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Some Statistics ? Feasibilitystudiescostbetween2% & 3% of capital andrequire8% to15% of total engineering effort ? Feasibilitystudiesusuallytakebetween8 and16 months ? Historically more than80% of projects fail to achieve all their objectives, usually blame the feasibility study ? What is bankable? Means that your promises will long be remembered. ? Poorly executed feasibility studies ? Driven by inexperience, unrealistic expectations, time constraints, financial constraints, lack of objectivity, front end loading activities incomplete or poorly done ? lack of minimum standard to provide a consistent approach Trend to improve???

May 1, 2010

By Zhanyou Huang

The logic and capabilities of a short-term planning tool are presented. It was developed using mixed integer linear programming (MILP) techniques to solve the open-pit and underground mine planning problems that include multiple mining areas, multiple processes, multiple destinations and blending requirements. It finds the optimum schedule that achieves the objective while satisfying comprehensive product quality and quantity requirements, equipment utilizations, as well as physical and technical constraints. A case study is given to demonstrate its applications.

Oct 1, 2009

By Melissa Whellams

?? What is a social risk assessment (SRA)? ?? Why do a SRA? ?? When do you do a SRA? ?? How do you do a SRA? What is a social risk assessment? ?? SIA vs. SRA ? SIAs determine how a company?s project will affect social/cultural conditions in a region ? SRAs determine how social/cultural conditions will affect the risk profile of a company?s project Social risk context includes: ? review of human rights record ? analysis of conflict situation ? analysis of political climate ? stakeholder identification ? stakeholder concern/interest identification ? And so on?

May 1, 2008

By Zhanyou Huang

The logic and capabilities of a short-term planning tool are presented. It was developed using mixed integer linear programming (MILP) techniques to solve the open-pit and underground mine planning problems that include multiple mining areas, multiple processes, multiple destinations and blending requirements. It finds the optimum schedule that achieves the objective while satisfying comprehensive product quality and quantity requirements, equipment utilizations, as well as physical and technical constraints. A case study is given to demonstrate its applications.

Oct 1, 2009

By G. B. Bosworth, M. J. Lake, J. W. Hogg

The Quintette Coal operation in northeastern British Columbia has one of the world's largest Preparation Plants, with a design capacity of 6.5 million tonnes per year of clean coal.This paper will discuss several innovative aspects of the flowsheet and plant design with particular reference to the selection of process equipment, materials handling and control systems.The operations and maintenance experience during the first two years of production will be described and discussed in relation to the design objectives.

Jan 1, 1987

By H. Zniber El Mouhabbis

Ore dilution or stope overbreak increases the cost of production and ultimately reduces the profitability of a mining operation. The adverse economic impact of ore dilution is due to the added costs associated with the mucking, haulage, crushing, hoisting, milling, and treatment of waste rock or low grade ore in the hangingwall and footwall. One factor that could have a significant influence on stope overbreak is the undercutting of the stope into the walls. Undercutting stope walls is often necessary, in particular in narrow vein mines. Moreover, equipment size has a role in drift sizing where stope undercutting may become a must in order to fit the mobile equipment while respecting legal clearances.

May 1, 2009

By Nathalie Gauthier

Bien que le système de ventilation du Puits Penna soit de taille imposante et que plus de $30M y seront engloutis pour son développement, aucun budget spécifique n?avait été préalablement consenti pour refroidir l?air acheminé aux places de travail dans la partie profonde de la mine. Le système de ventilation a été conçu en deux étapes distinctes : le réseau du haut de la mine lequel dessert jusqu?à 1550 m de profondeur et le réseau du bas de la mine (de 1550 m à 2200m) qui a été créé ultérieurement. Le réseau inférieur a été imaginé de façon à acheminer l?air frais directement au gisement et de permettre l?évacuation aux extrémités afin de rejeter l?air chaud immédiatement après l?avoir utilisé. Au total, lorsque le réseau de ventilation sera complété, plus de 670 m3/s d?air sera véhiculé dont jusqu?à 495 m3/s pour la partie inférieure de la mine considérant une capacité totale maximum de 710 m3/s en utilisant la mine adjacente.

May 1, 2003

Introduction ?MT involves the measurement of naturally occurring magnetic and electric field oscillations. ?The ratio of E/H (wave impedance) is measured as a function of frequency to give resistivitydepth information. ?The ratio of vertical and horizontal magnetic fields (tipper) gives information about the location of (channeled) current systems.

