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By Haipeng Li, Jacob Masliyah, Barun Gorain, Jian Huang, Qingxia Liu, Zhenghe Xu, AuTec Innovative Extractive Solutions Ltd.

"Froth flotation is widely used to selectively separate one or more minerals from an ore over a wide range of particle sizes with high efficiency. Bubble–particle attachment is one of the most critical steps in flotation. The objective of this project is to demonstrate the need for an innovative dual bubble generator to improve flotation efficiency. This dual bubble generator was designed to generate two different sizes (micron size and typical flotation size) bubbles. The micron size bubbles generated on the crevices of particle surfaces in venturi type of cavitation tubes enhanced the attachment of fine particles to the bubbles in conventional flotation systems. They also acted as a secondary collector, which has the potential to reduce operation cost and improve flotation recovery. The dual bubble generator was evaluated for a double refractory gold ore with 3g/t Au, 1.5 wt% TCM (total carbonaceous matter) and 0.7 wt% sulfides. The results were compared with those obtained using a commercial bubble generator. Compared with the commercial bubble generator, the dual bubble generator showed not only a higher gold recovery, but also an improved separation efficiency, demonstrating the potential of dual bubble generator in fine particle flotation.INTRODUCTIONFroth flotation has been widely used in mineral processing and waste water treatment. However, flotation has been proven inefficient for fine particle recovery although it becomes increasingly inevitable to process fine particles with the depletion of easy processing ores. The critical problem of fine particle flotation is the low attachment of fine particles to flotation size bubbles due to their low collision rate. Based on a commonly acceptable flotation model given by R =F*[Pc*Pa*(1-Pd)], the probability of bubble–particle collision (Pc), attachment (Pa) and particles detachment from air bubbles (Pd) collectively determines fine particle recovery (R) (Yoon and Luttrell, 1986). Since Pc = (3Dp/Db) where Dp and Db are diameters of particles and bubbles, respectively, bubble size and particle size impact the bubble-particle collision in opposite directions. It is evident that the probability of bubble–particle collision decreases with decreasing the size of particles, leading to a low recovery of fine particles. In this case, reducing the bubble size and/or increasing the apparent size of particles by fine particle aggregation are clear means to improve fine particle recovery."

Jan 1, 2016

By Horace Freeman

"IN THE writer's opinion, the most important industrial re-search problems in Canada concern development of technology for the treatment and commercial utilization of the recent discoveries of v.ast quantities of easily concentrated iron ores in both eastern and western Canada. They exist in both magnetite and hematite forms. The subject is doubly important because of the lack of metallurgical coking coal in Canada. Methods for utilizing our lower grade eastern and western coals for reduction purposes must be developed. We are fortunate in our supplies of oil and gas, which can supply the heat requirements for processing or for thermal electric plants, which are now competitive with hydro-electric plants in the industrial areas. These are among the reasons which have prompted the writer to continue the development of the co-current rotary kiln direct-reduction process outlined •in his report to this Institute at the 1956 Annual Meeting ( 1) in the face of the scepticism which has surrounded the numerous costly failures in 'sponge' or 'direct' iron production. The work involved in bringing the concentrating ores of Canada to the metallic state involves, firstly, concentration of the ores; secondly, preparing the concentrates for reduction; thirdly, reduction of the 'reconstructed' ore; and finally the steel making process. These briefly will be dealt with in order, giving emphasis to the most important of these steps, the reduction process which is the main subject of this paper."

