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By K. Iturralde

The article discusses the possibility of automation in refurbishment processes of social dwelling built from 1950 to 1970. These massively produced buildings were mostly designed prior to the law enforcement regarding thermal insulation or accessibility. Nowadays, many of these buildings are being retrofitted. The article focuses on the works in the external envelope. The task of renewing the whole social building stock is big and it requires a systematic process that facilitates a rapid upgrading, without neglecting the specific situation of each case. How could an automatic refurbishment process of these buildings be defined? The process should start with the data collection of the building and the creation of a 3D model using software such as BIM. The project, drafted in 3D, should facilitate the manufacture of building elements by robotics. In turn, it should be noted that during the assembly at the site, the pieces must be fixed quickly and efficiently. Is it possible to implement an automated process for the refurbishment of apartments built in the second half of the twentieth century? To approach the answer, a virtual refurbishment project is performed. The article focuses on the rehabilitation of the building envelope. Furthermore, it gives special attention to the double skin facade. It is well known that a second skin in this type of building can be an element that integrates several functions. Finally, needless to say that refurbishment of residential buildings is a need in our society. By extending its life cycle, robotic refurbishment provides more favorable socioeconomic and environmental capabilities than the sole construction of new buildings.

Aug 1, 2013

By Yuki Tsunazawa, Sho Fukui, Chiharu Tokoro

"A milling process is one of the important unit processes in mineral processing. In the milling process, the control of particle size distribution is necessary for the later physical separation process. Since the milling process is strongly affected by the equipment designs, operation conditions and raw materials, the control for particle size distribution of milling products is mainly based on empirical rules. Recently, the discrete element method (DEM) has been widely used as an effective tool to investigate the behavior of grinding media. Although the behavior of grinding media can be accurately simulated, it is not well-established the way to predict particle size distribution after milling by the DEM simulation.The objective of this study was to develop a new method to predict particle size distribution in ball milling using the DEM simulation. To predict particle size reduction, a correlation between experiments and the simulation was investigated in various operation conditions, that is, wide range of the rotation speed and the filling ratio of grinding media. In experiments, after lime stone was ground, the average and variance of particle size distribution were evaluated using some kinds of distribution equations. In the DEM simulation, direct simulation of particle disintegration in milling process is generally very difficult because of huge computational load. Therefore, collision energy between grinding media balls orgrinding media ball and wall was used as a factor of particle disintegration.As a result, a good correlation between experiments and simulation was obtained. In addition, the particle size distribution in ball milling could be predicted using this correlation. Therefore, these results indicated that the use of the correlation between experiments and the DEM simulation was an effective approach of predicting the particle size distribution in milling process."

Jan 1, 2016

By Michael L. Wayman

Native copper is copper which exists in nature in elemental, metallic form, rather than being chemically combined as is the case with the more usual oxides, sulphides, carbonates, etc. Several other metals, including gold, silver and platinum also occur in native form as do, rarely, iron, lead and mercury; a few naturally occurring native metal alloys, notably electrum (gold-silver) and tumbaga {gold-copper or gold-silver-copper) are also known. An analysis of the relative availabilities of native metals as nuggets in a useful size range111 shows native copper to be by far the most abundant of the native metals, exceeding both gold and silver by at least two orders of magnitude. While such an estimate is crude, it serves to illustrate why copper was one of the first metals to have been used by ancient peoples. Native copper is known to occur on all inhabited continents, although its exact occurrence and abundance in ancient times cannot be unambiguously determined because many surface deposits may have been totally exploited and are therefore no longer identifiable. It is clear, however, that native copper does or did occur in all areas inhabited by the early metal-using cultures, for example in the Andes, in Central America and in the Near East. It is remarkable that most of the world's native copper occurs in the deposits of the Lake Superior region, primarily on the Keweenaw Peninsula of northern Michigan and on Isle Royale, an island in Lake Superior some 50 miles north of the Keweenaw deposits. Canadian deposits of native copper are found in Newfoundland and Labrador, Nova Scotia, Quebec, Ontario, British Columbia, the Yukon and the Northwest Territories (on Victoria Island, Bathurst Inlet and the Coppermine River area). It was to locate the latter deposits that the explorer Samuel Hearne was sent overland from Hudson's Bay in 1770; they were also surveyed by Sir John Franklin's expeditions in the 1820s.

