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By J. Buckle

"Recognition of the diamond potential of the Wawa subprovince was initially determined from regional data using a kimberlite model. The world’s largest stable Precambrian craton, the Superior Province, is considered to be favourable for the emplacement of diamondiferous kimberlite. The Wawa area is located near the intersection of intra-craton structures visible in the regional magnetic data.The Enigma project is located north of the town of Wawa in northern Ontario. From field evidence and background research, it became obvious that in the Wawa area there were at least two potentially diamond-hosting events, Archean lamprophyric volcaniclastics and Proterozoic kimberlites. The host lamprophyric rock does not contain the classical KIM signatures. However, to complicate the Enigma, stream sediment samples within 200 m of the diamond-bearing lamprophyre produced a typical suite of kimberlite indicator minerals.The micro- and macro-diamond content of the Wawa lamprophyric volcaniclastic rocks is typically 0.2 ct/t to 1 ct/t, although it can be higher locally. The economic diamond potential of these Archean dykes, sills and irregular lamprophyre bodies is still under-explored (Kaminsky, 2002, unpubl.). Oasis Diamond Exploration is currently exploring the area using geophysical, geochemical, and geological data."

Jan 1, 2002

By R. A. Bergman, C. A. Pickles, J. M. Toguri

"Black calcium cyanide is utilized mainly as a reagent for gold extraction. It is produced by reacting calcium cyanamide, sodium chloride and calcium carbide at temperatures in the range of 1200°C to 1400°C in a smothered arc furnace. The equivalent sodium cyanide content of the product is in the range of 45% to 50% and the calcium cyanamide conversion efficiency is in the range of 90% to 95%. Since black cyanide contains impurities such as salt and lime and also because the conversion efficiencies are below 100%, the product contains unwanted materials which significantly increase the shipping costs.The impurity content of the raw materials can not be lowered without increasing their cost and/or the processes to produce them, and therefore the present research was focussed on studying those factors which affect the cyanide grade. The major variables investigated were: the heating rate, the reaction temperature, the salt to cyanamide ratio, the nitrogen content of the calcium cyanamide, moisture additions and calcium carbide additions. It was found that each of these variables had a significant effect on the product grade. The highest cyanide content of the product was obtained for salt to cyanamide mass ratios of 0.55 to 0.60. The salt reduces the decomposition rate of the cyanide and, therefore, at low salt to cyanamide ratios and at higher temperatures, the product grade is decreased. It is likely that the salt evaporates at the higher reaction temperatures and this decreases the cyanide capacity of the melt. High heating rates minimize the residence time and thus salt evaporation is reduced and higher grades can be obtained. As expected, the cyanide content increased with the nitrogen content of the cyanamide. Calcium carbide additions resulted in an increase in the product grade. The presence of small amounts of moisture in the charge caused a significant decrease in the cyanide content of the black cyanide. An equilibrium reaction is postulated in order to explain the black cyanide process and in particular the effect of calcium carbide on the product grade."

Jan 1, 2002

By Finch. J. A., C. Perez, J. M. Ortiz, G. Cortes, A. B. Yañiez, F. Coddou, P. Morales, H. Elgueta

A campaign to perform characterization tests in a TankCell®-300 flotation cell installed at Chuquicamata Codelco's concentrator was conducted. The campaign included integrated gas dispersion measurements (gas velocity radial mapping and single point gas holdup and bubble size) and determination of frother concentration. Cell streams were sampled to assess metallurgical performance at the same time. The experimental program was designed to establish the bubble surface area flux operating range and its effect on performance, and the effect of using longer residence times and of a device designed to enhance mixing in the collection zone (FlowBooster(TM)). The gas dispersion results and their relationship to metallurgical performance are discussed.

