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By A. J. Keen

"Cominco's Polaris Mine is an underground lead/zinc operation located on Little Cornwallis Island in the Canadian High Arctic. Polaris is the world's most northerly base metal mine, situated at about latitude 75°N and longitude 97°W (Fig. 1). The closest community is Resolute Bay about 100 km to the southeast.During the construction and development phase Cominco adopted a unique scheme to save time and money. Many facilities including concentrator, powerhouse, shops and warehouse were built on a barge in southern Canada. The barge was towed 4800 km to the site in August 1981. Production at Polaris began in November 1981. The current mining rate is 1 million tonnes per year. The mine employs 250 people with about 190 on site at any time.GeologyThe deposit is a Mississippi Valley type orebody and lies near the top of the Ordovician Thumb Mountain Formation. Ore minerals consist of sphalerite and galena with the gangue being predominantly dolomite with calcite and marcasite. The orebody is situated completely within permafrost, consequently the voids frequently found in the ore are filled with ice. The orebody strikes north-south, dips approximately twenty degrees to the east and takes up an area about 400 m wide by 700 m long. The upper portion of the orebody (60 m to 150 m below surface) lies in an area called the Panhandle Zone. The deeper portion of the orebody known as the Keel Zone extends to 300 m below surface (Fig. 2). The deposit is strongly zoned with a high grade zinc/lead and iron-rich tabular core overlain and underlain by vein, stringer and breccia mineralization. The ore reserves at January 1991 were 14.6 million tonnes at 3.6% Pb, 13.7% Zn, 3.2% Fe, after producing 8 million tonnes at 3.9% Pb and 14.2% Zn since November 1981"

Jan 1, 1992

By Richard S. Allen

"The casual visitor is not apt to think of the Adirondacks as a one-time hive of mining and manufacturing activity. However, where there are mountains there are usually minerals and northern New York State is no exception.The Adirondacks are a rocky shield, a great stone cap pulled down over what is now northern New York. The bedrock consists of layered metamorphic rocks which were once sandstones or limestones on the bottom of a shallow sea that covered the region 1000 million years ago. The highlands are composed for the most part of the igneous rock anorthosite. Ancient earth upheavals at temperatures of at least 750°C mixed molten masses of anorthosite and the minerals it contained with the older metamorphic rock, resulting in deposits of iron-titanium oxide s, red garnet and other valuable minerals. Of these, the most readily recognizable was iron.The first hint of the existence of iron ore in the Adirondack Lake Champlain region of upper New York State seems to have come from a Swedish naturalist, Peter Kalm (1716-1769), who travelled through French Canada and visited the military outpost of Fort St. Frederic in 1749. In July of that year, Kalm wrote:""Among the kinds of sand which are found on the shores of Lake Champlain; one is black and the other garnet-colored... and they sparkle when the sun shines. All the grains of this sand without exception are attracted to the magnet, the uppermost or black sand being about a quarter inch deep...""Concerned primarily with the fur trade, the officers and men who occupied this remote bastion of La Belle France were apparently unaware of the industrial and commercial possibilities beneath their feet. No deposit of iron was then known to exist any closer than the Three River s area in Lower Canada."

Jan 1, 1983

By J. L. Blaylock

Normally, the hydraulic system and structures are considered to be unrelated items. In reality, the two cannot be separated because one affects and depends on the other to function properly. This paper explores the potential failure areas of hydraulic cylinders, and suggests possible methods to prevent failures from occurring. The use of high-strength low-alloy steel in frames is reviewed and the benefits discussed. Fabrication techniques and handling of material are noted in the hope that this knowledge will aid in the repair of frames in the field.