Jan 1, 1999

By Andrew L. Mular, Robert P. Edwards

"The operation of flotation circuits is often regarded as a combination of art and science. Expert systems offer a method by which the art may be captured and supervisory control of flotation circuits fully realized. Operating knowledge, the art, can be consistently employed to enhance regulatory control through the judicious application of an expert system. Using an expert system, a supervisory control routine was developed, and success- fully implemented, in the copper flotation circuit at Brenda Mines Ltd.The expert system ran in conjunction with regulatory PI controllers on a personal computer. The expert system received assays via an on-stream analyzer and adjusted regulatory loop set points as required in real-time. From its commissioning in November, 1989, to the end of the mine 's operation in June, 1990, it was enthusiastically embraced by the operators and attained operating levels superior to those achievable manually.IntroductionExpert system (ES) software springs from research into artificial intelligence and is currently making significant inroads into business and industry. ES proponents make many attractive claims; they are a means of capturing the knowledge of experts and they can be programmed by non-programmers. To date, most uses of this software in the process industry are in off-line applications, meaning that the applications are not tied directly to operating (on-line) environments. Moreover, in on-line environments, they are typically employed as advisors and only suggest changes. Human operators are required to close-the-loop to the process. Yet, an ES should be applicable to operating environments and, if the claims of the proponents are valid, should also be better than existing tools. As an intelligent controller an ES must use the knowledge of experienced operators, apply it directly to a process and do this without the intervention of human operators. On-line applications have been successfully employed in the closed loop control of SAG circuits (Herbst et al., 1989) and flotation circuits (Hales, 1989). Harris and Kosick (1988)detail an implementation for flotation control at the Polaris Mine."

Jan 1, 1992

By Lyall J. Lichty

THE property of New Calumet Mines, Limited, is on Calumet island, in the Ottawa river, about sixty-six miles northwest of Ottawa. Lead and zinc orebodies were discovered here in 1893. A gravity concentration plant was built in 1912 but was not a success metallurgically, and the plant was later destroyed by fire. A programme of diamond drilling on the property, started in 1937 and continuing to 1942, indicated ore reserves amounting to 1,300,000 tons averaging 2.75 per cent lead, 8.82 per cent zinc, and 0.041 oz. gold and 6.24 oz. silver per ton( l ). These orebodies have been developed underground by cross-cutting and drifting from a three-compartment vertical shaft, sunk to a depth of 745 feet. 'The ore is a contact metamorphic deposit occurring in rocks of the Grenville series, on or near the contact between biotite gneiss and an overlying calcareous amphibolite(2,3). It consists chiefly of iron-bearing sphalerite, galena, pyrrhotite, pyrite, and minor amounts of chalcopyriteand argentite. The gangue minerals closely associated with the ore are calcite, quartz, and various lime-silicate minerals.

Jan 1, 1945

By Francisca San Martin, Tomas Vargas, Willy Kracht

"In Cu-Mo deposits it is usual to find considerable amounts of pyrite (FeS2). When processing this kind of ore by flotation, pyrite is rejected using lime to increase the pH to alkaline conditions (pH ~10.5). In the case of using seawater without pre-processing, i.e., raw seawater, the lime consumption increases dramatically and the recovery of molybdenite drops due to the precipitation of magnesium hydroxide on its surface. In order to avoid these negative effects, alternative ways of depressing pyrite should be considered.The current work introduces the use of Acidithiobacillus ferrooxidans, bacteria commonly used in bioleaching, as an alternative to depress pyrite in seawater flotation. The paper presents the results of biodepression in three systems: fresh water, water with added sodium chloride at 35 g/L (which corresponds to the salt concentration in seawater ) and seawater. The results show that it is possible to bio-depress pyrite with A. ferrooxidans in natural seawater pH (7.8-8.2). A similar behaviour is observed when running the experiments in fresh water, and in water with sodium chloride added.INTRODUCTIONWater is a scarce but essential resource for human development. The main reason for this scarcity is that, although 70% of the earth's surface is covered with water, only 3% of the total is fresh water and an important part of this water is frozen, so that only 1% of fresh surface water can be used for human activities. In Chile, most of the mining activity is concentrated in the north of the country, located in the Atacama Desert, considered the world's driest desert. That is why some mining companies have chosen to use seawater in their processes. For example, Esperanza (Antofagasta Minerals), and Sierra Gorda (KGHM International) use raw seawater in their flotation processes."

