsibility. If the operator does not report problems and perform daily checks, and if the production supervisor runs equipment until it fails, then nothing the maintenance crew does will prevent emergency breakdowns and lost production. More importantly, equipment will be operated in unsafe conditions, putting employees at risk and, with today’s regulations, leaving supervisors open to prosecution.The Maintenance Management System outlined in this paper is designed to establish the present best practices as standard procedures, to provide a continual review so that these practices are improved in the future, and to identify instances where the system fails so that corrective action is taken. The mine referred to above is using this approach to make sure that, this time, the system it implements will survive."

Jan 1, 1997

By John B. Phillips

The mine is entered by a central vertical shaft, strongly timbered, and containing two compartments-one for the passenger cage, the other for the large skips bringing the ore to the surface. A man-way, for emergencies, is also provided, parallel to the shaft. The cage is a single-deck steel box, carrying about thirty persons; by means of arrangements above and below, it can also hoist and lower materials needed in the workings. Levels are run at intervals of 100 feet. In special cases, where the ore conditions warrant, sub-levels are operated, such as those at 1,113 feet and 1,123 feet (Fig. 7), which are connected by winzes with the 11 th level. One of these was pushed for 40 feet, and then abandoned because it was unprofitable to take up ore of the grade encountered. The ore between levels is removed by stoping. The drifts follow the course of the veins as much as possible, with numerous cross-cuts. Winzes, raises, connections, etc., are blasted out where needed. The main drifts are at least 8 ft. high by about 9 ft. wide. All former narrow drifts had to be widened some time ago, by ruling of the Ontario Department of Mines, to lessen the danger of accidents with cars in the small passages. Accurate plans of the under-ground workings are kept in the office, and extensive surveying is always being done underground to keep the maps up to date, measure the cubical contents of stopes, and so forth. Timber is extensively used in the construction of supports and chutes, and in the sinking of the shaft. Steel and concrete are too ex pensive to compete with timber, which 1s abundant in such sections as have escaped forest tires.

Jan 1, 1926