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By L. Dorador

"In block caving projects, the rock mass fragmentation process plays a controlling role in the design and success of the operation. Poorly understood, however, is the secondary fragmentation that occurs as blocks of caved ore move through the draw column and interact with one another. The initial size of these blocks can be considerable, as can their strength and stiffness as the presence of non-persistent joints and veining will be variable. Intuitively, more planes of weakness within the blocks should facilitate early fragmentation, but this assumption could depend on additional factors such as contact type between adjacent blocks and loads imposed through varying heights of the draw column. This paper reports the findings from a laboratory investigation examining the role of block strength and planes of weakness on secondary fragmentation. Testing was carried out on small-scale concrete cubes of uniform size, with and without embedded planes of weakness. The results obtained demonstrate the significance of veining and other planes of weakness on secondary fragmentation under one-dimensional compression, and allow for the development and constraint of empirical guidelines.INTRODUCTIONThe fragmentation process during block caving involves the initial (primary) fragmentation of rock in the cave back through stress-induced fracturing, release and fall of individual blocks onto the broken ore muck pile. This is followed by secondary fragmentation involving splitting and rounding of blocks as they move downwards through the draw column towards the draw point. The degree of secondary fragmentation achieved involves many variables related to the mechanical properties of the rock blocks as well as different operational factors. With respect to the block properties, the presence of planes of weakness in the form of veining and non-persistent joints is a topic of special interest given the significant influence it potentially has on the overall fragmentation process. However, the inherent heterogeneity and variable size of individual blocks generated from the cave back makes it difficult to develop any empirical relationships relating secondary fragmentation to compressive loading based on insitu observations and mine data. More preferable would be to keep constant block parameters, such as shape (aspect ratio and angularity) and size, through controlled laboratory testing. This work presents an efficient technique to fabricate concrete cubes in order to keep constant different block properties. These are then tested under one-dimensional compressive loading. The objective of these tests is to emulate a tight packing condition of single blocks such as that which would occur when the air gap between the cave back and broken ore in the draw column is small. When the air gap is small, detached blocks are unable to fall and rotate but instead maintain a very tidy arrangement with minimal voids left between adjacent blocks."

Jan 1, 2015

By Gonzalo Díaz, Diego Mesa, Willy Kracht

"It is well known that frothers affect the amount of water that is transferred to the froth, which has an effect on both the froth stability and the water recovery. On the other hand, since non-selective recovery by entrainment is directly related to water recovery, it can be said that frothers have an indirect effect on flotation selectivity. Recent research on this subject has shown that the non-selective recovery by entrainment, which is characterized by the entrainment factor, is frother dependent. In other words, the entrainment factor is not unique, but depends on frother type.Having different entrainment factors implies that for the same water recovery, the amount of undesired particles reporting to the concentrate may vary if one changes the frother type, which suggests, as a possible explanation, that it is not only the amount of water in the froth what is affected by frother type, but also the froth structure.The purpose of the current work is to study the effect of frother type on foam structure (two phase froth). A quasi-2D cell operated with a slot sparger was used to study the foam structure in the presence of three different frothers: Methyl Isobutyl Carbinol (MIBC), OrePrep®549, and Octanol at the same gas flow rate and reagent dosage. The foam structure was studied using image analysis, and an algorithm based on textural analysis was developed to classify the foams. The results show that it is possible to classify foams according to the frother used, which proves that frothers have an effect on the foam structure.INTRODUCTIONFrothers are usually dosed paying attention to froth stability, condition that is commonly estimated by sight, according to the operator's criteria and experience. This happens because there is not an established procedure or technique for frother characterization, generating qualitative descriptions such as “powerful” or “selective” frothers, which lack of scientific thoroughness and remain under subjective factors. Nevertheless, several works have been done in this line of research. Moyo et al. (2007) classified frothers based on their water-carrying capacity, proving that this characteristic is related with gas holdup and frother type. Previously, Trahar (1981) had related water recovery and gangue particles recovery, defining the entrainment value (ENT). Nowadays it is known that entrainment affects both hydrophilic and hydrophobic because it is not a selective process. In the last decade some studies (for example the one of Konopacka and Drzymala (2010)) delved into different entrainment behaviours dependent mainly on the flotation type (batch or continuous, agitated or columnar, etc.), but there were no studies on the effect of frother type regarding entrainment, since Rahal et al. (2001) argued that the ENT factor was independent of the frother type and concentration, and froth height."