Jan 1, 2016

? The Mining Association of British Columbia (MABC) was established through an Act of Parliament in 1901 ? The MABC represents the interests of B.C.?s ? Coal and mineral mining companies ? Smelting companies ? Advanced stage development projects ? Key areas of work: ? Environment, Health and Safety ? Policy & Government Relations ? Knowledge and Information Services

May 1, 2008

By Stephen Hardcastle

Personnel Heat Exposure Issues In Canada?s Deep Mechanized Mines ?Project developed in 2004 ?Base/precious metal industry identified heat stress/management as a major challenge affecting productivity and operating costs ?Project started in 2005 ?Current research nearing completion ?Guidelines, further data analysis and ?Communicating the Science? will continue into 2011

Oct 1, 2010

By M. Leroux, C. J. Martin, S. R. Rao, J. A. Finch

"The effect of nitrogen on the flotation separation of sulphides from complex ores from Brunswick Mining and Smelting (New Brunswick) and Mattabi Mines (Ontario) was investigated. The most significant finding was enhanced pyrite floatability after as little as 3 minutes nitrogen conditioning. This was used in a novel sphalerite/pyrite separation process developed on the Brunswick ore. After aeration and Cu/Pb bulk flotation in air using xanthate the slurry was nitrogen conditioned, xanthate added and the pyrite floated in nitrogen. As an example up to 70% pyrite recovery with about 20% sphalerite recovery was achieved. Sphalerite was recovered from the pyrite tailings and the pyrite concentrate by copper-activation, raising the pH to 10 and floating in air. About 65-70% recovery at 35-40% Zn grade was achieved compared to 25% Zn grade by the conventional route. The process offers a promising alternative to current practice which seeks to depress pyrite at all stages. A possible mechanism of the effect of nitrogen is presented. INTRODUCTIONUse of gases other than air in froth flotation has been reported from time to time. [Podobnik and Shirley, 1982; Lin and Metzer, 1975]. Of all the gases, nitrogen would appear to hold the greatest practical promise because of its easy availability and chemical inertness. It is used in froth flotation in chalcopyrite-molybdenite separation [Redfearn, 1983]. The use of nitrogen in polysulphide chalcopyrite. this case is mainly to reduce the oxidation of a compound (Nokes reagent) used as a depressant for There is no reported use of nitrogen in the flotation of other sulphide minerals."

Jan 1, 1988

By R. R. Stone

"This paper will examine the role of debt and equity in project financing and will illustrate the impact on the return to the project sponsor of each type. Conventional debt sources will be examined, as will product purchaser advances, foreign export-import bank loans and lease financing. The paper will review guarantees, charges against the project, dividend restrictions and other commitments. It will also discuss various features of sales contracts and the degree to which they can assist in securing financing. IntroductionThe cost of bringing new mining projects on stream is escalating significantly more rapidly than general rates of inflation. Reasons for this include the higher costs of safeguarding the environment and ensuring the health and safety of workers. The need to develop properties in more remote areas is also a significant factor. These higher costs have not been matched by increases in metal prices, making the task of financing these projects ever more difficult. At the same time, the imagination of borrowers and lenders seems boundless, and innovative schemes for financing projects are constantly being unveiled.It is probably safe to say that no two projects have ever been financed in precisely the same way and the number of financing options for any project is limited only by the imagination of the sponsors themselves. The objectives of the project sponsor represent the most important factor in determining the scope of possible financial arrangements. For example, the sponsor may wish to maximize over-all company leverage by isolating each of its projects in separate companies. In so doing, it hopes to facilitate more ventures than would otherwise be the case. These objectives point toward true project financing. Additional objectives may be to develop a number of its properties by joint venture and to reduce the amount of debt on the sponsor's balance sheet. Those sponsors whose objectives include minimizing over-all financing costs will wish to increase the number of financial options and, as a result, will not be so concerned with effecting true project financing. This approach may also provide ""greater certainty that tax benefits are utilized quickly."