Jan 1, 1979

By G. Kollberg

"IntroductionThe SALA Caravan Mill system represents a proven concept for the design and operation of mobile and semi-mobile ore dressing plants.The Caravan Mill has been developed to meet the demand for a flexible processing plant to be used for small and medium-sized orebodies or for pilot investigations of deposits directly at the mine site e •The first Caravan Mill installation was put into operation in 1970 and a number of plants have been delivered world-wide since then.The Caravan Mill system has great flexibility both in capacity, ranging from 50 to 1000 tons per day, and in process combinations. The process modules available are:• crushing by jaw and cone crushers;• pre-concentration by the Dyna Whirl Pool dense media system;• grinding by wet rod or ball mills;• separation by gravity, magnetic, flotation or leaching-CVP adsorption methods;• dewatering by lamella or conventional thickeners and vacuum filters.To form complete plants, auxiliary equipment is also available, such as:• bins, feeders and conveying systems;• power generator units;• water tank and pump for process water;• interconnecting piping and cables;• erection and service tool kits;• set of spare and wear parts.For mine sites with rainy or winter conditions, a plastic tent with air heater can be supplied to cover the ore dressing equipment. Each module is workshop assembled complete with slurry pumps, internal pipe work, electric wiring with plug-in connections, hoses, etc., all arranged for quick and simple connection between the units. Before delivery, each unit is tested in the workshop."

Jan 1, 1982

By Ian Rozier

"Emphasis in recent years in western Canada has been placed on the development of large open-pit coal mines, the most notable developments being in northeast British Columbia. However, vast resources exist below the limit of economic open-pit mining, and with world demand predictions of the late seventies in mind, the potential of underground coal mining in western Canada has been investigated. Particular emphasis has been placed on the Plains coalfield of Alberta, and there is optimism that underground coal mines will be developed in the Lethbridge area of southern Alberta.With no existing operations in southern Alberta with which to compare mining conditions, any mine planning and feasibility level studies rely heavily on the engineering/geotechnical data obtained from surface investigation to predict ground control problems and technical constraints on mining. Such investigations have been integrated with exploration drilling programs. Emphasis has been placed on extracting maximum information to provide an over-all appreciation of potential ground conditions and to identify specific ground control problems that could be encountered.The acquired geotechnical parameters are then used to evaluate the mine properties from an engineering standpoint for input into the determination of optimum mine layouts, development directions, mining methods and roadway and face support requirements. These geotechnical studies have been primarily directed toward the longwall mining method, but the acquired data base could equally be applied to alternative mining methods.In addition to the lithologic and structural controls which relate to roof stability, caving characteristics, floor heave and subsidence, investigations have been directed at gaining an understanding of the over-all surface and ground water regime with respect to potential inflow into the mine openings and ground control problems that could be caused by inflows encountered during mining. Experience has shown that soft floor conditions and water control are important factors to be considered in a longwall layout, and without doubt these parameters will play a major role in the design and operation of a successful longwall operation in the Lethbridge coalfield."

Jan 1, 1986

By Lionel C. Kilburn

"This geological engineering method is based on jour main characteristics of mineral properties, viz; location: inclusion of valuable mineralization; inclusion of geophysical and/or geochemical targets; and inclusion of geological targets. These are subdivided into a total of 19 subcategories, which are used to determine the value of the property.The nineteen subcategories are prioritized and assigned relative value factors from 1.3 to 10. Value of each mineral claim unit is determined by applying the appropriate subcategory factors to a base value of $400per 16.2 hectare unit. Property value is calculated by totalling the values of such individual claim-units.The boundary between ore grade and sub-ore grade must be estimated for each property under valuation, thereby making the method sensitive to mineral commodity prices.A clear and disciplined sequence of decisions based on personal experience forms the basis of this method. The method utilizes all factors normally used to value a mineral property.IntroductionIt is generally accepted in the exploration industry that valuation of exploration properties is a subjective rather than objective process (Roscoe, 1986; Lawrence, 1988; Lawrence, 1989; Woodcock, 1985), and that it is greatly influenced by the experience and qualifications of the person who is doing the valuation. However, the significantly low degree of objectivity in mineral property valuation at this point in time invites effort to achieve a more quantitative engineering basis.Value of a mineral property depends basically upon metal prices, recoverable grades, mining and metallurgical practices, commodity supply and demand , and political-economic conditions, all of which vary with time. Therefore, any valuation is valid for only that point in time when it is made. Mineral deposits can decrease as well as increase in technical value with time."