Jan 1, 2016

By A. Ignatieff

"THE WORLD'S coal resources represent the largest component of non-renewable energy resources. Coal is now regaining Its position following a temporary decline, particularly in North America during a period of about a quarter of a century. This period provided the opportunity to improve both surface and underground mechanization, thereby increasing the productivity and improving conditions for humans in the mines. Similarly, in preparation, improved cleaning of coal from various impurities including sulphur was achieved, to meet the more demanding requirements for coking coal. Progress was also made in combustion, particularly related to the reduction of pollution. Canada participated in most of these developments, despite the country's strong commitment of the use of hydrocarbons during this period. _Bearing in mind the vastness of this land (3.85 million sq. miles) by comparison with countries like U.S.A., U.S.S.R., and China, Canada's coal resources estimated to date are not large and they are scattered. The original evaluation of 1913 estimated the ""reserves"" from seams over one foot in thickness and a limiting depth of 4,000 ft at 1.2 trillion metric tons. D:. ~.R. MacKay, in his evaluation for the 1946 Royal Commission on the coal industry, known as the Carroll Commission, reduced the ""reserves"" to 99 billion short tons. The increased knowledge now available would indicate that the 1913 estimated was too liberal and the 1946 estimate too conservative but both were closer to a resource than to a reserve designation. Some adjustments of Dr. MacKay's estimates were made in 1970 by B.A. Latour of the Geological Survey of Canada and L.P. Chrismas of Energy, Mines and Resources Canada (EMR). In the last decade the Alberta Energy Resources Conservation Board has developed its own methods of evaluating coal resources and reserves. A methodical approach of exploration and evaluation was carried out by Saskatchewan jointly with the federal government of the lignite resources of Southern Saskatchewan. A similar joint program is in progress in Nova Scotia. Meanwhile, the industry itself carried on an extensive exploration program on the outcrops of promising projects in the Inner Foothills belt of Alberta and British Columbia in preparation for surface mining on a very large scale, with some development of hydraulic mines. All these activities have been reflected in the increase of the country's resources and reserves, which now fortunately are separately defined. In 1979 EMR issued Report E.R. 79/9(1>; the data were developed in 1978 and provided to the World Energy Conference Organization<2>. In 1980 the World Coal Study (Wocol), an international group that included Canada carried out a study which updated the W.E.C. data, indicating some reduction of the 1978 figures; quantities were reported in million metric tons of coal equivalent (C.E.)*(Jl."

Jan 1, 1985

By S. Kodama, G. Sasaki, K. Matsugi, K. Sugio, Y. B. Choi

"Pure aluminum (Al) matrix composites with changing the volume fraction of TiB2 particle content from 10 to 30% was fabricated by spark plasma sintering (SPS) process. Then the microstructure, density, dispersibility and thermal conductivity of the composites was estimated. As increasing TiB2 content, the dispersibility of particles and the density of the composites degraded slightly. And, the effect of the dispersibility of TiB2 particles on the thermal conductivity was quite little. The thermal conductivity of the composites was less than the theoretical value calculated by Maxwell-Eucken equation considering the effect of the density. It is due the influence of the interface heat transfer rate, because these composites have many small sized particles and have high interface density.INTRODUCTION Recently, metal matrix composites (MMCs) have been used widely in electric / electronic components, architectural materials, transportation equipment, aerospace and a precision instruments, because it’s superior properties have been greatly watched. Demand of MMC for industrial use has been increasing gradually. Furthermore, multifunction properties are required for the composites strongly. By integrating the dissimilar materials, the composites have various properties that we cannot get from monolithic materials. On the other hand, the response to the thermal management is required for materials, recently, and the need for the structural material controlling the thermal conductivity has been increasing. Especially, superior thermal conductivity and good mechanical properties from room temperature to high temperature are required for heat sink and heat exchanger at the same time. In late years, a study on the composites combining carbon materials and aluminum and copper has been developing, and actually the composites with high thermal conductivity which is not provided in the conventional materials is developed. On the other hand, non-oxide ceramics particles such as SiC and AlN, TiB2 have good thermal conductivity. Particularly, as TiB2 has good electrical conductivity, TiB2 containing MMCs is expected as innovative materials used as electric/ electronic components. Furthermore, as TiB2 has low density, high melting point, low thermal expansion and good deformation resistance, the development of high performance composites with multi-functional properties is expected. As thermal conductivity of pure Al and TiB2 are 225 and 66.4 W/mK, respectively, it is expected that the degradation of thermal conductivity by adding dispersant in Al matrix is suppressed. The authors have carried out a thermal conductivity, electrical conductivity, mechanical properties of 20 vol.% TiB2 dispersed Al composites (Sugio, 2016, Sasaki, 2016). In this study, the influence of quantity of addition of TiB2 on microstructure, thermal conductivity was studied minutely."