Jan 1, 2009

By Douglas M. Smith, G. A. Maki

"The initial development of the massive potash deposits of the prairie evaporite formation took place over a decade ending in 1970. The potash mining and refining facility near Rocanvi11e, Saskatchewan was the 1ast of ten mines to come into production during that era. This operation, known as Sylvite of Canada Ltd., was designed to produce 1. 2 million short tons per year of KCl product in granular, coarse, standard and special standard grades.In 1977 the parent company, Hudson Bay Mining and Smelting, sold the Sylvite property to the Potash Corporation of Saskatchewan. Shortly thereafter PCS slated its new Rocanville Division for a two phase program of expansion. The first phase, completed in the spring of 1979, was relatively small, involving mill debottlenecking and additional equipment in the compaction circuit and the product and ore storage areas. The second phase was a major undertaking which included additional mining equipment and a new 300 STPH milling circuit. This work was completed during the fall of 1981 and has increased the Rocanville Division's nameplate capacity to two million STPY.Thickening equipment operating in the Saskatchewan potash industry is generally situated within the main refinery building or a separate insulated and heated structure due to the harsh winter climate and the need to closely control plant brine temperatures to ensure good flotation circuit performance. Since these thickeners process large volumes of slurries, conventional basin type designs tend to be large, ranging up to 150 feet in diameter or more. As part of the general effort to minimize capital costs, the potash industry has begun investigating the use of alternate high capacity, compact thickener designs. In this regard, PCS Rocanville undertook a program in 1978 to evaluate a Lamella™ Thickener and one other type of 'High Rate' thickener* as alternatives to a conventional design for the phase two expansion project."

Jan 1, 1983

By Dara L. Hrytzak-Lieffers

Canada has long since been a place that has led the world in mining development, in a safe, clean, and sustainable manner. This has led to the integration of corporate social responsibility (CSR) philosophy in corporate governance, policy, and programming. The paper will identify the basis of CSR practise in Canada?s mining industry and provide a Canadian example of CSR implementation. Biography Dara Hrytzak-Lieffers is the manager, corporate social responsibility at Cameco Corporation. She oversees corporate CSR initiatives including the Sustainable Development report and public engagement programs. Dara received her BA in International Studies from the University of Saskatchewan and an MA in International Conflict Analysis from the Brussels School of International Studies. She is a recent graduate of the World Nuclear University summer institute.

May 1, 2011

Taking Up the AFN Corporate Challenge ?? About MAC ?? ?Towards Sustainable Mining? ??Mining and Aboriginal Peoples Framework ?? AFN-MAC Relationship ?? A New MAC Northern Initiative ??Social and Economic Progress ?? A View to the Future?

May 1, 2009

By C. J. Hodgson

"IntroductionThe Kitsault molybdenum mine is located 600 m above sea level on Lime Creek at the head of the inlet of Alice Arm, 140 km northeast of Prince Rupert, British Columbia (Fig. 1). The area of the mine is characterized by rugged topography and deeply incised creeks which drain into the Portland Canal - Observatory Inlet fjord system. Access is by air service or boat from Prince Rupert, or by secondary road from Terrace.HistoryThe deposit was first staked in 1911, at which time the main feature of interest was a polymetallic vein with values in silver located southeast of the molybdenum deposit (Woodcock and Carter, 1976). Turnbull (1916) was the first to describe the extensive zone of crisscross quartz stringers with Mo~ on the banks of Lime Creek which, although it clearly had the potential to contain a major deposit, was not then believed to be of commercial value.Following sporadic work through the 1920s and early 1930s, the ground lay idle unti11959 when Kennco Explorations (Western) Ltd. commenced a program of systematic diamond drilling on the stockwork-type mineralization adjacent to Lime Creek. In late 1964, Kennco announced the presence of an orebody of 36 million tonnes averaging 0.230Jo Mo~ which was to be put into production at a rate of 5450 tonnes per day under a new subsidiary, British Columbia Molybdenum Ltd., at a forecasted capital cost of $20 million (revised to $30 million).Between January 1968 and April 1972, 10.4 million kg of molybdenum were produced from 9.3 million tonnes of ore, at an average mill recovery of 90%, and with an average mill head grade of 0.206% Mo~. The ore was mined in an open pit with a waste to ore stip ratio of 1.5 to 1. The. operation was terminated in 1972 due to weak molybdenum prices and escalating costs.In May 1973, the deposit was purchased by Climax Molybdenum Corporation of British Columbia, Limited and in 1979 transferred to affiliate Amax of Canada Limited. In early 1979, following completion of detailed feasibility studies, Arnax commenced construction of the 10 900 tonne per day Kitsault mine and mill complex based on a mineable open pit reserve of 95 million tonnes at an average grade of 0.192% Mo~, sufficient for a mine life of 25 years. The original capital cost estimate was $143 million; it subsequently escalated to approximately $200 million."