Jan 1, 1990

By A. Zarei-Hanzaki, O. Golmahalleh, S. M. H. Hosseini, H. Azizi-Alizamini

The main importance of acicular ferrite microstructures arises from their desired combination of mechanical properties in comparison with the bainite and ferrite-pearlite microstructures. Several factors affect the microstructural transition from bainite microstructure into the acicular ferrite one. As is well established any factor corrupting the prior austenitc grain boundaries nucleation potential, such as the thin layer of allotriomorph ferrite and the austenitc deformation inhomogenities may promote the acicular ferrite formation instead of bainite. Accordingly, this study deals with the effects of the aforementioned features on the acicular ferrite formation in low carbon microalloyed steel. The results indicate that the formation of strain-induced ferrite at the prior austenite grain boundaries accompanied by deformation inhomogenities in the austenite grains change the effectiveness of allotriomorph ferrite on acicular ferrite formation from active to inert one.

Jan 1, 2004

By A. Montini, M. H. Moys

"A conductivity probe mounted in the shell of the mill has been used to measure the behaviour of the load in the mill as a function of operating variables. It was found that certain properties of the conductivity signal correlate strongly with the per cent solids of the slurry passing through the mill; in particular the angular location ?D of the shoulder of the load is an increasing function of the per cent solids. A method for measuring the viscosity of the pulp discharging from the mill has also been developed. The use of the measurements in mill control is illustrated by simulating various control strategies for open circuit milling. It is shown that the use of ?D allows very tight but imprecise control of the slurry rheology in the mill, while the use of viscosity is subject to severe limitations in speed of response. A cascade control system involving both measurements provides adequate control of slurry rheology within the mill. Applications to closed circuit milling are discussed.IntroductionMultivariable control of milling circuits continues to receive a lot of attention in the literature. Hulbert and co-workers and Niemi, et al. have described the use of Inverse Nyquist Array (INA) techniques while Herbst has recently described the use of Optimal Control. It is significant that in neither of these three projects was any variable associated with the grinding mill itself (e.g. power or properties of the mill discharge) used in the control strategy. Pauw, et al.do, however, use mill power in their multivariable peak-seeking controller for pebble-mill control. Little work has been published on the use of measurements of the properties of the slurry being discharged from grinding mills, in spite of the fact that milling efficiency is known to be strongly affected by slurry rheology».Moys has recently developed a technique for measuring the dynamic behaviour of the load in the grinding mill. This method involves the monitoring of the response of a conductivity probe mounted in the shell of the mill which gives a measurement of the orientation of the load inside the mill. It was found that the load behaviour was strongly influenced by slurry rheology. In this project a technique was also developed for the measurement of the viscosity of the slurry in the mill discharge. It was, thus, decided that it would be worth investigating the use of these measurements in mill control schemes since direct control of the slurry rheology in the mill must inevitably increase the efficiency and productivity of the grinding circuit as a whole.This will be done by using the dynamic responses measured by Moys and Montini to simulate the behaviour of an open circuit ball mill. While the control of open circuit mills is of little interest, this simulation provides a simple but powerful demonstration of the advantage provided by these measurements, advantages which should apply to closed circuit operation of any mill type (including autogenous milling). Investigations into multivariable control of a closed circuit ball mill are currently nearing completion and will be published soon."

Jan 1, 1987

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

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

Jan 1, 1981

By P. Mayer

"Determining the correct mechanism of a boiler tube failure is important for the prevention of future tube failures. Proper corrective measures can be undertaken to alleviate the root cause or causes for a failure only when the correct mechanism is known. A mechanism of boiler tube failure is defined as the process which degrades the tube and produces a failure.An expert system package was developed for use by electric utility power plant personnel during investigation into the cause of a boiler tube failure. It is intended to assist their efforts to recognize and identify a basic failure mechanism that can produce the type of boiler tube failure under investigation. The program guides the user to the most likely failure mechanism by asking simple questions, answers which can be obtained by determining the failure location, type of fuel, and from visual inspection of the failed tube. Expert systems are a form of artificial intelligence which imitate the decision-making process of experts.IntroductionBoiler tube failures (BTFs) continue to be the single largest source of forced outages in fossil fired electricity generating stations. Because of this a concentrated effort is being made to minimize boiler tube failure occurrences. Eliminating boiler tube failures could be worth $5 billion a year to the electric power industry(1).The aggressive service environment of fossil-fired boilers is largely the reason for these failures because the combined effects of stress, temperature, corrosion, erosion and vibration cause deterioration of boiler tube material properties and reduction in wall thickness.Determination of the boiler tube failure mechanism is important for the prevention of future problems. The root cause for a failure can be established and proper ameliorative measures taken only when the failure mechanism is identified correctly. The correct identification of failure mechanism is a complex process which may include many individuals and institutions. Technical specialists in metallurgy, chemistry, combustion, and boiler design frequently cooperate with the station staff in a failure investigation . These individuals rely on personal experience and numerous reports , theories, studies, private communications and investigations concerning the different failure modes and mechanisms."

