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By Norman O. Lotter, Simon Yu, Tony Deng, Antonio Di Feo

"Xstrata Nickel’s Raglan operation, northern Québec, achieved paymetal recovery gains in 2007 by switching the collector from potassium amyl xanthate to sodium isobutyl xanthate. To follow on from that position, Xstrata Process Support (XPS) and A. Di Feo of Raglan proposed that a mixed xanthate system be formulated and tested towards further performance gains. This work selected ethyl and isobutyl xanthates as the candidates. An optimized ratio of these was to be determined by a designed experiment. This suggestion was based on an abundance of published literature that reported mixed collector systems outperformed single ones. A partial factorial design was used to configure four test conditions and a mid-square for the flotation work. The testwork was conducted using High Confidence Flotation Testing. The raw data were analyzed and modelled by Design-Expert software. An optimum ratio of 1.6:1.0 by mass (1.32:1.0 in molar terms) of isobutyl:ethyl xanthate was determined. Without this modelling, the optimum ratio would have been missed. Results obtained with the new baseline flotation test using this optimized mixture showed a 3.3% Ni recovery gain in the bypass concentrate and more than 1% recovery gain for PGM over the single PIBX system. This system has been proposed for and accepted as a plant scale trial in the first half of 2010.INTRODUCTIONConcentrator OperationsMilling and flotation of sulphide ores ahead of smelting and refining is a common practice. This choice results in the larger and more variable paymetal loss in the production of saleable metal [Cramer, 2001]. For this reason, it is common to see an ongoing performance improvement programme at the operations level. When successfully performed, these e"

Jan 1, 2010

By John Frostiak

"Kahama Mining Corporation Limited, a wholly owned subsidiary of Barrick Gold Corporation, poured the first dore bar and filtered the first concentrate produced at the Bulyanhulu mine on February 28, 2001. This event marked the completion of the initial development of the Bulyanhulu Mine – Barrick’s first mine located outside of the Americas.Bulyanhulu is a 2,500 tpd underground mine located in the Lake Victoria gold belt of northern Tanzania. Gold is recovered as a gravity concentrate and smelted on site to produce dore bars or collected in copper concentrate that is shipped to offshore smelters. The facilities were constructed to meet Canadian standards. Unit operations include single stage crushing, SAG milling, gravity recovery, flotation, thickening and dewatering. Tailings are converted to paste and returned underground as paste backfill or pumped to the surface tailing site. The surface paste tailing disposal system is believed to be first of its kind in the gold industry. Paste disposal has several advantages over slurry, including lower dam construction costs, reduced water losses, and lower reclamation costs. This paper describes the facilities and discusses the challenges faced during development and construction including logistics, lack of infrastructure, recruiting and training, security, and social issues as well as initial operating results.INTRODUCTIONBarrick Gold Corporation completed the Bulyanhulu mine development in 2001. Capital cost of the project was US$280 million. The mine produced 241,575 ounces from start of milling to year end at a total cash cost of $197 per ounce. Numerous challenges were overcome in the mine’s development due to the general lack of infrastructure in Tanzania and the mine’s location some 1200 km inland by road from the port of Dar es Salaam."

Jan 1, 2003

By James R. Wickens, David La Rosa, Robert E. McIvor, Adrian Dance

"The comminution circuit at Barrick Cortez Gold Mine uses an open circuit primary jaw crusher followed by a standard SABC grinding circuit. The grinding circuit incorporates a 26’Ø x 11’ SAG mill, an Omnicone 1560 pebble crusher and a 16’Ø x 28½’ ball mill. Both mills are driven by 4500 HP motors.In 2007, several comminution circuit studies were performed to assess circuit performance and map a course for improvement. This paper discusses the results of those studies including an analysis of mine-to-mill opportunities, grinding work index efficiency, and ball mill functional performance. Subsequently, improvements to the circuit were made to enhance operating efficiency. Specifically, improvements to the pebble crusher liner configuration, advanced process control system (expert system) and ball mill classification and ball charge are discussed. In addition, other current and future improvement opportunities are discussed.INTRODUCTIONThe Barrick Cortez property is expanding to include the new Cortez Hills open pit and underground mines. Ore from these new mines will be processed in the existing Pipeline mill facility. In conjunction with ore characterization work, performance of the comminution circuit needed to be quantified. Thus, in 2007, the comminution circuit was surveyed and opportunities for improvement identified.Figure 1 below shows the Pipeline mill flowsheet. It is a standard SABC grinding circuit using an open circuit primary jaw crusher followed by a 26’Ø x 11’ (7.92m Ø x 3.35m) SAG mill, in closed circuit with a Omnicone 1,560 pebble crusher, and a 16’Ø x 28½’ (4.88m Ø x 8.69m) ball mill. Both mills are driven by 4,500 HP (3,357 kW) motors. The SAG discharge screen aperture is 5/16” (8 mm) x 1-1/16” (27 mm) slots. Ball mill circuit classification is done with Krebs D20B cyclones."

