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By M. G. Lipsett

"Mining properties are becoming increasingly remote, a challenging situation for operating and maintaining equipment. Logistics of transporting workers and materials can be alleviated by having timely, accurate information of equipment location and operating condition, and by automating some activities. This paper discusses an infrastructure for remote operations, with strategies for communicating different types of data, and a design method so that systems can interact with either an operator or another system. A remotely operated excavator prototype is described, with on-board performance and diagnostic monitoring systems now used on production equipment. IntroductionSyncrude Canada Ltd. operates an openpit oil sands mine near Fort McMurray, Alberta. For twenty years, draglines and bucketwheel reclaimers have fed conveyors that transport dry oil sand to an extraction and upgrading plant. In converting to a truck and shovel operation, Syncrude has developed slurry pipelines and bitumen froth pumping to allow more remote leases to be mined more than 30 km from the base plant.There are organizational and resourcing challenges in operating and maintaining equipment in three nearby, but separate, mines. The logistics of transporting workers and materials to production and support equipment become more difficult, and operations and maintenance personnel and facilities become more distributed. Supervising mine operations will rely even more on having timely, accurate information about equipment location and operational status.Syncrude is typical of an open-pit operation. Voice communications are the preferred way to exchange information for making immediate decisions about operations and maintenance. A large number of narrowband FM broadcast radio channels keep teams of miners working together. Haul truck drivers, shovel operators, and dispatchers talk on one channel while maintainers coordinate activities with the control tower on another. Cellular phones have become popular for supervisors who have to talk with planners and engineers in offices without radios."

Jan 1, 2000

By Kazuhide Nakaniwa

In this research, we devised a measurement method using total stations (TSs) which have ?the Baum? which is a concentric circle reticle, as substitute for crosshairs. The Baum owes its name to the similarity between the concentric circles and trees (Baum in German). By setting one circle on both of edges of cylinders, operators can set their sights on points on the center line of the cylinders, and also can measure positional coordinates of the points. Also, by measuring two different points on the center line, operators can measure the position and tilt of the axes of the cylinders. Furthermore, we developed a pile driving navigation system. Foundation piles are used for various structures, and their forms are generally cylindrical. Especially, although it is difficult to drive tilted pile foundations, their usage are expected to expand due to their high earthquake resistance. Yet, a method to accurately measure the tilts of piles has not been established. However, we proved that operators can obtain adequate accuracy to control foundation piles through the measurement experiment using this system. Using this system, the information of the pile is measured using a TS, transferred to a PDA, and displayed from the operator?s view of the piling machine.

Aug 1, 2013

By W. A. Jones

THE estimation of the average value of gold ore involves many considerations, among them the correct sampling of the deposit, the dilution by waste, and the loss of high-grade fines. It is a common experience that, after all these factors have been evaluated, adjustment of the assays is necessary before satisfactory agreement between the calculated mine grade and the mill heads is obtained. In fact, at many mines the latter correction overshadows all others in the preparation of routine estimates. For this reason it is proposed to deal only with the mathematical treatment of mine assays and the problem of bringing estimates into conformity with the corrected mill heads. Mine assays differ from physical measurements because the range of values is very great and these are not symmetrically distributed above and below the average, there being fewer high than low results. There is no widely accepted mathematical procedure for determining the average of series of measurements which exhibit these characteristics. Customary practice consists in empirically reducing high assays until a satisfactory agreement with mill heads is reached. It was thought that more confidence could be placed in grade estimates if a logical basis for calculations could be devised .. In an attempt to find a fundamentally sound procedure, amenable to practical application, many series of assays comprising over 235,000 channel samples (1) were studied at Hollinger Consolidated Gold Mines, Limited. Such an investigation could only be made where records covering many years of operation are available and where tabulating and calculating machines are in use. The results are recorded in the hope that the relationships noted for the large groups of assays used are of fundamental character and that the data will be useful to others dealing with the problem of grade estimation.

