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By J. Güntner

A significant portion of Outotec's business relates to the application of fluidized bed for processing a wide range of industrial materials, including gold ore and gold concentrate. As part of the former Lurgi and Boliden organization, our division constructed the first industrial reactor for roasting sulphur-bearing materials in 1950, based on the principles of fluidized bed technology. This process, when combined with efficient heat recovery and off-gas treatment and its conversion to sulphuric acid, became the standard for processing sulphur-bearing ores. In the last 60 years we have delivered more than 265 plants and developed (in addition to the standard fluidized bed solution) variants of the fluidization technology, such as the circulating fluidized bed and the bubbling fluidized bed. This paper describes the different options of the fluidized bed technology for gold roasting reflecting on main process design criteria.

Jan 1, 2011

By R. Elliott, C. A. Pickles, J. Peacey

As the nickel sulfide ore deposits become decreasingly viable as a source of nickel metal, increasing attention is being paid to the exploitation of the nickeliferous laterite ores. Attempts to produce a high grade ferronickel concentrate from these ores by pyrometallurgical methods face several challenges, in particular the selective recovery of the highly disseminated nickel from the reduced ore. The current work explores strategies for maximizing the size of ferronickel particles formed in order to improve the selective recovery of the ferronickel by magnetic separation. The effect of various coal, elemental sulphur, pyrite and sodium sulphate additions on ferronickel particle formation and size at 1000°C have been investigated. It has been observed that increased coal additions leads to a moderate improvement in the size of the ferronickel particles, while the presence of any sulphur bearing reagent leads to a significant increase in particle size. The retention of sulphur in the reduced material has also been studied, showing sodium sulphate has the highest retention, followed by pyrite and then elemental sulphur. An inverse trend was observed in the efficiency of sulphur retention on the basis of residual mass of sulphur per unit mass of reagent added.

Jan 1, 2015

By A. W. Jolliffe

AEROPROSPECTING may be defined as the application of the air view to the search for mineral deposits. The term is suggested as a preferable alternative to either aerial prospecting (which may be confused with areal prospecting) or air prospecting. The air view may be obtained by visual observation from an aircraft or by examination of air photographs; each has its particular advantages and disadvantages. Aeroprospecting should be regarded only as an aid to, and not as a substitute for, accepted prospecting methods ( l ). The Precambrian region north of Great Slave lake consists of two well defined physiographic units, a feature first noted by J. T. Wilson (2). The boundary between these lies close to the north shore of the east arm of the lake and extends northwesterly near Spencer, Beniah, Carp, and Ghost lakes (Figure 1). South and west of this line, exposed bed-rock makes up the greater part of the land area; eskers are very rare, and overburden is largely limited to rock-walled valleys and depressions. North and east of the line, outcrops are rare or absent, eskers are abundant, and most of the surface consists of drumlin-like drift hills, elongated parallel to the direction of ice movement (Figure 2). Where this boundary passes through the area shown in Figure 1, it lies near the 1,200-foot contour and may mark the maximum extent of the lake or sea arm present in this vicinity toward the end of the Pleistocene period. For convenience, the first area may be called the 'bed-rock belt' and the other the 'drift belt'.