Jan 1, 1959

By R. Grau

"After commissioning and start-up of the first 500m3 TankCell® flotation cell in 2014, the over 300m3 mechanical flotation cells have earned their place in large-scale flotation operations. These 500 to 630m3 cells, designed for projects with large throughputs, are proven to provide savings in project capital and operational expenditure through savings in foot print, energy consumption, and less equipment to install and maintain. Addition to savings in different phases of a project, these cells provides operational flexibility and has shown improvements in metallurgical performance. In this paper a case study from Kevitsa TankCell® e500 installation and Buenavista del Cobre TankCell® e630 installations will be given.INTRODUCTION After development (Grönstrand and Bourke, 2008), characterization (Morales et al. 2009; Yanez et al. 2009; Grönstrand at al. 2009), validation (Elgueta et al. 2009; Coleman and Dixon, 2010), and more than 350 industrial installations of the Outotec TankCell® e300 flotation cell, the well proven energy efficient TankCell® product family introduced the TankCell® e500 forced-air flotation cell late June 2012 (Outotec.com, 2012). The introduction of the 500 m3 flotation cell followed by introduction of a 630 m3 flotation cell, TankCell® e630, in October 2014 (Outotec.com, 2014). These large flotation cells are designed for projects with high throughputs where the number of cells needed for operation with smaller equipment would become large. The benefits of this size of flotation cells comes from the lower capital expenditures due to lower equipment costs, savings in plant footprint, less installation work with less auxiliary equipment, lower energy consumption, and less units per installation resulting in less components, spare parts and maintenance.The first TankCell® e500 was commissioned and taken into operation in October 2014 at FQML Kevitsa Cu-Ni-PGE concentrator, nowadays owned by New Boliden. The first TankCell e630 was taken into operation in January 2018 at GrupoMexico’s Buenavista del Cobre Cu-Mo concentrator. The start-ups of the first TankCell® e500 and TankCell® e630 followed with test work where the hydrodynamic performances of the cells were characterized and metallurgical performance studied. The results of the TankCell® e500 test work were presented in detail by Mattsson et al (2015a; 2015b) and TankCell® e630 by Grau et al. 2018. In this paper the metallurgical improvements achieved with the large cell installations will be presented."

Jan 1, 2019

By F. L. Casey

"Part 1 – Published Papers Baria, G., and Boshkov, S., ""Insights into Undercuttingin Block Caving"", Proc. 5th Rock Mech. Symp.,Mines Br. - Information Canada, 41-58, 1970.Barron, K., Coates, D. F., and Gyenge, M., ""ArtificialSupport of Rock Slopes'', Mines Branch ResearchReport R228, July, 1970.Barron, K., ""Criteria for Brittle Fracture Initiation inand Ultimate Failure of Rocks and Their Applicationto Fracture Zone Prediction"", Proc. 2ndCongr. Int. Soc. Rock Mech., Belgrade, 1970, 3-37.Bauer, A., and Calder, P. N., ""Projectile Penetration inRock"", Proc. 5th Rocle Mech. Symp., Mines Br. -Information Canada, 157-170, 1970.Bauer, A. M., ""Site Development and Rehabilitation ofPits and Quarries"", Canadian Mining Journal,Vol. 91, No. 7, 77, July, 1970."

Jan 1, 1971

By R. Yost

"This paper describes a case study that illustrates how detailed geological engineering results were communicated to address a range of stability challenges in a producing mining environment. Instead of using standard geological engineering terminology, findings and recommendations were communicated as mine design options and mining responses to accommodate possible slope instabilities and associated risk. The resulting medium- to long-range mine plan integrated the potential slope instabilities and associated mining responses to provide a higher probability of planned resource extraction. It also reduced the potential for long-lasting production and processing delays.RÉSUMÉ Cet article décrit une étude de cas illustrant l’intérêt de la communication de résultats détaillés de géologie appliquée pour résoudre un éventail de difficultés relatives à la stabilité dans un environnement minier en production. Plutôt que d’utiliser une terminologie classique de géologie appliquée, les résultats et les recommandations ont été communiqués sous forme d’options pour la conception d’une mine et de réponses dans le contexte minier permettant de surmonter les éventuelles instabilités des pentes et les risques associés. Le plan de mine sur le moyen à long terme qui a résulté intégrait les instabilités potentielles des pentes ainsi que les réponses connexes dans le contexte minier afin de renforcer la probabilité de l’extraction des ressources prévue. Il réduisait également la possibilité de retards durables dans la production et le traitement.INTRODUCTIONSlope failures in an active mining operation are unscheduled but expected events, in the sense that the geotechnical design often assumes the potential for slope failure but cannot predict exactly when a failure will occur. Unfortunately, the geotechnical engineering cycle—characterization, slope design, displacement monitoring, instability management, and failure remediation—that is necessary to manage slope-failure risk is not always well known or understood outside the geotechnical engineering profession. The first introduction many personnel have to geotechnical engineering is when a slope failure starts to develop and appears to threaten the safety and livelihood of their workplace.At that point, the task of communicating the risk management of slope failure falls to the geotechnical engineer, who must summarize analytical methodology, design concepts, monitoring trends, and analysis results, frequently to an audience with limited exposure to the geotechnical field. All too often, the response has been to present a risk-management plan in the vernacular of geological engineering— using terms such as factor of safety (FOS), pore-pressure reduction, and slope unloading—instead of expressing the problem and solution in more readily understood mine production terms."

