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By Orlando C. Gaspar

Abstract - The presence of fine-grained mineral intergrowths, the complex distribution of deleterious minor elements, and the variable base-metal contents in some assemblages commonly pose technical problems for the processing of volcanogenic massive sulfide ores. The beneficiation of most massive sulfide ores from the Iberian Pyrite Belt requires extremely fine grinding to liberation sizes of K80 = 15 µm to 25 µm. For several deposits, mapping of the ore types and metal zoning patterns has shown that the different ore types are distributed as ore lenses within the massive sulfides. Mineralogical, textural, and metallogenetic studies have provided an understanding of the distribution of both the vertical and the horizontal metal zonation in the orebodies. Because the efficiency of ore processing is affected by ore textures, and because the same mineral commonly has different textures and varies in chemical composition, a relationship between textures of the feed and the middlings must be established for all ore types defined at the deposit scale. Quantitative mineralogical methods have been developed to provide, on a timely basis, the information needed to optimize the concentration processes for the massive sulfide ores at the Aljustrel and Neves-Corvo deposits, Iberian Pyrite Belt, Portugal.

Jan 1, 1997

By Orlando C. Gaspar

The presence of ?ne-grained mineral intergrowths, the complex distribution of deleterious minor elements, and the variable base-metal contents in some assemblages commonly pose technical problems for the processing of volcanogenic massive sul?de ores. The bene?ciation of most massive sul?de ores from the Iberian Pyrite Belt requires extremely ?ne grinding to liberation sizes of K80= 15 µm to 25 µm. For several deposits, mapping of the ore types and metal zoning pat-terns has shown that the different ore types are distributed as ore lenses within the massive sul?des. Mineralogical, textural, and metallogenetic studies have provided an understanding of the distribution of both the vertical and the horizontal metal zonation in the orebodies. Because the ef?ciency of ore processing is affected by ore textures, and because the same mineral commonly has different textures and varies in chemical composition, a relationship between textures of the feed and the middlings must be established for all ore types de?ned at the deposit scale. Quantitative mineralogical methods have been developed to provide, on a timely basis, the information needed to optimize the concentration processes for the massive sul?de ores at the Aljustrel and Neves-Corvo deposits, Iberian Pyrite Belt, Portugal.

Jan 1, 1997

By B. Samanta

Abstract - Ore reserve estimation, based on sparse drill hole data, was conducted for a placer gold property in Nome, Alaska. A problem with sparse data is that random subdivision of the data into modelling and evaluation subsets (as is commonly done) becomes a problem, as random selection may result in biased/skewed subsets. Therefore, a technique that combined data segmentation with genetic algorithms (GA) was applied to divide the samples into three equivalent subsets: training, validation and testing. Data segmentation was done on the basis of the distribution of gold values. Neural network and a variety of kriging techniques were used to estimate gold grades. A multi-layer feed forward neural network along with "early/quick stop" training was used for neural network modelling. A comparative evaluation of kriging and neural network methods was then performed. The results revealed that neural network was generally superior to the kriging techniques for gold grade estimation in the Nome deposit.