May 1, 2008

By Y. Qi

A cell-level nonlinear dynamic model of solid oxide fuel cell (SOFC) based on physical diffusion principles is built in this note. It demonstrates that reactant diffusion processes from gas flow bulks to triple phase boundaries (tpbs) play an important role in the dynamic behaviors of SOFC. The simulation shows that under certain condition, the effect of the double layer capacitance may be neglected. The phenomenon of slow rise of voltage in current interrupt experiment may be explained by the dynamic behaviors of partial pressures in the vicinity immediately above tpbs.

Jan 1, 2005

By L. Kraszewski

"IntroductionPortland cement is produced by burning an accurately proportioned mixture (raw feed) of finely ground limestone, silica, alumina, and iron oxide. The kiln discharge (clinker) is a chemically complex mixture of calcium silicates, aluminates and ferrites which when ground and blended with from 2 to 5 percent of calcium sulphate is sold as Portland cement.ManufactureThe most common raw materials are limestone and clay or shale. The raw mix is finely ground and heated to about (2600°F) 1430°C to decompose the calcium carbonate and combine the calcium oxide with silica, alumina and iron to form a partly fused clinker. The clinker is then ground, usually with a small proportion of calcium sulphate (gypsum), which regulates set. Cements with special properties are produced by varying the oxide composition and also by adding small amounts of chemical agents at the clinker-grinding stage or later.Clinker is manufactured by either wet or dry process methods. In the wet process, raw materials are prepared, blended and fed to the kiln as a water slurry (about 30-35% water) . In the dry process, raw materials are prepared, blended and fed to the kiln as a dry powder (about 0.5% water). The processing procedure is as follows:"

Jan 1, 1982

By R. G. Bradburn

"Brenda Mines Limited is a low grade open pit mining and milling operation located near Peachland, British Columbia. The mill was brought into production in late 1969 at a rated capacity of 24,000 tons per day. Tt currently treats an average of 30,000 tons per day of an ore that has an average grade of 0.130% copper and 0.030% molybdenum.Description of Crushing and Grinding CircuitsRun of mine ore is delivered to a primary gyratory crusher. The minus seven inch product is separated into plus and minus one inch fractions on two parallel vibrating screens. The fine product is conveyed directly to the mill fine ore bins, while the coarse fraction is sent to a 45,000 ton stockpile.Material from the stockpile is fed to two standard cone crushers which operate in an open circuit with five secondary vibrating screens. The minus five-eighth inch product from these screens is conveyed to the mill fine ore bins while the coarse fraction is fed to four shorthead cone crushers. These crushers operate in closed circuit with the screens."

Jan 1, 1981

By V. Chatain

The environmental assessment of historical mining sites contaminated with various inorganic species, as also the determination of remediation targets require a better knowledge of pollutant-bearing phases. The objective of this paper was to investigate the operational fractionation of arsenic (As) in an As contaminated (ca. 3 wt%) soil collected from a gold mining site in France, where mining activities and smelting processes of gold ores took place until 2004. Single and sequential chemical extraction procedures were performed to evaluate the potential mobility of As according to the fractions to which it was associated in the contaminated soil, and also the part of As sorbed onto soil particles. These procedures used provided information on the nature of As fixation processes in the mining soil studied. Results showed that As appeared mainly sorbed (ca. 72%) with iron on the soil particles, in particular amorphous iron oxyhydroxides. These results confirmed a potential risk of arsenic mobilization under acidic and/or reducing conditions, which frequently occur in mining environment. This research evidenced the importance of the knowledge of As-bearing phases to better predict the mobility of this pollutant and in turn improve the management of As contaminated sites.

Aug 1, 2013

By Malcolm Scoble

School Values ?? Each other; ?? Students, & helping them develop intellectually, personally & professionally; ?? Freedom to pursue educational & research opportunities; ?? Home-work-life balance; ?? The geographic-business community in which we operate ; ?? The pursuit of excellence; ?? Our contribution to society; ?? Creativity & innovation; ?? Teamwork & collaboration; ?? Career development, achievement & reward.