Jan 1, 2017

By G. D. Garland

"IntroductionALTHOUGH the presence of rock salt in the Carboniferous basin of northern Nova Scotia has been known for at least one hundred and twenty years, and salt has been mined at Malagash continuously since 1919, certain characteristics of the deposits make exploration by drilling or surface examination difficult. The surface rocks of the basin are, in general, of Pennsylvanian age, while the salt occurs in the Mississippian Windsor group. The latter rocks are brought to the surface only along anticlinal folds, or as irregular fault blocks. Because of the limited areal extent of these Windsor exposures, and their complicated internal structure, geophysical surveys, especially gravimetric, can be of considerable aid in outlining the more favourable areas.The present paper describes the results of recent investigations by the Dominion Observatory, in cooperation with the Nova Scotia Department of Mines. It includes a regional study of that section of the Cumberland basin lying between Springhill and Malagash ( Figure 1), and a much more detailed survey of the immediate vicinity of the Malagash deposit itself. This deposit had been studied by Miller (6, 7) with the torsion balance nearly twenty years before, and a direct comparison between the results given by the two types of instruments is therefore possible."

Jan 1, 1955

By R. H. Duthie

As at any other mine in Canada, grade control procedures are used at Steep Rock Iron Mines (1) in order to ensure that concentrator and pellet-plant operator s have a uniform feed so that they can manufacture a pellet to suit buyers' specifications and (2) to maximize ore recovery so that as little as possible finds its way to the waste dump or is downgraded by contamination. At Steep Rock, material grading 40% to 66 % Fe is considered ore. The ore may contain up to 10% sulphur. These ranges create six different stock pile types, with the possibility of more if large concentrations of arsenic are encountered. Although grading and mining techniques used to accomplish these ends are fairly standard, there is an appreciation and willingness by hourly and staff pit personnel to make grade control effective. This produces vertical and horizontal communication, which is necessary for success in this field. At Steep Rock, the waste-to-ore ratio is greater than at any other iron ore mine in Canada. Also, a high percentage of the ore mined is direct pellet feed. For these reasons, .grade control is very important.

Jan 1, 1977

By N. B. Brown

ABSTRACT The effect of a low4emperature stress relief at 232.2°C. (450°?F.) on the fatigue properties of shot-peened SAE. 1080 steel has been investigated. Specimens of the steel were first annealed. One half of the steel bars were then normalized and the other half were water-quenched and drawn. Specimens of the steel with each heat treatment were tested in tensile, notched bar impact, and fatigue. The fatigue specimens were test in air and water in R. R. Moore high-speed rotating bending machines in the following conditions: un-peened, peened, and peened-and stress-relieved at 232.2°C. ( 450°F.) The 'endurance life' and fatigue properties of specimens given a stress relief heat treatment after shot peening were superior to those of specimens given a smooth machine finish or shot peened. INTRODUCTION THIS investigation was initiated to obtain preliminary information on the effect on the fatigue resistance of shot peening the machined surface of a high-carbon steel similar in composition to that used in hollow drill steel. The data obtained in this investigation could be applied in analysing the application of shot peening hollow drill steel shanks. It is well known that the 'endurance life' and fatigue limits of steel are greatly ?improved by shot peening. References to this in the literature are numerous.

Jan 1, 1951

By Burns Sutherland

Although some mine hoisting systems incorporating steel wire ropes on drum hoists experience completely dependable performance on the hoist ropes for many years, other rope records illustrate an erratic behaviour pattern and, as such, become a source of concern to the operator. This paper describes the causes of the difficulties most commonly encountered and incorporates methods of providing preventative or corrective maintenance. When such a program is utilized wisely, within the allowable limits of shaft time available, it can be the means of avoiding many unforeseen circum-stances and of reducing operating costs, as well as rope costs, to a mini-mum.