Jan 1, 1980

By G. N. Nnadi, R. J. Mitchell

"The response of cemented backfills subjected to simulated blast loadings is studied using centrifugal modelling techniques. Scaling requirements for centrifugal modelling are developed and the results of the similitude analysis show that an acceleration field is required to capture the true dynamic response of backfill models. Experiments have been conducted at various centrifugal accelerations. The effects of ring blasting were simulated by an impact loading on the exposed fill face. The behaviour of the cemented backfill was monitored with accelerometers as well as dynamic stress gauges.Cemented backfill response to impact loadings was found to depend strongly on simulated gravitational stress level. Results also show that the characteristics of the response changes with distance from the impact. Finally, the results of the models were used to predict prototype peak accelerations, velocities and displacements. The results reported in this study indicate that centrifuge modelling may be a useful tool for dynamic studies of blast damage to backfills. Centrifuge modelling can be carried out at low costs and can be used to design prototype instrumentation systems. IntroductionThe response of cemented mine backfills to blast loadings is of concern to the mining industry because these backfills provide local and regional support during ore pillar extraction. Considerable research has been reported on the static stability (Smith et al., 1983) and on effects of reinforcements on cemented backfills (Mitchell, 1989). However, information regarding dynamic aspects of cemented backfill is limited. O'Hearn and Swan (1989) reported on the response of cemented backfill to blast loading, but these blasts were not very dose to the backfill . A schematic representation of a rock-backfill system is shown in Figure I.The mechanics of transfer of explosive energy to rock and subsequently to the backfill, and the resulting responses, are complex. Achison (1968) listed more than twenty factor s affecting the blast fragmentation of rock and grouped these into the categories of explosive parameters, charge parameters and rock parameters. Although significant advances have been made, during the past two decades, in understanding the mechanics of blasting, the degree of uncertainty associated with predicting the behaviour of backfills subjected to dynamic loadings makes the application of simple design safety factors insufficient. Comprehensive testing programs or prototype instrumentation is required to evaluate the risks associated with blast or earthquake loadings on backfill."

Jan 1, 1991

By Alfredo Bambaren

First Encounters between Communities and Mining 1. Importance, meaning and process 2. Antamina?s study case 3. ?Self-organization? theory (NLP) 4. The story we tell, the values we live 1. Importance, Meaning and Process ? First encounter stays in mind as a model. ? First encounter means foundation. ? First encounter builds the story.

May 1, 2010

By R. Saulters, M. Garshasb

The Transportable Moisture Limit (TML) is the copper concentrate moisture content beyond which liquefaction may occur during shipping. This study indicates that TML is a function of mineralogical characteristics of concentrate, which in turn may directly affect moisture retention properties. A comprehensive mineralogical and chemical analysis was conducted to determine the impact of composition and mineral content on concentrate’s TML. The analysis indicates that the high TML value is associated with particular minerals such as gypsum, swelling clay, muscovite and pyrite. Since higher TML values allow higher moisture contents for shipping, this property is desirable for concentrate inventory management and shipping flexibility. Scarcity of minerals that may increase TML contributes to limitations of shippable inventory. INTRODUCTION TML is the maximum moisture content of copper concentrate beyond which liquefaction may occur. Moisture content above the TML is considered a shipping hazard as it may result in loss of lives and cargo. The details of TML testing are given in ISO 12742:2007 (ISO 12742). In principle, TML is 90% of the Flow Moisture Point. The method of testing for Flow Moisture Point and TML is based on procedures that provide pulsations that simulate the cyclic force of ocean waves to determine moisture levels at which the onset of concentrate flow may occur. International Maritime Organization (IMO) provides guidelines for developing and approving TML testing and moisture determination in the context of its Moisture Management Plan (MMP) for shipment of copper concentrate cargoes (IMO 2013). The IMO regulations are specifically provided in MSC.1/Circ. 1454 “Guidelines for developing and approving procedures for sampling, testing and controlling the moisture content for solid bulk cargoes which may liquefy”. Since each port has its own operational characteristics, resource availability, peculiarities of governmental structure, and desired methods of interaction with the authorities, it is necessary to adopt the IMO guidelines to the local requirements. In order to establish a TML and MMP measurement system, it is required to implement and follow proper guidelines for the relevant procedures. For example, sampling procedures are developed in accordance of ISO 12743, “Copper, lead, zinc, and nickel concentrates – Sampling procedures for determination of metal and moisture content”. Moisture content of copper concentrate samples are determined in accordance with ISO 10251, “Copper, lead, zinc, and nickel concentrates – Determination of mass loss of bulk material on drying”. To assure strict adherence to the MMP procedures, the overall system needs to be integrated into the site QA/QC system, which would make them auditable and certified in accordance with standards such as ISO 9001, ISO 17025, and ISO 17020.

