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By John C. Gagliardi, Walter K. Utt

The U.S. Bureau of Mines, in cooperation with Carter Mining Co., conducted vibration tests of four off-road vehicle seats. The purpose of the tests was to determine which seat provided the best vibration attenuation under laboratory conditions. Laboratory tests were constructed to simulate the mining vibration environment within the limitations of the test equipment. The acceleration test levels and corresponding response of the seats were low compared to IS0 2631's fatigue-decreased-proficiency time limits. Two of the seats employed mechanical suspensions and two seats employed air suspensions. The seats were tested using a 22,241-N (5,000-lbf) electrodynamic shaker. Mechanical suspension seats were tested with various preload-to-mass ratios (PMR's) and cushion densities. Air suspension seats were tested with various air pressure levels and seat cushion densities. Air suspension seats provided good vibration attenuation if pressurized greater than 552 kPa (80 psi). Mechanical suspension seats' attenuation performance decreased if the PMR exceeded 9.8. Seat cushions of lower density provided less vibration damping.

Jan 1, 1993

By Tony Brunger, Abid O. Adekunte, George Munteanu, David Greentree

A number of novel solutions have been proposed in recent years as alternatives to props and tie-backs in deep excavation support e.g. Adekunte (2008), Deschamps et. al. (2008), Adekunte et al. (2010) and Adekunte (2014). A number of these non-standard restraining solutions involve the construction of permanent or temporary vertical or raking buttress piles that are rigidly connected to the excavation support wall at regular intervals along the wall run. This paper chiefly focuses on the design and construction of twin-vertical buttress piles as restraining systems behind or in front of embedded retaining walls. The system essentially relies on the push-pull mechanism that develops between the twin piles, to maintain the overall stability of the excavation support. The paper’s main areas of concentration include; finite element modelling, geostructural design, construction procedure, instrumentation and monitoring that are associated with the application of twin- buttress pile systems. These are supported with project details of three recently completed high-end luxurious residential developments in Greater London, England, on which the twin-buttress pile system was used to restrain the excavation support walls for the basements on the sites. The mode of application of the system varies across the three sites. While the system was adopted as a long term solution behind the retaining wall on one of the sites, it was designed and constructed for temporary use in front of the retaining walls on the other two sites. Instrumentation and monitoring results from all the sites show the non-traditional system to be safe and effective, whilst having significant beneficial effects on construction programme, sequence of works and project cost.

Jan 1, 2018

By Trenton Cohen, Joseph McDivitt, Shimi Tzobery, Joseph Sinacori, Scott Zylstra

The 2-mile Beach Interceptor Sewer Tunnel was constructed in 1954 to then-current mining and construction standards. Due to its lifespan and deteriorating condition it is now being stabilized and rehabilitated using conventional excavation and ground support. At its southern end, below the prestigious Three Arch Bay community, the original tunnel alignment passes under a historic landslide where the tunnel was sand-backfilled and capped by bulkheads in 1957 due to severe and caving ground conditions. Video footage of the existing 21- inch clay pipe showed that the pipe is severely damaged, which could potentially cause a catastrophic pipeline failure and sewage spill into the Pacific Ocean. This paper summarizes the thorough investigation and design process, tunnel realignment construction and monitoring, and the notable cooperation between all parties to overcome the project risks.