Jan 1, 1943

By G. A. Vissac

METHODS of coal preparation have been greatly developed and improved during the past few years. Under the pressing competition from substitutes that have been displacing coal as a source of heat or power, the coal industry has been able, in many cases, not only to hold its own but to regain much of the lost ground, by offering better products of a higher value. The purpose of this paper is to present, in a brief and simple form, the principles of the latest methods and machinery used in coal preparation, in order to enable the coal operator t0 select methods and equipment capable of solving his own problems in the most efficient and economical way. The paper will deal, in the main, .with coal cleaning. It must be emphasized, however, that a complete coal preparation study covers many other operations, such as handling, screening, de-dusting, dust-proofing, and ash-conditioning. Handling Coal From the producing face to the railway car, coal must be handled with great care, t0 prevent degradation, because the coarser sizes are not only easier to clean than fines but, for our markets, they are often the more valuable. Generally speaking, such care is less important or is unnecessary in the Old Country, where conditions are different. The best way to minimize breakage is to avoid gravity methods in coal transportation. All chutes in a preparation plant should be shaken mechanically, and cleaning processes requiring large surge bins must be avoided. De-Dusting De-dusting of coal is accomplished by the use of vibrating screens, fans, or classifiers, or by a combination of these. Fines below 1/32-in. (or coarser than this, with some coals) can very seldom be cleaned efficiently. Common practice is to discard them immediately, if the moisture content of the coal allows this to be done. Otherwise, they are liable to give unnecessary trouble, either in the form of dust or sludge, which are difficult to collect or to settle. Flotation is the only process which will effectively clean fines.

Jan 1, 1937

By Robin Sheremeta

What is the goal of every organization when it comes to safety? Everyone Going Home Safe and Happy Every Day Good old days: Era of Death (accidents will happen) Era of Engineering: (Eg. hand rails, limitswitches, machine guards, etc.) Era of Legislation: procedures, laws and regulations (Eg. SWP?s, Mines Act) Era of Behaviour-Based Safety: (eg. STOP program)

May 1, 2010

By Dave M. Jakelski, Gerhard W. Heinrich, Peter F. Wells, Daniel F. Suarez, Jamie B. Beauchamp

"A need for increased copper concentrate production and for less nickel contamination in that concentrate at Falconbridge's Strathcona Concentrator during 1993 required the installation of a third flotation column and improvements in the operation of the existing circuit. Innovations in wash water distributor and launder design were fundamental in achieving objectives on a new 3 meter diameter column. Minnovex plug-type spargers were tested on a 2.1 meter diameter column in order to reduce maintenance requirements. The paper details the measures taken to enhance column flotation circuit performance and the results obtained.IntroductionFalconbridge's Strathcona Mill receives 10% of the ore feed from a rich copper zone in the Strathcona mine. This ore typically grades 7% copper and 1 % nickel and, because of its high copper content, it is processed in a separate circuit ('C' circuit) which consists of conventional grinding, rougher flotation with the concentrate being treated with lime to pH 12.3 and cyanide followed by column flotation. The columns are operated with mechanical flotation scavengers and the scavenger concentrate is returned to the column feed. Testwork conducted in 1991 showed that the original flotation column (Column 2) could only produce 5.5 mtph of concentrate with less than 0.5% nickel (Figure 1).Between 1991 and spring of 1993, production was increased at times by open circuiting the scavengers. Metallurgical improvements were obtained by improving the wash water distributor of Column 2 and by wash water sprays in conventional cells (1 ). However, the scavenger concentrate assayed 0. 7 -0.8% nickel and was not acceptable for long term operation. When Copper ore production targets were significantly increased for 1993, it became clear that an additional flotation column was required. The new flowsheet employs mechanical scavenger cells on the column tails as in Column 2 circuit (Figure 2). A -parallel configuration was chosen as pulp solids fraction has been shown to be a critical variable and the second column in series would receive a lower density feed."

Jan 1, 1994

"The QEMSCAN system is the third generation of automated mineral analysis systems that began with the QEM*SEM at CSIRO 30 years ago (Butcher et al. 2000). It is now a successful commercial instrument with 39 instruments in operation around the world. Back Scattered Electrons (BSE) and Energy Dispersive (EDS) X-Ray spectra are used to create digital mineral images with mineral identification occurring online. Low-count EDS spectra are used preferentially to BSE brightness, allowing minerals to be accurately identified by chemical composition. Individual minerals or groups of similar compositions are identified by comparison to a comprehensive mineral database incorporated into the QEMSCAN software. Optical mineralogy and Scanning Electron Microscopy is a metallurgists’ tool for determining the ore process mineralogy and delivering a better flowsheet. These techniques have limitations, provide limited information and sometimes fail to provide representative information. In contrast, QEMSCAN provides information on the nature and occurrence of all mineral species present plus the liberation characteristics, looking at thousands of particles in the sample presented. Some of the data presented includes:• Particle and grain sizes• Dominant mineral species• Particle shape• Calculated metal content• Density• Deportment of elements of interest between the mineral phases• Quantitative mineralogy• Mineral associations, locking and liberation• Textural relationships (particle images)It can also be used on concentrates, polished sections or drill core. This is a significant improvement in ore characterisation providing lithology, mineralogy, liberation, ore grade and porosity from a sample. Theoretical grade-recovery curves can be created to be mineralogically limited from QEMSCAN analysis which, when compared with metallurgical results, are valuable in evaluating whether liberation or chemical selectivity is driving flotation performance. A number of case study examples are given where the QEMSCAN had a significant bearing on future project development at an early stage of exploration and mine development."