Jan 1, 1990

By W. B. Evans, D. P. Taylor

"ANFO has two major disadvantages as an explosive low density and no water resistance. ANFO can be blended with more dense, water-resistant explosives to form ""Heavy ANFO"". The use of emulsion or slurry explosives as a matrix is an attempt to correct deficiencies on the basic ANFO while maintaining cost effectiveness.This paper will deal with four main topics.1. Product description, general properties, strengths and weaknesses.2. Technology of ""Heavy ANFO"" , the emulsion matrix concept and the range of products.3. Relative performance and economics in various rock types.4: Current status in Canada and worldwide, and the expectations for future use.IntroductionANFO has been in use for roughly three decades and remains the explosive of choice where conditions are suitable. ANFO has not become the universal explosive - despite its undoubted superiority in cost effectiveness - because it has serious flaws as an explosive. The most serious of these flaws are the low density and absence of water resistance in ANFO. Low density implies a low concentration of explosive energy in a borehole. The amount of energy available can be increased by. adding an energetic material, generally aluminum, or by drilling more holes. Both solutions add considerably to the over-all costs. The absence of water resistance in ANFO is inherent and can only be overcome by changing the fundamental nature of the product. The history of research in the explosives industry since the advent of ANFO is mainly the story of the various attempts to overcome one or both of ANFO's shortcomings.Many technologies and products have been developed to compete against ANFO, among them slurries, emulsion s and the so-called Dense ANFOs (ANFO with an extra nitroalkane liquid sensitizer). None of them was cost-competitive with ANFO so their market penetration has been limited to wet holes or specialized applications. The exception to this result is Heavy ANFO. The aim here was to have the best of both worlds, the high density and water resistance of emulsions or slurries plus the low cost of ANFO. The concept is very simple. ANFO is about 50 % air, roughly 30% in the prills and 700,10 between the prills . The air in the prills provides the necessary sensitivity but the air between them is waste volume. If one fills this volume with a high density, waterproof product, the resultant mix will be denser and more water resistant than ANFO and with very little added cost. This basic concept was invented by B. Clay in the 1970s and is covered by Canadian Patent No. 1 115 959. The water resistance and/or density of the mix can be tailored by changing the emulsion level. Because Heavy ANFO is relatively inexpensive while providing good in-hole densities and water resistance, it can compete successfully against all other bulk products. It competes against ANFO and Al / ANFO by allowing pattern expansion and reducing over-all costs while it competes against emulsions and slurries on price."

Jan 1, 1987

By J. Peck, M. J. Scobie, M. D. Pollitt

"IntroductionOne aspect of current research in the Canadian Centre for Automation and Robotics in Mining (CCARM) involves the automatic identification of different rock types based on particular drill performance parameter responses. In this paper, the four drill performance parameters of torque, pulldown pressure, rotary speed and penetration rate, were measured from an instrumented rotary blasthole drill during field investigations undertaken at the Fording River Mine, Elkford, British Columbia. The variations in these parameters were subsequently correlated with the corresponding rock types using the results from gamma, neutron and core logs in the same or adjacent boreholes. Work to date has sought to understand the relationships between drilling performance parameter variation and rock properties. Using the results of these studies, the present research is aimed at developing techniques whereby classical statistical pattern recognition methods are applied to drill data to permit the discrimination of different rock units. A monitoring system incorporating such a capability would greatly enhance the quality and amount of geological information on a per borehole basis while drilling. This data in tum could be used economically and directly towards explosive loading, geological exploration and reserve estimation. Background and PhilosophyThis work is an extension of equipment monitoring studies at the Fording River Mine. At this site over a two-year period, 5180 m of data was acquired on an instrumented Bucyrus-Erie 60R drill during routine production blasthole drilling. Throughout these studies, a 311mm diameter S8M Security tungsten-carbide tricone bit was used. The mine, located in southeast British Columbia, is a large-scale, open pit coal operation. The means of excavation revolves around a drill-blast-muck cycle and employs a standard shovel-truck system of transport. Four main rock types are present: sandstone, siltstone, mudstone and coal, with average compressive strengths ranging from 10 MPa to 150MPa respectively (peck 1989). However, based on the field studies, very few differences in terms of strength and compositional properties were seen between the sandstones and siltstones at the site. Therefore, they are referred to as sandstone/siltstone in all further discussions."