Jan 1, 1945

By E. M. De Souza, R. Penner

"Water is encountered at the majority of underground mines, both over their lifetime and during each stage of development and production. The dewatering system is one of the most important and costly components of an underground mining operation and it is often not well designed and analyzed. An effective design of a mine dewatering system will greatly reduce its energy cost as well as improve working conditions and reduce production costs. A computer-based system, called Qpump, has been developed to assist the underground operator to effectively design and/or assess over-all and local mine dewatering systems. The design features and principles used in the development of Qpump are introduced and an example which illustrates typical applications is presented.IntroductionTraditionally, dewatering operations have been given lower priority than many other operations in underground mining. Invariably water will be encountered during the sinking of the mine shaft, during development and subsequent production. The dewatering system thus becomes a very important component of an underground mine operation and, in fact, any mine manager will attest to the importance and necessity of an efficient mine dewatering system.The water problem is of varying importance at different mines. There are several factors that contribute to the water encountered. It is a function of the mining method and techniques utilized (backfill system, drilling and raising technology, dust control sprays, shaft water rings, etc.) and of prevailing conditions (ground water, rock structure and permeability). In some cases a mine may be so dry that little pumping is required while in others, the weight of water pumped may exceed by many times that of ore mined.The successful design and application of a mine dewatering system is dependent upon the operating conditions of each specific operation. There are no standard procedures and systems which can be used for all mining situations. However, an effective water system will greatly reduce the energy and production costs of a mine, improve working conditions and eliminate headaches because of flooded working places."

Jan 1, 1993

By C. E. Ells

Current knowledge of the behaviour of inert gases in metals is reviewed, with particular emphasis given to the phenomenon of the growth of gas-filled bubbles.

Jan 1, 1960

By K. Turgeon, D. Larivière, L. Whitty-Léveillé, J. -F. Boulanger, C. Bazin

"The processing of ore containing rare earth elements leads to the production of an impure solution of these elements. The separation of the rare earths from the impurities and the production of individual elements is usually carried out by solvent extraction. The effectiveness of the extraction conditions and of the reagents is generally tested in the laboratory. This paper deals with the processing of results from solvent extraction laboratory tests planned to generate data redundancy. A method is proposed to take advantage of the data redundancy by accounting for the pH variation during the extraction. The parallel processing of several tests also allows estimating the equilibrium constants for the extraction. The proposed method produces equilibrium constants that are more reproducible than values estimated using conventional approaches. The method is illustrated with solvent extraction tests conducted on synthetic solutions of rare earth elements.INTRODUCTIONThe processing of ores containing rare earth elements (REE) usually includes the production of a concentrate of the minerals carrying the REE. These minerals, for instance monazite and bastnäsite, contain the 14 elements from La to Lu plus yttrium and scandium. As an example monazite has the general formula of (La,Ce,Pr,Nd,Sm,Eu,Gd,Tb,Dy…Lu)PO4 with a typical lanthanum content of 20-26%, cerium content of 40-50%, praseodymium of 4-6%, neodymium of 16 to 20%, and decreasing concentrations of heavier elements (Gupta & Krishnamurthy, 2005). During the processing of a REE mineral, it is generally not possible to isolate and separate a single REE from all the rest. The mineral molecules need to be broken (usually via a heat treatment followed by leaching with a base and/or an acid) to produce an aqueous solution of the REE of the ore. After purification of the solution, the REE can be precipitated as a bulk concentrate and sold to a refinery that separates the REE into particular groups of REE such as the light versus heavy REE or into individual elements such as lanthanum, neodymium, or europium oxides to yield value-added products."