Dec 1, 2022

By S Lal, S Rost, Q Williams, K Collerson

"An EXTENDED ABSTRACT is available for download. A full-length paper was not prepared for this presentation. Shoshonite suite (absarokite-shoshonite-banakite) and adakite-hosted epithermal Au deposits are a feature of circum-Pacific magmatism. Fijian examples include Tavua (Emperor) and Tuvatu on Viti Levu. New discoveries of shoshonite suite and adakite-hosted epithermal Au mineralisation have been made in the southern Yasawa Islands and in central-northern and central-western Viti Levu. The Fijian shoshonites define four NE–SW trending suites. The oldest is the northern 7.9–5.0 Ma Yasawa suite, followed by the 4.7–3.5 Ma Sabeto–Tavua–Rakiraki suite in northern Viti Levu, the 4.7–4.2 Ma Yanuca–Vatulele suite approximately 20 km south of Viti Levu and the 3.4 Ma Astrolabe suite approximately 75 km further south. Shoshonite suite lithologies with 3.8–3.0 Ma ages also occur in the Lomaiviti islands between Vatu-Cake and Moala, to the east of Viti Levu, defining a trend oblique to the NE–SW shoshonite belts. Seatura, a 3.3–2.8 Ma ocean island basalt (OIB) volcano, sits at the northern end of the Lomaiviti trend shoshonites. Trace element/isotopic chemistries indicate that shoshonite arc magma genesis involved the melting of a hydrated supra-subduction zone mantle wedge and also a lower mantle-derived plume (OIB) component. The upwelling plume provided heat for melting and possibly Au enrichment. Accessing the melt generation zone associated with the plume required a slab conduit or window. Such slab windows form by tearing during subduction or occur at slab edges. Adakites form by plume-induced slab melting. The four NE–SW Fijian shoshonite suites are interpreted to occur in back-arc extensional zones above a slab window (tear) that migrated southward during rollback of the New Hebrides–Vanuatu subduction zone. The plume (Seatura OIB) that is interpreted to have caused mantle wedge melting and formation of the Lomaviti trend shoshonites was focused along the interface between the north-dipping Vanuatu–New Hebrides subduction zone and the west-dipping Tonga subduction zone, which we have seismically imaged at approximately 400 km depth. Our model ‘cracks the metallogenetic code’ for shoshonites and adakites and has regional and global implications for Au exploration.CITATION:Collerson, K, Lal, S, Williams, Q and Rost, S, 2015. Cracking the metallogenetic code for Fijian epithermal gold mineralisation , in Proceedings PACRIM 2015 Congress, pp 219–226 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Mar 18, 2015

By John R. McWilliams

This report is one of a series published by the Bureau of Mines describing methods and practices at various mines throughout the United States. A previous program, conducted from 1928 to 1939, was well received by the mining industry and technical institutions and provided much source material for engineering textbooks and technical handbooks. The stringent wartime demands on the mining industry, the rapidly changing postwar economic situation, and greatly accelerated technologic growth have combined to render many of the previous data obsolete. The objective of the present program is to assemble reliable technical information on mining methods and practices throughout the country and present it for the use of the mining industry, technical schools, textbook authors, and other interested persons. This report deals with the design and development of the Berkeley open- pit mine at Butte, Mont., owned and operated by The Anaconda Company. The Berkeley pit is but one facet of a well-organized and integrated copper-mining operation involving the entire Butte district. Vein-type mining, important for 75 years, is still in progress at depths from 600 feet to nearly 1 mile; on intermediate levels, low-grade ore left untouched by earlier vein-type mines is being extracted by block caving entire ore zones,3/ and secondarily enriched but lower grade near-surface portions of the same ore zones are being mined by open-pit operations (fig. 1). The Berkeley pit itself is named for the Berkeley mine, one of the old mines that extracted copper ore from high-grade veins in the area that now will be mined by open-pit methods.

Jan 1, 1959

Council for 2004/2005 President F.M.G. Egerton President-elect W.H. van Niekerk Vice-presidents Senior R.P.H. Willis Junior R.G.B. Pickering Immediate Past-president T.R. Stacey Honorary Treasurer J.A. Cruise

Jan 1, 2005

By William B. Schmidt

In July of 1974 a study team comprised of the authors was formed by the Department of the Interior. It was supported in part by funding from the National Science Foundation. The purpose of this study group was to visit coal mines and research and manufacturing facilities in England and Germany, to review the status of mining in these countries, and to identify mining technology which might have application to U. S. mining conditions. The duration of the visit was 18 days. The first week of the trip was spent in England. Time does not permit a complete recitation of the team's impressions but a few of the more interesting technologic developments will be discussed. These fall into the following categories- High Speed Development Ground Support Chainless Haulage and Face Conveyors Nucleonic Steering of Shearers Miscellaneous

