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By A. Mayton, W. Porter, A. O’Brien

In 2004, management at Unimin’s Gleason, TN operation began implementing ergonomic interventions specifically targeted to reduce risk of musculoskeletal injuries (MSIs). Together with corporate and site management, Unimin identified work site hazards and began to modify work practices/equipment. Some interventions were relatively simple and were implemented immediately. Others, like improvements to a mobile shredder, were more complex but were eventually resolved through a participatory approach with employees, management, manufacturers and NIOSH. This paper discusses ergonomic interventions that were successfully implemented using a bottom-up approach to reducing the risk of injury.

Jan 1, 2007

By Sohta Takatsu, Hachiroh Mizubata, Shigeki Kudoh, Kazuya Takekuni, Yoshinori Yamada

A special type of shotcrete is used to improve the performance of open-type TBM in difficult situations. The Hakamagoshi and Johana tunnels are expressway evacuation tunnels of 3.2 km and 5.1 km in length, respectively (total 9.1 km) that were excavated by one open-type TBM. The geological conditions at the sites were estimated to be good before excavation. However, 95% of the rock turned out to be two ranking orders worse than the estimated classes. Therefore, we used a special shotcrete for bad rock conditions, and succeeded in excavating the tunnel at an average rate of 270 m/month.

Jan 1, 2001

By N. O. Lotter

The reliability of a set of flotation results is key to minimizing project risk either at concentrator commissioning, or at the point of implementing an improvement to an existing concentrator operation. High-Confidence Flotation Testing was developed for this purpose, and is part of the list of technologies of various scales used by Xstrata Process Support (XPS) in addressing these projects. The methodology is based on two principles: one, to ensure that the ore sample is representative and has been well-blended and subsampled; two, to perform the flotation tests in sufficient numbers of replicates with appropriate quality controls, so as to improve the reproducibility of the test data. Across ten years of practice and continuous improvement with this methodology at Xstrata Process Support, Sudbury, several improvements to this method and complementary connections into sampling and quantitative mineralogy have been developed. Two case studies are reviewed. These show the capability of this system in both optimizing an existing concentrator operation and in serving a new mine scenario. Further work to improve the efficiency of this procedure has been identified.

Jan 1, 2009

By Michael Taylor, Thomas W. BoBo

Currently two of the most important characteristics of construction aggregates are (a) the particle size distribution (psd) and (b) the “shape” of the aggregate particles. The long established test methods and standards for these properties require substantial resources and most suppliers can take samples and conduct tests at intervals measured in days (psd) or even months (shape). Furthermore these tests require time: so the results are available only after material has been stockpiled or shipped. In the rare cases where problems are found the out-of-spec material has often been shipped to points unknown. There are substantial advantages to be obtained if the psd and other geometrical properties could be obtained from the material as it moves through the production processes and if the results could be reported back within seconds or minutes to Plant Control Managers. This paper describes a single on-line system used to evaluate production of crushed material in a production quarry. The system consists of an enclosure (containing the camera and lighting etc.) mounted over a production belt. Images are fed by fiber optic cable to a nearby control room where the data are analyzed; stored; displayed; and made available for integration into a process control system. Numerous forms of display can be created according to the needs of the producer. Once programmed by an automation engineer all functions of operation are fully automated. The system has permitted over 400 tests per hour with a feed back time less than 2 seconds. Sufficient geometrical measurements are made so that many different “shape” factors can be computed on a similar time scale. The paper summarizes the results from approximately 100 shifts of about 8 hours each and compares the imaging method with the current standard hand methods. Study of the data generated showed that, when combined with additional plant information, the system can be used to generate additional useful control information.

Jan 1, 2005

The Mining Foundation of the Southwest (MFSW)promotes public understanding and education related to the mining industry. Towards this goal, the Foundation has funded several projects from donations and fundraising activities. The MFSW was incorporated in 1993 by combining the Mining Club of the Southwest and the Mining Club of the Southwest Foundation. The Mining Club began in 1971 as a social organization. It provided members of the mining community an opportunity to meet. The club also provided a means for public education about mining. In the early 1990s, the club’s efforts were directed mainly toward educational activities. And in 1992, discussions began concerning incorporation into a non-profit foundation to further the public understanding of mining. In 1983, the American Mining Hall of Fame was inaugurated to honor significant contributors to the industry and profession. The Hall of Fame serves to educate people about prominent persons associated with the mining industry, present and past. The honorees number 75. Plaques commemorate their induction and are on display at the Arizona Historical Society’s Museum in Tucson, AZ. The combined honors ceremony and banquet have remained one of the fund raising activities.