Jan 1, 2019

By Julian V. Simela

Conventional methods of underground surveying use theodolites/total stations and 3D laser scanners to obtain information about the underground environment. Current methods of geo-referencing these instruments to a mine reference system include triangulation, trilateration and resection. However, despite technological advancements, surveying procedures have remained slow, laborious and relatively unchanged during the last half-century. Recent innovations in the robotics community have shown that automated mapping of underground mining tunnels can be undertaken using 2D/3D laser scanners. These techniques have the potential to, in turn, improve upon current underground surveying and mapping methods. Automating surveying and mapping using current surveying tools without changing the setting up procedures or removing current constraints, or even changing the type of equipment used, does not change the status quo. The problem of moving from a static, tripod based surveying and mapping system to an unconstrained mobile surveying and mapping system is the subject of this paper. A current challenge for automated mapping is the ability to automatically geo-reference a mobile mapping system to a mine reference system. For a mobile mapping system that uses a horizontally mounted 2D laser scanner to gather data of the underground environment, the challenge of determining its position and orientation within the mine environment is magnified even more. This paper introduces Mobile Automated Scanner Triangulateration (MAST), a technique under development at Queen?s that is designed to geo-reference a mobile mapping system to a mine reference system for the purposes of underground mine surveying. MAST quickly and automatically determines scanner 2D position and orientation (azimuth) in a mine reference frame by using minimal human input.

Aug 1, 2013

By A. B. Isaeva, A. Yu. Lein, A. A. Karpenko, V. V. Serova, A. P. Lisitzin, V. Yu. Rusakov, V. N. Lukashin

Abstract - The flux of sediment matter was determined using sediment traps near a black smoker ("Saracen’s Head," Broken Spur hydrothermal field) and the mineral and chemical compositions of the settled matter were examined. The metallic minerals are represented by Fe sulfides (pyrite and pyrrhotite), and Cu and Zn sulfides are also found in small and equal quantities. The hydrothermal suspended matter contains abiogenic calcite in amounts comparable to that in Ca sulfates. The content of silica and, specifically, of amorphous Si is unusually low. Such correlations between chemical elements and minerals, together with the isotopic compositions of S and C, are characteristic of a relatively young and active stage in the evolution of a hydrothermal system. Sediment traps within and under neutrally buoyant hydrothermal plumes collected biogenic material in addition to hydrothermal components. Microbial chemosynthetic production of organic carbon near the hydrothermal vent is comparable to primary production in the euphotic layer. Fe, Zn, Ca, Si, Ba and P are enriched in particulate matter in comparison to the background. A vast compound plume containing the discharge of multiple hydrothermal vents was found to the south of the Broken Spur hydrothermal field.