Jan 1, 2018

By Walter S. Bergholz, Michael L. Schreder

"Since Escondida began operations in fiscal 1991, a series of aggressive expansion projects have enabled market share to be increased and ever larger profits to be realized. This was possible due to the very large size of the ore body and its high grade - averaging 2.7% copper from startup through fiscal 1997. The situation has now changed: ore grade is falling rapidly and is projected to be only 1.55% by 2003. Since revenue is directly proportional to ore grade, while costs are proportional to quantity of ore processed, profits will begin to fall dramatically. The Phase IV Expansion Project is intended to forestall this drop in profits by increasing ore processing capacity by over 85%.The Phase IV concentrator is designed for a nominal capacity of 110,000 MTPD and the key to achieving this value is through the proper design of the grinding circuit. This paper presents the general design criteria for the grinding circuit, as well as a description of the facility.INTRODUCTIONThe Phase IV Expansion Project consists of a new copper concentrator located 8.5 km south of the existing operations, a new tailings disposal and water reclaim system, a new concentrate slurry pipeline to the coast, and added concentrate handling capacity at the port of Coloso. The new concentrator has a nominal capacity of 110,000 tonnes per day (MTPD), compared to the existing concentrator’s capacity of 127,500 MTPD. The Laguna Seca concentrator is based on using the largest and most efficient ore grinding mills now available.The concentrator has been designed for a 110,000 MTPD nominal capacity. The process design criteria for the Phase IV project were established from in-house operating information and from test work. Unlike a green field project, Escondida already had an operating plant and it processes ore from the same pit that feeds the Phase IV plant. It is expected that the current mineralization will be similar for the first 6 years of operation of the new project. Therefore, some of the current plant operating conditions were incorporated directly into the design criteria."

Jan 1, 2004

By Xuanxue Mo, Zengqian Hou

"Yidun Island Arc in Sanjiang Region is one of the important Kuroko-type volcanogenic massive sulfide deposits (VMS) districts in southwestern China. Tectonically, the region is situated in the eastern portion of the Tethys orogenic belt, and is a late Triassic extensional island-arc. The island-arc underwent earlier arc construction, intra-arc rifting, later arc construction and backarc spreading during its evolution and formed a complete trench-are-basin system, i.e., the Ganzilitang suture zone, forearc basin, outer are, intra-arc rifting zone, inner arc and back-arc basin from east to west across the island-arc.Kuroko-type VMS deposits and occurrences discovered so far are limited to within the intra-arc rifting zone of the Yidun Island Arc and tend to occur in groups or clusters distributed in separate faultbound basins; e.g., Zengke, Gacun and Xiangcheng basins, in which submarine volcanic rocks, especially bimodal volcanic suites, were extensively developed. The VMS deposits formed in the waning stages of volcanic eruption in the late Triassic and are hosted in the uppermost section of acidic volcanic rocks (rhyolitic-dacitic) within a bimodal suite. The orebodies are associated with these host rocks: rhyolitic-dacitic pyroclastic rocks and exhalites and chemical sedimentary rocks.All VMS deposits in Sanjiang are of the Zn-Pb-Cu type. The architecture of the deposits is twofold, consisting of concordant lenses and layers of massive sulfides and an underlying discordant stockwork. All deposits show metal zoning. The hydrothermal alteration related to mineralization is strong and asymmetrical, and is found dominantly within the stockwork zone and host rocks surrounding the ores. There are two alteration patterns: (1) chloritization - sericitization - silicification from outer sides to core of the alteration pipe; and (2) silicification + sericitization - silicification + carbonate from the lower to upper part of the alteration pipe.The mineralization temperatures of ore-forming fluids vary in the range 200°C to 335°C. Thermal evolution of the fluids displays temperature profiles that first increase and then decrease with progression of mineralization processes. The majority of black-ore minerals (Groups I and informed during intensifying stages of hydrothermal activity, and the majority of semi-yellow-ore minerals (Group III) formed during a thermal maximum. There followed the formation of fine-grained black-ore minerals (Group IV), which interacted with barite layers during decreasing temperature phases.Oxygen and hydrogen isotope studies show that the sources of ore-forming fluids for the Kurokotype VMS deposits are two-fold: seawater and magmatic hydrothermal solutions, represented by the Kuroko deposits in Japan and Kuroko-type VMS deposits in Sanjiang, respectively. In the latter case the hydrothermal solutions reacted with host rocks and mixed with cold seawater percolating downward, and circulated through volcanic rocks resulting in development of alteration zones and formation of ore minerals in Kuroko-type VMS deposits."

