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By P. Cleyle, K. McDermott, M. Hall, C. A. Harris

"This paper describes the implementation of an expert system for monitoring and control of the NO. 4 autogeneous mill and spiral circuits at Wabush Mines.This process control system incorporated the mill operating expertize of Wabush Mines operating personnel and was implemented to improve spiral iron recovery and mill productivity by:1. Continuously monitoring the mill power draw and ensuring that the mill feedrate is regulated to prevent damage to the mill motor, while simultaneously maintaining the feedrate at or as close as possible to the maximum feedrate determined by the process supervisor.2. Improving control over the spiral density and feed rate.3. Improving control over both tbe rougher and cleaner wash water.4. Reducing the frequency with which pumps are plugged.5. Allowing modifications to be made easily and quickly to test various operating strategies.This system was installed using COMDALE/C, a real-time Expert System for Process Control. It was readily accepted by the process operators and produces higher production performance in comparison to the other 5 parallel mill lines at a lower power draw."

Jan 1, 1992

"Many underground mines are achieving extended life and optimizing existing facilities by mining at greater depths. The challenges to do this require a sound engineering approach to mine design and mine services, as well as ingenuity in safety design. The social consequence is full utilization of existing infrastructure.Accessing ores at depths of 2000 m to 3000 m requires exceptional hoisting design. May’s theme issue includes a paper that examines a case study of one such hoisting plant, with emphasis on the hoist rope selection at Agnico-Eagle’s Penna shaft. The paper also describes the process whereby consultation with provincial safety authorities resulted in a revised safety factor suited to the hoist. Another paper examines the challenges of ventilating mechanized mines to 3000 m, including air cooling and dilution of diesel exhaust emissions. Vent system designs are discussed, using sound engineering design, and proven technology that minimizes emissions to achieve cost efficiencies. The paper suggests design based on process and ventilation simulators to obtain realistic economic data at the design stage. Increased ground pressures present unique challenges for production and safety. While this is not confined to deep mining, one paper examines rock pressures and seismic events at the Brunswick mine, for which experience may be applied at depth. It describes seismic monitoring as a predictive tool in a real mine situation, and how it is used to improve overall recoveries and maintain worker safety."

Jan 1, 2004

By L. Frost

Physical Conditions Great Britain The physical conditions in the mines investigated in Great Britain are similar to those found in the mines of the Dominion Steel and Coal Corporation, with the important difference that many of the coal seams visited were interspersed by a large number of heavy faults, making the development of a continuous face operation difficult, and in many cases the life of a unit development was exceptionally short, adding to unit cost; but in spite of these difficulties, a great deal has been accomplished in the application of mechanical loading units in a number of the mines in the areas visited. The coal-bearing measures, as in Nova Scotia, consist of shales and sandstones, and in some sections mussel bands overlie the coal seams making roof conditions difficult'. In several mines, the main roof consisted of weak shale bind, being held by a coal roof of varying thickness. This shale bind had a tendency to flow when the coal roof was broken. The floor, in some cases where cutter loaders were operated successfully, consisted of weak, flaky shales with very little resistance and a tendency to disintegrate into powder when broken. The depth of cover under which these mines were operating varied from 250 feet to 2,340 feet, with an average of 1,700 feet. The coal seams varied in height from 3 feet to 8 feet 6 inches, and the gradients from level to 33 per cent. The seams vary in hardness, but all-with the exception of one seam, the 'Morrison Busty'- presented a cutting problem similar to that found in Nova Scotia. The structure and cleavage of the coal was well defined and uniform. Some of the seams visited were gassy, ?but the temperature of the workings generally was not in excess of 70°F.