Jan 1, 1975

By Dimas de Andrade Pacheco

O estudo do efeito da adição de nióbio em um ferro fundido branco alto cromo tratado termicamente com 25%Cr e 3%C foi estudado neste trabalho por microscopia ótica, microscopia eletrônica de varredura e difração de raios X. Partindo de uma liga hipereutética, a adição de 2% de nióbio foi definida considerando que todo Nb adicionado se encontraria na forma de carbonetos de nióbio, NbC, e com o objetivo de obter uma microestrutura próxima à eutética. A adição promoveu um refinamento da microestrutura, sendo que uma fração volumétrica de 27% de carbonetos M7C3 foi observada. Carbonetos grosseiros, inicialmente formados, não são facilmente observados. Uma microestrutura formada por NbC e eutético, M7C3 + matriz (austenita ou martensita), foi obtida. Os carbonetos de nióbio formados são encontrados principalmente na forma compacta. É esperado, portanto, que, a liga com adição de 2% de nióbio apresente melhor resistência ao desgaste abrasivo que a liga sem nióbio, em razão dos carbonetos primários, frágeis e grosseiros, terem sido praticamente suprimidos após a adição de Nb e uma microestrutura mais refinada tenha sido obtida.

Oct 30, 2017

By D A. Cuello, G B. Sharrock

The Prince Lyell orebody at Mount Lyell Mine has a rich mining history commencing with the open pit in 1935, which transitioned underground in 1972. Between 1972 and 2014 a total of 64 Mt was mined underground as the mine extended from 210 m to 1100 m below surface. As the depth increased, three separate transitions in the mining method occurred to meet the changing geotechnical conditions, ore grade, mining costs and metal prices. The first was open stoping with pillar recovery in 1972, followed by front caving and longitudinal sublevel caving (1995), and finally transverse sublevel caving (2004 to 2014). This paper provides an overview of key geotechnical and planning milestones relating to the evolution of the mining method including underground stability, gravity flow, cavability and subsidence. Key aspects of the mine design, geotechnical parameters and rock mass response are described and critiqued with reference to observational, numerical and empirical methods.CITATION:Sharrock, G B and Cuello, D A, 2016. Geotechnical milestones at Mount Lyell Mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 427–438 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By Jeanie Wills, Theresa Nyabeze, Samantha Espley, Donna Beneteau

This presentation reports survey findings that aim to modernize the definition and understanding of the term 'mining.' The survey, conducted via LinkedIn in Winter 2024, garnered responses from a diverse group of individuals, including current or former employees of mining or exploration companies, mining consulting firms, service providers, supplier firms, as well as students and retirees with industry experience. The data, ethically approved by the University of Saskatchewan, offers valuable insights into satisfaction levels within the mining sector and suggests an expansion of the identifying characteristics of definitions of mining. This marks the third CIM gaining insights paper by Beneteau, Espley, and Nyabeze, following previous works on 'Career Satisfaction for Women in Mining' (2010) and 'Mentorship Initiatives in the Canadian Mining Industry' (2018*)."

Oct 1, 2024

By A. Moergeli

The Swiss are currently building the world’s longest tunnel, the 35-mile long Gotthard Base Tunnel. At Sedrun, for the first time in tunneling, four Roadway Support Machines will drive through most difficult ground, supporting variable diameters of up to 13 m. The machines are prepared for their first deployment. At Amsteg, two Hard Rock TBMs have successfully crossed a known fault zone by applying full circle steel arches and shotcrete immediately behind the cutter head. Comparisons between Drill& Blast and Hard Rock TBM are shown.

Jan 1, 2005

By A. Adu-Acheampong

Stope instability at Ashanti Goldfields Company Ltd. (AGC) is a major concern. Using information from field mapping, major discontinuity sets were defined, Rock Quality Designation (RQD) was determined. The stability of wedges in the stope walls was assessed using the commercially available computer program UNWEDGE(Rock Science, 1992). Analytical results indicate that the presence of graphite infilling in joints contributes to instability, while steeply dipping joints control wedge slabbing and wedge toppling in the hanging wall. Stable stope widths and dimensions were determined to range from8.1 to 30 meters (m).

