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The Anglo Platinum Mogalakwena North concentrator was one of the first three hard rock mineral processing applications to utilise a HPGR circuit in preference to a SAG milling circuit. This was driven by the extreme competence of the ore that had given rise to throughput issues on the original South Plant. Despite more than adequate capacity and performance of the individual comminution units, the circuit has struggled to obtain full design capacity. A thorough review of the integrated performance of the circuit revealed a wide range of bottlenecks and underutilised parts of the circuit arising from design issues. Interestingly, the major opportunities lie in materials handling issues and mismatch of loads about the circuit. This paper presents the high-level outcomes and the associated opportunities, and is pertinent to all HPGR circuit designs.

Jan 1, 2012

By Deni Côte, Michel Dagbert, Marcel Vallée

"Greater reliability of mineral deposit and reserve estimates can be attained through better quality control of the data and information acquisition, and the estimation processes. This paper reviews the following key requirements:1. greater awareness of the significant figures of both data and estimates, and better understanding of the probabilistic aspects of the estimates, their confidence limits and margins of error;2. greater reliability of the information that supports the estimates, by more explicit and more rigorous methods and standards for data acquisition and for interpretations;3. more quantitative estimations of geological/mineral continuity, based on improved three dimensional sampling patterns and the use of geostatistics; and 4. better integration at the project engineering and mine production stages, of the mineral deposit characteristics and mining method constraints, for more efficient mineral recovery and mine quality control.RÉSUMÉUne plus grande fiabilité des estimations des gisements et des réserves minières requiert plus d'emphase sur le contrôle de la qualité de I ‘acquisition de l'information et du processus d'estimation. Les exigences suivantes sont revues:1. le respect du niveau d'exactitude des données et des estimes en n'utilisant que le nombre approprie de chiffres significatifs des observations et mesures, et en exprimant le niveau de confiance et la marge d'erreur des estimations;2. l'amélioration de fa fiabilité des données par des normes plus rigoureuses pour leur acquisition et leur vérification, et par des méthodes plus systématiques d'interprétation et de modélisation;3. l'estimation plus rigoureuse de la continuité des minéralisations dans les trois dimensions des gisements, par des patrons échantillonnages mieux adaptes awe paramètres géologiquement minéralogiques, et par l'utilisation des méthodes géostatistiques; et4. l'intégration plus poussée, particulièrement lors de la planification de l'exploitation minière, des caractéristiques des gisements avec les contraintes des méthodes d'exploitation, pour améliorer la récupération et le contrôle de la qualité en exploitation."

Jan 1, 1993

By K. J. Boser

"Medium Voltage (MV) metal clad switchgear is referred to as the voltage class from 2.4 kV to 38 kV. Technological advances in circuit breaker designs over the last 20 years have given rise to retrofit options in lieu of complete replacement for older outdated circuit breaker technology. This paper examines the four MV breaking techniques that exist in industry and investigates various retrofit versus refurbish options for switchgear modernization and life extension. IntroductionThe life extension and upgrade of medium voltage circuit breakers is becoming an increasingly important issue in today’s modern industrial facilities from both a reliability and safety standpoint. Unscheduled downtime, loss of production, and plant safety issues are just some of the concerns that need to be addressed with aging switchgear. A thorough examination of the available breaking mediums allows an informed decision to be made when the time comes to assess equipment performance. If you look back over the history of medium voltage breakers, you will find that there have been four breaking techniques developed and widely used:• air magnetic;• minimum oil;• vacuum; and• SF6.Many facilities that were constructed 25 to 30 years ago relied on air magnetic or minimum oil circuit breakers in their distribution systems. At the time, these were the only “tried and tested” options and they afforded good service. Since then, however, newer technology has given us the vacuum and SF6 mediums which have both proven their reliability and monopolized the market. All the methods have their particular place in industry and what follows is a summary of the advantages, disadvantages, and chronological development of each breaking technique."