Jan 1, 1970

By H. Sano

Most of the dust generated from the copper smelting process in Chile has been stored after the stabilization by hydrometallurgical process because it contains high concentrations of arsenic. However, in recent years, the dust generation has increased because of degrading the quality of concentrate. In addition, the environmental regulations become stricter. On the other hand, valuable metals such as copper and zinc are contained in the dust at high concentrations and it is desirable to recover them. In this study, the effect of dust recirculation to the smelting process was examined in order not only to decrease the amount of dust but also to recover copper. Dust generation and the distribution of arsenic, lead, zinc etc. among the matte, slag and gas phases were evaluated as a function of the amount of recirculated dust, partial pressure of oxygen and temperature. It was found that the direct dust return to the smelting process was quite effective for the recovery of copper and the reduction of dust generation, but the acceptable dust amount was limited by the produced matte quality.

Jan 1, 2007

By K R. Brentley

"Tshepong Mine, Harmony’s largest gold producing mine, is situated in the Free State portion of the Witwatersrand Basin, east of Odendaalsrus and north of Welkom, South Africa. The Basal reef is a narrow tabular conglomerate and is the main gold bearing ore body. The strata strikes mainly in a northsouth direction with an average dip of 22 degrees. Currently mining takes place at depths of between 1 690m and 2 150m below surface. The Basal reef unit consists of a conglomerate ranging between a few and 30cm in thickness. Some 80-90% of the gold occurs in the lower portion of the conglomerate. Directly above the conglomerate is a quartzite placer unit, the Basal quartzite, which is a clean, hard competent rock and varies in thickness between 50cm and 200cm. The Basal unit is overlain by the Khaki shale which can vary between 30cm and 500cm in width. It is weak and incompetent khaki coloured chloritic shale.A method of stoping, termed “undercut”, is practiced in order to remove the lower 15-20cm of the gold rich strata. The method entails removing this portion along with some 70-80cm of footwall host rock which is a strong competent quartzite. The hard competent quartzite overlying the conglomerate is left in-situ to form a competent hangingwall which can stabilize and prevent exposure of the weak Khakishale. This method of extraction was developed through trial and error and has been used reasonably successfully since its inception in the early 1960’s where the method was developed to extract the Basal reef at the Western Holdings Mines. Recently prospect drilling and a number of localised hangingwall failures indicated that the residual quartzite beam could be less than 60cm and in some instances as thin as 30cm in certain areas of the mine. The result of this is a less stable hangingwall which not only poses a safety risk to workers in these areas but also had the potential of locking up some 840 000 Tonnes of gold bearing ore. At the present gold price this amounts to revenue of approximately ZAR1.5 billion (U.S. $143 million).This paper discusses the method of “undercut stoping” and existing practices in place at Tshepong Mine. It also explores new initiatives such as the use of a simple freely-supported elastic beam solution to perform back analysis, on-site data capturing of beam thickness and support geometries in order to develop empirical design charts and numerical modelling to assist in the verification of the empirical design method."

Jan 1, 2015

By Larry M. Southwick

There have recently been executives at major metals companies who have recommended that Greenfield Projects not be pursued. Greenfield includes not only new geographical locations, but also new technologies and new types of feed materials. In the middle part of the 20th Century, two such projects were successfully commercialized to recover nickel from Cuban lateritic ores. One project (at Nicaro) used the Caron ammonia-ammonium carbonate leach and the other (at Moa Bay) a high pressure acid leach. How both of these projects dealt with these Greenfield issues will be reviewed, based on the original reports that described the research and development of the plants. This study will include a review of the critical ore characterization and sorting issues, as well as the extractive metallurgical, product recovery and equipment selection and sizing problems and how they were solved at each stage of project development, from laboratory through one or more pilot scale plants to start up and operation. In one case, a major revision of the plant was made after several years of operation to correct operating, equipment selection and materials of construction problems that hindered economical operation. These descriptions will provide a guide through the complicated and critical issues that in recent times have caused many companies to give up on similar development. Even with the more advanced analytical and computational tools available to today’s mineralogists, engineers and metallurgists, the basic concepts with which these projects successfully addressed their sets of problems are still required. In addition, upper management, now perhaps further removed from hands-on experience than was common then, will see how complicated problems require intense and detailed effort to avoid failure in the field and capital blowouts. Build it and we will make it run, kicking the can down the road and borrowing operating and design concepts incorrectly on technological issues, or nine year olds on a sugar high making financial decisions are not philosophies by which to succeed with Greenfield Projects.

