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By R. D. Brown

Higher metal prices have resulted not only in increased exploration and production, but also increased activity in the purchase of mining properties and mines. This article discusses some of the basic income tax considerations to be taken into account on the disposal of an interest in a mining claim or an active mining operation. It notes the importance ofan appropriate allocation of the purchase price amongst the various categories of assets, and discusses the tax implications to both vendor and purchaser of the transfer of the comm on types ofassets involved in mining operations. In the space available, the article can only outline the basic tax considerations, and point to areas where both vendor and purchaser need to be o

Jan 1, 1980

By Rae Simpson

"This paper provides insight into the elements of computerized maintenance systems and identifies some of the factors which influence their effectiveness. The paper describes what to expect in terms of benefits and problems, the nature of effective computerized maintenance systems, some of the systems available and a process for selecting a system for your organization.The paper will be of interest to mining company executives and maintenance or computer personnel who are involved with, or contemplating, the introduction of computerized maintenance systems.IntroductionIn the drive to improve profits in an increasingly competitive world, mining companies are now using some of the most sophisticated equipment available. The introduction of large and complex equipment such as drag lines, haul trucks, and high-capacity milling equipment has resulted in order-of magnitude improvements in productivity. However, this productivity is now, more than ever, dependent on the continued operation of the equipment. A prolonged breakdown of a critical component can have a significant effect on companies' bottom-line results. As more technologically sophisticated equipment is introduced, maintenance costs become an increasingly important factor for mining companies.Fortunately, sound modern management principles are being used more often in maintenance departments. Progressive maintenance managers are turning to computers to help manage the myriad of details associated with running a maintenance organization.Some maintenance departments in larger mining operations would find it difficult, if not impossible, to operate at current productivity levels without their computer systems. Unfortunately, some other companies gain very little from their computerized systems and would probably be better off without them.How can you be sure that computerized maintenance will improve the maintenance picture for your company? What benefits can you expect to achieve? How do you go about selecting a maintenance system for your organization? These are some of the questions facing industry managers and executives today. In the following sections, we will provide some guidelines and insights to help address these challenges."

Jan 1, 1988

By B. F. Giyani, D. Rahal

"Stirred media mills have proved to be more energy-efficient than the conventional ball milling for fine grinding applications. The mill performance is governed by a number of operating variables including mill stirrer speed, feed particle size, solids content and slurry rheology. A study was conducted to assess effects of mill speed, media size and density, and slurry density on the Stress Intensity (SI) in a VXPmill and thereby the relationship to mill performance. For the mill speeds tested, it was found that the optimum tip speed is 7 m/s. If the speed is too high (12 m/s) energy losses result due to mechanical friction losses and heat generation. If the speed is too low (3 m/s), the kinetic energy is not sufficient to promote breakage. The size reduction ratio increases with the increase in mill speed and the decrease in solids content especially in the coarse fraction particle sizes. The effect of slurry rheology on mill performance was shown by assessing the effects of increasing solids concentration and decreasing particle size. Rheological effects seemed to interact with mill speed such that the mill was less energy-efficient at higher solids content and at higher mill speeds particularly for grinding to fine particle sizes. There is an opti"

Jan 1, 2017

By A. R. Farkoosh, K. Korgiopoulos, McGill University, O. Rodop, L. A. Villegas Armenta