Jan 1, 2012

By J. Stiksma, J. Dennett, R. Kalanchey, J. Ji, M. Collins, T. Chan, R. Berezowsky

A pilot plant campaign has been conducted by Sherritt Technologies in support of Eldorado Gold Corporation’s evaluation of pressure oxidation technology for the treatment of refractory gold concentrates from the Certej deposit in Romania. Four separate concentrates, containing 3.5 to 5.4 g/t Au, 13.0 to 14.5% S2- and 12.0 to 32.5 g/t Ag, were tested in the eight-day campaign. The major gold-bearing mineral was pyrite. Preliminary batch tests indicated that gold extraction from the oxidized concentrates in subsequent cyanide leaching was adversely affected by the presence of organic carbon in the pressure oxidation feed when chloride in solution was at an elevated level. As such, the process conditions that were tested during the pilot plant operation were selected to either counteract the negative impact of the organic carbon, or to deactivate it during pressure oxidation. Both process routes proved feasible, yielding gold extraction of 95 to 98% in cyanide leaching of the oxidized concentrates. Silver extraction was typically in the range of 80 to 90%, provided that the oxidized concentrates were also processed in a lime boil step prior to cyanide leaching.

Jan 1, 2014

By G. Archibald, M. McSaveney, J. Wartman, M. Yetton, C. Massey, C. Holden, A. Kaiser

"The 2010/11 Canterbury earthquakes triggered many mass movements in the Port Hills including rockfalls, rock and debris avalanches, slides and slumps and associated cliff-top cracking. The most abundant mass movements with the highest risk to people and buildings were rockfalls and rock/debris avalanches. Over 100 residential homes were impacted by landslides, leading to the evacuation of several hundred residents.Volumes of rock leaving several of the larger cliffs during the earthquake sequence were determined from terrestrial laser scan change models. There were no seismically instrumented cliff sites and there was some distance between the cliffs and nearest strong-motion sites. Therefore, we synthesised free-field rock-outcrop seismograms by employing a stochastic approach controlled by source models and regional parameters derived using spectral inversion of the extensive strong motion data set. Relationships between volumes leaving cliffs during the earthquakes and site peak ground acceleration (PGA), peak ground velocity (PGV) and Arias intensity were compared for different sites. Multiple linear regression was used to analyse the variables that best predict the volumes of debris that fell from the slopes during the main earthquakes. The best correlation between the volume of debris falling per square metre of slope face and the seismic forcing parameters was for vertical PGV. The results from the multiple linear regression incorporating slope height, inclination, PGV horizontal and PGV vertical, improved the statistical relationship.Field data and results from the 2D seismic site response assessment indicate that the following factors affect dynamic performance of the modelled cliffs: 1) cliff geology—mainly material modulus, shear strength and shear wave velocity; 2) slope geometry—ridge-scale versus site-scale effects; and 3) the temporal aspects of the earthquake shaking (i.e., single acceleration peaks of large amplitude versus multiple peaks of smaller amplitude). Model results show that amplification of shaking does not increase linearly with increasing height, but instead reflects changes in the cliff geology where material strength, modulus and shear-wave velocity contrasts lead to acceleration contrasts.These factors show that the use of well documented case histories provide the basis for more certainty in seismic landslide assessments compared to those that are only empirically based."

