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By Mohammad. M. Khajeh

Rock mechanical properties are important parameters in geomechanical simulation. Considering stochastic heterogeneous models rather than conventional homogeneous layer cake models leads to more realistic simulation results and uncertainty assessment. These heterogeneous models are usually fine scale models generated by geostatistical techniques. Although considering high resolution property models is desirable, geomechanical simulation with a fine scale model is not computationally feasible for full?field, coupled geomechanical-flow simulation. Upscaling of property models is necessary to move from fine scale/high resolution property models to coarser scale/low resolution models appropriate for simulation. Local numerical upscaling was proposed by Khajeh et al. (2012) to describe the macroscopic elastic behavior of complex heterogeneous media and is expanded upon in this work. This numerical technique is not restricted to specific geologies as typical analytical techniques are. Moreover, transversely isotropic deformation is considered rather than the usual assumption of isotropic deformation. To compare the accuracy of the upscaling methodology, in this study shear strain is considered as the geomechanical response of a synthetic facies model and the response of the coarse scale model is compared to other conventional analytical averaging techniques. It is found that the numerical upscaling technique better approximates the geomechanical response of the fine scale model.

Jun 1, 2012

By John S. Stevenson

Zeballos mining camp is on the west coast of Vancouver island; 195 nautical miles northwest from Victoria.; The spectacularly rich gold-bearing veins that made Zeballos an important; gold camp were found early in 1934. Small pockets of very coarse; gold had been found earlier under large boulders at the mouth of Spud; creek; and in the autumn of 1933 rich gold-quartz float was found near the; mouth of the creek. The rocky beds of the steep creeks entering Spud creek; were searched for its source and as a result the veins on the White Star property; were found. The Goldfield vein on the Spud Valley property was discovered; in 1935; and the No. 1 vein on the Privateer in 1936. In the general; prospecting activity that quickly followed; other veins were found; not; only in Spud creek but in other creeks draining into Zeballos river.

Jan 1, 1954

By V. Maazallahi, A. Rouleau, A. Saeidi

"The geometry of the terrain topography before and after the failure are the essential factors for analyzing a landslide and for the design of remedial works. This paper presents a method to determine these factors, considering that the determination of the slide surface profile is difficult and costly using traditional methods and the pre-slide topography data is often not available. The presented method to locate the 3-dimensional geometry of the slide surface is based upon determining the slide surface in 2- dimensional vertical sections. This method utilizes post-slide topography of the area to determine the pre-slide topography and uses equations to estimate the pre-slide situation using a statistical process applied to points located on the sliding mass. This method is tested on the Maskun landslide in Iran. The results indicate the applicability of the proposed method to obtain the key factors for the back analysis of a landslide in a cost effective manner.INTRODUCTIONProbably the most reliable method of determining the strength of soil and rock mass is to back analyze a failed or failing slope (Caia et al. 2007; Wyllie & Mah, 2004). This method is used in geotechnics for estimating geotechnical parameters of the rock and soil mass (Sakurai et al., 2003; Frayssines and Hantz, 2009; Cepuritis et al. 2010), but it requires that the failure mode is well established and that there is complete and precise information available on the slide surface and the sliding mass (Sjöberg, 1996). Measurement of the slope profile before failure provides the basic information required for a back analysis (Hock & Bray, 1981). The post-slide topography is another key factor. The back analysis process for determining the actual strength parameters of soil or a decomposed rock mass after a landslide requires knowledge of the sliding mass geometry, both before and after the sliding event. Many studies are reported in the literature about the application of back analysis for determining geotechnical and geomechanical parameters of rock and soil mass (Sakurai et al., 2003; Cepuritis et al. 2010; Frayssines and Hantz, 2009, Hussain and Stark, 2011), but they generally present little information about the geometry of the slide surface, and the weight of rock and soil mass that slid, although these factors are the most important parameters for back analysis process. Liang and Xue-song (2012) determined the slip surface having the minimum factor of safety (called critical slip surface in deterministic analysis of slopes) and the slip surface with the minimum reliability index (called critical reliability slip surface), but they have not considered the actual profile and geometry of the slide surface. Rocscience (2013) proposes the back analysis option in the Slide software for slope stability study, but it requires an imposed slide surface as input; alternatively, one can estimate by a finite element analysis the surface with the minimum factor of safety. However, this estimated surface is very likely different from the actual sliding surface, considering the uncertainties in input data of the finite element method."