"New generation of Al-Mg-Si alloys with thermally stable dispersoids that prevent recrystallization and grain growth during hot deformation are currently used in automotive components requiring good formability. Alloy chemistry controls the phase formation especially age-hardening precipitates, dispersoids, and primary intermetallic which have pronounced effect on grain structure, strength and formability. In this work, thermodynamic calculations have been used to predict the effects of varying levels of Si (0.5-1.5wt%), Mg (0.5-1.5wt%) and Mn (0.1-2.5wt%) on phase selection. Thermodynamic calculations have been performed in equilibrium and non-equilibrium conditions via the FactSage™ software using the FTlite database. Selected compositions have been cast, heat treated, extruded and characterized through scanning electron microscopy with energy dispersive spectroscopy and electron channeling contrast imaging techniques. The calculations showed that at the hot deformation temperature of ~540 oC, exceeding certain Mg and Si levels would lead to retained *-Mg2Si intermetallics and Si particles at the grain boundaries in addition to a-Al-(Mn,Fe)-Si. It was found that retained *-Mg2Si phase which adversely affects formability can be avoided for Si+2Mg levels lower than 2.3wt%. FactSage calculations also showed that increasing Mn from 0.5wt% to 1wt% leads to an increase in the amount of dispersoids (from 1wt% to 2wt%) that can potentially slow down recrystallization and grain growth during hot deformation and improve formability. Calculations at room temperature also show that for an alloy with 0.7wt% Mg, excess Si beyond 0.7 wt% promotes the precipitation of Si clusters in the Al matrix that accelerate natural age-hardening. Results were confirmed by experimental investigation.INTRODUCTIONAluminum alloy 6082 (Al-Mg-Si) is used in the automotive industry because of its high strength, and good weldability (I. J. Polmear, 2006). The alloy is age-hardenable through the precipitation of ß-Mg2Si and its precursors, and the recrystallization is usually inhibited by Mn- and Cr-containing dispersoids formed through high temperature heat treatments (I. Polmear & Couper, 1988). However, it is known that minor changes in alloy chemistry (Mg/Si ratio) can have significant influences on the ductility and formability of these alloys by altering phase selection and the resultant microstructure (Gupta, Lloyd, & Court, 2001; McQueen & Celliers, 1997; Zajac, Hutchinson, Johansson, & Gullman, 1994). For automotive applications where wrought alloys (usually extrusions) are cold-formed to produce suspension components, the chemistry of the alloys and the extruded structure are of crucial importance as they determine the formability at room temperature (Asensio-Lozano, Suárez-Peña, & Vander Voort, 2014). In this study, thermodynamic calculations along with experimental investigations were carried out on the Al-Mg-Si system to understand their phase formation and precipitation hardening as a function of alloy composition."

Jan 1, 2016

By Gene O. Cowie

"Zinc, which once enjoyed an unchallenged position in the field of decorative applications, has lost a substantial share of its markets to other materials, particularly plastics. This turn of events has led the zinc industry to explore new market areas, particularly those applications where the engineering properties of zinc can be utilized. This paper gives an overview of the zinc industry's efforts to develop the data base and product development technology which have enabled zinc alloys to emerge as engineering materials. It also indicates those areas in which the research facilities of the zinc industry must be employed to ensure that zinc alloys keep pace with developments in competitive materials and processes.The Materials RevolutionThe development and utilization of new materials and manufacturing processes progressed for centuries by evolution. Recently it erupted into a revolution, which may become as significant as the industrial revolution. The materials revolution has impacted upon many industries, but none has been affected more traumatically than the North American automotive industry. The plight of that industry is of great importance to us because their problems have, to a great degree, become problems to the zinc industry.Much of the impetus behind the automotive trauma came from the battery of motor vehicle regulations promulgated by the United States government in the 1970s. These regulations required that the efficiency of passenger cars, in terms of miles per gallon, be approximately doubled in ten years. In view of the fact that major changes in the automotive world require three years of lead time to implement, the industry was left with only seven years to perform the task. The automotive industry was simultaneously required to make progress in other areas, such as reduced emissions, reduced cost of repairs and increased levels of occupant safety. These added demands not only diverted some of the available resources away from efficiency goals, they often ran in direct conflict. For example, when you are required to provide a front bumper which will absorb the energy of a 5-mile -per-hour barrier collision, you must add both hardware and structure to the vehicle. This adds weight, and increased weight reduces miles per gallon."