Jan 1, 2014

By D. Rylander

The operation of Quarry and Aggregate sites are similar to factory production, since it contains sequential production processes, tasks and activities to produce the output product. Compared to the plant though, the quarry processes are generally not synchronized and controlled towards the overall throughput of the site in real time. Some quarries control parts of the production but do generally not utilize real-time technologies for the whole site and all its activities. This fact indicates a general improvement potential in increased productivity at quarry sites, but also unsolved challenges for the same reason. The main contribution of this paper is the presentation of a Lean based method for how to describe the processes to identify control improvement potential within a site. The aim of the identified improvements is to increase overall site productivity by optimizing site, fleet and machine utilization towards the overall throughput, and minimizing operational expenses and inventories. Further the paper exemplifies the method?s usability with field studies at operational quarry plants successfully identifying and quantifying potential wastes and improvements. In addition the identified productivity improvements based on increased control and automation indicate challenges and needs in wireless communication and sensing technologies.

Aug 1, 2013

By Suzie Nantel

Crystalline igneous rocks, known commercially as granite, are exploited in Quebec f rom more than twenty-five quarries for building, ornamental and monumental purpose$. Quebec is the main Canadian producer of construction granite, accounting for nearly 90 per cent of total production. Jn the last three years, this industry has experienced an important growth due to improved marketing and use of modern equipment in rock-cutting and polishing. Jn /983 a 35 per cent sales increase is forecast. The main rock varieties extracted are the following: porphyritic pinkish grey granite and green charnockite from Riviere-dPierre, mahogany brown granite and black anorthositic rock f rom the Lac Saint-Jean area, fine-grained pink granite from Guenette, coarse-grained brown quartz monzonitefrom SaintA lexis-des-Monts. All these rock types occur in the Grenville tectonic province whereas a medium-grained, light grey granite, Devonian in age, is extensively being quarried in the southern part of the Appalachians. In the Superior province a greenish black diabase and a deep red granite are extracted. Search for new varieties and deposits is actively being carried out by prospectors and by the minis/ere de /'Energie et des Ressources du Quebec following growing demand for granitic and gabbroic rocks as dimension stone.

Jan 1, 1984

By A. McLean, Q. R. Yang, Y. D. Yang, G. F. Zhang, P. Wu

A considerable amount of waste slag from the pyrite roasting process is discharged every year. Recovery of iron from the waste slag is of great interest for comprehensive use of mineral resource, reduction of environment impact and improvement of economical benefit to related companies. The objectives of the present work are focused on: (1) Compare various procedures for recovery of iron from the waste slag and select a best procedure for industrial trial which is roasting of the waste slag under reducing condition followed by magnetic separation; (2) Investigate the optimum conditions for maximum recovery of iron from the waste slag. The experimental result shows that under the treatment condition found in this work about 36 to 40% of the iron oxide was recovered from the waste slag, where the iron content in the concentrate is 57%. The total recovery ratio of iron, up to 70%, from the waste slag was achieved. After the treatment, sulphur content in the waste slag was reduced significantly and gangue materials, such as SiO2, Al2O3 and TiO2, were reduced effectively.

Jan 1, 2011

By Peter Chmara

The measurement of dust concentration in Ontario mines since 1926 has been accomplished by konimetry, based on South African experience and methods. The introduction of a voluntary program of semi-annual surveys of air conditions at all operations throughout Ontario mines created a need for an instrument that would assess konimeter spots rapidly and accurately. The development of the Electronic Scanner, it is felt, answers this need. A program whereby all konimeter spot samples taken at Ontario mines will be counted at the MAP AO field offices in North Bay is described.