Jan 1, 2009

"RésuméDans la première partie de cet article on discute Ie mode d'écail age aetueJJement en usage dans des mines souterraines. Par la suite, on presente la problematique d'écaillage à l’aide de barres conventionnelles et on discute les plus recénts développements des outils d'ecaillage portatifs et mécanisés ainsi que les techniques de détection des roches branlantes. Plus tard, on analyse la tâche d'écaillage avec des barres conventionnelles. Dans les chapitres qui suivent on présente un concept d'un outil d'écaillage portatif et mécanisé développe à l'Université Laval, ainsi que les résultats des essais de cet outil, effectués dans quelques mines au Québec. On constate que Ie nouvel outil d'écaillage démontre un potentieJ intéressant tant au niveau de l'effort requis pour effectuer la tâche d'écaillage que de la sécurité des mineurs.On conclut que l’application de cet outil fera un pas important sur Ia voie d'amélioration des conditions de travail dans les exploitations souterraines, tout en assuarnt une qualité accrue de l'écaillage.AbstractThe first part of this paper discusses the type of scaling operations presently in use in underground mines and derma; a scaling factor which is expressed as the:: area necessary to scale to extract one ton of ore. Subsequently, the problems associated with conventional scaling methods are discussed as well as recent developments in mechanized hand-held scaling devices and methods of loose detection. The elements of the scaling process are further analyzed. In subsequent sections of this paper, the conception and design of a mechanized scaling device, developed at Universite Laval is described. The results of field tests conducted in Quebec hard rock mines are presented. The experimental findings show that the mechanized hand-held scaling device shows great potential in improving the productivity and safety of underground mining operations."

Jan 1, 1995

By N. Maleki

Magnesium matrix composites are widely used in automotive and aerospace industries for achieving higher performance due to their light weight. The Mg2Si intermetallics compound in Mg/Mg2Si composite exhibits many excellent properties such as high melting temperature, high hardness, and low thermal expansion coefficient. However, under normal cast conditions, the primary Mg2Si phase exhibits coarse Chinese script or dendritic morphologies and the eutectic structures is very brittle resulting in the low ductility and strength of the alloys. Modification treatment is a very effective method to obtain fine microstructure and improve the mechanical properties of the alloys due to low production cost. In this investigation various amount of bismuth addition have been carried out on Mg?5wt %Si alloy to refine and modify the morphology of coarse Mg2Si in order to improve the corrosion resistance of the composite product. The effect of Bi content on microstructure of Mg2Si/Mg composite was investigated by optical and scanning electron microscopy followed by EDX analysis and X-Ray diffraction. In order to compare corrosion resistance of unmodified and modified specimens, Immersion test and potentiodynamic polarization (PD) were used. The results showed that by Bi addition, the size of primary phase Mg2Si was considerably reduced and the morphology was modified from a coarse dendritic shape to a polyhedral shape. The results also indicated that the corrosion resistance of Mg?Si alloys was improved by the addition of 1%wt of Bi due to the reduction, refinement and evenly distribution of Mg2Si phase. Indeed, both the morphology and distribution of Mg2Si intermetallic had a great influence on the corrosion behavior of Mg/Mg2Si composite.