May 1, 2008

By Edouard Masengo

A long dyke will be constructed in a lake with rockfill placed by end dumping method. Its crest will be at elevation 521.5 m compared to the nominal lake level at 520 m. In the first portion, its height will vary from 1.5 m on a 35.1 m thick tailings layer to 18.3 m on about 0.5 m of tailings. In the second portion, the dyke will be built on native silty clay and will vary from 18.3 to 15.2 m in height. The tailings consist in stratified layers of fine-grained soils showing lateral and vertical segregation. The tailings are compressible and may develop excess pore water pressure on loading. The tailings overlie a thin layer of relatively soft native silty clay. The till beneath the silty clay is considered incompressible compared to the material above. After construction, as the tailings and silty clay consolidate, pore water pressures will dissipate and dyke stability will improve. Since dyke stability will increase with time, the primary concern is its stability during construction. As a result of construction activities, three potential modes of failure were identified and recommendations were provided regarding the measures that should be undertaken to increase dyke stability during construction.

May 1, 2003

By P. Hickey, A. Oliver

"In March 1993, Ram Raising Limited was faced with a challenge. Placer Dome Incorporated, Dome Mine Division requested from Ram Raising that they design station excavation into the existing No. 8 shaft from No. 3 mine levels. This work had to be done without loss of production time in the underground department.Due to the time frame of the project, every detail had to be carefully considered, with extra care that all pros and cons had been worked out.Ram Raising submitted a work Plan that had been worked out with the Redpath Group which included the infrastructure requirements; the engineering design; the scheduling and sequence of work; and the excavation design and blasting procedures.A proposal was' put together by both Ram Raising and Placer Dome outlining the infrastructure requirements, including the engineering design, scheduling and sequence of the work, excavation design and blasting procedures. The proposal accepted by Placer Dome and, on July 3D, 1993 work commenced to breakthrough eight stations. Work continued until December 1993 with the completion off our stations. The project was then stopped to allow the station access drifts from No.3 mine to be completed. The second phase of the project began on May 27 and was completed on September 15, 1994.This paper shows how, through innovative design and the full cooperation between client and contractor, a project of this nature can be completed successfully."

Jan 1, 1995

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 K. Sasaki

Ventilation measurements were carried out in a shallow underground-quarry space with relatively large internal volume of 14,600 m3 in order to evaluate its effective ventilation characteristics. Based on air velocity measurements with an ultrasonic anemometer in the exhaust airway connected to the space, it was found that the space was ventilated by natural ventilation airflow with intermittent changes in direction. It was difficult to measure the ventilation flow with typical methods of flow measurement provided from the intake portal and throughout the mine, because the cross-sectional area and volume of the openings were too large and the flow was variable. In the present study, a tracer gas method was applied to evaluate the effective ventilation airflow rate in the space. A photo-acoustic infra-red gas monitor, highly sensitive to SF6 gas used as a tracer gas, was set in the space to determine air exchange rates from gas concentration-time decay curves. The seasonal variations of airflow and thermal environment in the space were investigated through 13 sets of measurements taken over 15 months. Airborne rock dust concentrations were also measured at same time in the opening. The correlations between the effective ventilation airflow rate, thermal environment and dust concentrations in the opening space were analyzed and are discussed based on the presented measurements taken during year. It is concluded that seasonal variations in effective ventilation flow and the dust concentration are mainly due to differences in air temperature in the space, as affected by the rock?s surface temperature and atmospheric temperature. In summertime, the air temperature and associated air density difference generated lower natural ventilation flows resulting in higher dust concentrations.