Jan 1, 1998

By D. G. Champion

"A comparison of diesel engine power ratings with in-service capability, and the selection of unit size and total number of units are discussed in the paper. Engine specific fuel consumption and its evaluation in relation to manufacturers' tolerances and equipment load factors is reviewed along with the suitable plant layout. The potential for heat recovery is discussed in connection with simple and operable recovery systems f or exhaust and cooling circuits. Maintenance standards as related to improved reliability and reduced fuel and operating costs are also outlined. IntroductionDiesel generators are used in Canadian mining operations to provide electrical power for "" base- load"" requirements in some instances and for ""stand-by"" or ""emergency"" power in almost every producing mine in the country . There are over 300 mines in Canada of which only a handful have to generate their own electricity. Only one or two mine s enjoy access to a hydroelectric site. Consequently, the diesel engine is the principal prime mover because of its high efficiency relative to other prime movers in the size range in question.The author has been associated with several “base-load” plants in addition to participation in numerous projects requiring emergency diesel generators. Records indicate that engine performance in term s of reliability and efficiency lags behind other industries where the diesel engine is used more extensively, such as the shipping industry which is able to make a more prudent selection of original equipment and enjoy easy access to highly skilled operating and maintenance personnel. It is hoped that the contents of this paper will be of value to Canadian operators of diesel generators, in the generation of prime power or applications for back-up power."

Jan 1, 1986

By D. H. Ryan, J. T. Graham, A. Navarra, J. A. Finch, S. Somot

Pyrrhotite (Po) is widely considered to be the most significant mineral in the self-heating of sulphides. It is therefore desirable to determine the amount of Po in mineral samples. This is commonly accomplished through x-ray diffraction (XRD) or quantitative evaluation of materials by scanning electron microscopy (QEM-SEM). This paper introduces another quantitative method based on Mossbauer analysis that requires limited sample preparation and has the additional potential to detect the sulphur/iron ratio within Po. The technique is explored using pentlandite/pyrrhotite mixtures.

Jan 1, 2009

By H. Thomasson

THE war, like all destructive agencies, has focused attention on salvage and conservation, and to such an extent that a decade of normal progress has been crowded into a few months. This is particularly true as regards the repair of cutting tools. As a consequence, there has arisen a wide demand for comparable data by those engaged in such work, and for basic information by others who wish to repair tools. These repairs may be grouped in three classes: (1) The repair of broken tools of relatively slender cross-section, such as broaches, reamers, drills, etc., of a type that could be returned to service if a means to join the broken surfaces were available, as fortunately it is in the low-temperature silver solder process; (2) the repair of tools that possess shanks, tangs, and other non-cutting portions that may be broken or damaged to the extent that only the addition of metal will permit their return to service; and (3) the repair of special rotating tools, such as end-mills and milling cutters, that may have portions broken from the cutting edges or have their edges so worn in service as to require building up.

Jan 1, 1943

By J. S. Roper

"IntroductionSNOW LAKE is situated in northern Manitoba at latitude 54° 55 and longitude 100°, 400 miles northwesterly of Winnipeg, 80 miles northeast of The Pas, 80 miles east of Flin Flon. A 38-mile road from Wekusko, on the Hudson's Bay railway, serves the community.The mine is located in and close to the southern edge of the Precambrian Shield in typical low-relief muskeg and lake country.The Howe Sound Exploration Company, Limited optioned the property from Nor Acme Gold Mines, Limited, after preliminary diamond drilling had outlined two orebodies of low-grade arsenical gold ore.Following the examination and study of geological data and of 50,000 feet of diamond-drill core, and metallurgical tests made during 1942 to 1945, a decision was made to develop the mine and build a 2 ,000-ton mill concurrently. This development has been described by G. C. Lipsey in a paper entitled The Development of a Mining Operation from Diamond-Drill Data which was published in the August. 1952, issue of Mining Engineering.Geological Features of the OrebodiesThe orebodies at Snow Lake occur in volcanic rocks of acid to basic composition and, to a lesser extent, in intrusive hornblendite. The hornblendite is a massive, uniform, .coarse-textured rock except in the immediate vicinity of the ore zone, where it becomes sheared and carbonatized. The acid volcanics have been converted to quartz-garnet-biotite gneiss, and the basic volcanics to amphibolite gneiss. Orebodies have been formed by the replacement of all three rock types."

Jan 1, 1955

By J. J. Fitzpatrick

"This paper deals with the methods used by Quebec Cartier Mining Company in the evaluation and selection of new haulage equipment and in increasing the productivity of the existing fleet.Selection of new equipment is based upon the comparison, for each model under consideration, of the capital investment required and the estimated operating costs and production rate. The calculation of the production rate is based on a widely used estimating procedure. Actual operating conditions considered in the method include: payload, haul distance, road grade, rolling resistance, loading and dumping times, and operational efficiency. A digital computer is used to handle the large volume of repetitive calculations required. Where a fleet of haulage equipment includes trucks of different size and performance characteristics, the problem exists of assigning each truck type to the different working locations to minimize total cost. Linear programming can be used in the solution of this problem."