Oct 1, 2011

By A. Rajan

"Drawing upon the experiences of a gold extraction plant startup in the Southern Pacific, this paper will describe the importance of the commissioning phases to the project outcomes to achieve early target production despite an overall time compression to attain full plant production. Some of the highlights of the paper include: impact of roles played by the Owner’s construction and operations representatives during project commissioning, the formation of a capable and competent “Mod Squad,” availability of trained operating personnel, control over work priorities and the scope of work needed to bring the plant to safe initial operations. The commissioning team comprised subject matter experts skilled in process technology supported by “generalists” thoroughly conversant in overall plant operations. The merits of a structured team approach to brainstorm and resolve commissioning challenges as opposed to direction from individual subject matter experts is discussed. IntroductionStartup or commissioning is a unique period in the life of a project. Each stage of a project-exploration, feasibility, design, construction, commissioning, initial operations and continuing operations-requires special talents, know-how, and practices. Each stage makes particular demands of the people involved. Initial operations are no exception.Having experienced the 1997 startup phases of oxide and sulfide facilities for a gold extraction plant at a remote island in the Southern Pacific, I can attest to the many challenges and rewards. Commissioning for both facilities was extremely successful and brought the entire project on line well ahead of the targeted completion dates. Using this specific project as an example, this paper will highlight some of the key features of project commissioning. In this paper, the term “pre-commissioning” denotes all activities that lead to mechanical completion; “commissioning” occurs when feed is introduced; and “initial operations” are defined as the duration when operations accepts the system/facility and takes over."

Jan 1, 2000

By P. D. R. Maltby

"With the narrow vein structure of Nova Scotia gold deposits, selective mining is rarely possible and mill heads will be too low (below 0.10 oz per ton of gold) to support a conventional mill of up to 1000 ton per day capacity at present gold prices. The recent operation of a small 100 t.p.d. mill at Cochrane Hill using fine grinding - leaching - filtration supported this assertion. Milling costs exceeded $25.00/ton of feed mainly due to high capital, labour and maintenance costs.Accordingly, since 1981, efforts have been directed towards the development of a cheap gold extraction process in terms of both capital and operating costs. The main criteria is to produce gold below US $200 per oz including all administration, mining and process stages. This paper describes such a process development for Cochrane Hill. LOCATION AND HISTORY OF THE PROPERTYThe Cochrane Hill property is located about 8 miles North of Sherbrooke, N.S. on highway No. 7. Sherbrooke is about 180 miles east of Halifax. Gold was originally discovered at Cochrane Hill in the 1860's. Early work consisted of trenching. In the 1930's a small shaft was sunk to about 80 feet and some tonnage treated using a stamp mill with gravity concentration of gold.Northumberland Mines Ltd. acquired a 70% interest in the property in 1977. Subsequent drilling indicated a potential zone of gold mineralization with a drill-indicated tonnage of one million tons having a grade of 0.07 ounces per ton of gold (all high assays cut to 1 oz) down to a depth of 300 feet recoverable by open pit mining methods. In broad terms, the goldbearing zone is about 50 feet wide and 800 feet long and dips at about 70°."

Jan 1, 1984

By Stephen R. Grano, Jon Glatthaar, Philippe Steinier, Christopher J. Greet

"The importance of the oxygen content of sulphide mineral pulps in determining which reactions occur, and their subsequent influence on flotation behaviour is grossly underestimated in most operating concentrators. While pH is routinely monitored, Eh and dissolved oxygen measurements are obtained infrequently. However, dissolved oxygen measurements in conjunction with other pulp chemical parameters (i.e. pH, Eh, and EDTA extractable metal ion analysis), can provide valuable insight into where and what type of reactions are occurring within a circuit. Unfortunately, these readings yield “instantaneous” measurements of the pulp chemical parameters.What is needed is a means of establishing how reactive a pulp is, and how this reactivity changes as components of the system are manipulated. Oxygen demand provides an opportunity to do this. Several attempts at measuring the oxygen demand of a pulp have been made in the past with varying degrees of success. Most notable among these are Noranda and BOC Gases.Learning from these experiences, Magotteaux have developed the MagO2 ® demand vessel to measure the oxygen demand of mineral pulps. This paper described the apparatus, and through a case study on Broken Hill lead/zinc ore demonstrates how the MagO2 ® demand vessel is used.INTRODUCTIONThe role of oxygen in flotation is complex. While a considerable body of work exists demonstrating the strong involvement of oxygen in the interactions between sulphide minerals and collector (Gaudin and Finkelstein, 1965; Gaudin, 1974; Woods, 1984; Laajalehto, Nowak and Suoninen, 1993), the presence of oxygen can also affect the oxidation state of sulphide and non-sulphide minerals, which can impact on their flotation behaviour. Further, sulphide mineral oxidation is related to their oxygen demand (Spira and Rosenblum, 1994)."