Jan 1, 1991

By D. H. Whiting, A. J. Sinclair

"The San Antonio gold mine, in the Archean Rice Lake Greenstone Belt, was in continuous production from 1932 to 1968, during which period the mine yielded 1.35 million ounces (41 985 kg) of gold and 195,000 ounces (6065 kg) of silver from 4.88 million tons (4.44 Mt) of ore for average grades of 0.28 ounces per ton (9.0 g/t) gold and 0.04 ounces per ton (1.3 g/t) silver. After the 1968 closure, several publications appeared implying that gold grade of ore decreased with increasing depth.Recent observations by the authors show that the relatively low grades in the middle levels of the mine are controlled geologically. However, the reduced average are grade in the lower levels of the mine was due to inadequate mining control that led to a high level of dilution. The similarity of geological factors such as vein styles within structural domains, variations in mining control, recent ore muck sampling results and lithogeo chemical profiles all indicate the similarity of ore in both upper and lower levels.Strict mining control should yield improved grades of gold for future production from the lower levels at San Antonio, in contrast with the production grades of the late 19605that represented extensively diluted ore. High-quality production records are an essential component in re-evaluating a past producer, particularly where workings are accessible. Poorly founded conclusions which cannot be checked by access to workings can have a negative impact on the evaluation procedure."

Jan 1, 1990

By J. J. McDougall

Until quite recently, the coal in the Cape Breton field was won from comparatively thick seams with light cover, and from submarine areas, and the system of mining naturally followed was pillar-and-stall. This sytem permitted of cheap extraction, and enabled production from localities where other methods could not be employed to good advantage. Thus the pillar-and-stall system, applied to conditions as stated, justified its adoption. Our working seams today, however, are practically all under heavy cover, or are moving in that direction, and with this gradual increase in cover came the increased cost of roadway maintenance. At Princess colliery, the system of pillar-and-stall was followed until roof and bottom conditions became such that further operations were unprofitable, and the longwall method was then adopted as an economic necessity. This fact should be borne in mind when operating costs of both systems are being compared. The longwall method is not held as a cure for all difficulties of heavy cover, but through it these difficulties can be overcome with less expense than by pillar-and-stall. The longwall system of mining, strictly speaking, is one by which a seam of coal is totally extracted in one operation. There are, however, many modifications of longwall, and in some cases it is difficult to determine whether certain practices should be classed as longwall or pillar-and-stall, or a combination of both.