Jan 1, 2015

By D. T. A. Symons, M. M. Kapnistos

"Gravity profiles were established over five known Middle Silurian pinnacle reef s in Lambton County, southwestern Ontario. The profiles were approximately 3 km long, with stations every 60 m. Four fairly recent technological developments were used which now make the gravity method relatively efficient and inexpensive compared to the techniques available two decades ago. These are: (1) a La Coste-Romberg model G gravimeter to measure the gravitational attraction with a sensitivity of 0.01 mgal; (2) a Sokkisha model B-2 semiautomatic engineers level to measure the station elevations with an accuracy of 0.5 cm; (3) a Huntec FS-3 hammer reflection seismograph to determine the overburden thickness to an accuracy of ± 7%; and (4) a modern microcomputer to process the data sets and mathematically filter the gravity values. Thus, two men can measure and analyze approximately 1 km of profile per day and obtain the residual gravity profile to an accuracy of ± 0. 05 mgal. Positive gravity anomalies of 0.17 to 0.72 mgal were observed along all five profiles that approximately delineate the dimensions of the known pinnacle reefs, which have an average height of 120 m, diameter of 1500 m and depth to top of 575 m. The relative ease of the gravity survey method makes it a cost-effective technique for hydrocarbon exploration in southwestern Ontario. IntroductionPinnacle reefs are important sources of oil and gas. Although the pinnacle reefs in southwestern Ontario are small, they may contain commercial pools of oil and gas because of their proximity to refineries. They are also useful for subsurface storage of gas to meet the winter surge in gas demand.At present, geophysical exploration for new pinnacle reefs is done primarily by relatively expensive seismic methods, which are also limited in southwestern Ontario by prohibitions on blasting. Gravity methods of exploration were attempted more than two decades ago in this region. (Pohly, 1954); however, the level of technology at that time made the method marginal in sensitivity and quite expensive. Several subsequent developments- gravimeters with greater sensitivity and operating ease, ""self-levelling"" levels for elevation control, hammer seismic reflection units for determining overburden thickness and portable microcomputers for efficient data analysis-have significantly improved the precision and cost effectiveness of the gravity method. Five known pinnacle reefs were selected in Lambton County, southwestern Ontario (Fig. 1), to test the effectiveness of integrating these developments to locate and define additional reefs. Isolated reefs were chosen to avoid the problem of the gravity effect s of one reef interfering with those of a neighbouring reef. The surveys were facilitated by choosing reefs with a concession road passing directly over them ."

Jan 1, 1980

By Michel L. Bilodeau, Brian W. Mackenzie, Dallas W. Davis

"The paper formulates an evaluation procedure for examining the effects of location on the economics of developing mineral deposits. This methodology is applied to assess locational aspects of Nova Scotia's competitive position f or mine development relative to other Canadian regions and provinces. The appraisal concerns two representative mine development opportunities, a medium-size open-pit tungsten deposit, and a small underground gold deposit. The influence of regional economic conditions is initially assessed. Then, the consequences of taxation are isolated. Finally, the combined impact of regional and taxation conditions is examined. SettingThe economic potential of mining may be assessed in a number of ways. One approach, increasingly used for both corporate planning and government policy purposes, is to evaluate the competitive position of an actual or potential mineral producer in the international marketplace relative to other suppliers.Such examinations of competitive position vary from cost league comparisons of breakeven costs for operating mines, through the assessment of medium-term costs associated with developing new mine capacity, to long-term evaluations of the economics of mineral supply from the start of exploration. The complexity of the analysis increase s with the scope and timeframe of interest. Many factors are involved. One component of competitive position is the quality of the mineral resources available. Other key factors include existing technology, wage and salary rates, labour productivity, the cost of capital, infra structure requirements, distances from sources of materials supply an d to mineral markets, management attributes, organizational efficiency, government mineral policies (particularly taxation), and inflation and exchange rates. The paper fits within this competitive position framework.The variable economic conditions which exist within Canada have a direct bearing on the viability of mine development and, thereby, on mineral exploration potential. The paper examines locational aspects of Nova Scotia 's competitive position."