Jan 1, 1995

By P. A. Selvadurai

This paper presents the results of a research investigation leading to the development of a technique for the measurement of the surface permeability of Indiana Limestone. The tests are conducted on a cuboidal block of the limestone with a flat surface that can be sealed to create a circular aperture through which water influx can take place. Computational results for Darcy flow are used to interpret the results of the experiments. The water entry area can be moved over the surface area of the block to investigate, quite conveniently, the distribution of permeability across the surface of the limestone block sample.

May 1, 2009

By Glenn K. Nolan

"Today, more than any other time in recent history, aboriginal communities are looking for ways to be understood as more resource development companies continue to explore and develop Canada's vast resource potential.Recent Supreme Court rulings have affirmed the need to engage aboriginal communities early on in resource development projects. There are many conflicting ideas on how, who, and when to engage. Given the large number of communities and varied cultures, each resource development company must equip itself with a better understanding of the people they are planning to work with.The lecture will begin with a basic historical perspective on treaties and the various societies across Canada. We will also explore the current situation many communities find themselves in today. Building a meaningful relationship with a community is the foundation for a lasting partnership. Every community is unique and every approach to engage communities must be just as unique. The lecture will outline some basic steps that can lead to a better relationship building process between the communities and companies."

Jan 1, 2008

By S. Belair, V. Weigel

As a growing mining company, ERAMET is looking for new positions on the strategic metals market. In this context, the Gabonese Maboumine pyrochlore deposit is currently being studied for the recovery of niobium, tantalum, rare earth elements (REE), and uranium. This ore shows mineralogical and chemical characteristics that make it challenging to process by already known practices, from both technical and economic points of view. In this context, ERAMET has developed since 2008 an innovative hydrometallurgical process which has been successfully operated at a pilot plant scale. While the upstream part of the process aims to dissolve the valuable elements in sulphuric acid, the downstream part of the process aims to recover them separately in a marketable form. The focus here will be on the recovery of the REE. The ore deposit contains approximately 1.4% of REE including 87% of light REE and 13% of medium-heavy REE. The challenge in this process lies in the fact that the major elements in the matrix are iron and aluminum. An innovative process has been developed in order to recover all of the REE in these unfavourable conditions, described in this paper.

Jan 1, 2014

By H. R. Bullis

"Abstract- This paper discusses what appears to be a flaw in the current belief, widely held within the gold mining industry and investment community, that the creation of ever-larger gold mining companies is desirable for mining companies and investors alike. The basis of the flaw is in the underlying assumption that very large gold producers can discover or acquire new gold deposits of the size necessary to replace extracted reserves on a year-on-year basis over the intermediate to long term (i.e., five to ten years and longer). As it will be noted in this paper, deposits of the size required to replace annual production of very large gold producers (VLGPs) are relatively few in number. Although discoveries of new gold deposits continue to be made, they are predominantly in the 0.5 to 2.0 million ounce range. Data represented here suggest that, although gold production from individual VLGPs continues to increase, the change is due to merging or acquiring other companies or projects with similar reserve life profiles. Therefore, the reserve life profiles of VLGPs have remained flat or have decreased.The paper will note recent changes in the industry and the remarkable increase in gold production reported by individual mining companies over the past several years. It will provide an overview of the geographical and geological distribution of known gold deposits and the range of deposit sizes. Finally, the paper will discuss the challenges that face large gold producers in replenishing their reserves that are being depleted at an ever-increasing rate. Unless otherwise stated, all production and reserve data have been taken from company documents in the public domain or publicly available information."