Jan 1, 2003

By W. W. Adams

The first full year of the second World War for the United States presented a picture of the metal-and nonmetal-mining 4 industry which, without proper analysis and explanation, would convey a distorted view of achievements during 1942, especially because employment at gold and silver (lode and placer) mines-the largest group-declined to such an extent that the over-all totals for the country were reduced even though increases were made at mines producing copper, lead-zinc, iron, miscellaneous metals, and non-metals. A complete panorama of the metal-and nonmetal-mining industry, exclusive of coal mining, reveals a decrease in the number of men employed, the man-hours of employment, and the accident-frequency rates. Were the gold and silver (lode and placer) mines to be considered as a separate category; it would be seen that the number of men employed at all the other groups of mines increased appreciably over 1941. These other increases must be considered important, since these mines produced the vital war minerals that made valuable contributions to the military successes of the United States and its Allies during the year. A separate analysis of each of the various groups of mines may be found elsewhere in this bulletin. For the purpose of maintaining continuity in this series of bulletins, however, the discussion in this introduction will be confined to the entire metal-and nonmetal-mining industry (excluding coal mining, for which a separate bulletin, No. 462, has been published).

Jan 1, 1945

By R. J. Sweigard, C. T. Justice, T. Beckham, E. D. Thompson, T. C. Hopkins

Fine coal refuse is often pumped, as slurry, into surface impoundments as a means of permanent disposal. As the available volume is filled, the height of the embankments are frequently increased. Many times the additional embankment material is placed upon consolidated fine coal refuse. There has been some concern about the long-term effect of consolidation of this material at or above the liquid limit upon its shear strength. A laboratory investigation was performed using three different types of fine coal sluny taken from Central Appalachian coal preparation plants. The refuse was consolidated in 10-foot plexiglass columns under incremental amounts of surcharge loading. The incremental loads were designed to simulate the effect of increasing the height of a refuse embankment on top of the consolidating coal slurry. After the refuse in the columns had consolidated for several months, the columns were cut apart and triaxial tests were performed on both the consolidated material and unconsolidated material for comparison of their shear strength parameters.

Feb 24, 1997

By A. U. Miller

"Ventilation is one of the meet important factors in mining, although until recent years less thought has probably been given to effective ventilation than to any other one phase of mining. In the past, very little, if any, attention was given air courses until they became so constricted by falls that the volume of air was greatly reduced; and, in addition, the stoppings and doors were so poorly constructed that only a very small percentage of air reached the face workings.As a matter of fact, mines have been visited where the volume of air being circulated in certain sections was much larger than in others, and where the management was striving to increase the flow of air in those sections with the least air current, believing the ventilation to be deficient. After sampling and analyzing the return air from the various sections in such mines it has been found that the quality of the air in certain places with the largest flow was more impure than in some of those with the least flow.In past years, practically all mine fans were operated by steam-driven engines supplied with steam from the mire boiler plant. No check was made on the steam consumption or the power cost of operating the fan, therefore the management had very little if any definite information as to cost of ventilating the mine.With the increased use of electrically-driven equipment in mines electricity is being used more and more to drive mine ventilating fans, and since in many instances the current is purchased from central power plants operators have come to realize that in many cases the cost of operating the fans is very high. Some engineers estimate that it ranges from 20 to 50 per cent of the total power cost of the mine. This information, together with the fact that mines are now being developed on a larger scale, requiring larger quantities of air for the men to dilute the gases liberated, has caused the large progressive companies to make, a more comprehensive study of mine ventilation, resulting in a decided improvement in the quality and quantity of air at the face workings, as well as reducing materially the ventilating costs."

Oct 1, 1930

By G Siboni, A Correa De Araujo, M Gotelip Barbosa, M J. Venturini

In support of the development of its Liberian iron ore project, ArcelorMittal Mining Research and Development (AM Mining R&D) has performed characterisation and beneficiation test work on drill core samples received from the proposed mine area. In addition to this, a sinter feed product was composed by blending and processing the drill cores in order to predict sintering performance of the ore. This article presents the methodology used to prepare the drill core blend for characterisation, as well as describe the sinter pot trial. The results are presented, demonstrating how important this type of study is for the development of an iron ore deposit.CITATION:Gotelip Barbosa, M, Siboni, G, Venturini, M J and Correa de Araujo, A, 2017. The use of drill core blends to predict sintering performance, in Proceedings Iron Ore 2017, pp 297–302 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Gary Cavanough, Stuart Addinell, Hector Parra

Drilling deep, straight, accurate holes in hard rock to achieve efficient blasting is a challenge for the mining/quarrying industries with short holes normally drilled using “top hole hammer” (THH) and deep holes using “down the hole Hammer” (DTH).