Jan 1, 1967

By G. F. Colborne, A. Thunaes

"When the Canadian uranium milling plants went into operation during the early 1950's, they utilized flowsheets developed at the Radioactivity Division of the Federal Mines Branch in Ottawa. Since then, numerous process improvements have been made by the Mines Branch, by the operating companies themselves and by other research organizations. This paper will consider uranium milling technology from the standpoint of a new mine operator charged with the responsibility for the design of an economic flowsheet, and will indicate the range of process elements available to him and the testwork required to enable an intelligent decision to be made."

Jan 1, 1968

By F. N. Smith

The carbon steel casings of Heat Recovery Steam Generators (HRSGs) in a co¬generation plant were found to have developed cracks that originated on the inside surfaces. The HRSGs receive hot exhaust gases from the primary Gas Turbines (GTs), which are fuelled with pipeline natural gas. The GTs was initially operating without any suppression of nitrogen oxides (NOx). After being in service for about two years, some of the cracks were found to have penetrated right through the 1/4 in. thick casings. The casings are fitted with insulation on the inside (hot gas side). Examination of steel samples cut from the casing walls revealed (i) fine cracks propagating through the steel from the inside surfaces, and (ii) the presence of relatively large amounts of nitrate ion on the inside surfaces. It was concluded that the nitrate ions originated from nitric acid that was condensing on the relatively cool walls of the casings behind the insulation. Nitric acid was formed in the GT exhaust gases by the combination of water vapour (formed from combustion of the hydrocarbon fuel and from moisture in the combustion air) and nitrogen oxides (formed from nitrogen and oxygen in the combustion air).

Jan 1, 2005

By M. W. Airth

ON THE 6TH JULY in the year 1953 an announcement was made to the public that touched off one of the greatest staking rushes in the history of mining in Canada and resulted, in tl1e space of a few short years, in the development of the greatest reserves of uranium-bearing ore in the world. It was ?On this date that the famous "Blind River back-door staking bee" was completed with the acquisition of some 2,000 claims by the Preston East Do me-Technical Mine Consultant teams under the direction of Mr. Franc Joubin and Mr. Robert C. Hart. That story has been told from coast to Coast and is too well known now to re-quire elaboration. Suffice to say that, in the short elapsed time of less tl1an five years from that momentous summer of 1953, three of the Algoma mines are in full production, three more are rapidly nearing full production, five more 1are approaching the production stage, a new hard-surfaced highway, 108, has been built to serve the area, and a brand new, completely planned city, Elliot Lake, is being built to provide the amenities of living to the 22,000 people already in the area.

Jan 1, 1958

By F. J. McMulkin

This paper, the 1965 Airey Memorial Lecture, reviews the world-wide technical advances in iron and steelmaking, and offers an appraisal of the new techniques which will be applied in the future. After a review of blast furnace operations, the continuous steelmaking process is described, and the resulting techniques of degassing and continuous casting are discussed at length. Pressure pouring, hot rolling, cold rolling and coating practices are also outlined, and considerable space is devoted to the direct reduction process. Finally, the application of the computer to steelmaking operations is discussed in some detail.

Jan 1, 1966

By R. L. Dunsmore

Introduction If one had been called upon to describe petroleum oil refining seventy-five years ago, he could have acceded to the request quite satisfactorily in about fifteen minutes. Fifteen years ago, an hour and a half would have been sufficient to give a general idea of oil refining, and of the equipment used for this purpose. Today, so extensive has been the research into all phases of the refining and manufacturing of petroleum products, and so rapid the strides in improvement in technique and equipment, that I doubt if a week would suffice to give an adequate outline of ail the ramifications of present-day oil refining. I propose to only 'hit the high spots', dealing particularly with the equipment and methods employed at the Imperoyal refinery, which you are to visit. Crude oil, the refiner's raw material, contains essentially only two elements, hydrogen and carbon. These are not present in the free state but are combined in various proportions as 'hydrocarbons'. A given crude oil is not made up of just one hydrocarbon, but of myriads; some solid, others liquid, and still others gaseous at atmospheric temperature and pressure, ail dissolved one in the other. Moreover, the nature and the relative amounts of the several hydrocarbons vary very considerably in crude oils from different sources. That is, a 'crude' from Oklahoma will contain hydrocarbons not present in crude from Mexico, and is different again from the Venezuela crude. Not only this but oil in a certain well in, say, Peru may be differently constituted from that in a well half a mile distant from it.