Jan 1, 1948

By T. A. Rickard

FROM AN OLD MANUSCRIPT THE text for this contribution to the history of the Patio process is a page taken from a Spanish manuscript of Bartholomé Arzaj Sanches y Uela, now in the possession of the library of Brown University (see Figure 1). I owe the photographic print to the courtesy of the librarian. The date, as will be seen, is 1577. The subject is the treatment of silver ores at Potosi, in old Peru, but in modern Bolivia. The group of drawings (see Figure 1) is entitled "Arrangement of the machines in which the ores of silver are ground on the bank of Potosi, the one of two batteries and the other of one". First, top-left, we have the sketch of a "machine of one battery" operated by a water-wheel. From this mill the water runs in part along an aqueduct supported by pillars to the two-battery mill and in part down the hillside, where men are at work with "tubs, which are called cochas, in which are washed the charges of ore and amalgam". Along the top of the page are shown the "various offices in which are stored the copper, the salt, the ucha [llama dung, used for fuel], the lime, and other materials for the re-duction of the ores". To the right of these are "apartments and warehouses in which is stored the ore brought down from the mountain"?the cerro de Potosi. Through the arched portal come the "sheep [llamas] on which is brought down the ore". To this is added a reference to "the second gate, which closes the whole works". On the level above the aqueduct are seen six men carrying skin-bags that contain water. This is being sprinkled on the ore. On the extreme right are six more of these water-carriers. Next comes the two-battery mill. The mortero, or mortar, is marked on the right. Another description says, "Stone, on which the stamps crush the ore, which is called a mortar". To the left of these are indicated "screens of wire in which the ore is sifted after it has been crushed". Farther to the left, near the ore-washers, is a "shed, in which is placed the metallurgist to test the ore of the boxes". Along the left side of the page are sundry buildings, one of which is labelled a "shed in which are placed the cones of silver". Near it, lower, to the right, is the "furnace, in which are roasted the sulphides to facilitate treatment". Farther to the right is the "place where the Indians mix the charges of sulphide ore, which is called a buitron". Alongside is a "buitron in which the charges are prepared for reduction". Inside is a container, to which are attached the words "measure, called topo" On the extreme right is "another buitron in which the Indians mix the ores with their feet, as well as the heaps for the preparation of the reduction". Near the bottom, on the extreme left, is the "chapel where the holy sacri¬fice of the mass is celebrated". Under the first buitron is the "place where they dry the moist ores, called pãpear".

Jan 1, 1935

By B. Tiryaki, M. Ayhan, O. Z. Hekimoglu

"This paper discusses the aspects of tracking cutters related to the computer-aided design of shearer drums. A comprehensive computer analysis of drum dynamic parameters for multi-tracking tool arrangement is not presently available, as the current computer programs mainly consider the aspects of single tracking. Despite the fact that the single-tracking arrangement is recommended for efficient cutting, some major drum manufacturers have been seen to persistently adhere to multi-tracking, probably due to a lack of information. Further studies in this field are believed to contribute greatly to the current understanding of the computer-aided design of shearer drums.A number of laboratory simulation trials and long-term underground investigations were carried out in detail on tracking cutter arrangement, and an equation required for a computer program was derived. The results obtained from computer assessment of dynamic parameters for drums with multi-tracking arrangement were found to be in accordance with those of the underground trials, indicating the validity of the equations. The procedure adopted for the computer appraisal of the shearer drums designed with a multi-tracking concept, as described in this study, is therefore recommended to be considered in the currently employed computer programs."

Jan 1, 2003

By D. H. Rubisov, V. G. Papangelakis

Sulphuric acid pressure leaching is the process of choice to recover nickel and cobalt from laterites with variable iron and magnesium contents. The latter influences the acidity levels required for effective leaching of nickel and cobalt, and during leaching, iron is rejected in-situ as hematite. Classical solid/liquid separation is performed via a CCD circuit, the performance of which depends upon the size and shape of precipitated particles. In this paper, precipitates obtained by acid-leaching of various lateritic feeds at 270°C are characterized using SEM/EDX and laser particle size analysis. It is shown that as acidity increases, the shape of the precipitates gradually changes from platelets to spheres, thus improving the S/L separation properties of the residue. The use of hydrogen ion concentration “at temperature,” calculated from a speciation analysis, allows the explanation of this change of morphology independently of the type of the ore feed. The possibility of precipitating magnesium sulphate “at temperature” is also discussed. In order to take advantage of this precipitation for scale reduction (as has been proposed in the past) without compromising the residue quality, [H+] “at temperature” must be controlled within an optimum range.