Jan 1, 1986

By STEPHEN V. FORGERON

The Loch Lamond celestite properties in central Cape Breton Island were mined by Kaiser Celestite Mining Limited from 1970 until 1976. Poor market conditions in J976forced operations to cease. Kaiser holdings included the Lake Enon, MacRae and A mac prospects. A total of about 272,000 tonnes of raw celestite have been mined. Celestite deposits are situated in the Loch Lamond Basin, specifically in Lower Windsor sedimentary rocks. Of the five formations in the Lower Windsor Group, celestite is found in the upper four. Celestite in the Enon Formation occasionally replaces shale that separates stromatolitic dolomite columns; elsewhere in the formation it occurs in association with siltstone and gypsum. Jn the B2 Limestone Formation celestite fills pores or grades between limestone and gypsum. It replaces both limestone and silty limestone conglomerate in the Loch Lamond Formation; this limestone is of unusually high grade (60 to 70% SrSO,J for the area. Evidence indicates that the Uist Formation may hold important celestite reserves. Original celestite mineralization probably resulted from evaporation of seawater on mudflats or 'sabkhas'. Secondary mineralization also may have occurred. Strontium ions could have been leached from pre-existing concentrations and overlying gypsum, moved downdip in groundwater and combined with sulphate rich waters to deposit as celestite in porous B2 limestones.

Jan 1, 1984

By R. Simard

"Conventional exploration strategies identify many mineral deposits as potentially interesting, although only a few of them turn out to be of economic importance. In the context of exploration for sulphide nickel deposits in the Canadian Shield, a decisional model, based on a statistical study of parameters relative to nickel deposits as well as to barren sulphide occurences, has been developed.Because such geophysical variables as gravimetry, aeromagnetism and topography could be related to the relative importance of nickel-bearing deposits, a statistical analysis of 13 such variables was carried out for 98 targets which were considered promising after conventional exploration. Among these 98 targets are36 sulphide nickel deposits in the Canadian Shield and 62 drill-tested non-economic occurrences. The results of this study led to the development of a linear logistic model that permits evaluation, for each of the targets, of the probability of finding a nickel deposit of potential commercial interest. This decisional model can thus complement conventional exploration strategies.RésuméLes stratégies conventionnelles d'exploration définissent un très grand nombre de cibles comportant un inténet minier potentiel dont seules quelques-unes correspondent à des gisements économiquement importants. Dans Ie cadre de l'exploration des dépôts nickélifères du Bouclier Canadien, nous avons défini un modelé de décision fonde sur l'étude statistique de divers paramètres relatifs tant aux gisements d'importance qu'aux cibles dites stériles.Ayant fait l'hypothèse que certaines variables géophysiques (gravimétrie, aéromagnétisme et topographie) peuvent suffire à fournir des indications sur l'importance relative d'un gisement nickélifère, nous avons entrepris l'analyse statistique de 13 variables évaluées sur un échantillon de 98 cibles considérées comme potentiellement intéressantes par les stratégies conventionnelles d'exploration. Ces 98 cibles se composent de 36 dépôt nickélifères d ‘importance recontrés sur tout Ie Bouclier Canadien et de 62 cibles stériles reconnues par forage. Nous avons défini à l'aide de ces données un modèle logistique linéaire. Ce dernier nous permet d'évaluer pour chacune des cibles les chances de trouver un gisement. Ce modèle de décision peut done s'inscrire comme outil complémentaire aux stratégies conventionnelles d ‘exploration."

Jan 1, 1980

By Emmanuel John M. Carranza, Martin Hale

Abstract- An application of logistic regression to mapping of gold potential in the Baguio district of the Philippines is described. Categorical map data such as lithologic units and proximity classes of curvi-linear features, based on spatial association analyses, are quantified systematically and used as independent variables in logistic regression to predict the probability for presence or absence of gold mineralization. Regression experiments to compare between using all independent variables that are associated spatially with the response variable and using only statistically significant independent variables are performed. The results of the regression experiments are similar; however, the use of all independent variables produces slightly optimistic results but better prediction rates for the known gold deposits in the test district. At least 68% of the ‘model’ large-scale gold deposits and at least 76% of the ‘validation’ small-scale gold deposits were predicted correctly. The predicted geologically favorable zones are also similar to delineated geochemically anomalous zones. The technique presented using logistic regression as a data integration tool is effective for geologically constrained technique of mapping mineral potential.