Jan 1, 2002

By W. Banda

"Trial application of air decks on a production shot improved fragmentation (32% reduction in x50). Empirical fragmentation models and digital image processing software were used to estimate fragment size distribution of the blasted muck pile. The x20, x50, and x80 passing fractions, and top size were 42, 265, 683, and 1,455 mm, respectively. Air-deck application reduced explosives load in blastholes, lowering total charging cost by US$20/hole (15% decrease) and the powder factor to an average of 0.86 kg/m3 (12% decrease). Blast results were 443,624 t of blasted material from the block (90% of total muck pile) was smaller than 900 mm.RÉSUMÉ L’application pilote de trous d’air dans le cadre du coup de mine effectué pour commencer la production a amélioré la fragmentation (une réduction de 32 % des x50). Des modèles empiriques de fragmentation et un logiciel de traitement numérique des images ont permis d’estimer la composition granulométrique des fragments du tas de déblais abattus. Les fractions de passé de crible de x20, x50, x80 et la dimension supérieure étaient représentées par des dimensions respectives de 42, 265, 683 et 1 455 mm. L’application de trous d’air a permis de diminuer la charge d’explosifs nécessaires dans les trous de mine, réduisant ainsi les coûts totaux de chargement de 20 $ US/trou (soit une réduction de 15 %) ainsi que le facteur de chargement (facteur poudre) à une moyenne de 0,86 kg/m3 (soit une réduction de 12 %). Les coups de mine ont résulté en 443 624 tonnes de matériaux abattus du bloc (soit 90 % du tas de remblais total) mesurant moins de 900 mm. INTRODUCTIONThe main objectives of production blasting are to achieve optimum rock fragmentation and to minimize overall production costs. Because blast fragmentation significantly affects the profitability of a mine, blasting is the first step of the size reduction in mining: An optimum size distribution is required to maximize the performance of mining and subsequent milling processes. If the fragmentation size distribution can be modelled and controlled, operations performance will improve. Blast fragmentation modelling is important in mineto- mill optimization: It allows the estimation of blast fragmentation distributions that can be modelled in downstream mining processes to determine the optimum blast design."

Jan 1, 2018

By Askari-Nasab, D. Checkel, K. Awuah-Offei

Life Cycle Assessment (LCA) is an emerging environmental management tool for examining environmental impacts from cradle to grave. In this paper, LCA is used to evaluate the acidification potential (AP) and global warming potential (GWP) of belt conveyors and truck haulage systems in a surface gold mine using the ISO 14040 standards. The results show that, for AP, the truck system has 32 kg of equivalent SO2 per functional unit, compared to 8 kg for the conveyor system. However, for GWP, the conveyor has 2,820 kg of equivalent CO2 per functional unit, compared to 648 kg for the truck option.

Jan 1, 2009

By W. J. Asselstine

Introduction This paper is prepared from data gathered for a similar paper to be submitted to the United States Bureau of Mines, for publication as one of their information circulars. It covers the history and development of the present milling practice at Premier. The authors wish to acknowledge the assistance and suggestions given during the preparation of this paper by D. L. Pitt, Manager of the Premier Gold Mining Company, Limited; also their indebtedness to various members of the Engineering Staff and of the Accounting Department who have assisted materially in gathering the data used. Location The Premier mine and mill are situated in northern British Columbia, approximately fifteen miles north of the head of Portland canal, in the Salmon River section, about half a mile east of the Alaska-British Columbia boundary line where it crosses die Salmon river. The mill is located on a rather steep hillside on the horizon of the main haulage level of the mine, and is within a hundred feet of the mouth of the tunnel. Both the mine and mill are connected with tidewater at Stewart, B.C., by an aerial tramway (1) eleven and one-half miles in length, which delivers both ore and concentrate to the bunkers at the dock for shipment to the smelters. All mine and mill supplies are transported from Stewart dock to Premier over this tramway, except heavy machinery. Heavy pieces have to be hauled either by truck in summer or sleighs in winter over a good road which runs from Stewart dock to Premier.

Jan 1, 1933

By L. Lariviere, M. Grenier, R. Khalili, D. Shook

A mineral processing facility near Montreal, CEZinc, Noranda Inc., has recently implemented a leading-edge intranet solution for monitoring the performance of plant operations, and providing condition-based maintenance. This innovative multi-faceted software implementation incorporates: web-delivered plant information systems; area-wide control loop performance assessment (using sophisticated algorithms to evaluate poorly performing controllers); and integrated alarm management functions.The system has enabled a project to improve plant operations through better process control. Maintenance technicians, engineers, supervisors and managers all can see the performance of the controllers, and the performance of the plant itself, through webdelivered graphics and reports. Information is combined from many sources, real-time, historical, relational and analytical, to provide a complete picture of plant operation.The web-based solution centralizes the administration of user access, and simplifies the deployment of several different kinds of information to many desktops. It is an extensible system that allows users to create and share their own web pages and data views.The paper will discuss the solution architecture and the improvements the IT, operations, maintenance, and engineering groups have experienced, and overall benefits to the facility.