Jan 1, 2004

By Y. Faitakis

In the mining industry, maintenance is a key priority and a major expense. As mining equipment is large in scale, high in cost, and difficult to tow, it is key to maintain equipment on a timely basis. Breakdown in -40°C or away from a maintenance station can cause great costs in repair as well as lost production. It has often been quoted that about 5% of the North American production is lost every year due to unscheduled downtime. About one-third of the downtime is attributable to equipment failures. From this fact alone, it is evident that proper equipment maintenance can add tremendous value to the bottom line. As organizations and equipment become more sophisticated, maintenance expectations begin to evolve. This evolution can be traced through three generations: The first generation (1940?1950): A ?fix it when it broke? attitude prevailed during that time, mostly because the industry was not highly automated. The second generation (1950?1980): Automation and mechanization of the industry increased. The industry now was dependent on machines performing the majority of the work. Preventive maintenance (overhauls at fixed intervals) appeared as the first maintenance practice. Maintenance costs started to rise rapidly. The third generation (1980?): Assets become more complex. Failure modes are better understood and computerized maintenance methods are becoming mainstream. Condition-based maintenance (CBM) starts to gain ground as a cost-effective alternative, replacing the fixed interval overhauls. As corporations amalgamate and market places are becoming more complex, multi-functional teams become responsible for maintenance. At the beginning of the third generation, maintenance organizations began embracing technology to provide efficiencies in maintenance management. A strong push was made to transition from reactive maintenance to proactive maintenance. At the forefront of this push is condition-based maintenance.

Jan 1, 2004

By Y. Faitakis, G. J. Powley, C. Mackenzie

"In the mining industry, maintenance is a key priority and a major expense. As mining equipment is large in scale, high in cost, and difficult to tow, it is key to maintain equipment on a timely basis. Breakdown in -40°C or away from a maintenance station can cause great costs in repair as well as lost production.It has often been quoted that about 5% of the North American production is lost every year due to unscheduled downtime. About onethird of the downtime is attributable to equipment failures. From this fact alone, it is evident that proper equipment maintenance can add tremendous value to the bottom line. As organizations and equipment become more sophisticated, maintenance expectations begin to evolve. This evolution can be traced through three generations:The first generation (1940–1950): A “fix it when it broke” attitude prevailed during that time, mostly because the industry was not highly automated.The second generation (1950–1980): Automation and mechanization of the industry increased. The industry now was dependent on machines performing the majority of the work. Preventive maintenance (overhauls at fixed intervals) appeared as the first maintenance practice. Maintenance costs started to rise rapidly.The third generation (1980–): Assets become more complex. Failure modes are better understood and computerized maintenance methods are becoming mainstream. Condition-based maintenance (CBM) starts to gain ground as a cost-effective alternative, replacing the fixed interval overhauls. As corporations amalgamate and market places are becoming more complex multi-functional teams become responsible for maintenance.At the beginning of the third generation, maintenance organizations began embracing technology to provide efficiencies in maintenance management. A strong push was made to transition from reactive maintenance to proactive maintenance. At the forefront of this push is condition-based maintenance."

Jan 1, 2004

By Russell A. Luke

"Modular Mining's computerized LHD position monitoring and dispatching system commenced operation at the De Beers Finsch Mine in mid- J99J. A sophisticated blend of proven and new technologies links the dispatcher at the workstation console on the surface with the LHD operators several hundred metres below. The dispatcher allocates each LHD to a priority tip and loading drive based on instructions provided by the miners and shift bosses underground. LHD operators receive tip and loading drive allocations on the vehicle computer console which communicates data via a Leaky Feeder radio network. The operators interact with the console to notify the dispatcher of delays, breakdowns, and changes in tip and tunnel status. The underground terminal displays allow shift bosses to monitor the progress of the LHDs as they pass infrared beacons (IRs) located in the tips loading drives and rim tunnel main haulage ways. The terminals also provide on-line statistics for the current and previous shifts. Future enhancements include optimized dispatching and interfacing to a PLC system controlling ventilation. Further, token ring-based loop UHF radios are being investigated as an alternative to the Leaky Feeder data radio network. IntroductionFinsch first contacted Modular about an LHD monitoring and dispatching system in late 1988. At that time, Modular declined a request for a formal quotation but agreed to perform an engineering feasibility study. The study was issued in mid-1989 and confirmed Finsch's belief that an underground system could be developed with technology available at that time. A contract for the system was signed the following year and, in May of 1991, the system began operation. By the end of 1991, LHDs on both production levels of the mine were under the control of the system."