Jan 1, 1983

By Donald Roberts

"Parameters f or design and development of an emergency hoist system (Fig. I) were submitted to Timberland Equipment Limited of Woodstock, Ontario by the Potash Corporation of Saskatchewan Mining Limited.The unit is the first of its kind in Canada. Not only does it comply with the province of Saskatchewan's mining regulations, but has the added advantage of being completely mobile and self-contained.As well as being useful in the mining industry, the mobile hoist unit could be used in other emergency situations such as rescuing people trapped in wells.JustificationRevisions to the Mines Regulations under Section 13 of the Occupational Health and Safety Act, 1977, of the Province of Saskatchewan stipulate as follows:"" Section 410 .04(4) The Mine Employer shall make adequate provision at every mine where any worker is hoisted in a shaft not equipped with a manway to enable an y such worker trapped in a conveyance in the shaft to be rescued . "" It was not possible to equip the shafts at PCS Mining' s Divisions with "" manways"" and therefore an alternative was required.BackgroundThe Potash Corporation of Saskatchewan Mining Limited, a subsidiary of the Potash Corporation of Saskatchewan, operates four potash mines. Of these, three, Cory, Rocanville and Lanigan Divisions are wholly owned while the fourth, Allan Division, is 40% owned by Kidd Creek Mines Ltd., but managed by PCS Mining. The four underground operations all have a service and production shaft.From 1979 to 1981 the PCS Mining Division, along with Central Canada Potash, were developing an idea to use the existing ground-mounted timberland hoist at Lanigan as an emergency hoist. This hoist was used in the past for rope-up work at both Rocanville and Lanigan and other potash mine s. The Department of Labour at this time had concerns about the time it would take to load, t ran sport and re-install the hoist on a foundation when needed for an emergency. Weight and size made this particular unit very cumbersome for transporting.In addition, the speed at which this hoist operates is too slow for rescue work. When the Department of Labour expressed concern that this unit would be unsuitable for these rea sons, a search for a suitable unit was initiated.The project responsibility for procuring an emergency hoist for the Potash Corporation of Saskatchewan Mining Limited was assigned to the author, a shaft/ hoist specialist a t PCS Mining."

Jan 1, 1986

By S. K. Paul

"This paper briefly describes the underground crushing and conveying system at Sherritt Gordon Mines' Ruttan Mine. A series of three steel-cord belted conveyors, with a total length of 2J55 metres and a total vertical lift of 407 metres, convey the muck from the underground crushing station to the mill at the surface. The maximum size of the crushed rock is 6 in. All the conveyors are provided with numerous safety and fire suppression devices. IntroductionThe Ruttan Mine of Sherritt Gordon Mines Limited is located 20 km east of the town of Leaf Rapids, 760 km north of Winnipeg. The orebody is multilensed, with lens width varying from 6 to 45 m. Ore production started in 1973 with the opening of a 10,000-tpd open-pit mine. Initial development of the underground mine was started in 1972 with the driving of parallel conveyor and access declines at minus-2507o gradient to the I 220-m level, and then the access ramp was further extended to the 1160-m level. Exploration drifting was done on the 1280-m and 1160-m levels from the access ramp. The final development plan for the underground project was approved in January 1977, and full-scale development and constructionwere resumed.At present, Ruttan Mine is in a period of transition from open-pit to underground mining. Ore production is now coming from both operations. By mid-1980, open-pit production will cease and all production will come from the undergroundmine.The underground mining method at the Ruttan Mine is sublevel open stoping with delayed backfilling. The orebody is divided along strike into a series of 27-m-long stopes and 15-m pillars, both 60 m high."

Jan 1, 1980

By Sabine Noelte, Mikko Petteri Rantamäki, Christopher Robben, Anssi Takala, Karl-Erik Rånman

"Sensor-based ore sorting is on its way to establish as a standard option for physical separation. The increasing number of installations in coal, iron ore, industrial minerals and hard-rock metal mining segments underlines the technological and financial potential that is beginning to be untapped. The Ma’aden Phosphate installation with 1.650 t/h sensor-based ore sorter feed sets a new benchmark for the possible capacity of stationary installations. Besides stationary installations, including multiple sorters parallel in different size ranges and multiple stages, containerised semi-mobile plants are applied. These offer two advantages, first being the reduction of transport costs when applied close to the mining face. The second is that semi-mobile systems enable processing of tens of thousands of tonnes of ore in a piloting phase with an approximate duration of 0.5 to six months, verifying the results laboratory mini-bulk tests on 5–10 tonnes of sample. This is especially important for low-grade metal ores because of the inherent Fundamental Sampling Error, as well as the Grouping and Segregation Error. The paper elaborates the results achieved within the I2MINE project, treating polymetallic ore at the Boliden Concentrator in Sweden.INTRODUCTIONSensor-based ore sorting (SBS) is becoming a standard option for physical separation, applied in all segments of mineral production. The Umm Wu’al project sets the bar for stationary SBS installations with 1,650 t/h feed (TOMRA, 2015). TOMRA Sorting Solutions has finalised an agreement in cooperation with Outotec to supply Outotec-branded sorting solutions for the mining and metallurgical industry (TOMRA, 2014). Especially for low-grade hard rock metal ores, an interdisciplinary approach is necessary applying experts for all aspects of mineral production. Due to the impact on the whole process stream, it is important on the end user side to have high level managerial support and involve all disciplines to ensure that all stake holders are involved in the analysis."