Jan 1, 1931

By A G. Rogers

This paper discusses the lubrication of surface and underground mining machinery and equipment from the standpoint of machine components. The machine components considered are bearings, cylinders, gears, chains, couplings, fluid drives, hydraulic systems, screws and wire ropes. The best selection of lubricants for these machine components, and for sub-divisions of the components, are outlined. They form general recommendations, for average operating conditions in both surface and under-ground mining operations. The American Petroleum Institute's service classification of both engine crankcase oils and gear oils is de-scribed and used in recommending products for these applications. The practical aspect of lubrication is kept foremost in the recommendations, which are designed to meet the requirements of a wide variety of equipment with the minimum number of lubricants. THE lubrication of mining machinery and equipment presents a variety of problems peculiar to the industry. The type of mine, the ambient temperature, water, dust, and operating and maintenance practices, as well as the age and condition of the equipment, are variables which have to be considered in making lubricant recommendations.

Jan 1, 1963

By A. Ouellette, E. Nilsson

"Preventative maintenance is a burden for equipment users but a demand from the machine suppliers to ensure performance. Machine availability depends on preventative maintenance being followed.Mining equipment is becoming more and more sophisticated and productive, yet less and less time is available for preventative maintenance. Manufacturers invest in reducing costs, simplifying operating requirements, and lowering maintenance requirements, but it is the users who must invest more heavily in the advanced maintenance systems to keep the units operating.IntroductionPreventative maintenance has been, and still is a key factor in avoiding disturbances in production due to equipment downtime. Manufacturers ask for it in extensive maintenance schedules, check lists, programs, etc. often with a ""threat"" that, if not performed, the machine guarantee will not be valid. Modern mining and construction machinery has become sophisticated, like all other machinery, with elaborate hydraulic, electric and electronic systems and computerized controllers. Maintenance organizations within the mining industry have grown to heavy cost centres just to keep up the availability of the equipment.It is difficult for machine manufacturers to have maintenance programs that suit every user. International suppliers have to deal with different cultures, education levels, environments, organizations, etc. Maintenance programs recommended by manufacturers often do not meet some user's needs while they are ""overkilling"" to others. Preventative maintenance schemes recommendations of what to do, in what frequency, etc.) usually fit mechanical components in the equipment, e.g. wear measurements, crack indications, lubrication, oil changes, etc. But how does one perform preventative maintenance on huge hydraulic systems, electrical and electronic systems and computers? Failures in these systems usually occur without any warning and are more or less impossible to predict. Another difficulty in creating effective preventative maintenance programs for these kinds of systems is the relatively low volume of mining and construction equipment that is produced per year. For example, although Atlas Copco is one of the largest manufacturers in the world of underground blast hole drilling machines, the company still does not produce more than a few hundred drilling jumbos per year. These are made in more than 10 different models, with different systems and components, and very often are custom adapted to the end user's requirements."

Jan 1, 1992

By K. C. Grogan

"GeneralGIANT ORE is complex, with the gold values for the most part occurring in extremely close association with arsenopyrite, stibnite, jamesonite, and a wide group of antimonial minerals locally termed 'the grey minerals'. Pyrite is the most abundant of the sulphide minerals• and minor quantities of chalcopyrite, galena, and sphalerite also occur. Pyrrhotite has been found in some sections of the mine, but to date none of it has been nickeliferous. Native gold occurs in varying amounts throughout the ore bodies.In 1944, ore dressing investigations were commenced on diamond-drill core rejects and samples of surface outcrop ore. Results soon indicated that treatment to produce satisfactory recovery of the gold values would involve fine grinding to 80-85 per cent minus 200 mesh, recovery of free gold by jigs, followed by flotation, roasting of the flotation concentrate, and subsequent cyanidation of the calcine. Proceeding from this information, the flow-sheet was prepared, plant design worked out, equipment purchased, and construction of the treatment plant commenced in May, 1947.The crushing, grinding, and flotation units of the plant were rushed to completion and commenced operation on May 12th, l.948, at 225 tons of ore per day. This rate was maintained until January 27th, 1949, when the Allis-Chalmers roaster and cyanide plants were completed and commenced operation. During the period May 12th, 1948, to January 27th, 1949, gold recovered by amalgamation was the sole source of revenue. Flotation concentrate was stockpiled pending the completion of the Allis~Chalmers roaster and cyanide plants."

Jan 1, 1953

By John Dasher

The analyses reported on in this paper indicate that there are hydrometallurgical routes from sulphide concentrates to copper that are potentially competitive with smelters which are not permitted to emit sulphur oxides. The various hydrometallurgical processes, and their economics, are discussed.