Jan 1, 2015

By L. M. Lowe, D. B. Chambers, D. G. Feasby

"The presence of the naturally occurring radioactive elements uranium and thorium in rare earth (RE) resources can present challenges in achieving regulatory and social acceptance. The discovery and awareness of radioactivity in mineral resources radioactivity typically generates strong public intuitive responses that may be project prohibitive; a significant proportion of such resources contain radioactivity.The objectives of this paper are to demystify the presence of uranium and thorium in RE resources and to demonstrate how a RE project can be safely developed, operated and closed from a radiological perspective. Radioactivity in RE resources is principally thorium-based. Thorium is interesting and challenging from a metallurgical perspective – one of those stubborn metals commonly assessed as refractory. Thorium is difficult to mobilise into solution and easily precipitates out. Thorium is a common element in the earth’s crust – about 10 ppm on average, and natural geophysical systems conclusively demonstrate its immobility. Specific mine tailings contain elevated levels of thorium, but the contained thorium is neither a significant ecological nor a personal hazard.Waste management for a hard rock rare earth project includes the management of mineral processtailings, waste rock, and metallurgical residue. Proven strategies are available for tailings and waste rockfor all climate conditions. The management of the metallurgical residues is potentially more challenging.Example robust strategies for addressing these challenges are presented.A potential way to reduce the radioactivity of rare earth metallurgical wastes is to selectively remove uranium and thorium. Uranium oxide is readily marketable, but its concentration as a byproduct typically triggers extensive regulatory processes. Thorium is presently not marketable, but may be so in the not-too-distant future with the development of thorium-based nuclear energy. The pro’s and con’s of uranium and thorium byproduct recovery are summarized."

Jan 1, 2016

By Thomas G. Madgwick

Introduction Development of oil and gas is still centred in the Province of Alberta, much as it was when C. C. Ross read a paper on this subject three years ago at the Annual General Meeting in Montreal; but so far as gas is concerned, its early production in Saskatchewan seems now assured. The three years that have elapsed since Mr. Ross' paper have witnessed a growth in the world's production of oil that has created a potential supply out of all proportion to the demand for petroleum products, and one that has resisted the most energetic efforts of the industry entirely to control. The natural result has been very much to retard the active prospecting of new structures in the Prairie Provinces with any immediate view to oil production, although the same factor has not hindered the search for gas to the same extent. One consequence has been to divert the attention of organized oil operators from wildcat drilling to more detailed geological investigation than had hitherto been customary, sometimes accompanied by test drilling with a view to the elucidation of geological structure rather than to the immediate development of production which at the present is not needed. Nevertheless, in spite of the growth of this phase of oil prospecting - which the writer would be the last not to welcome as a very real blessing and of far greater value than indiscriminate wildcat drilling in either the complex structures of the foothills or the simpler but largely concealed formations of the plains- it is most satisfactory to have to record that in these three years the growth of production both of naphtha and the heavier crude-oil has kept pace with the by no means inconsiderable growth in the production and utilization of natural gas.

Jan 1, 1929

By K. R. Nichol

The author points out that corrosion works 24 hours a day, every day. It is an economic reality that the cost of corrosion is inevitable and that its cost should be incurred in the least expensive way. An economic evaluation technique to properly assess its relative impact is the Discounted Cash Flow Method. Various remedial and corrosion control measures are available and these, when coupled with a planned corrosion control program, help reduce the cost of corrosion.

Jan 1, 1973

The JKRBT (JK Rotary Breakage Tester) is a newly developed impact breakage testing device for rapid ore breakage characterisation, and has recently been commercialised after a three year comprehensive validation study, involving five major mining companies and six industrialised JKRBT units deployed worldwide. Comparisons of breakage mechanisms and characterisation data between the JKRBT and the Drop Weight Tester (DWT) indicate that, despite the differences in the breakage modes, the JKRBT can provide statistically similar A*b parameters, by using a data reduction procedure which takes into account the difference in the number of contact points, strain rate and potential for secondary breakage. Feedback from the validation sponsors has indicated higher productivity and better repeatability of the JKRBT compared with the DWT. This better precision, combined with the JKRBT?s wider particle size capability and wider specific energy range, provide a more powerful tool, ideally suited to rapid mapping of ore hardness in geometallurgical and comminution applications.

Jan 1, 2012

By Hajime Miki, Gde Pandhe Wisnu Suyantara, Tsuyoshi Hirajima, A. M. Elmahdy, Keiko Sasaki