Jan 1, 2003

By D. Berkley

"The competitive pressure, the increasing energy costs and the environmental regulations impose substantial challenges to the definition of power plants serving industrial facilities. Primary mining and metallurgical facilities have even greater challenges because they are often located remotely, where the fuel supply can be a problem. The absence of a power grid imposes challenges on the reliability and quality of the electrical energy supply. In addition, the facilities usually require thermal energy too, not only electricity.This paper outlines these types of issues that have to be considered when defining a cogeneration plant integrated with a remotely located industrial facility. It is addressed to the “users” of cogeneration facilities rather than to “generators.” The focus is on analyzing various site-specific design considerations to prescreen the feasible cogeneration alternatives and minimize the number of options to be analyzed from the economics viewpoint. This approach could substantially reduce the engineering effort and schedule during the feasibility phase of the project.The front-end of the paper provides a basic understanding of cogeneration plants of various types to establish a common language. Subsequently, the paper outlines and analyzes specific issues that could be of help in the definition of cogeneration installations for remotely located industrial facilities, with a focus on mining and primary metallurgical plants"

Jan 1, 2003

By John G. Henning

Unplanned ore dilution has a direct and large influence on the cost of a stope, and ultimately on the profitability of a mining operation. This paper presents results of a study on the influence of a variety of factors on ore dilution in a blasthole stoping environment. A series of 3-D numerical models were developed and analyzed to examine the effect of mining depth, stope geometry and stope setting within the orezone extraction sequence. To quantify modelled ore dilution from the three-dimensional simulations, the ore Dilution Density (DD) is a term introduced in this study to denote potential hanging-wall overbreak. It was found that hanging-wall overbreak is not significantly influenced by depth alone, and that stopes with large or small axial ratios are more stable than large rectangular stopes. It was also demonstrated that, in addition to stope dimension, the amount of unplanned dilution differed according to stope type. Five stope types were identified, based on their position within a tabular blasthole mining sequence. The methodology presented in this paper can be adopted to develop mine-specific design tools for the estimation of ore dilution associated with a proposed mine design. This can prove extremely helpful in the process of underground mine planning and optimization.

May 1, 2007

By W. R. Lindsay

Considerable attention has of late been given to the blasting of large amounts of ore in one operation, on account of the saving in labour and explosives and consequent low cost per ton, and also on account of the additional safety to employees. The blast here described, at the Hidden Creek mine. at Anyox, B.C., is not necessarily unique either in size or methods employed, but some interesting p10blems were encountered and the solutions of these may be of interest to others engaged in similar work. The ore consisted mainly of old scope-bottoms and sill pillars, although there also were some braces and parts of vertical pillars included. Some of the stope-bottoms were overlain by caved waste, and one of the problems was to break them in such a manner that the maximum amount of ore could be recovered without serious dilution with waste. The ore blocks, designated as the 385 silt and the 7 A-103 blocks, were under preparation for blasting for over a year, as conditions permitted. This work consisted in drilling long machine drill holes, varying in length from 14 to 20 feet. These holes were drilled with the Numa detachable bit, made locally, starting at 2~-inch diameter and bottoming at 2 inches for the longest length. The long hole drilling was used in the thinner sections of the area. For the stronger, thicker portions, powder drifts (3 ft. by 4 ft. in section) were driven for the powder charges. Reference to the plan and sections (Figures 2 co 8 inclusive) show the relative location of these, as well as the long drilling. The amount of explosives used in the powder drift charges averaged 0.25 pounds per ton of estimated burden, varying from 0.2 to 0.3 pounds per ton.