Jan 1, 1993

By James L. Parks, David M. Kjos

"Significant increases in mill liner life and plant availability can be achieved by following guidelines that have evolved from over twenty years of practical experience with autogenous grinding (A0) and semi-autogenous grinding (SA0) mills. A0 and SA0 mill liner functions, performance criteria, designs, wear-resistant materials and maintenance procedures are reviewed. Operating practices that can lead to accelerated wear and breakage are discussed.IntroductionEfforts to improve the performance of liners for autogenous grinding (AG) and semi-autogenous grinding (SAG) mills began as soon as the modern, large-diameter versions of these comminution machines were first intalled in commercial plants twenty years ago . While concentrators with conventional circuits were typically running at 95010 or better mill availability, many of the new autogenous and semi-autogenous circuits were struggling to achieve 80% availability. Liner maintenance, which involves not only material and labour costs but also loss of production, was quickly identified as one of the major reasons for downtime.Today, liner designs and materials have evolved to the point where virtually maintenance-free liner life of two to three years is possible in autogenous mills and one year in the more severe operating conditions encountered in semi-autogenous mills. Of concern, however, is that hard-won lessons from the past sometimes seem to be forgotten or ignored during the design of new mills and the operation of existing mills. As liner suppliers, we are often confronted with performance problems that could have been avoided by applying well-publicized guidelines for liner design and materials selection.This paper provides an overview of AG and SAG mill liner functions, criteria for evaluating performance, designs, wear-resistant materials and maintenance procedures. Also, operating conditions that can lead to accelerated wear and liner breakage are discussed in detail."

Jan 1, 1990

By H. Warren Newcomen, Dennis C. Martin

"This paper describes the investigation of a large, progressive slope failure on the southeast wall of the east pit at Highmont Mine, British Columbia Geotechnical investigation s consisted of geological and structural mapping, assessment of blasthole drilling records, review of rock core information, slope movement monitoring and back analysis of various possible failure modes. Climate records and mining history were also assessed to determine their relationship to slope movement .Analysis of movement monitoring records and geotechnical information indicates that the failure is deep seated. The upper portion of the failure surf ace occurs along clay filled discontinuities. The lower portion of the failure surf ace appears to occur through the highly altered rock mass. High groundwater pressures and mining at the toe of the slope are documented to have had a major influence on stability at various times during the failure. Stability analyses results are presented and possible remedial measures are discussed.IntroductionHighmont Mine is located near Logan Lake in the Highland Valley approximately 50 km southwest of Karnloops, British Columbia (Fig. I). Mining of the porphyry copper and molydenum ore bodies began in 1980. In May, 1983, when mining in the east pit had progressed to a depth of about 60 m (200 feet) , a failure (designated the Southeast Failure) began to develop in the southeast corner of the east pit. Subsequent mining to a depth of 110m (360 feet) was accompanied by frequent and substantial slope movements involving between 500000 and I 000 000 m3 of rock . The slope was monitored extensively to assess short-term movement trends for operational safety. Geological mapping, core logging and rock mechanics testing were used in conjunction with the long-term monitoring information to determine the failure mechanism, conduct stability analyses, assess the effects of instability on pit design and enable design and installation of remedial measures."