"Seawater has been reported to depress molybdenite in a copper-molybdenum (Cu-Mo) flotation process at high pH due to the precipitation of Mg(OH)2. Meanwhile, to improve mineral recoveries, collectors are usually added into the flotation cells, thus adding the complexity to the mechanism of bubble-particle interactions involved in Cu-Mo flotation. Therefore, understanding the interaction mechanism in seawater flotation and in the presence of collectors is important to explain the minerals depression. The present work investigated the effect of kerosene on the bubble collision and attachment to pure chalcopyrite and molybdenite surfaces in MgCl2 solution as one of the seawater major components at pH 6 and 11. Mineral surfaces were characterized using atomic force microscopy (AFM). In addition, minerals floatability in the same system were tested in a column flotation. The study of bubble-particle interactions shows that following several collisions, bubble could displace the intervening liquid layer on the mineral surfaces, forming a three-phase contact (TPC). A TPC formed more rapidly in the presence of emulsified kerosene in a 0.01 M MgCl2 solution at pH 6 for both minerals. The reason is kerosene increased the surfaces hydrophobicity and destabilized the intervening liquid layer on the surfaces. Moreover, the average time required to form a TPC was shorter on molybdenite surface. This can be attributed to the effect of adsorbed kerosene on molybdenite surface and molybdenite surface roughness.INTRODUCTIONIn froth flotation, bubbles are used to separate hydrophobic mineral particles from hydrophilic particles. In this process, bubble-particle interactions (i.e., collisions, attachment, and detachment) are crucial with regard to mineral recoveries. The effectiveness of froth flotation depends on the formation of stable aggregates between the hydrophobic particles and the bubbles, allowing the bubble to carry the particles to the froth layer. To form such aggregates, the bubbles and particles must collide, and the intervening liquid layer must be drained below the liquid layer critical thickness, forming a stable threephase contact (TPC) (Ralston & Dukhin, 1999). Particles detachment may take place if the particles still have sufficient kinetic energy and the TPC is not formed. Previous studies of bubble-particle interaction in electrolyte solutions have been conducted using atomic force microscopy (AFM) (Assemi, Nguyen, & Miller, 2008), and by approaching the bubble using mica plate (Pushkarova & Horn, 2008), however, these studies did not focus on the bubble-particle collisions. Bubble collisions and attachment to hydrophobic (Teflon) and hydrophilic (glass) surfaces in a a-terpineol solution have been investigated by Krasowka et al. (2003)."

Jan 1, 2016

By G. F. Miller

ONLY IN THE Province of Saskatchewan is natural sodium sulphate found in Canada in amounts large enough to make recovery economically sound. Geologists have estimated that the numerous deposits within the Province contain upwards of 200 million tons of Glauber's salt. There are twenty-one deposits in the Province which contain 500,-000 or more tons and about two dozen with lesser amounts. The first recorded production of sodium sulphate in Saskatchewan was in 1918. The company concerned, and others that attempted to develop the industry in its early stages, were unsuccessful. Their failures were caused by two main factors -lack of knowledge of efficient operating methods and the unstable market situation for the finished product. Today, the situation is changed in both respects and the product, commonly referred to as 'saltcake", is a very important chemical requirement of many industries throughout the world. Before proceeding with remarks on manufacturing methods it should be stated that, although this is a general paper on the manufacturing methods and end uses of the saltcake produced in the Province, the writer is, of course, more familiar with the plants operated by Saskatchewan Minerals than with other operations and perhaps may be excused for dealing more particularly with the plants of that Compa11y.

Jan 1, 1958

By Ross Gallinger

In 1997 a group of Canadian mining companies met to review the Mine Environment Neutral Drainage (MEND) program and to consider future activities. They concluded (i) that Canadian industry and NRCan should fund a small secretariat in Ottawa to support technology transfer in Canada and (ii) that it was important for industry to continue the momentum of MEND on an international scale. The need for INAP (International Network for Acid Prevention) was strongly endorsed by company, university, consultant and government experts from Australia, Canada and the U.S. who were convened in Vancouver in February 1998. The initial focus was the development of a solid knowledge base covering the collective experience of INAP's members to promote the dissemination of successful practices, the identification of knowledge gaps and the formulation of effective research proposals. The sharing of information on past successes and failures alone was viewed as sufficient justification for the formation of INAP. INAP was officially launched in October 1998, and is now an effective, industry based initiative to globally coordinate research and development in the management of sulfide mine waste. Significant improvements in the management of sulfidic mine materials through knowledge sharing, research and development of technology by INAP will reduce liability associated with acid drainage. This paper will explore the international efforts and activities of INAP.