Jan 1, 1934

"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 Y. Yhang, D. C. Sego

ABSTRACT This paper evaluates the potential of freeze-thaw dewatering using Albian mature fine tailings (MFT). Freezing tests were first performed to study the effect of freezing rate on dewatering efficiency. Lower freezing rate resulted in higher thawed solids content and shear strength. Subsequently, large strain consolidation tests were conducted to investigate consolidation behaviour and how it is affected by freeze-thaw. The consolidation behaviour was presented in terms of effective stress versus void ratio and permeability versus void ratio. The results can be used to predict the field behaviour of Albian MFT and optimize the application of freeze-thaw for MFT dewatering.

Jan 1, 2014

By S. Y. Tshipeng, A. T. Kaniki

"RÉSUMÉ La lixiviation acide d’un minerai oxydé cupro-cobaltifère en milieu non réducteur et en milieu réducteur en utilisant le Fe2+ et le métabisulfite de sodium (SMBS) a été étudiée et les résultats ont été comparés. Les tests de lixiviation ont été effectués à température ambiante, dans une pulpe à 30 % solide, avec une vitesse d’agitation de 600 tr/min, un potentiel redox de 350 mV pour les tests en milieu réducteur, et un pH de 1,8. Les tests de lixiviation avec usage du SMBS comme réducteur ont donné la meilleure cinétique de lixiviation du cuivre. Pour le cobalt, c’est l’usage du Fe2+ qui a donné la meilleure cinétique de lixiviation. L’augmentation de la dose du fer dans la solution au-delà de 5 g/L a influencé négativement les rendements de lixiviation du cuivre et du cobalt. ABSTRACT Acid leaching of a copper-cobaltiferous oxide ore in a non-reducing environment and in a reducing environment using Fe2+ and sodium metabisulfite (SMBS) was studied and the results compa¬red. The leaching tests were performed at room temperature, in a 30% solids pulp, with a shaking speed of 600 rpm, a redox potential of 350 mV for the tests performed in the reducing environment, and a pH of 1.8. The leaching tests using the SMBS as a reducing agent produced the best copper leaching kinetics. As for cobalt, the best leaching kinetics was achieved using Fe2+. An increase in the amount of iron in the solution above 5 g/L negatively influenced copper and cobalt leaching yields. INTRODUCTION La République Démocratique du Congo (RDC) est un pays reconnu dans le monde pour son sous-sol qui regorge d’énormes quantités de cuivre et de cobalt (USGS, 2014; Palisade Research, 2016). La technique qui semble être la plus recommandée pour extraire à la fois le cuivre et le cobalt des minerais oxydés cupro-cobaltifères est la lixivia-tion acide en milieu réducteur. Cette technique est appliquée par la majorité des sociétés minières qui exploitent ces minerais dans l’ex-province du Katanga en RDC, à savoir: Tenke Fungurume Mining, Mutanda Mining, Kamoto Cop¬per Company, Sicomines, Gécamines, Boss Mining, Chemaf, Ruashi Mining et Somika. L’usage d’un agent réducteur est indispensable pour l’obtention d’un bon rendement de lixiviation du cobalt. En effet, plusieurs chercheurs s’accordent sur le fait que le cobalt trivalent de l’hétérogénite (CoO·2Co2O3·6H2O) est insoluble à l’action de l’acide seul; il ne devient soluble qu’après réduction en cobalt bivalent (Mwema, Mpoyo, & Kafumbila, 2002; Mulaba-Bafubiandi, Ndalamo, & Mamba, 2007; Ferron, 2008; Seo, Choi, Kim, & Tran, 2013; Stuurnam, Ndlovu, & Sibanda, 2014)."