Jan 1, 1928

By D. T. A. Symons, M. M. Kapnistos

"Gravity profiles were established over five known Middle Silurian pinnacle reef s in Lambton County, southwestern Ontario. The profiles were approximately 3 km long, with stations every 60 m. Four fairly recent technological developments were used which now make the gravity method relatively efficient and inexpensive compared to the techniques available two decades ago. These are: (1) a La Coste-Romberg model G gravimeter to measure the gravitational attraction with a sensitivity of 0.01 mgal; (2) a Sokkisha model B-2 semiautomatic engineers level to measure the station elevations with an accuracy of 0.5 cm; (3) a Huntec FS-3 hammer reflection seismograph to determine the overburden thickness to an accuracy of ± 7%; and (4) a modern microcomputer to process the data sets and mathematically filter the gravity values. Thus, two men can measure and analyze approximately 1 km of profile per day and obtain the residual gravity profile to an accuracy of ± 0. 05 mgal. Positive gravity anomalies of 0.17 to 0.72 mgal were observed along all five profiles that approximately delineate the dimensions of the known pinnacle reefs, which have an average height of 120 m, diameter of 1500 m and depth to top of 575 m. The relative ease of the gravity survey method makes it a cost-effective technique for hydrocarbon exploration in southwestern Ontario. IntroductionPinnacle reefs are important sources of oil and gas. Although the pinnacle reefs in southwestern Ontario are small, they may contain commercial pools of oil and gas because of their proximity to refineries. They are also useful for subsurface storage of gas to meet the winter surge in gas demand.At present, geophysical exploration for new pinnacle reefs is done primarily by relatively expensive seismic methods, which are also limited in southwestern Ontario by prohibitions on blasting. Gravity methods of exploration were attempted more than two decades ago in this region. (Pohly, 1954); however, the level of technology at that time made the method marginal in sensitivity and quite expensive. Several subsequent developments- gravimeters with greater sensitivity and operating ease, ""self-levelling"" levels for elevation control, hammer seismic reflection units for determining overburden thickness and portable microcomputers for efficient data analysis-have significantly improved the precision and cost effectiveness of the gravity method. Five known pinnacle reefs were selected in Lambton County, southwestern Ontario (Fig. 1), to test the effectiveness of integrating these developments to locate and define additional reefs. Isolated reefs were chosen to avoid the problem of the gravity effect s of one reef interfering with those of a neighbouring reef. The surveys were facilitated by choosing reefs with a concession road passing directly over them ."

Jan 1, 1980

By M. Lytle

"The Corbin area of southeastern British Columbia has been a coal mining area since 1908. Byron Creek Collieries Ltd. Has operated its Coal Mountain Mine in this area from 1974 until the present. In February 1981, this company was purchased by Esso Resources Canada Ltd.Coal Mountain is structurally complex and standard computer algorithms are not applicable to model the overturned synclinal structures and faulted bedding surfaces. This paper discusses two approaches used by Esso Resources staff to model the geology of Coal Mountain.The first approach projects digitized cross-section data along trend to develop a large data base which correctly approximates the shape of the structure. The spatial orientation of the structure is corrected by merging the generated data set with drill-hole data. The second approach uses digitized cross-section and bench-plan geology to generate a block model of the coal reserve.HistoryThe Coal Mountain Mine, also known as the Corbin Mine of Byron Creek Collieries Ltd. is located 24 kilometres south of Highway 3 in southeastern B.C.In 1905, two American businessmen recognized the coal potential of the area during a horseback tour. The two businessmen, D.C. Corbin and E.J. Roberts, formed the Corbin Coal and Coke Co. to mine and market coal from their newly acquired 6075 hectares of coal licenses. By 1908, the town of Corbin was under construction, a 22.4-km rail spur was constructed from the mine to the main CPR line and the first underground mine began to produce coal. An open-pit operation was also developed at the 1828-metre elevation using a steam shovel loading into rail cars. The company operated continuously until 1935, when a lengthy strike forced suspension of operations.In 1943, the Consolidated Mining and Smelting Company Ltd. (now known as Cominco Ltd.) operated two surface mines to produce coal for its smelters at Kimberley and Trail, B.C. This operation ceased in 1948."

Jan 1, 1982

By F. W. Wellmer

"This paper discusses the changing nature of reserve/consumption ratios, using data from Canadian operations and focussing particularly on copper.IntroductionStudies in world metal consumption and world metal reserves are done regularly by the U.S. Bureau of Mines, the German Federal Institute of Geosciences and Raw Materials, and other institutions. Formerly, on the basis of these data, the following figures were calculated:• a static lifetime of reserves-reserves at year end divided by the consumption of the previous year;• a semidynamic lifetime of reserves-reserves at year assumed constant growth rate.These figures were severely criticized because they were purely theoretical and did not consider the availability of the raw materials.Recent practice is to calculate reserve/consumption ratios (R/C ratios) for periods(1) or for different years(2,3) and to interpret the trend. For base metals, these R/C ratios are increasing (Table 1). This had led to the conclusion that today the relative availability of base metal reserves has increased as compared to 10 or 15 years ago(4,5) As there are normally numerous deposits for each commodity, the anticipated production rates of deposits are irrelevant to this conclusion as long as the statistical distribution of possible production rates does not change significantly.The above conclusion is only justified if the quality and the nature of the data base remain the same. This is certainly the case for the consumption data. It is also assumed for the quality of the reserve figures, which usually take into account only proven and probable reserves. For the nature of the reserve figures, however, this does not seem to be true.Undoubtedly, the reserves increased in absolute terms between 1966 and 1978. To put the absolute reserve figures into perspective, it is common, as said above, to compare them with the mine production, which increased in the free world between 1966 and 1978; e.g. for copper by 40%, for Pb by 17% and for zinc by 36%. However, the reserves are also influenced by other factors, such as average size of the mines, changes in the grade of the mined ore, price-to-cost relationships and the like.The purpose of this paper is to examine the nature of the reserve figures in more detail. Because the completeness of mining data published in Canada is rather exceptional, Canadian .data serve as an example and it is assumed that the conclusions can be extrapolated to other mining countries or at least to those with free market systems."