May 1, 2002

By G. Issid, J. McGinty, C. Lee, Y. Pepin

For more than a decade, Hatch has used process and logistics models to assist Rio Tinto Fer et Titane (RTFT) with capacity planning, debottlenecking, and optimization to help ensure design capability, capital effectiveness, and operational efficiency of the integrated production chain. Process models are used to optimize the physics-based aspects of the system, such as mass and energy balances, flow rates, yields, and equipment specifications. Dynamic logistics models are used to optimize how the various plant areas work together to achieve the desired ends and deal with such things as plant scheduling and synchronization strategies, sizing of buffers between processes, defining the required number of process and material handling units, and designing a plant layout that minimizes plant interferences and inefficiencies. The combined use of process models and logistics models enables the overall plant to be optimized from both a productivity and quality point of view, with each plant area working in harmony with one another to achieve targeted capacities and efficiencies. This paper describes the many benefits derived from such modeling efforts over the past 15 years for each of the major plant areas at RTFT: Beneficiation Plant, Smelter Plant, Steel Plant, UGS Plant, and Powder Plant (RTMP).

Jan 1, 2011

By G. E. Agar, W. B. Kipkie, R. A. Tenbergen

"This paper describes the successful pilot plant testing of a flowsheet, developed at INCO Ltd.'s J.Roy Gordon Research Laboratory (JRGRL), for improved separation of the constituent minerals in a bulk copper nickel concentrate.The flowsheet utilized the fact that xanthate concentration on the mineral surfaces is the most important variable affecting the high lime separation and that reduction of the xanthate concentration could be effected by an oxidative conditioning stage.When the adsorbed xanthate was reduced to a suitably low level, chalcopyrite and pyrrhotite could be floated to leave a high grade nickel concentrate as the residue. Sodium cyanide was added to the froth product to depress pyrrhotite and any remaining pentlandite. The temporary depression of chalcopyrite by the sodium cyanide was overcome by introducing a conditioning step following cyanide addition. The advantages of the flowsheet; improved copper-nickel separation, operation without heating of the pulp, production of both high grade nickel concentrate ( 29. 5% Ni, . 26% Cu) and copper concentrate ( <O. 5% Ni, 30% Cu) were all realized."

Jan 1, 1984

By J. A. Russell

MR. M. W. Boom: I would like to congratulate Mr. Russell on his fine paper. One very good point which has always appealed to me is the smooth working of a steam hoist as compared with electrical. He does not mention the steam hoist at Springhill which has been working there for a good many years. MR. S. R. NEWTON: I have read with a great deal of interest the paper presented by Mr. Russell on the development of haulage engines in the mines of the Dominion Steel & Coal Corporation. He is to be congratulated on having produced a comprehensive article showing, step by step, the various improvements that have been made over the years in the design of such engines. I am quite in accord with Mr. Russell&apos;s statement that the positive tooth clutch can have too many teeth, and also that the method of driving a sliding clutch hub of any design should be by means of a hexagon or octagon on the shaft. Where the clutch hub does not of necessity slide on the shaft it can be pressed on and keyed to the shaft in the normal manner. With regard to the &apos;Cramp&apos; internal-expanding jaw-type clutch, while it is true there are more moving parts than with the clutch consisting of a ring with internal cut teeth and a driver having a fewer number of teeth as .described by Mr. Russell; there are compensating advantages to the internal expanding jaw-type of clutch. The V shaped profile of the teeth permits of engagement of the clutch with very much less &apos;jockeying&apos; of the drum. This is particularly the case in vertical-lift mine hoists, where it may be necessary to engage and disengage the clutching mechanism at frequent intervals.

Jan 1, 1944

By A. A. Millar

THE output of coal from the Province of Alberta reached its peak; in the year 1928, when 7,334,179 tons were produced. Following this, a steady decline was recorded, and in 1930 a low mark of 4,564, 290 tons was made. Since that time, however, the tendency has been upward, and this year (1937) 5,551,682 tons were produced, compared with 5,696, 375 tons in 1936 and 5,462,973 tons in 1935. The value of the output in 1937 was $14,434,969, against $14, 720,004 in 1936. The coals of Alberta have been classed under three heads, viz., domestic, sub-bituminous, and bituminous The domestic (or lignite) and the sub-bituminous coals are used chiefly for domestic purposes, with the possible exception of the smaller sizes and the output of the two stripping pits at Stereo and Coal Valley The bituminous output is used mainly by the railways, for locomotive purposes, which, in 1937, accounted for 80.6 per? cenr of the total sales of bituminous coal. A fair proportion is sold for stationary engine and steam purposes and, in 1937, 25,000 tons were used in making briquettes at plants operated by the Canmore Coal Company, Limited, and Brazeau Collieries, Limited. The International Coal & Coke Company, Limited, used 99,500 tons in their plant at Coleman, for making coke. The bulk of the 66,000 tons of coke produced was sold for use at the smelter at Trail, B.C.

Jan 1, 1938