Jan 1, 2018

By Steve W. Ciccone

The Red Dog Mine is both the largest known zinc reserve and the largest zinc producer in the world. The mine started in 1989, and by 1999 had increased production from approximately 300,000 tonnes per year (t/yr) of zinc concentrate to in excess of 900,000 t/yr. The VIP Mill Optimization Project further increased zinc concentrate production to 1.1M t/yr while improving both product quality and zinc recovery. The Mill Optimization project also addressed a number of issues related to risk reduction: power generation capacity, water treatment capacity and concentrate thickening. The project was faced with numerous challenges, the most daunting of which was the schedule. This US$105M project was executed, from conception to completion, inside of two years. Less than nine months elapsed from concept to delivery of materials and equipment to site. The project also faced a 100-day icefree shipping window, the challenges of construction in an Arctic environment, and an extremely tight labour market for qualified craft personnel. These challenges were successfully addressed with several innovative approaches to project execution, including an Alliance contracting arrangement between the owner, engineer and contractor; full integration of the team; construction of modules in Anchorage; and fast-track engineering, procurement and construction. Steve Ciccone, AMEC?s project manager on the Mill Optimization project, works for the Mining & Metals unit of AMEC, a world leader in the provision of engineering and construction services. He obtained his BASc from the University of British Columbia and is currently midway through his MBA program at Simon Fraser University. Steve has 15 years of experience providing engineering and project management services on mining and metals projects, and has been involved in the execution of five capital projects and several studies at Red Dog since 1995. George Hope was responsible for process design and engineering on the Mill Optimization project and has been Manager, Project Development at Teck Cominco since 1995. Prior to this time, he was a project manager and chief metallurgist for Lac Minerals for 14 years and a mill superintendent and metallurgist for Noranda for 5 years. George received his BSc in Mineral Technology from the Royal School of Mines in England.

May 1, 2002

This paper aims to increase our understanding about existing capacity-building approaches and their implications for obtaining a social license to operate in the mining industry. The notion of ?capacity building? is gaining increasing currency in the mining sector in developing countries due to a rapid rise in the globalisation of mining operations. Capacity-building is conceived here as a process that lasts after the mine-cycle, intended to provide local mining communities with tangible skills and knowledge to gain meaningful employment in mining or other industries relevant for the local economy. Building community capacity to understand and effectively respond to these transformations is vital for obtaining a social license to operate, as it promotes sustainable and locally relevant development. Accountability mechanisms such as global norms and international standards increasingly highlight the need to build capacity among stakeholders, particularly among local communities adjacent to mining operations. International frameworks and mining companies have embraced the notion of capacity-building as a driver to assist corporate social and operational performance. However, this narrow understanding of capacity-building through the prism of corporate social responsibility and ?best practice? is preventing the industry from meaningfully impacting communities and maintaining a social license to operate. This latter notion is being widely embedded across multiple industry sectors, as a social and economic reward from mining companies to compensate communities for natural resource extraction and gain social acceptance. Although both concepts are widely recognised in the minerals industry, insufficient attention has been paid to the implications of applying a top-down (mining-orientated) or a bottom-up (community-orientated) capacity-building approach for obtaining a social license to operate, or indeed how these two concepts are linked and applied in practice. At times, communities lack the necessary capacities in the form of education and skills to deal with mining-led livelihood transformations. This is preventing both mining companies and communities from forging sustainable livelihoods and responding to mining-led livelihood transformations, a situation that is creating discontent among communities and reducing the possibility of obtaining and renewing a social license to operate for the industry. Based on a review of current scholarly debates, accountability mechanisms in the mining industry and fieldwork findings in Colombia, this paper will contribute to an understanding of the implications of existing capacity-building approaches that support a social license to operate.