Jan 1, 1999

By D. Kovachevich, M. A. Pfeifer

"A t remote locations typical of mines and associated ore processing plants, diesel electric generators are ideally suited for power plants due to their inherent operating flexibility, efficiency and reliability. In recent years rapid escalation in fuel and related transportation costs has made extensive waste heat recovery from generating sets financially attractive to a much greater extent than previously.The paper outlines key considerations during planning and design stages for utilizing the various waste heat sources available to best advantage. Based on two /980 mining projects built in the Canadian Arctic, data is presented on potential operating and capital costs savings. A review of heat balances, engineering flow diagrams and major equipment selections for process and building heating systems utilizing waste heat is included.IntroductionResource projects increasingly occur in remote areas requiring on-site self sufficiency in electrical power generation. For such projects, the low- or medium-speed turbo-charged diesel engine is very often the preferred choice as a prime mover for the generating sets . It is inherently reliable, has good response to load changes and has comparatively high fuel efficiency over a wide load range . From a project execution standpoint, It is capital cost- competitive and procurement lead-time normally ' fits ' within tight schedule constraints. In addition, its potential for waste heat recovery is excellent , particularly in northern climates where space heating requirements are usually substantial, and also where there a re requirements for heat for process and plant services.The high cost of fuel , with add-on transportation costs , provides a major incentive to fully exploit the available waste heat recovery potential o f such installations.As a result of the rapid escalation in the price of petroleum products following major crude oil price increases in 1973 and again in 1978-79, liquid petroleum fuels, having the desirable properties of comparatively high heat content and transportability, are no longer 'cheap' commodities and have become so valuable that industry has widely undertaken serious conservation efforts.Currently, it appears that petroleum cost trends of the 1970s may not continue, at least in the near term, and that we may see somewhat reduced energy costs for a time. In the longer term , and certainly within the life spa n of major projects, however, it is generally believed to be inevitable that these fuels will be increasingly expensive . Energy costs are today a major operating cost for remote minerals processing plants and will remain so for the foreseeable future.In order to meet the economic challenge posed by high energy costs, future projects should be thoughtfully planned from the outset with the goal of minimizing energy requirements and maximizing the use of waste heat recovery to meet such requirements. There is also considerable potential for significant energy savings by retrofitting of existing installations."

Jan 1, 1984

By Frank Ebbutt

Introduction The property of the Britannia Mining and Smelting Company, Limited, is situated on the east side of Howe sound, about six miles from its head. It is roughly thirty miles by water from Vancouver, one of the important ports of the Pacific and the industrial and financial centre of British Columbia. Howe sound is navigable for ocean-going vessels and Britannia Beach is a daily port of call for the commodious boats of the Union Steam-ship Company, sailing from Vancouver. Few mines are so ideally situated or have so many or varied natural advantages. Copper was first found on Britannia mountain in 1888, by Forbes, but it was not until 1898 that five claims were staked here by Oliver Furry, a trapper. It is from these claims that the major production during the past thirty years has come. In 1900 the Britannia Copper Syndicate was formed and development of the property was commenced. In 1903 the late Grant B. Schley obtained control, and through his efforts the Britannia Mining and Smelting Company was organized in 1908 as a subsidiary of the Howe Sound Company. Since that time, a persistent and progressive policy has been followed, which has resulted in a prolonged and profitable operation. The country in the immediate vicinity of the mine is marked by strong relief, with mountains rising abruptly from tide-water to elevations of 5,000 feet and more. Two broad transverse valleys deeply dissect the area. These are the valleys of Britannia creek and Furry creek. The region has under-gone prolonged and relatively recent glaciation. Over much of the surface there is deep overburden and dense vegetation. The geology of the mine and vicinity has been described in reports by S. J. Schofield (1), H. T. James (2), J. G. Barry, and others (3). The present writer is in accord with much of this literature on Britannia, but during recent years, extended observations made underground have shown that the 'quartz porphyry', or 'mine porphyry', of several of the earlier writers is not the host rock to the commercial mineralization; and he contends that the mineralization occurs in highly altered phases of a complex series of ruffs, flows, and pyroclastics and their autoclastic metamorphosed products.

Jan 1, 1935

By L. M. Guayacán-Carrillo, G. Armand, A. Noiret, D. Seyedi, S. Ghabezloo, J. Sulem