Jan 1, 1999

By Ira Sohn

This article revisits global projections made in 1981of eight metallic and fertilizer minerals for the year 2000. The objectives here are to quantify the differences between the projected and observed levels of consumption for the year 2000 for eight of the 26 nonfuel minerals covered in the earlier study. An attempt is then made to attribute these (often) large differences to the major determinants of minerals demand — income, technological, regulatory and other policy changes, and changes in the recycling rates of the metallic minerals. The eight minerals covered are aluminum, copper, iron, mercury, nickel, phosphate rock, potash and tin. This summary article presents the actual population, gross domestic product (GDP) and per capita GDP changes from 1970 to 2000, compared with the projected rates for these important determinants of mineral use, along with the observed growth rates of minerals consumption for the eight nonfuel minerals included in this study. When the projections are compared with the observed global consumption levels for the year 2000, the differences range from +43 percent for nickel to +229 percent for potash.

Jan 1, 2005

By D. Richter

The Pyrometallurgical refining stage of ferronickel manufacturing produces a slag rich in iron and nickel, which is usually further processed for metal recovery. The recovered material is returned to the refining or smelting stages, depending on the amount of impurities. A series of tests was carried out on the Mineração Morro Azul refining slags, aiming at the recovery of the metallic particles through physical processing. Minor changes in the process showed improved results. This paper compares the textures of these slags after being cooled at ambient temperature and granulated under water at high pressure and flow. It concludes that the cooling process is intimately connected to the work index of such slags, thus resulting in direct impact in operating costs.

Jan 1, 2011

By B. K. Mishra

In order to maintain higher grinding efficiency in tumbling mills the mill interior and dynamics must be known. For this purpose, several different types of non-intrusive methods have been proposed and are being tried in the industry. We have made an effort to develop a diagnostic tool based on vibration signal. Here we discus results of our experiments pertaining to ball as well as SAG mill. In each case, a triaxial accelerometer was used to capture mechanical vibration generated due to the tumbling action of the charge. The vibration signal was transmitted to a remotely placed computer and the signals were analyzed by standard signal processing technique. In case of a ball mill (5m diameter), qualitative mill information could be obtained by correlating the vibration signal to feed rate and mill filling. An effort was also made to identify different motion characteristic of the charge by analyzing its vibration signal. In case of the SAG mill (10m diameter), liner wear was estimated by comparing the vibration signal emitting out of a freshly lined mill with that of a worn out mill.

Jan 1, 2011

By S. Frimpong

Cable shovels are used for primary excavation in in-situ and/or pre-fragmented formations in surface mining operations. Poorly fragmented hard rock formations and random occurrence of hard boulders in soft formations cause extreme variability of material diggability, resulting in varying shovel stress loading. The stress loading of a shovel’s front-end assembly could result in fatigue failure. Conventional design process, which uses physical shovel simulation studies, is very costly and time consuming for achieving statistically significant results. In this paper, rigid and flexible multi-body dynamic theories are used to develop component stress loading and deformation models of the cable shovel, and solved in the ADAMS/NASTRAN/FLEX environments. Detailed simulation experiments are carried out to examine the performance, reliability, durability and efficiency of the P&H 4100A under varying in-situ formation conditions. The results show areas of high stress fields with a maximum stress of 313.31 MPa at node 441 within the hoist rope. The reliability of the results is confirmed by comparing existing test data. The study is significant because it provides a solid foundation for further study of failure life analysis of the cable shovel components.

Jan 1, 2007

Market confidence is on the rise and industry leaders turning toward the vast and diverse region of Latin America are faced with abundant, yet daunting, opportunity. From the iron orebodies of Brazil to the renowned copper mines of northern Chile, drilling teams in Latin America are often faced with abrasive, broken ground. These types of ground conditions tear up coring bits rapidly, making it extremely difficult for even the most seasoned drilling teams to maintain effective productivity. The drilling challenges faced in this rich and opportune region are being met today by advanced coring technology, bringing with it the potential for increased productivity in Latin American mineral exploration.

Jan 3, 2010

By Thom Seal, S. J. Jung

This paper will combine three SME annual meeting presentations on reducing gold inventory in cyanide heap leaching. Information on Part I – Side slope leaching (SME 2003), Part II – Determining the dry zones using geophysical resistivity (SME 2004), and Part III - Presents a new technology “Hydro-Jex”, to introduce the required lixiviants to the un-leach or under-leach zones in heaps (SME 2005). This paper will describe how Newmont Mining Corporation continues to improve the economics of the heap leaching process for precious metals recovery.