Jan 1, 2001

By Denis Thibodeau

his paper describes a study of an altered mining extraction and the resulting Rockmass response at VALE?s Creighton Mine. Typically, the deep mining zones have strict stope extraction guidelines to ensure safety and productivity; however, these guidelines offer low flexibility or few options for stope sequencing. The 402 O. B. being in a good rock mass, at moderate depth and stress regime at Creighton, offered an opportunity to drive a more flexible mining sequence with stopes and a pillar. A three-phased approach was used to mitigate risk of the mining plan: 1- Numerical modelling to fully anticipate rock mass response to the proposed mining sequences. 2- In situ seismic monitoring to collect stress and seismic activity data. 3- Analysis of the in situ data to correlate to the modelling results. The creation and the extraction of a pillar in the 402 O. B. was successfully completed. The recorded seismic activity agrees well with the numerical modelling since most of the seismic activity is localised in the hangingwall where the deviatoric stress corresponds to an early damage process. The moderate levels of deviatoric stress cause localised failure with low level of seismic activity.

May 1, 2013

By D. E. Gorse, R. G. Anderson

"Indusmin's history dates back to 1937 when they developed the Blue Mountain Nepheline Syenite deposit at Nephton, Ontario, and began supplying material for the glass, fiberglass, paint, ceramics and rubber industries.Since then, as a subsidiary of Falconbridge Nickel Mines, Indusmin has expanded the Nephton operation, diversified into the aggregate quarries for the construction industries, with operations at Acton and Halton, Ontario, established silica plants at St. Canut, Quebec and Midland, Ontario, to supply the glass, carbide, ceramics, cleanser and concrete products industries, and the purchase of a foundry, Fahramet Limited, Orillia, Ontario, supplying steel and alloy castings to the mining, construction cement and petrochemical industries.Indusmin also has a Technical Resource Centre and Head Office facilities in Toronto.As this paper deals with Indusmin's experience with dust abatement, and although dust control is a concern at the Nephton, St. Canut and Orillia plants, we will be confining this paper to the experience gained at the Badgeley Quarry and Midland plant of the Ontario Silica Operation."

Jan 1, 1980

Material scheduling, sequencing planning and execution are the core tactical mine plan for achieving production targets that maximize the objective function of any mine production entity. This objective function is constrained by several exogenous and endogenous constraints including geological, operating, technological, marketing, financial, political, social and local field constraints. Linear and dynamic programming techniques have been used to formulate algorithms to solve the problems associated with scheduling and sequencing operations. These algorithms possess the mathematical rigor for dealing with the fundamental problems but they fail to provide adequate answers to random and dynamic process problems. Materials scheduling and sequencing are carried out within the bounds of random and dynamic fields. The functional relations between the output and dependent variables are random, and thus, current algorithms are limited in their abilities to address the problems arising from these random field processes. In this study a production simulator is developed to capture the random field process associated with materials scheduling and sequencing in an open pit environment. The algorithm incorporates a geometric pit evolution model, using solid geometry of an ellipsoidal frustum to capture material displacement dynamics. Taylor series expansion about the dimensions of the initial frustum is used to provide numerical solutions to the resulting partial differential equations governing the pushback dynamics. A production simulator, derived from the stochastic and dynamic models, is developed, validated and used to simulate the changes in the pit volume resulting from periodic incremental pushbacks and the random field process. The hybrid stochastic-optimization algorithm provides a powerful tool for addressing the random field and dynamic process problems. Combined with a hybrid stochastic-optimization dispatch system, tactical production planning and execution will be efficient and economic for achieving desired.