Jan 1, 1988

By H. Warren Newcomen, Dennis C. Martin

"This paper describes the investigation of a large, progressive slope failure on the southeast wall of the east pit at Highmont Mine, British Columbia Geotechnical investigation s consisted of geological and structural mapping, assessment of blasthole drilling records, review of rock core information, slope movement monitoring and back analysis of various possible failure modes. Climate records and mining history were also assessed to determine their relationship to slope movement.Analysis of movement monitoring records and geotechnical information indicates that the failure is deep seated. The upper portion of the failure surf ace occurs along clay filled discontinuities. The lower portion of the failure surf ace appears to occur through the highly altered rock mass. High groundwater pressures and mining at the toe of the slope are documented to have had a major influence on stability at various times during the failure. Stability analyses results are presented and possible remedial measures are discussed.IntroductionHighmont Mine is located near Logan Lake in the Highland Valley approximately 50 km southwest of Karnloops, British Columbia (Fig. I). Mining of the porphyry copper and molydenum ore bodies began in 1980. In May, 1983, when mining in the east pit had progressed to a depth of about 60 m (200 feet) , a failure (designated the Southeast Failure) began to develop in the southeast corner of the east pit. Subsequent mining to a depth of 110m (360 feet) was accompanied by frequent and substantial slope movements involving between 500000 and I 000 000 m3 of rock . The slope was monitored extensively to assess short-term movement trends for operational safety. Geological mapping, core logging and rock mechanics testing were used in conjunction with the long-term monitoring information to determine the failure mechanism, conduct stability analyses, assess the effects of instability on pit design and enable design and installation of remedial measures."

Jan 1, 1988

By B. L. Dorey

"Performance management is a systematic, practical approach to managing people. It is founded on some basic assumptions about people and is designed to focus on people in the work place. Organizing meaningful information and using it to involve people is a cornerstone of this system.Some common sense practices are developed to involve people in an organization's effort to improve performance. The successful implementation of this program requires solid commitment and total involvement from all levels of supervision and employees for maximum results and lasting impact. All levels of supervision participate in training sessions to tailor the systems for implementation in their areas. This style of management is data-oriented and the bottom line of success is to measurably improve performance. Basic Assumptions about PeopleMost people in an organization, regardless of level, take pride in their work and generally want to do a good job. When performance falls off, there is usually some explanation other than the employee not really caring. People like to know their exact responsibilities and clearly what is expected of them. People like to know where they stand with the boss and would like to be evaluated on what they do and accomplish, rather than on what others think or feel about them. Further, people like to be rewarded for their good results, indeed, to understand what motivates people, we must look at what happens as a result of their actions. Another belief is that supervisors often have a greater influence on the performance of their people than they fully realize. Simply letting people know how important their performance is can have an impact. The Key ElementsGiven these basic assumptions and beliefs about people, some common sense practices have been systematically developed to manage more effectively."

Jan 1, 1989

By A. J. Keen

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

Jan 1, 1992

By G. J. Reid, D. H. Stewart

"A diversity of structures and rock types in the Aft on pit has resulted in the occurrence of several different types of wall failure. Delivery of ore to the mill has not been affected and safety has not been compromised thanks to effective remedial 1V0rk and to a system of structural mapping, back analyses of failures, groundwater monitoring, and simple movement monitoring. Remedial measures have included artificial support, dewatering (including vacuum-assisted drainage), flattening of slopes and temporary buttressing. This paper describes six different wall failures at Afton and highlights the features of each. Examples given include rates of movement, extent and direction of movement, and piezometric responses. The practical, low-cost monitoring system was sufficient in one case to allow the prediction of date of failure. IntroductionThe Afton copper deposit is located 13 km west of Karnloops, British Columbia and has been mined for nine years out o f an expected eleven-year life. Open pit mining has reached 700 feet below sur face and is designed to proceed to 970 feet below surface by the time the pit is completed. The excavation is in a structurally and lithologically complex environment. Inevitably, some wall failures have occurred but these have been limited to small, manageable failures which have not compromised production or safety. To handle the failures it has been necessary to understand their nature. Of prim e concern has been the rate s of movement, but displacement vectors and hydrology have been monitored as well. The monitoring system is based on EDM surveys and on wire extensometers and plates set across cracks. Water levels have been read in standpipe piezometers. At Afton the emphasis has been on simple, practical, and inexpensive monitoring and because rock type s and structures play such a major role in any failure, detailed geologic al mapping is carried out."