Jan 1, 2016

By G. R. Baiden

"An Automatic Haulage Truck (AHT) has been developed for manless tramming of run-of-mine material in an operating mine. The AHT has a 70-ton capacity and uses an electric trolley system in combination with a computer control system to operate the vehicle. The purpose of the AHT was to provide a high capacity, high productivity material transfer system where conveyor belt applications are not immediately practical.The AHT project was started in 1983 at Inco Limited, Ontario Division as a result of the need for rapid material transport to match increased extraction rates resulting from bulk mining methods. The original concept was to use a continuous loader with the truck. However, in order to minimize development problems the truck project was considered a stand-alone project.The AHT project consisted of concept development, preliminaryand detailed design, manufacture, surf ace testing and mine implementation.The AHT was manufactured and ready for testing in 1988. At this point the truck was first moved onto the test track for debugging. This proved successful and in 1989the decision was made to install the AHT at Little Stobie mine on 2000 level. Commissioning of the system was started in 1990and at present a fully functional automated haulage system is in place at Little Stobie mine producing 3000 tons/day.This paper describes the project presenting results achieved to date."

Jan 1, 1992

By Glenn Ferguson

BACKGROUND Metals Risk Assessment at Contaminated Sites ? The field of metals risk assessment has advanced rapidly over the last five years ? Significant uncertainties and data gaps remain that require additional research if accurate assessments are to be conducted ? Research is being conducted by regulators, external institutions and academia ? Risk assessment practitioners are in need of answers or solutions TODAY

Apr 1, 2005

By Stephen G. Hardcastle, Michel G. Grenier

"Safety and health issues are and have been in the last decade a very high priority item with all parties involved in the Canadian mining industry. As a result of this high level of concern for workers' safety and health, Canadian mines are at the leading edge of environmental control technology. For the most part, the occurrence of pollutants in mines is unavoidable. Dust from mining operations, airborne radiation, gases and heat from the strata as well as gases and particulate from diesel engine emissions will undoubtedly be found to some level in most Canadian mines. A lot of work remains to be done, however, in order to bring all Canadian mines at the same level of proficiency when it comes to safety and health. Also, more work is needed in order to maintain our status as world leaders in this field.CANMET's Mining Research Laboratories (MRL) in Elliot Lake and Bells Corners, Ontario, with the cooperation of the mining industry, have contributed to improving environmental conditions in underground and surface mining and milling operations. The extent of collaboration and efforts vary widely from long-term, multi-million dollar projects between several interested parties to smaller projects involving one laboratory and a single mining operation. This paper gives examples of such collaborative efforts and potential future directions as they apply to: mine ventilation analysis using tracer gas techniques, optimization of mine ventilation network efficiency using real-time monitoring and controlled recirculation (heat saving), respirable dust and radiation sampling and control techniques, diesel emission control using regenerative ceramic filters and, finally, the control of sulphide dust explosions and resulting sulphur dioxide production."

Jan 1, 1990

By Unknown

Diesel locomotives for underground haulage have been used in coal mines in Continental Europe for twenty-five years or more. In Great Britain, it was not until 1935 that permission was granted to use them in gassy coal mines, but since that time they have been employed in increasing numbers both in gassy and non-gassy coal mines and in metal mines. Their use underground in coal mines in the United States is still prohibited and the same was the case in Canada until 1946, when permission was granted to operate a Diesel underground in the Adanac mine of West Canadian Collieries, Limited, at Bellevue, Alberta. The locomotive used here is a 50 h.p. Hunslet Mark II. More recently, a 100 h.p. Diesel was placed in operation for underground haulage at No. 18 Colliery of the Dominion Steel and Coal Corporation, in the Sydney coalfield, N. S. Thus, on this continent, Canada has been a pioneer in the use of these locomotives underground in coal mines and there is no doubt that more and more of them will be employed as time goes on. We feel, therefore, that the following notes concerning their design and performance, which we have received from the High Commissioner for the United Kingdom, will be of interest to our members.