Jan 1, 1981

By S. C. Cohen, A. F. Mikkelsen

"This paper describes the improvements made to the operation of a liquid phase, 300°C, heat transfer system in the paste plant of an aluminum smelter. These improvements were achieved by replacing the original heat transfer fluid, a synthetic aromatic, with a new technology, petroleum-based product. This new fluid, Calflo HTF, provided better thermal stability, with lower toxicity, and improved plant working conditions.The procedures for fluid selection, changeout and performance monitoring are described along with a summary of control analysis over the last three years."

Jan 1, 1993

By D. K. Storer, W. Lee, S. Tkach

"A microcomputer-controlled multi-probe K-40 monitoring system was developed internally for the Phase II mill at the Lanigan potash mine. The K-40 probes were mounted in a variety of positions in several process streams, ranging from dry ore on a conveyor belt to brines and slurries. A description will be presented of the objectives, the equipment and the difficulties encountered in correlating results.IntroductionThe successful control and optimization of most metallurgical processes involves monitoring not only physical parameters such as flow rate and temperature, but also the chemical compositions of critical streams. Composition has proven difficult to measure on -line in industrial scale processes. However, in potash processing there is a convenient chemical parameter that has long been utilized to measure in situ the concentration of potassium chloride (KCl). Potassium has a long-lived isotope which is slightly radioactive. K40 decays by beta elimination to Ca40, ultimately radiating a characteristic gamma-ray photon. This gamma emission when detected by scintillation counter can be used to estimate the concentration of potassium in a process stream."

Jan 1, 1990

By J. A. Bossert

"In 1957, the Department of Mines and Technical Surveys (now Energy, Mines and Resources Canada) issued their first certificate for a fire-resistant conveyor belt. The testing procedure used was a combination of those used in the U.S.A. and the U.K. Subsequently, certification was granted to fire resistant electric cables (1974), fire-resistant mine duct material (1976) and fire-resistant hydraulic fluids (1978).Until recently, the testing procedures were copied from either the U.S. or the U.K. However, since the founding of the new Canadian Standards Association (CSA) Steering Committee for Electrical/Mechanical Mine Safety in 1981, these requirements have come under the close scrutiny of new CSA technical committees who will attempt to adopt or change the existing procedures to meet Canadian needs. This paper outlines the existing test requirements and attempts to predict how they will appear after ""Canadianization"" by the CSA committees.IntroductionFires in underground mines have always been considered more serious than in other locations because of the confined space and limited atmosphere. A fire can make escape difficult or impossible if it is blocking all of the routes to the surface. Also, the products of combustion from an underground fire can asphyxiate anyone not having self-contained breathing apparatus.In an underground coal mine, the consequences of a fire can be even more serious because of the presence of methane and coal dust in the atmosphere (which can explode) and because the coal itself is combustible.For these reasons, the inspection authorities having jurisdiction over underground mine s in Canada are quite concerned about the flammability of any materials that are used in quantity in the underground environmentAs early as 1957, the Canadian Explosive Atmospheres Laboratory (CEAL) was asked to certify conveyor belting as fire-resistant. This is because many miles of this material are used in underground mines in Canada and, as it generally travels through the mine, it is a perfect vehicle for spreading a fire."

Jan 1, 1982