"The main purpose of this paper is to analyze the convergence measurements in a drift excavated in the Callovo-Oxfordian claystone. The drift axis is in the direction of the major principal horizontal stress whereas the stress state is quasi-isotropic in the drift’s section. The initial geometry of the drift being circular, the anisotropic character of the deformation is taken into account by assuming that the drift shape evolves in an elliptical shape. The convergence measurement data on six different points around the drift are analyzed to identify the main axes of the deformation ellipse, following the methodology proposed by Vu et al. (2013, Rock Mech Rock Eng, 46, 231-246). Then, using the semi-empirical law proposed by Sulem et al. (1987, Int J Rock Mech Min Sci, 24, 145–154), the convergence evolution is fitted independently for each axis of the ellipse. This method permits to distinguish two effects: the face advance effect and the time-dependent behavior of the ground. The results for the two directions of the ellipse axes show very close values for the parameters describing the time-dependent properties of the ground, the distance of influence of the face, and the extension of the decompressed zone around the gallery. Such model can provide valuable insights for predictions of the convergence evolution in the long-term. INTRODUCTIONDeep disposal of radioactive waste has been studied in France for more than two decades. The French National Radioactive Waste Management Agency (Andra) began in 2000 the construction of an Underground Research Laboratory (URL) with the main goal of demonstrating the feasibility of a geological repository in Callovo-Oxfordian claystone. Several research programs have taken place to improve the knowledge of the rock properties and its response to the excavation progress. The optimization of supports design for long-term behavior is an important point to develop. A network of experimental drifts has been constructed with variations on: excavation method, structure geometry, supports system and orientations with respect to in-situ principal stresses’ directions. In each drift different sections have been instrumented to monitor the convergence evolution and the rock deformation. Continuous monitoring of the excavated zone around the drifts revealed the development of a fractured zone (extensional and shear fractures) induced by the excavation. The extent of this fractured zone depends on both the drift orientation and the in-situ stress field (Armand et al., 2014). Indeed, the fractures distribution has an important influence on the convergence of the drifts."

Jan 1, 2015

By T. Crivits, I. Bellemans, V. Cnockaert, K. Verbeken

It is well known that slag foaming can significantly complicate copper smelting processes. This is especially true for unpredictable events that generate large amounts of slag foam during a small period of time. These events are here referred to as eruptions and are typical for certain types of liquid bath furnaces such as modern top submerged lance (TSL) furnaces. A few authors already made the link between over- oxidation of the slag phase and slag foaming. In this work, the mechanism is studied in more detail and explained using the smelter chemistry and the behaviour of dynamic foam formation. Finally, the most influential parameters on the foaming behaviour of the process are presented. INTRODUCTION Copper remains one of the most important metals used in our modern society. In 2017, the annual amount of copper produced worldwide was about 23.5 million metric tons. This makes copper the third most produced metal in the world after steel and aluminium. The majority of this copper was produced by copper smelting, about 19 million metric tons, both from primary concentrate and secondary feed material as reported in ICSG’s World Copper Factbook 2018. In the past, copper smelting was mainly performed using Flash smelting, a technology developed before 1949 (Kojo, Jokilaakso & Hanniala, 2000). Nowadays, this type of smelter is being complemented by other smelter types such as ISASMELT and Ausmelt technologies. These are two types op smelter furnaces, based on the concept of a top submerged lance (TSL) furnace. These two technologies were both commercialized around 1990 (Arthur & Hunt, 2005). It is estimated by Wang et al. (2016) that at this time, both flash and TSL smelters contribute equally to the total amount of annually smelted copper. Flash smelting stays the most important technology for extracting copper from primary sources. TSL furnaces, on the other hand, are more suited than Flash smelters for the recovery of copper from secondary materials. This is because of the different ways that the feed material is inserted in both furnaces. In Flash smelters, the ore and fluxes needs to be fine and completely dry in order to be able to blow the mixture inside the burner area of the furnace. The feed material for TSL smelters show less constrains concerning humidity and particle size. The material is dropped from the top inside the molten bath. As a result, a more complex and flexible feed stream can be processed using TSL smelting (Wood, Hoang & Hughes, 2017). This feature will become more important in the future as primary copper sources gets more scarce and the need for a fully sustainable material cycle increases.

Jan 1, 2019

By Robert J. McCarthy

Mining has a record of achievement in developing and adopting new technology to facilitate the extraction of increasingly challenging resources. Certainly larger, or more capable, mining equipment has allowed mining companies to mine mineral deposits at lower unit costs; however, there has also been the advent of computerized systems that aid in the management and tracking of mining operations. Unfortunately, the latter computerized systems have not always had the success anticipated with their implementation. This paper explores the view that increased transparency of the planning and operating cycle in a mine, as provided by certain computerized systems, can result in some resistance from those whose work becomes ?exposed?. Examples are drawn from industry-leading technologies for both mine management and reconciliation that illustrate the issues and challenges that result. The adoption of appropriate change management principles is suggested as a best practice in planning and mitigating the challenges in implementing technologies which increase transparency in the mining environment.

May 1, 2011