Jan 1, 2000

By E. T. Turner

Introduction 1n assembling material for this paper on Wood Refuse Burning 1 turned first to the records of our early studies of the problem in order to learn how and why certain basic decisions were arrived at and also how it came about that the completed central steam plant differed so much from the original plans. It may be of interest, therefore, to outline the engineering problems as they presented themselves in the early part of 1948, and to indicate the economies involved. Although the principle of using wood refuse as boiler fuel instead of burning it to waste was quite sound, and in fact the practice had been in use for a long time in the boilers of many lumber companies, there was some guesswork as far as Hollinger was concerned in deciding how best to handle the large quantities of wood refuse involved and as to the type of boiler equipment necessary to .burn it efficiently. These problems will be examined first. Hollinger Boiler Equipment in 1948 Hollinger had four separate boiler houses, at Main, No. II, and No. 19 shafts, and a small unit at the compressor plant for heating purposes. Main and No. Il boiler houses operated all the year round; No. 19 and the compressor plant only in the winter. At Main there were four 36-year-old HRT boilers with total available h.p. of 500, at No. II, three 30-year-old HRT boilers with 195 available h.p., and at No. 19 two old field-type locomotive boilers capable of producing 95 h.p.

Jan 1, 1951

By Charles T. Harper

The uranium deposits discovered by Amok (Canada) Ltd. in the Cluff Lake area of north western Saskatchewan occur at or near the southern edge of the uplifted basement core of the Carswell circular structure. Two types of mineralization, distinguishable, by their geological and structural setting and mineral paragenesis, have been recognized. The N-Claude type is characterized by a relatively simple mineral assemblage, consisting of uraninite or pitchblende with coffinite, and is accompanied by variable amounts of graphite and organic matter, and Fe, Cu, Pb and Mo sulphides. Both N and Claude orebodies occur within quartzofeldspathic gneisses of the basement core. On the other hand, the D-type ore has a complex mineral assemblage consisting of: uraninite, pitchblende, thucholite and coffinite, along with native gold and selenium; gold tellurides, and selenides of Pb, Bi, Ni and Co; sulphides of Fe, Cu and Pb; and organic matter. The D orebody occurs within carbonaceous shales at the base of the Athabasca Formation as well as in fault zones in regolithic quartzo feldspathic gneisses above the inverted unconformity. An age of 1050 m.y., which is consistent with a period (circa 1200-1000 m.y.) of widespread hydrothermal activity and uranium mineralization or reworking within and adjacent to the Athabasca Basin, has been obtained from uranium mineralization from the D orebody. Later reworking (circa470 m.y.) of the mineralization occurred at the intersection of older mineralized shear zones with radial faults produced during meteorite impact.

Jan 1, 1978

By Lawrence Devon Smith

"The concept of risk is well established in the mining industry. It is acknowledged when estimates of reserves are expressed as proven or probable, when mining and metallurgical recoveries are applied to the ore, and when contingencies are added to costs. However, it is difficult to provide a quantitative assessment of risk. The significant sources of risk in a mineral project and how these are addressed in project evaluations are discussed. The discount rate is examined as a fundamental means of reflecting risk in discounted cash flow evaluations. Current industry practice is discussed, and a methodology for the analysis of risk levels is proposed that assesses the constituent components of the discount rate: real interest, mineral project risks, and country risk.IntroductionThis paper examines the components of the discounted cash flow discount rate and proposes a method of estimating project-specific discount rates. The motivation for this work comes from experience of project evaluations in which owners and purchasers had agreed on virtually every aspect of the evaluation except how much the project was worth. Agreement was reached on reserves, grad~, recovery, capital costs, operating costs, taxes, and, by combining these components, even on the fmal cash flow values. The only difference in opinion concerned the discount rate to be used in the calculation of the net present value. Depending on the life of the project, such differences of opinion can cause a variation of more than 50% in the value placed on a project! This is illustrated in Figure 1."