Jan 1, 1969

By S. B. Ballantyne, D. R. Boyle

"Detailed studies have been conducted on the dispersion of uranium in stream waters and sediments around various types of mineralization and hitherto unexplained anomalous areas in the Okanagan Valley and Highland region of south-central British Columbia. These studies were part of the jointly funded and planned Federal-Provincial Uranium Reconnaissance Program of the Geological Survey of Canada and the British Columbia Ministry of Energy, Mines and Petroleum Resources. Statistical analysis of regional data indicates that U in stream waters and sediments varies considerably for different rock types, thus affecting data interpretation. In addition, the data demonstrate a poor correlation between U in stream waters and their associated sediments which can be largely accounted for by variations in climate and water and sediment composition. Regional trends in the distribution of U can be explained in terms of the above secondary factors as well as primary metallization phenomena.Significant correlations between U and F, and U and Mo can be explained by certain magmatic and mineral-forming processes. U shows little correlation with other base metals.The dispersion characteristics of U in the vicinity of Miocene "" basal type "" mineralization ; uraniferous pegmatite terranes, anomalous lineaments in granitic terranes and high-background volcano-sedimentary areas are discussed. Highly anomalous U concentrations in waters and sediments may not always be indicative of mineralization, and guidelines for interpretation require a sound knowledge of the geological and secondary processes operative in the area."

Jan 1, 1980

By Denis Yaychuk, Gary Billingsley

The economic eva luation of a mineral property or mining venture should include the quantification of ri k as part of the analy is. The re ults of such an analysis provide the decision-makers not only with the most likely financial outcome and the probability of achieving that or any other outcome. but al o with a ranki ng of the relative impact of all the ri sk factors. These type of resu lts offer more complete information for investment and technical deci ions than the traditional cash flow/ ensitivity analysis. In addi tion. by attempting to quantify ri sk. the personnel providing the va ri able input are forced to take a much clo e r look at the data involved, and are fo rced to work together. the reby increa ing substantially the awa reness of the impact their work and others· work has on th e outcome of the analysis.

Jan 1, 1986

By Ron Davidson

"The Utility Mine in southeast Saskatchewan is owned by Saskatchewan Power Corporation and operated by Mana/ta Coal Ltd. Up to 3.3 million tonnes of lignite is supplied annually to Saskatchewan Power's Boundary Dam Generating Station. The coal occurs in two predominant seams which are covered by up to 37 metres of saturated fine-grained overburden. Overburden is removed by two draglines working in two pits. Coal is hauled to the mine mouth power station. Comprehensive drainage and reclamation programs are integral parts of the operation. IntroductionThe Utility Mine is owned by Saskatchewan Power Corporation and operated by Manalta Coal Ltd. It is located in southeastern Saskatchewan, approximately 200 km southeast of Regina and 8.5 km southwest of Estevan (Fig. 1). The climate of the Estevan area is semi-arid with long, cool winters and short, hot summers. The mean annual precipitation is 42 cm and the mean summer temperature is 20°C; mean winter temperature is -10°C. The Utility Mine supplies coal to the adjacent Boundary Dam Generating Station. Increases in the station's generating capacity during the past decade have resulted in an extensive expansion program for the Utility Mine. This expansion program, the geological conditions present in the area, and the mining/reclamation operations will be highlighted in the following sections<1.2). History The Estevan area has a long history of coal mining. In the early years, coal was mined via entries into coal seam outcrops along the slopes of the Souris River valley. Surface strip mining was introduced in the late 1920s and progressed to the point where it totally replaced underground mining by the 1950s. Surface mining methods are currently used exclusively by all of the Estevan area operators."

Jan 1, 1985

By A. Desbiens, A. Pomerleau

During the summer of 1994, a new PID-based control strategy was installed on line B of the grinding circuit at the Kidd Creek Division of Falconbridge Ltd. Part I of this paper described the methodology used to select the appropriate control strategy using a phenomenological dynamic simulator. Part II presents the implementation of the control strategy. Prior to the controller installation, it was necessary to solve various problems related to the process, such as a cyclic behaviour of the rod mill feed tonnage, a problem related to the mill water source and the calibration of the flowmeters. Once these problems were solved, the control strategy was accomplished in two steps. Step 1 corresponds to the installation of control loops to regulate the pump box level and the cyclone overflow density. Step 2 describes the implementation of a loop to control the cyclone feed density. According to Part I, a loop to control the circulating load is also part of the original design. However, reasons are given to explain the rejection of this loop. For both steps, technical procedures such as filtering, process identification and controller tuning are detailed. Finally, the operator’s interface is briefly described.

Jan 1, 1997