Jan 1, 1949

By Vishal Shukla, Prateek Singh, D. P. Chakraborty

"Continuous thickening by an operation called sedimentation is the separation of suspended solid particles from a liquid stream by gravity settling. The primary purpose of thickening is to increase the solids concentration of the feed stream. High rate thickeners are designed specifically to maximise the flocculation efficiency. A detailed investigation has been carried out to understand the influence of ore type and operating parameters such as bed level, bed mass, rake arm torque and flocculent concentration on thickening operation. Tata steel’s Noamundi plant data shows that variation in ore type, and operating parameters are major contributors to fluctuation in thickener performance. A lot of research has been done earlier on thickening operation but effect of ore type and operating variables by using plant data was never touched before.In this context, the performance of thickener was evaluated by daily data to study the influence of ore type and operating variables on thickener operation. Investigation shows that friable ore % in feed mix is proportional to slime density because friable ore is porous & brittle in nature. As a result, friable ore generates more fines/ultrafine during communition process in wash plant. Increase in flocculant concentration and bed mass is showing a positive change on high rate thickener performance Investigation shows that optimum bed mass and flocculant concentration is required to achieve desired pulp density in thickener underflow at different feed pulp density (g/cc).INTRODUCTIONOver the years, Iron Ore Beneficiation at Tata Steel, Noamundi has seen varied changes. Depletion of high grade iron and with increasing iron ore throughputs coupled with lowering of the hard ore a subsequent increase in slime generation, slime management and clear water requirement for wet Plant has thrown up myriad challenges. To overcome these challenges, many improvements initiatives were taken by Tata Steel in last decade. One of the major changes is the recent High Rate Thickener commissioning at Tata Steel Noamundi to cater the high iron ore throughput requirement. Slime reporting to Thickener has increased from 1.4 MTPA 2.5 MTPA over the last few decades. The above changes further aggravate the poor settling and dewatering characteristics of the slurry which is being feed to HRT. Considering the above mentioned constraints and stringent environmental implication proper water management has become a major challenge to reckon with. The thickener is used to increase the concentration of the suspension by sedimentation, accompanied by the formation of a clear liquid. In most cases the concentration of the suspension is high and hindered settling takes place."

Jan 1, 2016

By Eva Surová, Molák. Bohumil, Márta Polgári

The Úrkút rhodochrosite deposit and Branisko Mn showings (rancieite, manganiferous calcite), located in Lower Jurassic marine sedimentary rocks with black shale, were studied by organicgeochemical methods. Both depositional localities were affected by the Lower Jurassic Toarcian anoxic event. UrkUt shales are rich in organic matter (av. 2.94 wtOJo total organic carbon), the composition of which indicates derivation mainly from marine sources, with some terrigenous component. The shales matured in a bacterially active environment under reducing conditions of diagenesis-catagenesis. Branisko shales (~0.2 wt % TOC) with lenses of Mn oxide ore were weakly metamorphosed and their organic matter thermally degraded. The model for Mn carbonate ore formation envisages reaction of Mn derived from sediments, with carbonate generated by a bacterially mediated process of decomposition of organic matter that also involved Mn reduction.

Jan 1, 1992

By S. Shairp

At the Hudbay zinc pressure leach plant, filtration and washing of the second stage leach slurry takes place on a vacuum belt filter prior to disposal to tailings. Due to periods of poor filterability, laboratory studies were undertaken to investigate the effect of temperature of the filter feed slurry, and to compare filterability to the resulting cake particle size distribution.

Jan 1, 2014

By Shin-Kun Ryi

The world nowadays faces many challenges associated with excessive utilization of fossil, fuels, such as poor air quality and greenhouse gas emissions. Hydrogen appears to be an attractive alternative to the conventional, fossil, fuels with better energy efficiency and less environmental, impact. Pd and Pd-based alloy are the most often used membranes for hydrogen separation due to their superiority over other membranes. However, the stability of the commonly-used thin Pd-based composite membranes at high temperatures still, remains a big challenge. In this presentation, we will, report our progress on thin Pd-Ru alloy composite membrane by electroless plating high temperature applications.