Jan 1, 2001

By S. R. Noble, F. R. Harris, E. T. C. Spooner

"The Logtung deposit discovered in 1976, is an example of large tonnage (162 million tonnes), low grade (0.13% WO3 and 0.052% MoS;) W(scheelite)-Mo mineralization related to multiple felsic intrusions. Because mineralization is predominantly fracture-controlled (> 95 %) rather than disseminated, Log tung is not a skarn deposit. Metamorphism of the Logtung country rocks (interbedded calcareous shale and graphitic quartizite) to a series of competent reaction skarns (quartz-diopside-garnet calc-silicate, biotite quartzite and wollastonite-vesuvianite calc-silicate) clearly precedes W-Mo mineralization. Hence mineralization was related to permeability created by hydraulic fracturing and not replacement processes.Logtung shows a theme of several phases of mineralization (4) related to multiple intrusions (>2) which is similar to that of the Climax and Urad-Henderson Mo systems. The earliest quartzmolybdoscheelite vein system, which consists of a typical ""porphyrystyle"" crackle-breccia of thin (0.5 mm to 4 mm) quartz-garnetdiopside- molybdoscheelite veins, is related to a high Si02 (approx. 76%), seriate-porphyritic monzogranite stock (approx. 2 km by 0.5 to 1 km) of Cretaceous age (118 ±2 Ma [2u]; Stewart, 1983). Later quartz-pyrite scheelite (fluorite-KINa-feldspars-molybdenite) veins, with prominent green, hornblende-bearing alteration selvages, and quartz-molybdenite (-pyrite-jluorite-scheelite) veins are related to a quartz-feldspar-spessartine-rich garnet porphyritic felsic dike complex approximately 500 m across. Both intrusive phases have anomalously high Wand Mo concentrations of about 100 ppm and 50 ppm respectively, which Stewart (1983) attributes to a primary enrichment. The final stage of mineralization consists of a prominent 4.5 km by 1 km zone of 1 em to 1 m wide polymetallic sheeted veins centred on the felsic dike complex. The system is zoned from quartz scheelite-molybdenite-pyrite-blue-green beryl-jluoritebismuthinite veins in the core to Pb-Zn-Ag veins with abundant arsenopyrite and minor Sn (approx. 0.1%) in the northeast. The focus of recurrent intrusive and hydrothermal activity was located above a flank or nose of the monzogranite stock.The distribution of WO3 and MoS2 grades within the approximately 750 m (across) by 300m (evaluation depth) mineralized zone is a result of the variable superimposition of the four separate vein systems each with different W:Mo ratios. Well-defined Wand Mo ore, shells such as those at Climax, Henderson and Mt. Emmons did not develop at Logtung. The upper surface of the mineralized zone, as shown by the 0.03% MoS2 contour defines an elongate dome with an apical region approximately coincident with the felsic dike complex. Hydrothermal alteration occurs as well-defined vein selvages, and not as pervasive zones.The Logtung deposit shows many similarities to porphyry Mo deposits in the western Cordillera and may be identified as a porphyry W(scheelite)-Mo deposit, with a W:·Mo ratio of 3.3:1. The principal reasons are: (1) mineralization is spatially associated with porphyritic granitic intrusions and (2) much of the scheelite and molybdenite occurs in typical ""porphyry-style"" vein stockworks"