Jan 1, 1993

By A. Diaz, Minera Los Pelambres, C. G. Salinas, G. Leinenweber, F. Diaz, D. Rojas, R. Bernal, O. Jimenez

"Los Pelambres Mine (MLP) is located in the IV Region of Chile, a semi-arid region where water plays a key role in operations as a scarce resource and is vital for the sustainability of human life, animals and ecosystem. The conventional flow meters installed on pipes at MLP can fail to provide an accurate measurement due to corrosion and/or fouling on the inner wall or presence of elements in the water such as acids, salts and suspended solids. Conventional flow measurement methods require the inner diameter to be known, however it is not always possible to assess its real value due to scaling, fouling, corrosion, etc. Here we present a novel methodology to solve these problems, which consists of the measurement of flow by a method that does not require the internal area of the pipes: the fluorescent tracer dilution method. In addition, the fluid velocity can be determined by the transit time of a radioactive tracer method. With the flow rate and velocity, the equivalent area is determined and thus the equivalent internal pipe diameter as well. This methodology was applied in a recirculation pump station, for mineral processing from the El Mauro tailings dam.This work demonstrated adequate correlation between measurements from fluorescent tracers and velocity measurements from radioactive tracers, both of which lead to the assessment of the internal diameter of pipes with scaling. The results of both methods disagree with the data provided by the flowmeter installed on the line due to its miscalibration. This information is useful in validating and correcting the information provided by online flowmeters of all water and solutions transport processes in filled pipes.INTRODUCTIONPresently, the need to optimize water resources is increasingly ever important, due to various reasons such as water scarcity, community empowerment, an increased use of water for mining processes and environmental considerations. Taking into account those main considerations, Los Pelambres Mine decided to focus on water conservation to avoid losses of this vital element. They decided to demonstrate that all of the systems that used water (flow meters, pipes, pumping stations, lagoons, etc) were in good condition and that no evitable loses of this important resource occurred. A plan was proposed to conduct a “hydraulic assessment” of fluid flux and water speed at different points and courses at the mine, with the purpose of obtaining hard data to support, verify and correct the information provided online from specific instrumentation dedicated to those purposes. The final goal was to manage the water resource basin in a sustainable way, based on cross-checked information. The chosen points are representative of the processes present in the mine, such as recirculating water stations at different operating conditions and surface water courses, where the fresh water capture systems operate."

Jan 1, 2016

By M. Specht, D. Pörzgen, W. Lorenz, A. /. Buhr, R. P. Racher

The introduction of the near net-shape casting process at CORUS Staal IJmuiden in January 2000 required changes of secondary metallurgy processes including a development towards more aggressive slag compositions in the steel ladle. Therefore the steel ladle lining has been changed from fired andalusite bricks to magnesia-carbon bricks and, most recently, to fired spinel bricks to withstand the severe slag conditions. In comparison to the andalusite bricks the new steel ladle linings have a higher thermal conductivity. This requires the capability to keep the lining warm by ladle preheaters to sustain the overall thermal stability of the steel ladle in case of interruptions during hot cycling of the ladles.

Jan 1, 2004

By Bernard Tougas, Franco Chiesa, David Levasseur, Bernard Duchesne

"In the present paper, the optimization of a tilt poured permanent mold will be carried out using filling and solidification modeling. This exercise resulted in 3 modifications of the initial mold design which was based on the foundry experience. The optimization provided a 20% improvement in the yield while increasing the output from 10 to 15 castings per hour.In a subsequent study, the value of the critical fraction solid of AlSi7Mg (A356) alloy was verified by radiographic analysis of the castings produced in the first 5 cycles of a run, which are necessary to bring the mold to a dynamic thermal equilibrium."