Jan 1, 2005

By Paul Lynch

"Since being reported to the 2012 UMI in Shanghai, the Cook Islands has been steadily developing for the commencement of it Seabed Minerals sector in its large Exclusive Economic Zone which contain a vast and unique Manganese Nodule resource, estimated at 10 billion tonnes1. At the 2013 UMI in Brazil, it was reported that the Seabed Minerals Act had commenced and all the necessary complex Technical aspects of this developmental work was being undertaken. At the 2014 UMI in Portugal, full details of the final developments leading to the opening of the Tender of Exploration Blocks in the Cook Islands EEZ will be presented in a brief but comprehensive method, using Poster displays, Powerpoint and active Website interaction. This will show the drafted Regulations, prepared on best international standards, to address both Licencing and Environmental requirements, to give clarity and security to the Resources Owner, industry and stakeholders. This work in being coordinated by the Cook Islands Seabed Minerals Authority, with the valuable collaboration of many international, regional and national stakeholders, including the Cook Islands NGOs, Marine Resources, Marine Park and National Environment Service."

Sep 1, 2014

By Sean Masse

New Gold?s New Afton Mine, located 8 km (5 miles) west of Kamloops, British Columbia, is a 4.5-Mt/a (5-million stpy) block cave mine, making it the highest tonnage underground hard rock mine in Canada. The reserve is estimated at 52.5 Mt (55.9 million st) with grades of 0.65 g/t (0.02 oz/st) gold and 0.93 percent copper (2012). Commercial production was achieved in July 2012 and nameplate production was achieved ahead of schedule in September 2012, with the cave breaching to surface in 2013. The mill has a SAG and a ball mill with a froth flotation circuit.

Jan 1, 2014

By H. -J. Langhoff

"The paper describes not a result, but a starting point to implement sustainable development to a region characterized by a typical down river landscape, agriculture, and extractive industry. The NaturFreizeitNiederrhein GmbH (NFN) is a private company with associates from administrative bodies, the local mining companies and multiple representatives of environmental protection groups (local and national), tourism organizations, cultural societies and also aquatic sport and fishing clubs. Center of the concept is the "NFN Lake District." The development concept aims to provide the agricultural industry with alternative means of income, while protecting wildlife and the ecological balance as well as preserving the social und cultural system and enhance the safety against flooding from the river Rhine. The mining industry contributes their coordination of obligation concerning reclamation and recultivation of the already existing individual projects. While designing the landscape components and establishing the infrastructure for the different tasks, the production of gravel and sand is yield as a by product. The result is a long term perspective for region and industry."

Jan 1, 2005

By Michael Harris, David Mosch

The numerous small high grade gold and silver deposits of the Front Range Mineral Belt have been uneconomical because of the high costs of mill construction, transportation, and smeltering. Processing of these ores must be simple, cheap, with satisfactory recoveries, and be environmentally acceptable. Vat leach with direct electrolytic recovery satisfies these parameters. A battery of testing was conducted utilizing bottle and bucket tests. A five ton vat leach with direct electrolytic recovery gave excellent results while a five ton heap leach proved impractical due to channeling.

Jan 1, 1987

By K. Huttu, A. van Wageningen

"The Kittilä underground mine in northern Finland is extracting one of the largest known gold deposits in Europe. Kittilä achieved commercial production on May 1, 2009, becoming Agnico Eagle’s first mine to open outside of Canada. The Kittilä orebodies were initially mined from two openpits – Suuri and Roura – and underground operations were added in October 2010. The pits were mined out in November 2012, so mining is now entirely underground in the Suuri and Roura deposits. Additional, small openpits will mine any remaining near-surface reserves in the future.The Kittilä Mine is located in the Lapland region of northern Finland, approximately 900 km (560 miles) north of Helsinki and 150 km (93 miles) north of the Arctic Circle. With a mine life estimated through 2034, Kittilä is Agnico’s longest-life mine.The mine’s proven and probable reserves contain 32 Mt (4.7 million oz) at 4.6 g/t (0.13 oz/ st) gold. Ore has been mined from underground since 2010. The original 3 kt/d (3,300 stpd) operation underwent an expansion project to increase the throughput capacity of the mill by 1 kt/d (1,100 stpd), starting by the end of 2014.The region around the Kittilä Mine is underlain by mafic volcanic and sedimentary rocks of the Kittilä Greenstone Belt oriented nearly vertical. This greenstone belt is similar to those hosting Agnico Eagle’s Canadian deposits in Quebec’s Abitibi region and Nunavut. At the contact point between ironrich and magnesium-rich rocks lies a 100- to 200- m (330- to 660-ft) thick structural zone known as the Suurikuusikko Trend. This trend hosts the Kittilä deposit, where multiple mineralized zones have been traced over a strike length of more than 25 km (15 miles).Most of Agnico Eagle’s work has focused on a 4.5-km (2-mile) segment of the Suurikuusikko Trend that hosts the five main zones of the known gold reserves and resources. From south to north they are: Ketola, Etela, Suuri, Roura and Rimpi.The ore at the Kittilä Mine is refractory, making gold extraction relatively difficult because the gold is generally locked inside the two main sulfide minerals – arsenopyrite and arsenic-rich pyrite. Only about 4 percent is very fine-grained “free gold” (not locked in sulfide grains) and easier to extract. Most of this free gold is found in the outer, oxidized or eroded sections of the ore."