Jan 1, 1995

By Joanna LaForte

"IntroductionIn respect to The Human Dimension by M. Phyllis Bray, this author's impression is that research on long distance commuting (LDC) is long overdue. This type of mining is not new to many workers, especially those from areas such as the Maritimes, who have had to look for work away from their families for at least a decade. Perhaps to the industry the over-all set-up is new, but to workers who have faced mine shut-downs in their areas finding a job was the main objective and if the security of long-term employment was evident, then the families might join them later. This was the situation with which the writer' s family was faced.LDC LifestyleBeing the wife of an underground miner, the author has personally experienced this lifestyle for almost 10 years, and has never experienced accommodation in a company town. The first five years of marriage were spent in a small rural municipality within 50 miles of the worksite, but the town had industry separate from mining and was not affected by the mine shut-down.Since her LDC lifestyle began her family has been pretty much city-based, out-of-province commuters with two children and a third to arrive some years later. She therefore lived a fairly normal married life with a husband home daily. The author has experienced life with a husband who worked away for five-day stretches and then drove long distances to be home weekends or the portion of time left over from driving and fatigue. She has done the 3D-days in/l4-days out routine, and for approximately the past four years has been existing on a two-weeks in/two-weeks out ritual .The author does not agree that the ""bottom line is that mining families go where the jobs are"" . The miners go where the jobs are and the families fend for themselves with the assistance of the pay cheque making it home each pay period.Perhaps because there are many personal frustrations with this type of lifestyle, perceptions may be inaccurate. Having only dealt with underground operations, there may be gross differences between the pressures and demands of other forms of mining."

Jan 1, 1991

In most instances, the preferred mining methods in steeply dipping narrow vein deposits are selective methods such as cut and fill or shrinkage. The main advantage of these methods lies in the higher degree of control over dilution that can be achieved. However, where ore body geometry lends itself to it, high yield bulk methods can also be attractive. Higher productivity (and the associated lower costs) and lower worker exposure are some of the significant advantages that have made such methods so popular. The Lapa gold mine located in North-Western Quebec uses the long hole mining method (with cemented rock fill) very successfully despite challenging ground conditions. This paper focuses on the experience of the mine with regards to drilling and blasting practices. Firstly, the reasons that prompted the selection of this mining method at Lapa are examined. Secondly, the challenges that the difficult ground conditions found at Lapa pose to drilling and blasting are discussed. Finally, the results of trials of different drilling and blasting strategies that were performed at the mine are presented with particular emphasis on the lessons learned.

Aug 1, 2013

By B. Skrotzki, E. Augenstein, C. Rockenhäuser

"The aluminium alloy 2618A is an Al-Cu-Mg alloy with additions of Fe and Ni, which is designed for long-term operation at elevated temperature in transportation and aerospace industries. The alloy degrades due to coarsening and dissolution of GPB zones and coarsening of S-Phase precipitates (Al2CuMg). This work investigates the overageing process at the application relevant temperatures of 190 °C for durations ranging up to 25,000 h. The nm-sized precipitates were selectively imaged along the <001>a direction of the Al matrix using dark-field transmission electron microscopy. The resulting images were then evaluated and allow the statistically relevant determination of radii distributions and the average radius of the precipitates dependent on temperature and heat treatment duration. Ostwald ripening of the S-phase does not describe the ageing process adequately. Instead, the evolution of GPB zones during the initial ageing regime needs to be considered in addition to the coarsening process of the S-phase. DSC measurements were performed to determine the presence of GPB zones in different ageing states. This will allow a quantitative description of the ageing process and a comparison to samples aged under external load.INTRODUCTION Alloy 2618A is an Al-Cu-Mg alloy, which is part of the 2XXX series of aluminium alloys. It is used in aerospace and transportation industry due to its desirable material properties for long term operation at elevated temperatures (Polmear, 2006). Fe and Ni are added to form intermetallic compounds, which retain microstructural stability at elevated temperatures (Bergsma, Li, & Kassner, 1996; Elgallad, Shen, Zhang, & Chen, 2014; Oguocha, Yannacopoulos, & Jin, 1996; Wang & Yi, 2006). The size and distribution of the nm-sized S-phase formed from the supersaturated solid solution (SSSS) during heat treatments mainly controls the strength (Khan, Starink, & Yan, 2008; Liu, Zhang, Ding, Sun, & Chen, 2003; Parel, Wang, & Starink, 2010; Shih, Ho, & Huang, 1996; Wang, Starink, & Gao, 2006). The S-phase has the composition Al2CuMg and is orthorhombic under equilibrium conditions (Heying, Hoffmann, & Pottgen, 2005; Perlitz & Westgren, 1943). Early experiments proposed the following decomposition of the S-phase sequence during heat treatments (Hardy & Heal, 1954; Silcock, 1961):"

Jan 1, 2018

By M. Sturzenegger

This paper documents a field survey using long-range terrestrial digital photogrammetry at the Palabora open-pit mine, South Africa, for multi-scale characterization of rock mass discontinuities. Stereomodels covering the entire mine were generated based on photographs taken from a distance of 1600m across the pit, using a series of f=20-400mm lenses. Details on the methodology used and its accuracy are discussed. Preliminary results on discontinuity orientation, persistence and intensity are presented, highlighting the effect of observation scale. The potential uses of long-range terrestrial digital photogrammetry in open-pit mine and large natural rock slope environments is emphasized. The use of an f=400mm lens from distances larger than 1.5km may represent an important step forward in the geotechnical characterization of inaccessible remote rock faces.