Jan 1, 1988

By Akira Fujisaki

"The oil crisis accelerated the change of non-ferrous metals' demand structure. Maturing societies in developed countries and preference for lighter, thinner and smaller products are eroding the non-ferrous metal industries' growth potential. Inventory-control, stockpiling and developing new demand are measures Japanese smelters have taken to cope with the changing demand.The most effective means for risk management of product demand lies in the cooperation between ore producing countries and metal consuming developed countries to assist developing countries in their efforts to ""take-off"", which in turn will bring about a surge of demand for metals.SummaryThe non-ferrous metal industry in the world is suffering its most serious slump since the war. With some of the markets of the advanced industrialized countries approaching saturation point and economized usage of natural resources and substitution growing, the possibility of a quick recovery of the demand for base metals is dim.To cope with the changing product demand Japanese producers have had recourse to such measures as strict inventory control and stockpiling for the purpose of stabilized imports. They have also tried hard for securing raw materials and promoting new field s of demand but the very core of ""risk management"" has been the diversification of line s of business to bolster and stabilize the foundation of management of the non-ferrous metal industry in Japan.To see the demand for nori-ferrous metals recover from the slump and be put on a path of solid development, we have to wait for the economies of the developing countries to ""take off"" and for its realization the economies of the developed countries must be reactivated with new growth industries playing a leading role, and the transfer of technology and money recycling must be carried out smoothly under an orderly international trade system."

Jan 1, 1983

By D. R. Griffiths

"Oxidation of pyrrhotite prcxiuces sulphuric acid which in turn leaches out heavy metals, resulting in acidic contaminated seepages. The establishment of a marsh on top of the pyrrhotite would result in an anaerobic sediment, which should prevent further oxidation of the pyrrhotite. Initial data indicates that concentrations of sulphates and heavy metals in the seepage water are greatly reduced. Further hydrogeological studies are required however, to determine if metal and acidic loadings to the environment have increased.L'oxidation du sulfure de fer produit de l'acide sulfurique qui a son tour attaque les métaux ayant pour resultat une contamination d'acide et de métal des eaux d'infiltration. L'etablissement d'une couverture faite de boue et de vase au-dessus du depot du sulfure de fer réduit les effets de l'oxidation.Les données initiales indiquent que les concentrations de souffre et de métaux dans les eaux d'infiltration sent grandernent réduites.Des études plus poussées sent nécessaires pour déterminer si les quantités de souffre et de métaux dans les eaux d'infiltration ont augmentées.INTRODUCITONPyrrhotite tailings are readily oxidized through a combination of precipitation and atmospheric oxygen causing acidification of the unsaturated zone above the water table. This reaction is usually catalyzed by the bacteria, Thiobacillus ferooxidans. As the pH decreases, heavy metals become more soluble resulting in contaminated seepages to ground and surface waters.By creating a marshland on top of the pyrrhotite, an anaerobic intermediate layer should form between the organic covering and the tailings, preventing the oxidation process from progressing.In September 1986, Falconbridge Limited implemented a tailing reclamation project that involved creating a marshland on top of pyrrhotite tailings. The following paper will discuss and illustrate the preliminary results obtained during the sampling period of May to September 1987."

Jan 1, 1988

By D. Runnels, A. Allaire, J. Torrealba-Vargas

Data mining and modelling of operational data involves the discovery of patterns in large datasets for future use in benchmarking and plant optimization. The modern pattern of discovery in large data sets involves statistical techniques, machine learning and new visualization tools. Former examples of data mining are revisited and presented in this document. INTRODUCTION A network of enthusiastic and active professionals is currently developing and maintaining several open source statistical software tools (packages) for data analysis (example Rstudio, Orange, Spyder, etc.). The advantages of the open source software philosophy are the fast development and testing of the solutions presented to the community. Books and support are available for each software application. Since each modern work activity generates massive amounts of data, it is attractive to learn and test those available tools considering that we are at the door of the new work revolution coined as “Mine 4.0”. Data mining involves collecting large datasets, the preparation and cleaning of a dataset (term named data wrangling), the uploading of the data to a database program capable of handling big datasets, the development of prediction models and the presentation of the results. Machine learning techniques help to develop mathematical models and algorithms that could be used to improve the performance on a specific task. Mine operations are producing an incredible amount of data each day and the need to analyze those results seems to be impossible due to the lack of time, as well as the lack of skills to investigate the data collected. If we add to this the traditional habit of working in silos, an additional challenge is to consolidate databases from different departments in search of trends that could help to optimize production.

Jan 1, 2019