Jan 1, 2014

By Randolph R. Dreher, Michael L. Schreder

"In recent years, FFE Minerals has designed, installed and commissioned several large grinding mill circuits. This paper discusses the issues related to the erection and commissioning of large grinding mill circuits. The three circuits discussed are Collahuasi in Chile, Minera Los Pelambres in Chile, and Century Zinc in Australia. These circuits include large SAG and ball mills with both gear and gearless drive arrangements, as well as, both trunnion and shell supported mills. Aspects of these features are discussed with respect to their impact on installation and commissioning. While the normal challenges of mill erection and start-up were experienced, there were also a few unexpected challenges encountered partly due to the large scale of the equipment. An overview of the equipment and design ratings of these circuits is also provided.COLLAHUASIOverviewThe Collahuasi mills were started-up in November of 1998. The site is located in the Andes Mountains at an elevation of 4300 meters. The grinding circuit includes two lines featuring one SAG mill and one ball mill for each line. The circuit features a recycle conveyor around the SAG mills with provision for adding a pebble crusher in the future. The design tonnage of the grinding plant is 60,000 MTPD with an ore BWI of 10.5 kWh/MT.The SAG mills are 32’ x 15’ (1 3’ EGL) with 10,800 HP drives. The drive arrangements are dual pinion through pneumatic clutches. The mills are driven by low speed synchronous motors with CCV variable speed drives. The SAG mills are trunnion supported and use hydrostatic lubrication. Feed to the SAG mills is via a rock-box type feed chute on a cart. The mills discharge on to trommel screens with a bucket wheel to remove the oversize.The ball mills are 22’ x 36.5’ (36’ EGL) with 12,500 HP drives. The drive arrangements are dual pinion through pneumatic clutches. The fixed speed mills are driven by low speed synchronous motors with GE Quadramatic load sharing drives. The ball mills are shell-supported and feature multi-pad bearings with hydrodynamic lubrication. The mills are fed via a rubber lined sump box with feed spout on a cart. The ball mills also discharge on to trommel screens. Twenty-six inch (26”) diameter hydrocyclones are in closed circuit with the ball mills."

Jan 1, 2001

By David Lin

"Modal data from Red Dog Main Pit ores were collected and analysed on a size-by-size basis. The Main Pit data were compared to data from composite samples of Red Dog Aqqaluk ores. The data revealed that a large fraction of the sphalerite in the Aqqaluk baritic ore was tied up in sphalerite/galena binaries. This provided an explanation for its poor leadlzinc selectivity compared to Main Pit ores. The Aqqaluk vein ore exhibited levels of sphalerite/galena binaries comparable to that of Main Pit ores resulting in comparable lead/zinc selectivity.An attempt was made to correlate the modal and metallurgical data for Main Pit stockpiles. It was found that there was moderate correlation between the percentage of sphalerite locked in binaries with galena in the <C5>C6 size fi-action and sphalerite deportment to the leadconcentrate.INTRODUCTIONTeck Cominco’s Red Dog Mine in northern Alaska is one of the richest zinc districts in the world. Red Dog Mine has been in operation for over ten years and produces nearly 1 million tonnes of zinc concentrate per mum. Red Dog Mine is an open pit operation and current mining is conducted in the area known as the Main Pit. The Main Pit contains proven reserves of about 41 900 000 tonnes of ore grading 19.2% Zn and 5.2% Pb (Cominco 2000). To the north of the Main Pit is the Aqqaluk deposit. It contains probable reserves of 56 100 000 tonnes of ore grading 16.6% Zn and 4.1 % Pb. After the Main Pit has been exhausted, the Aqqaluk deposit will be exploited.The Aqqaluk deposit consists of three main geologic ore types: baritic, siliceous and vein. The siliceous ore type is dominant, representing 64% of the mineralisation. Composite samples of these ore types were created from drill core and batch flotation tests were performed on them. The flotation tests indicated that there were significant metallurgical differences between Main Pit ore and the Aqqaluk siliceous and baritic ore. The siliceous and baritic ores were found to suffer from poor lead/zinc selectivity (Lin 1999, G&T 1999). It was suspected that there were problems with the original Aqqaluk composite samples, thus a new set of composite samples were created and batch flotation tests were conducted again. In this set of tests, the new baritic ore still suffered from leadlzinc selectivity problems, but the new siliceous ore provided excellent metallurgical results. A summary of the flotation results is given in Table 1. Stockpile 132, which is typical of Main Pit ore, is given for comparison purposes. The mineral suite at Red Dog is relatively simple. The ore consists of galena, sphalerite and pyrite in a silicate matrix. The low zinc recoveries of the baritic ore were largely due to sphalerite losses to the lead concentrate."

Jan 1, 2002

By C. A. Pickles

Nickeliferous limonitic laterite ores contain considerable free moisture. In this research, the application of microwave radiation for the drying of this ore was investigated. The effects of sample mass, initial moisture content and porosity on the microwave drying rate were studied and the results were compared to those obtained with conventional drying. Microwave drying rates of two to three times the conventional values were achieved. Further enhancement of the microwave drying rate was realized by increasing the flow rate of air over the sample or by operating at reduced pressure. The high microwave drying rates were attributed to the inverted temperature gradient which resulted in internal heating and boiling and this in turn promoted movement of the water, both as liquid and vapour, to the surface.