May 1, 2009

By Kadri Dagdelen

Recent trends of the mining project show that there will be more and more mechanized, largescale mining operations with complex process options to make low grade deposits economically feasible to develop. The global optimization of large scale, complex mine operations will become more important for the future mining. To serve the industry?s future needs, the OptiMine® software program is developed based on expertise gained at the Colorado School of Mines (CSM) for more than two decades, by using the special solution methodology based on the Mixed Integer Linear Programming (MILP) technique in the Operations Research (OR). The program has been beta-tested on more than 20 projects as a multi-time period scheduling and cutoff grade optimization tool that handles large scale open pit and underground mining operations involving complex process options, many stockpiles and dumps, blending requirements, and truck hour limitations. In each project, various operational options are evaluated in OptiMine® to develop strategic planning to help defining company?s strategies and directions. This paper demonstrates how the OptiMine® can be used to optimize a large scale, complex production scheduling problem on a case study coming from real world project. The case study describes multi-pit mine production scheduling optimization with pit backfills in such a fashion that acid generating waste rocks are encapsulated to minimize environmental impact.

Oct 1, 2009

By David Christensen

The long-term performance of dry covers is being examined in a research study funded by the International Network for Acid Prevention (INAP). The study was separated into two phases. The two main components of Phase 1 of the study were the identification and research of the processes affecting the long-term performance of dry cover systems and an examination of available numerical models for simulation of long-term cover performance. Identification and research of the physical, chemical, and biological processes affecting long-term performance showed that cover performance could be related to the change in the saturated hydraulic conductivity of cover material, the change in the soil-water characteristic curve, and the physical integrity of the cover system. Seven numerical models were examined to evaluate their effectiveness in predicting the long-term performance of cover systems. VADOSE/W (Online Help v1.01, 2002) was selected for use in cover system modeling in Phase 2 of the project. Phase 2 of the research study is currently in progress and involved the selection of five mine sites with a minimum of three years of performance monitoring data for analysis of cover performance. Two of the mine sites will be analyzed with the two-dimensional VADOSE/W numerical model. In addition, field saturated hydraulic conductivity tests were completed at three mine sites to investigate the change in field hydraulic conductivity of the cover system materials. The objective of the field testing program was to evaluate changes in hydraulic conductivity of cover material with time. Measurements of field hydraulic conductivity were completed with a Guelph permeameter and a pressure infiltrometer at three sites. The field hydraulic conductivity data was used to evaluate whether a change in this key material property had occurred over time. Field observations and the historic performance monitoring data provided the necessary information to develop hypotheses as to the likely processes that led to any change in field hydraulic conductivity. This paper will briefly summarize the research completed in Phase 1. The remainder of the paper will focus on the field testing program completed to measure the field hydraulic conductivity of constructed cover systems.

Nov 1, 2002

By Lee W. T. Weitzel

This paper reviews the Falconbridge- SMRQ?s Raglan project in northern Quebec and the process that was used in developing its current long-term mine plan. Challenges were many and not only limited to the longevity of the project, numerous ore deposits (both underground and open pit), and a 40km property strike length. As a result of its remote northern location other factors such as progressive reclamation, leachable mine waste, water treatment, and waste management were also part of the plan. A combination of modern planning tools were used to formulate the plan including DataMine, Mine 2-4D, AutoMod Simulation, and an Excel based financial spreadsheet to bring the total plan together. The focus of this paper is to show the complexity of modern mine planning and associated economic modeling of mine processes.