Aug 1, 2013

By Dave Shook

A Mineral Processing facility in Montreal has recently implemented a leading-edge intranet solution for monitoring the performance of plant operations, and providing condition-based maintenance. This innovative multi-faceted software implementation incorporates: web-delivered plant information systems; area-wide control loop performance assessment (using sophisticated algorithms to evaluate poorly performing controllers); and integrated alarm management functions. The system has enabled a project to improve plant operations through better process control. Maintenance technicians, engineers, supervisors and managers all can see the performance of the controllers, and the performance of the plant itself, through webdelivered graphics and reports. Information is combined from many sources, real-time, historical, relational and analytical, to provide a complete picture of plant operation. The web-based solution centralizes the administration of user access, and simplifies the deployment of several different kinds of information to many desktops. It is an extensible system that allows users to create and share their own web pages and data views. The paper will discuss the solution architecture and the improvements the I.T., operations, maintenance, and engineering groups have experienced, and overall benefits to the facility.

May 1, 2002

By L. H. Michaud

"Albian Sands Energy (ASE), an oil sands surface mining and extraction operation, is currently undergoing start-up and is scheduled to ramp-up to full production by mid-2003. Startup includes the selection and implementation of over 75 IT systems or computer applications which include: engineering applications; systems required to control mining activities, maintenance, the processing plant and utilities; and also systems required to run the company, such as human resources, finances and inventory/ warehousing.This paper outlines the processes used for the selection, implementation and integration of these systems in order to optimize the use of information and to meet the technical, business and IT requirements of the company. The first step in ASE’s approach to identifying system requirements is the development of a business activity model, outlining all tasks involved in running the operations. The computer applications required to accomplish each task are then identified by having the IT team work closely with each technical and business unit. Historically, at some companies, the selection of systems has been led by the IT team or by consultants, with little input from the technical or business units. Typically, this results in products that do not meet the company’s expectations. To ensure a more positive outcome, ASE believes that it is imperative that the company’s technical and business people be closely involved in the selection process.Integration of the IT systems is also key, including linking all applications through a data warehouse and EDMS. Over 120 required integrations have been identified. This ensures the storage of all data in only one location, data security, and easy data and document retrieval for all requirements throughout the company"

Jan 1, 2003

By W. B. Boggs

The Noranda smelter was built by Noranda Mines, Limited, from the designs of A. E. Wheeler, consulting metallurgist, New York, for the reduction of ores and concentrates from the Horne mine, and to treat, on a custom basis, ores and concentrates from other mines in the Rouyn district. The smelter is situated at Noranda in western Quebec, about 330 miles directly north of Toronto. Ground was first broken for construction in November, 1925, before the completion of the branch railway into the district, which was not finished until October, 1926. After many difficulties and delays due to the Jack 'of transportation and the severe weather during the winter months, the smelter was started in December, 1927, and the first blister copper was poured on December 17th. The smelter was built throughout in two duplicate units, each with a rated capacity of 500 tons of ore per day. Operations were started with only one unit, and after several months it was found that one unit alone would smelt 1,000 tons of ore per day. At this time only one shaft, No. 3, existed, and its hoisting capacity and the capacity of the original crushing plant were insufficient to supply ore for two units at the increased tonnage. Accordingly No. 4 shaft was sunk and a new crushing plant provided to handle the ore hoisted there. This work was completed in the latter part of November, 1929, and since that time both smelter units have been operating.

Jan 1, 1930

By Meimei Zhang

In the overall open pit mine planning process, mining phase design is a strategic driver in guiding and constructing the block extraction sequence and determining the annual net cash flow distribution. Mining phase design should obey some practical constraints, such as ?minimum mining width? and ?flat mining phase bottom?, to allow space for haul road development and truck and shovel access on each bench. However, these practical mining phase design requirements are not taken into account in all first-cut mining phase design methods and post-processing is always required to convert an impractical design to a practical one, resulting in a potentially significant loss of Net Present Value (NPV) relative to the first-cut impractical designs. In this paper, we present a method using a meta-heuristic algorithm ? Simulated Annealing ? to enforce those practical constraints in determining a mineable phase design whilst ensuring minimum NPV loss.

Oct 1, 2009

By Karl J. C. Harries

Mineral Agreements and Royalties

Jan 1, 2003