Jan 1, 2016

By R. Lapcevic, P. Lokin

"Among other components, ore body „T“ was discovered in the Bor pit copper mine at a depth of app. 500m. The ore body is relatively small: 60-65m long, 40-45m wide and up to 50m high, but with an extremely high content of copper and accompanying metals. The rock mass containing the ore body is composed of altered andesite of relatively poor physical-mechanical characteristics. The exploitation of this ore body by way of conventional mining methods was associated with high risk, cost, and potential losses of the rich ore. Due to everything specified hereinbefore, the adopted solution involved ore exploitation with complete ensuring of excavation stability, thus forming an extremely large underground opening. The excavation and supporting were performed according to the NATM principles along with applying shotcrete, 9-25 m long cables, and horizontal and vertical lattice girders. The excavation of the ore body was completed in app. 2.5 years, all the while ensuring complete stability and security of people and equipment; construction works were constantly monitored. The proposed solution for ore excavation enabled more than 95% exploitation of ore as requested by the Investor, while depletion due to waste-rock excavation was less than the allowed 5%. INTRODUCTIONThe Bor copper deposit is located in Eastern Serbia. Copper exploitation in Bor commenced as far back as 1902. A total of 26 ore bodies varying in size and valuable mineral content have been excavated so far. One of the most recent excavated ore bodies is ore body „T“, which is one of the smallest bodies by volume, but also a body with one of the largest content of copper and accompanying metals. An important fact regarding its exploitation is that it is located at a depth of app. 500 m; that its shape is irregular: 60-65 m long; 40-45 m wide and app. 50 m high; and that it lays within a rock mass of relatively poor physical-mechanical characteristics. In addition, above it, in its immediate vicinity, ore body „F“ was previously excavated and its room was refilled with backfill and water. Excavation methods common in mining practice (excavation with caving, excavation with backfilling, excavation with protective pillars) were inadequate in this case for various reasons:• The immediate vicinity of the previous ore body „F“ room could cause expansion of the caving zone also to that room, along with penetration of groundwater and flotation sludge;• Possibility of deformation expansion caused by caving as far up as the surface of the terrain, including the urban area;• Difficulties in maintaining the stability of excavation sidewalls having steep slopes and great height;• Significant loss of ore mass with a relatively high content of metals etc."

Jan 1, 2015

By Marc Arpin

La Bolivie possède tout pour réussir. Son vaste territoire de plus d'un million de km2 et qui occupe une position stratégique au coeur du continent sud-américain recèle des ressources naturelles (forêts, minéraux, gaz naturel, etc) variées et abondantes. Elle a une frontière avec pas moins de 5 pays dont le géant que constitue le Brésil ainsi qu'avec l'Argentine, l'autre puissance régionale. Pourtant, malgré tous ces atouts, la Bolivie demeure l'un des pays les plus pauvres du continent. Ce paradoxe n'est nulle part mieux reflété que dans le secteur minier. Celui-ci fait face à une situation de crise en dépit d'une tradition minière de plus de quatre siècles et d'un potentiel géologique indiscutable ayant conduit à la découverte et à l'exploitation de fabuleux gisements d'argent et d'étain. Les habitants des districts miniers vivent dans des conditions de pauvreté extrême et les indicateurs de développement humain de ces régions sont parmi les plus bas en Amérique du Sud. La Bolivie réussit difficilement à attirer les compagnies minières alors que, chez les voisins, et particulièrement en Argentine, qui n'a pas de tradition minière, les investissements miniers majeurs affluent. Dans cette conférence, nous chercherons à expliquer les causes de cette situation et proposerons des solutions possibles.

May 1, 2001

Of the twelve known ore zones on the Sunro property, acquired by Cowichan Copper Co., only the "B" and "C" orebodies of the "River Zone" had been explored sufficiently to indicate the grade and tonnage. The "B" zone was selected for initial production. The portion of this orebody above the main adit level was developed for horizontal-ring, longhole mining. Ore from the stope would be scraped directly to the coarse ore bin. The lack of a suitable mill site on surface, as well as the 8,000-ft. tramming distance, led naturally to the installation ground. I N November, 1960, a lease was obtained by Co-wichan Copper Co. Ltd. (N.P.L.) from Sunro Mines Ltd., covering the main ore (River) zone of the Sunro property. A total of twelve zones had been located on the property. Nine of these lay within the leased area. With the exception of the "B" and "C" orebodies of the River Zone, there had been insufficient exploration for tonnage and grade calculations. Exploration by previous companies had