Jan 1, 2003

By M. Savella

The Runruno Gold Project is located on the island of Luzon, approximately 200 km north of Manilla in the Philippines. The mine is a surface mine operation and use the proven BIOX® and carbon in leach processes to recover gold, and the ASTER™ process for detoxification of the CIL residue prior to discharge to the Residue Storage Impoundment (RSI). Work to date has defined a mineral resource of 1.39 million ounces of gold, and the operation will produce 96,700 ounces of gold per annum over a mine life of 10.4 years. The BIOX® circuit is designed to treat 140,000 tpa of concentrate with a design capacity of 404 tpd of concentrate at a design sulphide sulphur grade of 17% S2-. The Runruno project is the first BIOX® plant to implement the Generation III BIOX® design principles. As part of the Generation III BIOX® program Outotec supplied a turnkey, containerised metallurgical laboratory to facilitate the first four stages of the BIOX® and ASTER™ inoculum build up requirements. BIOX® inoculum build-up was started during early January 2015 with 5 litres of stock cultures shipped from South Africa. The BIOX® culture was successfully adapted to concentrate produced from the mini plant during March 2015. The ASTER™ inoculum build-up commenced during early August 2015 utilising 27 litres of ASTER™ bacterial inoculum already adapted to similar process conditions expected during commercial operation. This paper will detail the various stages of inoculum build-up through to commissioning and ramp-up of the BIOX® and ASTER™ Processes at the Runruno Gold Project. The paper will highlight some of the factors affecting the commissioning process as well as the improvements seen through the introduction of the Generation III BIOX® design principles.

Jan 1, 2017

By J. Chenier, M. Boissoneault, D. Ducharme, R. Schonewille

The operation of Falconbridge's Sudbury nickel smelter has undergone significant change since the production was consolidated to a single electric furnace in 1994. In the late 1990's a capital program of about $100 MM (Cdn) was undertaken to expand and modernize the smelter. This project, known as Smelter 2000, was mainly driven by the need to process the new concentrate produced at Falconbridge's Raglan operation in northern Quebec. Included in the scope of the project was the installation of dry concentrate handling facilities, modifications to the roaster feed preparation system, installation of a matte granulation system and modification of one of the converters. Improvements to in-plant hygiene were also an important part of the Smelter 2000 project. Over the past 5 years much has been learned about the challenges in treating two significantly different concentrates. More recently, the introduction of a third concentrate from Falconbridge's new Montcalm operation near Timmins, Ontario has added another dimension to the operation. This paper will describe how the main challenges from the past 7 years have been overcome and discuss the path forward for the Sudbury Smelter Business Unit.

Jan 1, 2005

By L. B. Hale

"Introduction This paper will discuss the current operations of Westar Mining Ltd. and give a brief history of the company and of the Crowsnest Pass area. Westar is an integrated company involved in mining, processing and marketing coal from its mines in southeastern British Columbia and shipping coal from Westshore Terminals at Roberts Bank, located just south of Vancouver, B.C. It is two-thirds owned by the B.C. Resources Investment Corporation and one-third owned by the Mitsubishi Corporation of Japan and a consortium of Japanese coal consumers. Operations in southeast British Columbia consist of four coal mines and two processing facilities (Fig. 1). The Elkview Coal Processing Plant near Sparwood, B.C. receives its raw coal from Balmer operations (Harmer open pit), Balmer South (Panel 6) an underground hydraulic mine, and Balmer North an underground room-and-pillar mine. The fourth mine, Greenhills, an open-pit operation, is located near Elkford, B.C. and has its own processing plant. The Balmer mining and processing complex is the largest metallurgical coal facility in Canada producing up to 7 .5 million tonnes of clean coal per year. The Greenhills operation, completed in mid-1983, has a capacity of 2.8 million tonnes. The high-grade metallurgical and thermal coal produced is primarily for export markets. The major customers are Japan, Korea, Brazil, Pakistan, Chile and Taiwan.Our coal and that produced by other mines in Alberta and British Columbia is shipped to the international markets through Westshore Terminals Ltd., a wholly-owned subsidiary. Westshore will have an annual capacity of 22 million tonnes of coal and accommodate ships of up to 250,000 dead weight tonnes by 1984 when its current expansion program is completed."

Jan 1, 1985

By V. A. Cooney

Introduction For the compliment paid me by the Institute's kind invitation to speak this afternoon, I am very grateful. For the astuteness of your officers in determining that encouragement should be given, through the medium of a paper, towards accident prevention in coal mines, the coal industry cannot but be grateful. Some day, and let us hope soon, a more developed paper may supersede this one. In the meantime, if some knowledge of what one coal field has been able to accomplish, even in the initial stages of its effort, will induce other fields and other sections of the mining industry to launch similar experiments, much good will result and a more developed dissertation on the subject will make its appearance.