Jan 1, 2015

By Kiseong Hyeong, Young-Tak Ko, Gee Soo Kong

"The benthic environmental impact experiment addresses environmental impacts at a specific site related to deep-sea mineral resource development. For such a purpose, since 2010 we have carried out essential environmental research at both the BIS and a preservation site. We have acquired several tens multi- or box core samples at 32 sites within the BIS especially between 2011 and 2013, aiming to examine the basic properties of surficial deep-sea sediment as the potential source for deep-water plumes.In this study, we present physical the properties such as water content, shear strength and also geochemical properties such as major elements, rare earth elements (REEs), heavy metal contents at the BIS. Such proxies vary distinctly according to the Facies association. The lithology of all core sediments in the BIS corresponds to both Association Ib (Unit I/Unit II) and Association IIIb (Unit I/Unit III) on the basis of the KORDI classification (KORDI, 2004); Unit I is watery mud and dark grayish brown (10YR4/2) to dark brown (10YR4/3). Unit II is highly bioturbated mud and brownish yellow (10YR6/6). Unit III is very dark brown (10YR3/2) to black (10YR2/1) mud. Physical properties of these sediment types show that Association Ib is distinct from Association IIIb. The vertical profile of water content changed more sharply in Association IIIb probably due to compaction; water contents varied from 230 to 300% in Association Ib and changed from 200 to 250% in Association IIIb. The vertical profiles of shear strength are also quite different between Associations; the profile curve in Association IIb is much more gentle due to bioturbation."

Sep 1, 2014

By L. W. Berry

Drill and blast planning is critical to successful mine production, both in timing and in results. However, typical planning, reporting, and information exchange usually involves large quantities of data collated in a discordant set of spreadsheets, databases, and reports. Collecting, analyzing, modeling, and distributing all data necessary for efficient drill and blast operations is time consuming and cumbersome. MineSight Axis Drill and Blast provides an extensible core of functions, seamlessly integrated with other MineSight software tools, to make sense of this information. The benefits of improving the management of drilling and blasting processes are immense and result in improved fragmentation at a lower cost, improved shovel and truck productivity, and enhanced ore processing.

Jan 1, 2011

By W. Dziurzynski

The present article sets forward the results of field tests that made it possible to validate the mathematical model used in the VENTGRAPH ventilation engineer programmes. The case considered relates to the introduction of a new heading to the ventilation network of the mine. The utilisation of computer programmes in practice is justified by the necessity of ensuring expected performance and secure conditions in the network of mine headings, where - for example - plans are being made to utilise the transport dip-heading, taking into consideration fire and methane hazards. In the article we have presented the methodology of preparation of a database for computer programmes of the VENTGRAPH system, obtained on the basis of ventilation measurements. The next step consists in the execution of a design of the modified network and prediction, this on the basis of heading geometries, of parameters characterising the flow of air for the designed headings. Due to the fact that the heading was in the final stage of driving, following its introduction to normal operation and the stabilisation of flow values it was possible to retake ventilation measurements, which validated the results obtained through computer simulations. In order to execute measurements of the volume flow in the dip-heading, we employed a new wireless multipoint measurement system to determine the velocity field of air in the mine heading; the results are characterised by a high accuracy of measurement. As a part of fire prevention and incident management planning, a series of underground fire case studies for the a validated network flow model has been made. Results of simulations show the capabilities of the FIRE module of the mentioned software, including assessment of stability of flow directions and hints on counter and preventive measures for particular locations of fire.

Jan 1, 2009

By S. G. Gendler

The choice of ventilation schemes in the Northern Mujsky railway tunnel and definition of the nec-essary quantities of air ensuring regulated radiation conditions in the tunnel system has been accomplished. The influence of natural draught on the stability of tunnel ventilation has been estimated. The design of a portal venti-lation gate allowing minimal influence from natural factors is described. The dependence of pressure loss in the sliding ventilation gates on their spanning value of the vehicle tunnel section has been determined. The selection of parameters for an atmospheric air heating system in winter has been carried out. The operation regimes of air heaters, dependent on the temperature of atmospheric air, have been established.

Jan 1, 2009