Jan 1, 1965

By Daniel Hodouin, Robert Lanthier, Yve Dube

"A procedure f or constructing a grinding mill dynamic model is proposed. This model is used in a dynamic simulator of are grinding circuits. The simulator is designed for flexible flow sheets involving different grinding mills and particle classifiers and is able to accept several single variable PID control loops. The dynamic model is validated on a laboratory ball mill, and calibrated to an industrial installation. The simulator is used for characterization of grinding circuit dynamic behaviour and tuning of control strategiesIntroductionThe ore grinding operation is a critical step of the ore preparation process because it is the last comminution stage before the separation of minerals. The properties of the ground minerals to be concentrated, control the quality and efficiency of the separation process. This is why it is important to control properly the operation of the last grinding stage, commonly constituted of a closed circuit ball mill with classifier . To provide an adequate fine product, the grinding operation should compensate for the perturbations of the feed characteristics (size analysis, grindability, etc.). The main objective is to maintain a constant size distribution for providing stable operating conditions to the separation units. Simultaneously another usual objective is to operate the grinding circuit at a maximum capacity.Automatic control applied to grinding circuit s is the appropriate approach to improve its operation. Most frequently average optimal operating conditions are determined from steady -state performances of the circuit , and the automatic control is used for stabilizing the operation at selected values of the process variables . In the traditional approach, one or several single input! single output (SISO) control loops are implemented and empirically tuned. Advanced control practices'!' are based on a quantitative analysis of the circuit dynamics, which could also give a basis for the tuning of conventional SISO 100ps(2)."

Jan 1, 1987

By L. Gonzalez-Sardi, W. McCombe, M. Pearson

Pressure oxidation is increasingly being used for processing refractory sulphide ores and concentrates because it offers highly effective base metal and precious metal extraction while minimizing elemental sulphur, arsenic & mercury emissions. Yet pressure oxidation processes introduce new safety concerns and process risks as demonstrated by a number of safety incidents over the last 20 years, including overfilling, oxygen-metal fires, nozzle/sparger failures, and uncontrolled pressure relief events. Chemical Process Safety regulations in the United States and Canada mandate that companies constructing or operating chemical process facilities perform a rigorous hazard and risk analysis based on either ANSI/ISA-84.00.01 or IEC 61511 safety standards to determine the level of protection required for each hazard in the plant. This paper describes the application and implementation of three (3) unique safety instrumented systems developed by Hatch for ensuring the safe operation of three different pressure oxidation processes.

Jan 1, 2014

By Nicola Robjohns, Kenneth A. Grace, Jane Spooner

"The important volume end use sectors for the rare earth elements and yttrium continue to be in steelmaking, petroleum cracking catalysts and glass polishing. The market sectors which may provide future high volume demand, to replace the older sectors where demand has declined over the past decade, include magnets, automobile catalysts, ceramics and superconductors. Increases in production capacity in all major rare earth producing countries are expected to restrain large price increases for high purity rare earth oxides over the short term. A sharp increase in demand for yttrium in advanced ceramics and superconductors would lead to a shortage in separation capacity, however, and to a corresponding rise in prices for separated rare earths.IntroductionWhile visiting the Geology Department of the University of Toronto in 1981, Professor Lu from the Institute of Geochemistry of Academia Sinica at Gweiyang in China introduced one of his seminars with the observation that in China, rare earths are not rare at all.Indeed, while being rare in terms of abundance as measured by, say, the Clarke scale, the rare earth elements, like many other low abundance elements, are subject to geological, geochemical and mineralogical concentration.The rare earth elements comprise the fifteen inner transition elements of Group IIIB, Period 6, of the periodic table, from lanthanum to lutetium (the lanthanides), as set out in Table 1. The rare earths constitute a distinct group as they have extremely similar chemical characteristics due to the uniformity of their outer electron shells. The element yttrium is usually, by convention, included in the rare earth group as it occurs with the rare earths in nature and has properties very similar to them.The rare earths are divided into two subgroups, the ""light"" rare earths, made up of the first seven elements of the series, lanthanum to europium, and the ""heavy"" rare earths, comprising the remaining eight elements, gadolinium to lutetium, plus yttrium. These two subgroups are also referred to as the cerium subgroup and the yttrium subgroup, respectively. The subdivision is based on differences in the atomic radii resulting in somewhat different properties for the two subgroups."