Jan 1, 2010

By D. Crone, T. Watts

"The Lindsley project was a program of deep drilling to test the contact down-dip from two nickel-copper deposits, one uneconomical and the other mined out. The role of Borehole Pulse EM(PEM) was to detect the higher grade, more massive sulphide zones if they were missed by a drillhole, and to help determine geometry if the zones were intersected. Two problems appeared as the PEM survey progressed: (1) conductivity-thickness as measured by the PEM did not always relate to economic sulphides as determined by the market; (2) a pattern of unusual PEM anomalies was obtained that indicated something odd and big, but the cause was unknown. A large fold structure subsequently was indicated by a program of deepening previous holes, the third of which intersected high-grade mineralization below 1280 m. Falconbridge is in the process of shaft sinking and underground exploration.IntroductionThe Falconbridge Lindsley property is on the south rim of the Sudbury basin, 8 Ian north of downtown Sudbury. The original property was acquired by a prospector named James Stobie, who, in early August 1885, staked a showing that later became the Mount Nickel mine (Fig. I). On August 10 Stobie staked another property that would become the Little Stobie mine, and at the end of the same month he staked the main Stobie orebody.In 1888, the ground immediately west of the MOlU1t Nickel find was staked. This ground contained the Blezard deposit (Fig. 1) which was put into production in 1889 and was eventually acquired by Inco. Down-dip from the Blezard workings, on Falconbridge ground, is located the upper Lindsley No. 1 deposit which was drilled off by Falconbridge in the 1940s to 1950s. A decision to go underground on the Lindsley No.1 mineralization was made in 1969, but the project was cancelled in 1971 because of declining nickel prices. The shaft was stopped at 95 m, and the headframe and hoist were sold. Further surface exploration drilling in the 1970s discovered the deeper Lindsley No. 2 zone, but as it had grades similar to those of the No. 1 zone, it too was considered uneconomic."

Jan 1, 1992

By M. S. Millman

Close monitoring of performance at each process stage, from raw material through to finished product, is vital for operational consistency and the production of high quality steel. However, many of the integrated iron and steelmaking process route stages operate under such severe conditions of temperature, dust, water, thermal radiation, vibration, pressure, vacuum, extreme dynamic events, high material flows, corrosion, erosion, electrical-noise, electromagnetic-noise, or audio-noise that, in general, it is a very difficult challenge to obtain useful information for control. Thus, state-of-the-art non-contact and remote sensors are applied to help monitor and control specific process operations. Often, these sensor systems have been developed especially for the steel industry and they are based on four principal technologies: Laser, Microwave, Electro-Magnetics and Thermal Imaging with supporting technologies such as: X-ray Fluorescence, Audiometry, Digital Image Processing, Radio Telemetry, GPS and many others. These advanced sensor technologies are reviewed with respect to their application at various stages along the integrated process route.

Jan 1, 2004

By J. Cayouette, . Blatter, P. Cousin

The Laronde mill was commissioned in 1988 and has been treating the Laronde Perim ore since 2000. The Laronde plant, situated in the Abitibi region of Quebec, has experienced mill expansions to accommodate 7500 mtpd and to recover gold and silver as well as important amounts of base metals (Cu, Zn, Pb). Ten sequential metallurgical and environmental processes are responsible for metals recovery and process viability. Over 200,000 ounces of gold, 4,5 million ounces of silver, 7000 tonnes of copper, and 78,000 tonnes of zinc are produced annually. In 2008, the Goldex plant began trucking high wade (35-45 Wt Au) pyrite sulphide concentrate (TCGO) for gold extraction at a newly constructed treatment plant, increasing gold output at Laronde by 40,000 ounces. In 2009, the high gold wade Lapa ore processing facilities were annexed to the Laronde plant increasing output by 120,000 ounces of gold. TCGO and Lapa productions are forecasted until 2018 and 2015 respectively, with known reserves of each mine. Today, up to 140 permanent employees run and optimise the Laronde plant operation. As a result, Laronde has intricacies intrinsic to a large and varied operation. The paper will outline the metallurgical highlights, challenges, and future outlook related to the treatment of each ore type (Laronde, TCGO, and Lapa)

Jan 1, 2011

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