Jan 1, 2005

By R. Niechcial

As populations grow and industry expands, the limited fresh water resources available are increasingly under stress. This situation creates conflict between communities and industry; and the sustainability of both is threatened. The symbiotic relationship between community and industry highlights the need to develop innovative solutions to these water shortages. The sea may hold the key to providing the resource to permit the development of industry, the sustainability of communities, and the protection of the dwindling legacy water resources around the world. Desalination technologies have developed to where it is now economically viable to create industrial and potable water quality from seawater. Nowhere is this development more important than in the arid region of Northern Chile, where high copper prices have encouraged a boom in mine development.

Jan 1, 2007

By C. A. Campbell

"There has been a significant reduction in maintenance hours and improved performance by maintenance crews at the MacLeod mine since the introduction of a Maintenance Control system which includes the use of maintenance standards. This paper deals with the steps taken to develop and implement the program. The objectives of the program and the organization and training of the control group are outlined. The work-order system, standards application, classification of work and the preventive maintenance procedures will be discussed.All maintenance information is processed on a Model 360-20 IBM computer, which turns out maintenance records and control reports for management action. Information in these reports, and reasons for reporting, will be discussed and the benefits resulting from the program reviewed."

Jan 1, 1973

By E. Nurminen

Thermal transport properties of copper flash smelting flue dust have been investigated. Such values of the dust are needed to correctly model the process and to optimize its heat recovery performance. Dust accretions on heat recovery boiler walls may have a significant influence on the boilers heat transfer efficiency. Measurements of the thermal transport properties have been made for industrial flue dust and for pure sulphate components. The measurements have been conducted at temperatures up to 400 °C and the effect of porosity on these properties has also been investigated. The results indicate that the flue dust and the sulphate components are effective thermal insulators and the dust build-up on the boiler walls is likely to greatly decrease the heat transfer efficiency of the boiler.

Jan 1, 2007

By M. B. B. Research Council of Alberta Crockford

Introduction Kootenay strata of Lower Cretaceous age contain much of the highest rank coal produced in Alberta. These strata outcrop in the foothills and mountains of southwestern Alberta and southeastern British Columbia, and the economic value of the coal seams contained in them was evident to the earliest explorers, who refer co them in their journals. Lacer, investigation of the .coal measures was undertaken by prospectors and by a succession of geologists, most of whom were in the employ of the Federal government, but some acted for private interests. Surveys by these men proved chat foothills and mountain regions hold immense quantities of high-grade coal within easy reach of transportation facilities, and their conclusions have accelerated the development of the coal-mining industry m Alberta. Among geologists who have contributed much to our knowledge of the region are J. M. Dawson, G. M. Dawson, R. C. McConnell, D. B. Dowling, J. D. Mackenzie, B. Rose, J. R. Marshall, B. Rose, J. R. Marshall, B. R. McKay, J. A. Allan, and J. L. Carr. The present paper is to a great extent a compilation of the work of the above men and of several others who have investigated the area lying between Bow river and Crowsnest pass. Space does not permit a list of all the sources of information so chat only chose of prime importance are given in the text. Data for the map and ?cross-sections of Figure 1 were taken from the following published maps of the Geological Survey of Canada: Cascade Coal Basin, Pub. 933; Canmore, Maps 322 and 323; Upper Elk River and Upper Highwood Rivers, Pub. l980; Blairmore, Pub. 1584; Southfork Coal Area Map l03A; and of the Research Council of Alberta: Highwood-Elbow Area, Map 20; and Ribbon Creek Area, Map 21. In some cases, the cross-sections have been simplified or otherwise altered, and for these revisions the writer cakes full responsibility. The stratigraphic sections of Figure 2 have been taken from published reports of the above mentioned organizations. The area covered in this paper is shown in Figure l. It is wholly within Alberta, and reaches from township 5 to township 27 and from range 1 co range 11, west of the fifth meridian. Its location is about fifty miles west of both Calgary and Lethbridge. Topography of the area ranges from foothill on the east to mountainous on the west. In this paper&apos; the foothill region is considered to be chat which lies immediately east of the most easterly mountain ranges, such as Livingstone and Highwood. There are two principal coal mining districts in the area, one served by the main line of the Canadian ?Pacific railway and centring about Canmore, the other by a branch line of che same railway and centring about Bellevue, Blairmore, and Coleman.