Jan 1, 1991

By W. H. S. McFarland

THE Yukon Consolidated Gold Corporation, Limited, a Canadian company, operates alluvial gold dredges in the Klondike goldfields of Yukon Territory. Its operations are of unique interest to Canadian mining as it is the only large-scale placer mining operation of this type in Canada. Its properties lie in the valley of the Klondike river and its tributaries, Bonanza, Hunker, Bear, Last Chance, and All Gold creeks, and in the valley of Indian river and its tributaries, Dominion, Gold Run, Sulphur, Eureka, Montana, and Quartz creeks. At the end of 1938, they consisted of 1,650 placer mining claims and 9 leases or concessions. They cover a belt with an area of approximately 1,000 square miles. This vast area covers in part claims which have been previously worked by other methods such as 'drift' and 'open-cut' mining, and areas which were too low grade for such methods. The ground held by the Company is not held in freehold but in the form of mining claims and mining leases granted by the Dominion Government under the provisions of the Yukon Placer Mining Act. Full-size creek claims are 500 feet in length by 1,000 feet on either side of the base-line. Hill and bench claims are 500 feet up and clown the valley and 1,000 feet at right angles to the valley. All claims are held on the basis of an annual renewal fee of $10 for each claim plus 'representation work' of an assessed value of $200 per claim per annum. For the purpose of such representation work, claims may be 'grouped'. This means that work done by one dredge is sufficient to 'represent' a comparatively large block of claims. It is only in this way that it becomes possible to consider operations on a large scale over a term of years, for such operations would obviously be impossible on law-grade ground if representation work had to be done separately on each individual claim in each year.

Jan 1, 1939

By Andrew J. Freyman, George S. Barry

"Mineral endowment in northern British Columbia and the Yukon Territory was assessed on the basis of geological opinion which was gathered in a quantitative framework of subjective probabilities. The survey area encompassed 364,000 square miles and was divided into 310 cells having dimensions of one degree of longitude by one-half degree of latitude. The response solicited related to tonnage, grade and number of deposits of a particular mineral in each cell. The questionnaire sought an expression of mineral endowment down to mine-able depth as distinct from economic expectations. Details on the questionnaire and responses are presented in a series of contour maps on individual commooities, which illustrate the collective occurrence picture of the respondents. The approach is largely dependent on the cooperation of an adequate number of geologists familiar with the region being examined. This approach to an assessment of the mineral endowment of a region has a wide range of applicability, from the focusing of exploration effort to aiding government and development bodies in the formulation of regional strategies and the planning, for example, of road, rail and power facilities."

Jan 1, 1970

By P. Reyes

The start up and operational optimization of the No. 3 Oxygen Plant at the Caletones Copper Smelter of the Codelco - Chile El Teniente Division is summarized. In addition, the economic impact of such optimization on the production cost of oxygen and others aspects associated to the operational robustness as well is detailed.

Jan 1, 2007

By P. Kostuik

"Recent interest in the pipeline transport of solid mate-als has been sparked by the idea that, in an inflationary onomy, pipeline costs are more stable than the costs of any other transport systems. Pipelines have proved over 1e years to be dependable, records indicate that main-•nance and operating costs are comparatively low, and 1eir amenability to automation is of considerable im->rtance.The concept of hydraulic hoisting of solids from under-round, or cross-country hydraulic transportation of con-~ntrates and ores, is currently of prime interest to the ining industry. In general, this paper deals with a preliminary investi-ation of energy losses incurred while transporting a rela-vely heavy, crushed mine product, namely magnetite, oth vertically and horizontally. The basis and validity of everal equations derived by other experimenters to com-ute these losses is discussed. A theoretical analysis of ydraulic hoi:,,ting is made, and, based upon test results, calculation of horsepower requirements for hoisting an re under a given set of conditions is presented. Results indicate that:n vertical transport, the friction head losses are identical to those of clear water, and the total energy requirement for hydraulic hoisting then becomes a function of height of lift, concentration and specific gravity of the solids being hoisted. .-In horizontal transport, friction head losses can be calculated with reasonable accuracy using Bonning-ton's correlation curve. Losses computed utilizing Durand's correlation (K = 85) result in estimates which are too low by 10 to 30 per cent, an<l those calculated using Newitt's correlation (K = 1,100, K = 66) give friction loss values which are too high by 10 to 30 per cent . . -The theoretical horsepower (RMS-hp.) required for hoisting hydraulically is approximately half of that required for conventional double-drum skip hoisting."