Jan 1, 1946

By E. Watkins, J. C. LeRoy, A. Vivyurka

"TAILINGS REVEGETATIONWelcome to the Revegetation Session. My instructions are to introduce the Speakers and to provide a general introduction.I do the latter with humility not only because of a lack of personal experience or because tailings revegation is not well established technology, but because any general statement on a country or industry as diverse as the Canadian Mining Industry is bound to be wrong somewhere.Laying aside normal standards of accuracy I proceed as follows:In considering the question of tailings revegetation, one asks two basic questions:1. What ought to be done?2. What can be done?The first question can be broken down into three kinds of criteria or objectives:a) Legislativeb) Technicalc) AestheticThe first I leave to the politicians and the last I will avoid. Aesthetics is the philosphy of taste. It is concerned with the appreciation of things rather than what they really are. It is much easier to get into an argument on aesthetics than to get out of it feeling you have said something of consequence.Technical criteria can be divided into the following sub-objectives: 1. To isolate the tailings basin so surrounding land is not degraded. The first step here is stabilization of the surface to prevent wind and water erosion."

Jan 1, 1975

By Linda Hodgson

1. Introduction ?Northgate Minerals Corporation is a mid-tier gold and copper producer with mining operations, development projects and exploration properties in Canada and Australia. ?Kemess Mine is Northgate?s principal operation. Where in the world is Kemess? ?Kemess is located in north-central British Columbia,430 kilometres northwest of Prince George. ?The Kemess South complex consists of an open-pit mine, a 52,000 tonnes per day mill and various ancillary support facilities including maintenance shops and housing for Kemess' 340 full-time employees.

May 1, 2010

By Steven R. McCutcheon

ABSTRACT - The Bathurst-Newcastle district, a subcircular area approximately 50 km in diameter, contains 37 massive-sulfide Zn-Pb-Cu deposits that have defined tonnages, and has 58 additional significant occurrences. The largest deposit is Brunswick No . 12, with total reserves (including past production) of 148 million tonnes grading about 12.50% combined Pb-Zn. The deposits/ occurrences are spatially associated with a felsic volcanic pile that contains a significant sedimentary component. In the vicinity of the Brunswick deposits the pile is divisible into lower and upper sequences. The lower is characterized by megacrystic rhyolite (QFAS) and coarse- to fine-grained quartz ( ± feldspar) wackes and/or tuffites (QAS); the upper sequence is characterized by aphyric to sparsely porphyritic rhyolites (HWR), micro-breccias, and acid hyaloclastites with interbedded dark gray sedimentary rocks. A greenish gray to dark gray siltstone (GGS) separates the two sequences and hosts the sulfide deposits. Lithogeochemistry of !east altered samples shows that the QFAS and HWR have an igneous character, whereas the QAS and GGS have a sedimentary sig­ nature. The two types can be distinguished on the basis of total alkalies (Na2O + K2O) versus SiO2/Al2O3, and Ti02 versus Fe/(Fe+ Mg). Some trace elements, such as Sr and Y, also help differentiate the two types. The QFAS differs from HWR by having higher La/Yb ratios but lower Zr and Th. The Bathurst deposits do not show a close spatial association with rhyolites but rather are stratiform bodies (lacking clastic textures) within fine-grained sedimentary rocks. The scarcity of barite and other sulfates indicates that there was little mixing between the metal­ bearing fluids and cold seawater. High Fe/(Fe+ Mg) ratios in chlorites also indicate the fluids did not contain a significant seawater component. These features and the large size of many deposits suggest that the deposits formed from metal-rich pore waters that were released catastrophically from an acquifer in the footwall stratigraphy.

Jan 1, 1992

By J. L. Bowlby

Introduction In the following discussion, boiler-feed and mine waters will be considered from the point of view of the problems arising from the chemical nature of the mineral and gaseous impurities they contain. The theories underlying some of these problems will be reviewed for the purpose of getting a clearer concept of the problems themselves. Certain terms of a chemical nature, necessary to the discussion, will be explained on the assumption that they are not generally familiar to mining engineers. Finally, an attempt will be made to correlate theory and practice, with the abject of establishing certain limits to factors relevant to the problems, and to show that these limits are justified by practical experience. The general problems occasioned by the presence of mineral and gaseous impurities in boiler-feed and mine waters are: (1) Scale formation and corrosion in boiler systems. (2) Corrosion of mine pumps and pump fittings. These will be discussed separately. Boiler Scale Typical analyses of waters available for use in steam power-plants are given in the accompanying Table (Table I). All analytical data are expressed in grains per Imperial gallon. The bicarbonates of calcium and magnesium in the raw waters are shown as normal carbonates in the Table. Substances in the first five rows constitute the encrusting solids. All the waters listed in Table I would be classified as 'very good' in the schedule of classification for boiler waters adopted by the American Association of Railway Chemists in 1887. In spite of this classification, however, the waters contain sufficient encrusting solids to cause serious scale trouble after prolonged evaporation.