Jan 1, 1973

By V. J. Southey

HOLLINGER mining operations have required development by 24 vertical shafts having a total length of 28,160 feet. Seventeen of these are sunk from surface and seven are interior shafts. Four surface shafts and three interior shafts are now active and, excepting the recently completed new main ore-hoisting shaft, the remainder are either abandoned, or are used for passes or for ventilation. The new shaft bottoms 60 feet below the 3,050 level, but there is much work to be done before it is placed in service. The term 'shaft practice' is intended to include shaft construction and a general treatment o typical equipment. It is a large subject for an organization the size of Hollinger and this paper is intended only to present the salient features. The writer wishes to thank the management for permission to publish this information and to acknowledge the advice and criticism o A. G. Irving, chief engineer, and the willing co-operation of other members of the Hollinger staff.

Jan 1, 1939

By R. Pandher, R. Schonewille, N. Tripathi

Advanced process modelling tools were developed for the Xstrata Nickel Sudbury Smelter flow sheet using a combination of FACTSAGE TM METSIMTM and ARENATM software. These tools were employed to assist with plant optimisation, emission control, process design, troubleshooting and case studies as applied to the smelter. The development of process modelling tools in pyro-metallurgy commonly involves an in-depth study of the therm o-chemical properties (heat capacity, liquidus temperature, etc.) of all high temperature phases, usually matte and slag. The preferred tool for this purpose is FACTSAGETM, a well-known then-no-chemical modelling software package. The results from the therm o-chemical model have been subsequently incorporated into the development of a process model for the entire smelting facility using the METSIMTM platform. Such process model also includes a number of special features adopted to effectively simulate the complex industrial phases; matte and slag systems. To ensure the robustness and reliability of the process model, several process parameters and assumptions were verified with laboratory and plant data. Consequently, the model includes the ability to examine the impact of a number of plant parameters on potential plant performance. Primary variables are the percent sulphur elimination during concentrate roasting, furnace matte grade and degree of matte metallization. Key output parameters include operating temperature, furnace coke requirement, sulphuric acid production, CO2 emissions and overall energy requirements. Selected outputs from the process model (for example blowing time, slag production rate and matte converting rate) can then be utilised in the development of a discrete event model (DEM) for the smelter using ARENATM software. Incorporation of reliable and validated mass balance parameters enhances the robustness and reliability of the DEM model. The integration of then-no-chemical, process and DEM modeling tools has a distinct advantage in planning plant trials and examining process design initiatives at Xstrata Nickel's Sudbury Smelter. The present paper discusses the development of these three models and the synergies existing among them. Typical results from all three models are also presented.

Jan 1, 2011

By R. Pandher, R. Schonewille

Advanced process modelling tools were developed for the Xstrata Nickel Sudbury Smelter flow sheet using a combination of FACTSAGETH METSIMTM and ARENATM software. These tools were employed to assist with plant optimisation, emission control, process design, troubleshooting and case studies as applied to the smelter. The development of process modelling tools in pyro-metallurgy commonly involves an in-depth study of the therm o-chemical properties (heat capacity, liquidus temperature, etc.) of all high temperature phases, usually matte and slag. The preferred tool for this purpose is FACTSAGETM, a well-known then-no-chemical modelling software package. The results from the therm o-chemical model have been subsequently incorporated into the development of a process model for the entire smelting facility using the METSIMTM platform. Such process model also includes a number of special features adopted to effectively simulate the complex industrial phases; matte and slag systems. To ensure the robustness and reliability of the process model, several process parameters and assumptions were verified with laboratory and plant data. Consequently, the model includes the ability to examine the impact of a number of plant parameters on potential plant performance. Primary variables are the percent sulphur elimination during concentrate roasting, furnace matte grade and degree of matte metallization. Key output parameters include operating temperature, furnace coke requirement, sulphuric acid production, CO2 emissions and overall energy requirements. Selected outputs from the process model (for example blowing time, slag production rate and matte converting rate) can then be utilised in the development of a discrete event model (DEM) for the smelter using ARENATM software. Incorporation of reliable and validated mass balance parameters enhances the robustness and reliability of the DEM model. The integration of then-no-chemical, process and DEM modeling tools has a distinct advantage in planning plant trials and examining process design initiatives at Xstrata Nickel's Sudbury Smelter. The present paper discusses the development of these three models and the synergies existing among them. Typical results from all three models are also presented.

Jan 1, 2011