Aug 1, 2013

By Rodney G. Orr, Phil Robertshaw, Roland Loewer, Klau Lehnert-Thiel

This paper documents the 1988 discovery and subsequent evaluation (to 1991) of diamond bearing kimberlites in the Fort à la Corne area, Saskatchewan, by Uranerz Exploration and Mining Limited. Cameco Corporation began participating as a joint venture partner (50%) in mid-1989. The first indications that kimberlite-type intrusions might exist in the area carne from Geological Survey of Canada aeromagnetic maps. Because of the overburden thickness (over 100 m), magnetometer surveys continue to be the main exploration tool in defining pipe locations and sizes. Magnetometer surveys in varying levels of detail have outlined one main cluster and two sub-clusters, the main group being some 10 km by 50 km in size. In excess of 70 individual targets have been interpreted from the magnetics as probably representing kimberlites. The size range of the individual magnetically-defined bodies is between 1 ha and 74 ha. Proof that the magnetic anomalies were kimberlite intrusions carne in 1989 when each of seven test holes, all drilled on different targets, intersected the potential diamond host rock. The majority of the targets tested were diamond-bearing, with the indicator mineral chemistries suggesting that both peridotitic and ecIogitic diamond parageneses could be expected. To date, 18 individual kimberlite bodies have been drill-tested. A total of 39 bulk samples, amounting to 186 t (representing 360 t of theoretical sample recoveries) were processed in 1990 and 1991. One hundred and sixty diamonds were recovered, averaging 0.04 carats in weight, the largest being 0.6 carats. Most of the bulk sample grades are less than 2 carats/loo t; only three bulk samples have higher grades, the best being approximately 10.5 carats/l00 1. The diamonds are predominantly gem-quality stones.

Jan 1, 1992

By T. Hidayat

The distributions of minor elements between slag/metal and slag/matte in equilibrium with tridymite in the Cu-Fe-O-S-Si-Al-Ca system have been investigated in the range of conditions of interest to the high- temperature copper production, refining, and recycling processes. An improved experimental methodology has been used involving high temperature equilibration in controlled gas atmospheres, rapid quenching, and quantitative microanalysis techniques using Electron Probe X-ray Microanalysis (EPMA) and Laser Ablation Inductively Coupled Plasma Mass Spectrum (LAICPMS). The effect of oxygen partial pressure on the distributions of minor elements between slag/metal and slag/matte has been accurately measured. The effects of slagging components (Al2O3 and CaO) on the distributions of minor elements between slag/metal have also been experimentally determined. The present study is a part of a larger integrated experimental and thermodynamic modelling research program in the systems relevant to high-temperature copper processing. INTRODUCTION In the high temperature processing of copper, minor elements are distributed between different phases, i.e. liquid slag, liquid matte, and liquid metal. From a processing perspective, it is desired to have the valuable minor elements distribute predominantly in the metal and matte phases rather than in the slag phase, and to have the non-valuable minor elements distribute predominantly in the slag phase rather than in the metal and matte phases. Knowledge of the distributions of minor elements between phases in the smelting, converting, and refining processes is required if the distributions of minor elements between phases in these processes are to be optimized.

Jan 1, 2019

By I. Paredes, R. Díaz, H. Henao

Smelting of copper concentrate generates a significant amount of dusts which are collected in electrostatic precipitators. This material, which is a complex oxide of Cu, Fe, S, As, Sb, Bi and others, is difficult to recirculate into the smelting process due to the reported high concentration of arsenic. However, the dust also has concentration of copper above 10wt %, aside from reported contents of silver corresponding as much as 25wt% of the total inventories of this element in the smelters. Thus, it is of economic and environmental interest the development of a process able to reduce the concentration of arsenic in the dust and produce a material suitable to be recirculated into the smelting process. The present experimental work shows the results of a process of dust sulfidization-oxidition able to remove more than 65wt% of the arsenic present. INTRODUCTION Copper sulfide deposits worldwide exhibit increasing concentrations of arsenic. One case of interest would be the copper ores from the northern zone of Chile, which report high concentrations of enargite (Cu3AsS4) (Revista química, 2015) (Latinominería, 2014). The obtained concentrate from this ore is treated in a Fluidized Bed Roaster, producing calcines with low concentration of arsenic (<0.5 wt% As). This material is suitable to be treated in a Flash Furnace. At the roasting process, the arsenic is volatilized and then precipitated as fine particles of complex oxides. Most of this particulate material is removed from the gas stream through a device called Electrostatic Precipitator (Minería chilena, 2014). The experimental results reported in the literature indicate that arsenic present in these particulate materials (or dusts) cannot be eliminated in oxidizing atmospheres (air) or with inert gases (N2) in a Fluidized Bed Roaster even at temperatures as high as 700°C. There is also information that even the recovery of valuable metals from the dust is difficult through hydrometallurgical processes (private communication). This is how in some foundries these dusts are considered environmental liabilities. Regarding the decomposition of enargite (Cu3AsS4) in neutral atmosphere, it is reported in the literature (Padilla, 2001) that the main chemical reactions are:

Jan 1, 2019