Jan 1, 1934

By Larry M. Southwick

Extraction of gold and other metals from ores suspended in liquid slurries often involves gases (such as oxygen) as a participant in the reaction. An important factor then in setting the rate of extraction can be mass transfer of the gas into the liquid and/or solids. A number of recent studies have indicated that as solids loadings increase, mass transfer rates of gas into solid-liquid mixtures decreases. This would seem to imply that lower solids loadings would be beneficial to increased reaction rates. However, since it is the solids which are being reacted, a most intriguing paradox is created. More solids should lead to more surface area to react, but it seemingly also provides less gas to react. So is the reaction faster or slower as solids loadings increases? The creation of this paradox is imbedded in how mass transfer and reaction data is collected and measured, how it is analyzed and correlated, and finally on the rate controlling steps in the reaction. An alternative analysis of these studies is presented which clarifies and eliminates the paradox. The analysis applies to water slurries as used in gold or other metal leaching processes or in bio-hydrometallurgy, as well as to molten metal/solid/gas mixtures such as might be encountered in submerged gas injection.

Jan 1, 1999

By Stephen Se

Geological assessment of active mine faces enables ore grade control, geological modelling and exploration planning. Monitoring of the mine advancement at every drill-blast-muck cycle allows for effective production management. However, geological assessments are performed infrequently due to the need to travel to active mine faces, and detailed surveys to map the mine progress are performed at the end of the month. Instant Mine Modeller (iMM) is a portable ruggedized stereo-vision system that creates photo-realistic three-dimensional models of underground mine faces on-site. The 3D models are generated automatically within minutes and can be viewed underground and annotated with geological information. The overall ore percentages of the face are calculated automatically for grade control. Annotated 3D models are located in the mine coordinate system and can be imported into mine management systems. iMM allows for daily monitoring of the mine progress and geology, and for re-visiting the mine virtually as it existed. iMM has been deployed in an underground hard rock mine for 18 months, and it effectively brings the underground work face into mine management offices enabling the right decisions at the right time. iMM has demonstrated benefits to various mine processes including grade control, geological mapping, 3D photo-realistic as-built and production volume.

Oct 1, 2009

By Rajiv Kalra, Ji Jiangang

"This paper reviews the following aspects of the world’s largest manufactured Grinding Mill’s in terms of diameter and power, along with the world’s biggest shop assembly and trial run of the mills delivered to Sino Iron Magnetite Project in Australia.1. An overview of the basic flow sheet of the Sino Iron (Magnetite) Project located in Australia2. An overview of in-house designed CITIC Heavy Industries 12.2 m (40ft) F x 11 m(36ft) LG – 28MW AG mills including FEA and major components3. In-house manufacturing at CITIC-HIC work in Luoyang China of all major components for 6 off Ø12.2 m(40ft) AG mills and 6 off Ø7.9 m(26ft) x 13.6 m(44.6ft) LG – 2 x 7.8 MW Ball Mills4. Major aspects of design and preparation of the biggest shop trial run of Ø7.9 m(26ft) x 13.6 m(44.6ft) LG Ball Mill witnessed by international EPCM’s and clients in July 2009.5. Major aspects of one piece assembly of 1300 tonne rotating element of the Ø12.2 m(40ft) x 11 m(36ft) LG AG Mill and Ø7.9 m F (26) x 13.6 m(44.6ft) LG Ball Mill at the port of the export China and transport to Australian Port and then to site.6. An insight to unique installation methods used for Ø12.2 m(40ft) and Ø7.9 m(26ft) rotating element lifting on the mill foundation in one piece assemblies.7. CITIC Heavy Industries present capability for in house design and manufacture of Grinding Mills up to Ø13.7 m (45 ft) with 35 MW Gearless drives and Ø12.2 m(40ft) with 2 x 10 MW Geared Mill drives"

Jan 1, 2012