Jan 1, 1949

By N. Behnood, W. Pascheto

"Laboratory wear tests are important tools that can be used for the evaluation of materials for wear applications and mitigation of wear problems in the mining industry. However, laboratory test parameters must be fully characterized and test results must be carefully interpreted if a material selection is to be made. Failure to do so may lead to erroneous conclusions. Suitable lab-oratory tests are valid only if they reflect the field conditions to which materials are subjected. Therefore, it is important to know, in detail, the field conditions, as well as the wear test techniques being considered. It is important to recognize the limitations of the various wear tests and the wear test data published in the literature. This work will review present wear testing technology, including the various wear tests avail-able, wear test equipment and test limitations. Several wear test procedures will be related to common equipment used in the mining industry.IntroductionThis paper will concentrate on non-lubricated wear mechanisms, because they are the most costly to the mining industry. Very frequently we are faced with the task of selecting materials for wear applications or improving existing systems that are giving poor performance. There are plenty of examples in the literature of practical wear cases and ranking of materials for wear applications. It is also very common to find materials manufacturers’ data -sheets listing wear tests results by comparing their materials performances against those of competitors. Much of the published wear data lack the description of the type of wear test, test parameters and the type of wear mechanism to which the data should be applied (if any).Before considering wear test data for a specific problem one should ask which type of wear mechanism is involved? What type of test and what test parameters were used to produce the results? Even if the type of wear tests and parameters are known, how accurate and useful are the published wear data? How are the results related to a particular type of wear? It is important to point out that even the standardized wear tests, such as those in ASTM standards, have limitations. Such limitations are recognized and clearly spelled out in the standards themselves. Basically, wear tests may lead to erroneous results if the test is not able to repro-duce the same wear mechanisms encountered in the field. Therefore, the use of published results may be helpful, as a starting point, but may be of little value for a final material selection.This work will discuss the main types of non-lubricated wear mechanisms encountered in the mining industry. In addition, it will discuss the many wear tests available and their correlation with the various types of wear mechanisms. The limitations of several standardized wear tests and the limitation of using published wear data will also be discussed."

Jan 1, 1997

By E. Vesely, A. Saxena

"SAG mill liners are designed for protecting the mill shell and providing lifting power for ore charge and grinding media. Due to the impacts from the charge and the grinding media, the liner experiences dimple, plastic deformation, strain hardening, fatigue, peening and final failure. Because of the collisional environment directly measuring such dynamical loads is extremely difficult if not impossible. In this study we tried to evaluate the liner failure risk by simulating the collisions of solid particles with mill liner using Discrete Element Method (DEM). DEM simulation has been proved to be a very useful tool in evaluation of granular flow and its impacts on the solid structure. But there are certain limits in DEM coherently, such as the number of solid elements, the computer runtime, etc. Here we first present the general feature of the particle-liner collision in terms of impact force and collision energy. Then the effects of parameter selection is discussed. Our simulations show the fatal collisional event of huge impact force is very rare and the collisional events of low impact is much more frequent. The fatal event may contribute most to the liner failure. The rarity of the fatal events may be missed in a short runtime simulation. This technical challenge combined with lacking of criterion to evaluate varying impact loads in fatigue problems may further complicate the evaluation. Should we use the largest impact force alone or we should use the more frequent events is an open question and requires more effort. In order to evaluate the quality of liner design, we proposed a relative comparison method. In the end we show the implication and application of this method in liner optimization by a work example. In particular, the effects of the charge level of grinding balls and their size on the operation performance is presented.INTRODUCTION Grinding is one of the most important and expensive steps of mineral processing. A variety of grinding mills such as rod mills, ball mills, semi-autogenous (SAG) mills and autogenous (AG) mills are being utilized for comminution of mineral ores (Gupta & Yan, 2016). Up to today, SAG mills and AG mills have been widely used to reduce operation costs and increase throughput. In an AG mill, a rotating drum throws larger rocks of ore in a cascading motion which causes impact breakage of larger rocks and compressive grinding of finer particles. Unlike AG mills, SAG mills use steel grinding balls to break ores of size quite small such that they cannot be easily broken in AG mill. SAG mill liners are designed for protecting the mill shell and providing lifting power for ore charge and grinding media. Due to the impacts from the charge and the grinding media, the liner experiences dimple, plastic deformation, strain hardening, fatigue, peening and final failure. Quality and performance of SAG mill liners play a fundamental role to enhance efficiency of grinding mills, because failure of liners is the major cause for unexpected breakdown (Banisi, Hadizadeh, Mahmoudabadi, & Eilkhany, 2006)."