Jan 1, 2013

By C Tapia Cortez, C Sammut, S Saydam, J Coulton

‘Like every other commodity, the value of the metals is subject to variation’ (Ricardo, 1817). Mineral commodity price uncertainties have always been a significant issue in mining business due to the close relation between global economic conditions and commodity prices, which commonly generates significant and unexpected price fluctuations. Price forecasts have been driven by economic theory, which states that in the long-run market will be balanced and that prices tend to the marginal cost of production. However, this theory has been misunderstood in the mining industry and future prices through time, in real terms, are assumed to be unchanged. This is unrealistic due to regardless of the cycling nature of economy and the omission of uncertainties. Furthermore, using historical data in traditional price forecast approaches does not guarantee realistic predictions as past events will not necessarily be repeated at the same intervals and with the same intensity. Mining, finance and economic sectors have made significant research efforts to predict prices and control uncertainties through classic linear, Gaussian and probabilistic simulation approaches. However, by definition, uncertainties cannot be measured or accurately modelled. Uncertainties can be identified to measure and manage the associated risks; therefore, uncertainties in mining projects have been historically misinterpreted, erroneously measured and poorly controlled. It is widely known that supply and demand functions drive market prices. While technological development noticeably influences supply, demand is strongly driven by psychological factors, mainly related to customer preferences and lifestyle expectations. Thus, human behaviour is one, or if not, the most important variable to determine commodity prices in a competitive market. During the last decades, alternative methodologies have been used to study uncertainties in human, environmental and market behaviours. Chaos theory, fractals, artificial intelligence and econophysics have been widely and successfully used to investigate complex dynamic systems to address uncertainties over time in the fields of neurosciences, meteorology, aviation and market trading. The application of these techniques in the market suggests a more realistic approach to the business environment. Through the combination of the methodologies above a novel long-run price uncertainties simulation approach that emphasise the differences between risks and uncertainties is proposed in this paper. CITATION:Tapia Cortez, C, Saydam, S, Coulton, J and Sammut, C, 2015. Copper price uncertainties – chaos theory to manage risks in mining projects, in Proceedings Third International Future Mining Conference, pp 261–272 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Nov 4, 2015

By O. K. Mahabadi

The scope of this study is to simulate the behaviour of a layered rock sample under standard laboratory Brazilian Disc test using an innovative combined finite-discrete element method (FEM/DEM) research code. The influence of layering and the direction of loading on the samples behaviour are studied through various layering and loading configurations. A parametric study including the effect of loading rate on the tensile strength of samples has been carried out. This paper demonstrates the suitability of the numerical approach to explicitly model rock deformation and failure.

May 1, 2009

By M. G. Senyur

This study aims at investigating the structural characteristics of backfilling material. In this regard, spatial arrangement of solid particles and associated voids in a unit mass of coal mine refuse as backfilling material were tested. The materials were produced from coal mine refuse of Zonguldak Colliery, Turkey. The experimental procedures were developed to determine their void ratio (or its equivalent porosity), bulk density and the shape properties of constituent particles. The orientation fabric and the co-ordination number were the other two fabric elements determined. The filling materials were sieved and their particle size distributions were found. The results obtained by experiments were related to the particle size distribution parameters, namely, the coefficient of uniformity and the effective size. It was concluded that mean value of void ratio is correlated with coefficient of uniformity. The standard deviation of porosity as an index of fabric heterogeneity is clearly correlated to effective size. By an original experiment, the frequency distribution of coordination number was observed as binomial in uniformly graded materials. Also, the co-ordination numbers of test mixtures were calculated by the Marsal method and results obtained showed a good correlation between the minimum particle size and number of contacts per unit area.

Jan 1, 1998