May 1, 2002

By L. W. T. Weitzel

"This paper reviews the Falconbridge- SMRQ’s Raglan project in northern Quebec and the process that was used in developing its current long-term mine plan. Challenges were many and not only limited to the longevity of the project, numerous ore deposits (both underground and open pit), and a 40 km property strike length. As a result of its remote northern location, other factors such as progressive reclamation, leachable mine waste, water treatment, and waste management were also part of the plan. A combination of modern planning tools were used to formulate the plan including DataMine, Mine 2-4D, AutoMod Simulation, and an Excel-based financial spreadsheet to bring the total plan together. The focus of the paper is to show the complexity of modern mine planning and associated economic modelling of mine processes. IntroductionThe Raglan project is located 1660 km directly north of Quebec at the northern tip of the Quebec Peninsula in Nunavik. The main property is 40 km in length stretching from the Donaldson airport area at the eastern edge of the property to East Lake at the western edge. The Deception Bay port is 90 km north of the main complex/mill situated at Katinniq which lies approximately in the middle of the property (Fig. 1). The mine processes 1 000 000 tpy of ore from both open pit and underground sources. The mill is forecasted this year to produce more than 150 000 t of concentrate grading more than 18% nickel. All personnel and critical cargo are transported to the site via a company-leased 737 jet from Rouyn-Noranda where the main administration office is located. The majority of cargo is shipped to the site via Deception Bay from Quebec and on the return trip, nickel concentrate is shipped back. From Quebec, the nickel concentrate is sent by rail to the Falconbridge smelter in Sudbury and on the reverse rail haul, nickel matte from the smelter is sent to Norway via Quebec."

Jan 1, 2003

By George McIsaac

This paper discusses the formulation of a linear program with the objective of maximizing the cash flow of the long-term plan of an underground operation. A mine is split into eleven independent ore zones, each characterized by its reserves, required development and mining method. Based on practical considerations, maximum rates are set for each zone?s development and production capacity. As for the total mine plan, a minimum daily production rate is set along with a minimum feed grade to the mill. A maximum number of development metres per day is set based on the equipment and labour available. Proven and probable ore is mined preferentially over possible ore in the early years of the plan. Furthermore, the fixed cost of operating the mine is taken into consideration whenever mining activities take place. Once the linear program is solved, it can be critically reviewed, and unrealistic results can be identified. Some resource allocations constraints can then be changed in certain sectors, and new results can be analysed. What-if scenarios can also be examined, such as determining the impact of hiring a contractor to develop a given sector, or dropping an ore zone completely from the plan.

May 1, 2003

By G. McIsaac

This paper discusses the formulation of a linear program with the objective of maximizing the cash flow of the long-term plan of an underground operation. A mine is split into eleven independent ore zones, each characterized by its reserves, required development, and mining method. Based on practical considerations, maximum rates are set for each zone?s development and production capacity. For the total mine plan, a minimum daily production rate is set along with a minimum feed grade to the mill. A maximum daily development capacity is set based on the equipment and labour available. Proven and probable ore is mined preferentially over possible ore in the early years of the plan. Also, the fixed cost of operating the mine is taken into consideration whenever mining activities take place. Once the linear program is solved, it can be critically reviewed, and unrealistic results can be identified. Some resource allocations constraints can then be changed in certain sectors, and new results can be analyzed. ?Whatif? scenarios can also be examined, such as determining the impact of hiring a contractor to develop a given sector, or dropping an ore zone completely from the plan.

Sep 1, 2005

By G. McIsaac

"This paper discusses the formulation of a linear program with the objective of maximizing the cash flow of the long-term plan of an underground operation. A mine is split into eleven independent ore zones, each characterized by its reserves, required development, and mining method. Based on practical considerations, maximum rates are set for each zone’s development and production capacity. For the total mine plan, a minimum daily production rate is set along with a minimum feed grade to the mill. A maximum daily development capacity is set based on the equipment and labour available. Proven and probable ore is mined preferentially over possible ore in the early years of the plan. Also, the fixed cost of operating the mine is taken into consideration whenever mining activities take place.Once the linear program is solved, it can be critically reviewed, and unrealistic results can be identified. Some resource allocations constraints can then be changed in certain sectors, and new results can be analyzed. “Whatif” scenarios can also be examined, such as determining the impact of hiring a contractor to develop a given sector, or dropping an ore zone completely from the plan."

Jan 1, 2005