Jan 1, 2019

In Canada and other countries, legislation dealing with accurate factual disclosure for mining projects is being expanded to include more metallurgical design information. Grinding characteristics, metallurgical recovery of contained metal and environmental hazards associated with tailings disposal will be part of the Canadian package. This paper will examine only that portion of the plant design standard practice that relates to grinding ? in SAG mills and ball mills that grind ore from as received crushed material to final ground product that is fed to downstream plant recovery processes. Since grinding plants represent a significant portion of the overall concentrator cost, accountability in grinding design should no longer be left to chance, opinion, or hidden proprietary information. This is the 21st century. It is reasonable to expect that a factual basis will be needed so that a Qualified Person (QP) reviewing the grinding mill design can understand it. That will also involve how many and what quality of samples are taken to define the characteristics of the deposit, the accuracy of the tests used to measure ore hardness and the method by which the dimensions and power of the mills are determined. If these criteria are not met, the QP may have no choice but to call attention to the lack of convincing information regarding the grinding mill design for the project. At the same time clients are expected to demand getting the correct design information at a cheaper price, results in a more timely way, and accurate design to the point where the risk of tonnage shortfalls are reduced or eliminated. Tables will be presented to show how this can be done to current standards using existing technologies. At the same time it is acknowledged that current standards are ill-defined and that to achieve consensus among those involved in SAG mill design work, it may require that a consortium funded project be set up to establish what tests and methods for grinding design are suitable to meet the new standards for metallurgical disclosure. By running parallel design methods on several major projects over a period of 5 years, the process of how to design grinding circuits will be better understood because the projects will start at the design stage, include procurement of the mills and will end with a benchmark test on the plant. Selecting the samples and the best schedule for doing test work on core samples submitted and mill design, will be discussed in this paper. The issue of completing the grinding design in time for early procurement decisions is on the critical path for most major projects. Discussions between mining engineers, geologists and process engineers are needed early in the development cycle, at the scoping study level (SS), preliminary engineering assessment (PEA), prefeasibility study (PFS), and at the feasibility study stage (FS), to ensure that proper planning for design sample selection is done. Using adequate sampling and testing methods in a timely way allows early procurement of the grinding mills and minimizes project risk.

Jan 1, 2012

By J. H. Starkey, P. A. Scinto

"In Canada and other countries, legislation dealing with accurate factual disclosure for mining projects is being expanded to include more metallurgical design information. Grinding characteristics, metallurgical recovery of contained metal and environmental hazards associated with tailings disposal will be part of the Canadian package. This paper will examine only that portion of the plant design standard practice that relates to grinding – in SAG mills and ball mills that grind ore from as received crushed material to final ground product that is fed to downstream plant recovery processes. Since grinding plants represent a significant portion of the overall concentrator cost, accountability in grinding design should no longer be left to chance, opinion, or hidden proprietary information. This is the 21st century. It is reasonable to expect that a factual basis will be needed so that a Qualified Person (QP) reviewing the grinding mill design can understand it. That will also involve how many and what quality of samples are taken to define the characteristics of the deposit, the accuracy of the tests used to measure ore hardness and the method by which the dimensions and power of the mills are determined. If these criteria are not met, the QP may have no choice but to call attention to the lack of convincing information regarding the grinding mill design for the project. At the same time clients are expected to demand getting the correct design information at a cheaper price, results in a more timely way, and accurate design to the point where the risk of tonnage shortfalls are reduced or eliminated.Tables will be presented to show how this can be done to current standards using existing technologies. At the same time it is acknowledged that current standards are ill-defined and that to achieve consensus among those involved in SAG mill design work, it may require that a consortium funded project be set up to establish what tests and methods for grinding design are suitable to meet the new standards for metallurgical disclosure. By running parallel design methods on several major projects over a period of 5 years, the process of how to design grinding circuits will be better understood because the projects will start at the design stage, include procurement of the mills and will end with a benchmark test on the plant.Selecting the samples and the best schedule for doing test work on core samples submitted and mill design, will be discussed in this paper. The issue of completing the grinding design in time for early procurement decisions is on the critical path for most major projects. Discussions between mining engineers, geologists and process engineers are needed early in the development cycle, at the scoping study level (SS), preliminary engineering assessment (PEA), prefeasibility study (PFS), and at the feasibility study stage (FS), to ensure that proper planning for design sample selection is done. Using adequate sampling and testing methods in a timely way allows early procurement of the grinding mills and minimizes project risk."

Jan 1, 2012