Jan 1, 1966

By C. A. Campbell

"There has been a significant reduction in maintenance hours and improved performance by maintenance crews at the MacLeod mine since the introduction of a Maintenance Control system which includes the use of maintenance standards. This paper deals with the steps taken to develop and implement the program. The objectives of the program and the organization and training of the control group are outlined. The work-order system, standards application, classification of work and the preventive maintenance procedures will be discussed.All maintenance information is processed on a Model 360-20 IBM computer, which turns out maintenance records and control reports for management action. Information in these reports, and reasons for reporting, will be discussed and the benefits resulting from the program reviewed."

Jan 1, 1973

By A. R. MacLean

This mine is situated at Point Aconi, Cape Breton , Nova Scotia, and is a replacement for the 100-year-old Princess Collie ry. It is a slope mine which is the continuation of a s trip mine operation. There are fives lopes from the surface driven with Dosco Dintheaders - this marks the first time these machines were used in North America. There are four room -and-pillar sections, each equipped with a Lee Norse HH106 continuous miner, a "Top Dog" roof bolter and two Wagner diesel Teletrams. There are also two Eimco 913 diesel LHD&apos;s , which are used for clean-up in the mines. This paper describes the mining operations of this 800,000-tpy mine which, in less than a year and a half , has been developed to the stage where four sections are producing coal at the desired rate.

Jan 1, 1978

By M. W. Wadsley

"Physical and chemical property models are widely used in process engineering. There exist, in the published literature, completely empirical models of &apos;&apos;thermodynamic properties"", that is, property models that are not consistent with the laws of thermodynamics. There also exist property models that purport to be thermodynamically consistent but are flawed in their implementation. There are also published property models that are consistent with the laws of thermodynamics but that do not reproduce property values with an acceptable accuracy. A practicing engineer might be asked to assess very different property models for which there are a variety of claims. This paper discusses features of thermodynamic and empirical property models that may assist in their practical evaluation and implementation."

Jan 1, 2005

By A. Golabchi

Building Information Modeling (BIM) is an increasingly popular method for generating and managing facility information during the life cycle of a building, ranging from facility conceptualization, through design, construction and its operational life. Organizations involved in Facility Management (FM) have the opportunity to use BIM as a knowledge repository to document evolving facility information and to support decisions made by the facility managers during the operational life of a facility. This paper demonstrates the potential of using BIM to develop algorithms that automate decision making for FM applications. The potential of utilizing BIM as an analysis tool is demonstrated through the scenario of HVAC (Heating, Ventilation, and Air Conditioning) system failure in an operating facility. In case of a typical HVAC malfunction today, facility occupants record complaints in a ticketing database maintained by the FM organization. Upon receiving notification of HVAC system failure, facility inspectors visit the location to confirm the reported failure. Upon confirmation, facility managers review building plans and specifications to develop a detailed plan of action to repair any HVAC components suspected of damage. Based on the plan of action, inspectors visit the facility to inspect and, in case of damage, repair the appropriate HVAC system components. These FM practices ? as currently implemented across the industry ? are labor intensive, time consuming, and often rely on unreliable and outdated information. To address these shortcomings, the authors propose an alternative methodology of HVAC fault detection in operational buildings. The authors implement an algorithm that leverages complaint ticket data and automates BIM to determine potentially damaged HVAC system components. Based on the list of HVAC components suspected of damage, the algorithm develops a plan of action for the facility inspectors. Finally, the authors discuss the advantages of the proposed method as well as the challenges of implementing automated BIM-enabled decision making processes in the FM industry.

Aug 1, 2013