May 1, 2004

By L. J. Vincze

The high cost of constructing mineral processing plants in remote locations warrants a close examination of the alternatives available for reducing the amount of on-site construction work. Among the alternatives are portable process plants, modular design and barge mounted plants. Each alternative has certain advantages as well as limitations depending upon specific conditions. On the basis of practical experience and engineering analysis, the paper examines the potential benefits to be realized by these techniques and summarizes the conditions required to obtain them. The potential savings indicated by such studies should encourage consideration of innovative design features for new plants located in remote areas.

Jan 1, 1980

By A. Saigal

The effect of temperature on the cutting forces during machining of alumina reinforced aluminum composites was investigated, Aluminum 6061, 10% Al2O3 reinforced composite and 20% Al2O3 reinforced composite were tested, A 5/8-inch diameter high-speed steel end mill, a Micro 100 TiN coated single edge endmill cutter and a two-fluted solid carbide insert cutter were used for tooling, The results, in general, showed an increase in the cutting forces as the temperature of the material increased, From the raw data, there are temperatures ranges in which the force data did decrease but they were insignificant with regards to predicting a downward trend. A regression analysis was used to understand which variables had the greatest affect on the forces being generated, The correlation and regression analysis showed that at 600 rpm (velocity: HSS- 98,2 sfpm, Micro 100 cutter - 78,5 sfpm, solid carbide cutter - 192,4 sfpm) the tooling, the workpiece material, built up edge, and temperature were statistically significant factors in the test, Tooling was a significant variable in all testing, The smallest forces recorded during machining were generated with the solid carbide two-fluted endmill cutter, Visually, the solid carbide tooling produced a better surface finish during the testing which made it the tool of choice, In addition, the force data proved that as the cutting speeds were increased, the cutting forces decreased.

Jan 1, 2005

By B. W. Clyburn

"Coals from the Corporation's Lingan and No. 26 mines are classified as high-volatile A bituminous, with a very low inherent ash and containing a/l essential properties to provide metallurgical coal, with the exception of a high sulphur content. Only through proper cleaning at low specific gravity can the pyritic sulphur fraction of the coal be liberated to an extent where final sulphur meets coking standards. This first section of the paper deals with the operation of a Dutch State Mines heavy-media cyclone circuit to achieve an actual separation in the region of 1.30 specific gravity. A discussion of the parameter of control which must be applied along with an appraisal of the results obtained is included in the paper.IntroductionVery high fluidity and unusually low ash are the outstanding characteristics of coal from Devco's mines in the Harbour seam of the Sydney coal field.However, sulphur content, mainly pyritic, ranges from 1 to 2.5070. To obtain the low and consistent sulphur level required in metallurgical coking coals, preparation at low specific gravity is required .Metallurgical coke is used as the fuel in an iron blast furnace. Its sulphur content largely determines the quantity of slag required to remove it and therefore influences furnace productivity and unit costs.Typical data on the various coal properties of importance in the production of coke are included in Table I. Necessity of Low-Gravity SeparationThe design of any coal preparation plant requires the study of washability properties of the coal to be treated to determine the quantity and quality of coal produced at a given specific gravity along with the difficulty in accomplishing that separation.Their low ash content allows the important washability aspects of Harbour seam coals to be represented by sulphur! specific gravity curves (Fig. I). This particular example indicates that a yield of 54.5% is attained, at a sulphur content of 1.20%, for a perfect separating device operating with a 1.29 S.G. cut point.Material rejected from this separation still contains usable coal, which is recovered as middlings by separating at a higher gravity."

Jan 1, 1980

By Dave Bulled, Jim Thompson, Tim Leriche, Mark Blake, Troy Wilkie

"A commitment to a core testing, plant modeling and reconciling technique has shown substantial economic benefits to IOC in terms of accurate production forecasting, smoother operation of the mill, improved expectations of throughput and co-operation across production departments from geology, planning, mining, and processing, to shipping of concentrate to market.This paper describes a successful seven year program of forecasting throughput of the autogenous milling circuit at the Carol Lake concentrator of IOC. Work started with audits of the grinding circuit in 2001 and benchmarking of the data collected from samples of mill feed and plant operation to the CEET mill design and throughput forecasting model.Initially 390 drill core samples were tested for SAG Power Index (SPI) to measure the energy required in milling, and the data distributed using a geostatistical technique across the two operating pits, so that hardness was estimated in each of the 40,000 blocks (or 1500 million tons) of potential ore. In 2004 a forecast of energy requirement, i.e. forecast of throughput for a given power availability at the mill, was produced for each ore block using the CEET model and used for mine planning to smooth plant throughput. The forecast for blocks mined on a monthly basis was reconciled with plant results over the next 2 years and minor changes made to the CEET model. The forecasting exercise was repeated in 2006 and in 2008 with the latest model based on the testing of almost 1300 samples of drill core at closer spacing.INTRODUCTIONThe contracting of sales to clients and the timely supply of products to meet those contracts is a cornerstone of good business practice. Ensuring the correct scheduling of production is a major concern of mining companies where the supply and qualities of the raw material is uncertain and production facilities are not flexible. This is particularly challenging when the product is of high volume and produced far from the customer, such as iron ore.Apart from the metal content of the ore being mined, the greatest impact on production scheduling is the throughput of the comminution section of the extraction plant; most notably when size reduction is achieved by autogenous grinding. The response of the mills to variability in the hardness of the ore can change throughput by as much as 50% from day to day at some plants."

Jan 1, 2009

By Fathi Habashi

Extraction by organic solvents is a chemical process in which metal species in the aqueous phase react with an organic reagent to form an organometallic com- plex, thus, the metal species leave the aqueous phase and enter the organic phase from which it can be stripped back in the aqueous phase to obtain a pure and a concentrated solution. The metal in the organic phase is not bound to carbon atoms as in organometallic compounds but to oxygen, nitrogen, sulphur, or hydrogen by a co-ordination (dative) bond (Habashi, 1999).Solvent extraction was used for the first time in hydrometallurgy in connec- tion with the special and urgent materials requirements of nuclear energy during World War II. A plant was constructed in the United States for the preparation of high-purity uranyl nitrate solution. In this plant, the yellow cake (a high-grade sodium or ammonium uranate) was dis- solved in HNO,, and uranium was selec- tively extracted by ether then stripped by water to give a concentrated solution of pure uranyl nitrate. This was gradually followed by developing methods for other high-priced metals such as plutonium, thorium, niobium, tantalum, zirconium, hafnium, boron, beryllium, and molybde num. The second step took place in the 1960s when solvent extraction was applied for the first time to extract a rela- tively cheap metal-copper. At present, solvent extraction technology is wide- spread, well accepted, and highly efficient. Solvent extraction had its origin in the discovery, by Christian Friedrich Bucholz (1770-1818) in 1805, that uranyl

Sep 1, 1999

By Júlio C. Lúcio

Consider the case of a mining company with N investment opportunities in projects of different commodities. The problem is: since the company has limitation of capital, equipments, technical staffs, etc, what is the best portfolio of production projects in order to maximize expectations from shareholders? In the no-longer past, the traditional method for the selection of portfolio of projects was the rank-an-cut method. But, this does not properly account for the risk to which the company is exposed. The Markowitz?s Mean-Variance is an advance because the risk of the NPV can be estimated at the level of the company or even division of the corporation. The final product of the Markowitz?s model is the efficient frontier, in which, the manager can clearly understand the maximum return from existing assets and the associated risk level - but this model does not recommend which one is the best portfolio. In this paper we present a model to select the best portfolio considering not only economic indicators, but also requirements of production, constraint in investments, etc. We show that if investors are diversified, managers should select projects with highest return, regardless of risk. However, in practice, if bonuses of managers are tied to their performance, the choice for portfolio with lower return and risk can happen. Numerical application considering typical portfolio of large mining company is used as example.

May 1, 2009