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By K. W. Vincent

This paper, deals with the beneficiation of a low grade Western phosphate to ore. More specifically it summarizes the results of a study made to optimize a scrubbing step in the process, and to provide firmer data for use in plant design. The deposit is situated about 30 miles northeast of Pocatello, Idaho, in the Fort Hall Indian Reservation. It is a bedded deposit and throughout most o the orebody includes three contiguous layers of phosphatic material which differ in P205 content. The J. R. Simplot Company, as operator for a Simplot-FMC joint venture, mines the ore selectively by open pit methods The lower bed containing a nominal 30% P205 is shipped to the Simplot Company fertilizer complex near Pocatello; the middle layer averaging about 24% P205 supplies the FMC elemental phosphorus plant also near Pocatello, The top layer averaging around 16% P205 and designated as mill grade shale is stockpiled for future beneficiation. This paper is concerned with some aspects of the processing of this low grade shale.

Jan 1, 1965

By Henry A. Pohs

It is a rare work of art that attains the proportions of a major construction project. One instance of such a phenomenon is Bartholdi's Miss Liberty, which was designed and built section by section in Paris and then erected in New York Harbor. Another is Borglum's massive presidential quartet hewn from the granite of Mount Rushmore. Now, however, there is a new monument in the making which will completely dwarf all others. The sculptor of this supercolossus is Korczak Ziolkowski, a colorful, bearded genius who assisted Borglum on Mount Rushmore and is now carving his own granite masterpiece from Thunderhead Mountain near Custer, S. D., just ten crow-flight miles away from Rushmore.

Jan 11, 1966

By Joshua Hescock, Zach Agioutantis

"The Surface Deformation Prediction System (SDPS) has been developed as an engineering tool for the prediction of subsidence deformation indices through the implementation of an influence function. SDPS provides a reliable and fast method for the prediction of mining-induced displacements, strains, tilt, and so forth at any elevation between the seam and the horizontal or varying surface topography. One of the key aspects in obtaining reliable ground deformation prediction results is the determination of the edge effect offset. The value assigned to the edge effect corresponds to a virtual offsetting of boundary lines delineating the extracted panel to allow for roof cantilevering over the mined out area. The objective of this paper is to describe the methods implemented in updating the edge effect offset code within SDPS. Using known geometric equations, the newly developed code provides a more robust calculation of the offset boundary line of the extracted panel for simplistic, as well as more complex, mining geometries. Assuming that an extracted panel is represented by a closed polyline, the new edge offset algorithm calculates a polyline offset into the extracted panel by the user-defined edge effect offset distance. Surface deformations are then calculated using this adjusted panel geometry. The MATLAB® program was used for development and testing of the new edge effect offset feature. In completing rigorous testing regimes, the new offset features will be integrated into SDPS, further increasing the speed and reliability of the programs resulting in a retrospective increase in capability and flexibility. INTRODUCTION Underground operations have been known to cause mining-induced subsidence inside and outside of the mine permit area (Karmis, Agioutantis, and Andrews, 2008). Additionally, subsidence can impact surface water bodies, such as rivers, streams, lakes, and wetlands (Karmis and Agioutantis, 2015; Newman et al., 2016), as well as infrastructure, such as roads, railroads, pipelines, and buildings. With an increase in regulatory focus on mining-induced impacts to local structures, the calculation of mining-induced subsidence indices has become necessary in determining potential damage and mitigation efforts. The accurate prediction and evaluation of mining-induced ground deformations is required to obtain underground mining permits due to potential impacts to nearby structures, as well as hydrogeological sources. The prediction of ground deformation indices is often a complex task due to the number of input parameters required, such as mining geometries, overburden lithology, surface topography, the rate of mining (Karmis, Agioutantis, and Andrews, 2008)."

Jan 1, 2017

By Emilio Cordero Cordero

En los proyectos de excavaciones subterráneas, túneles de obra civil y galerías mineras es necesaria la realización de cálculos para el sostenimiento adecuado para cada situación y comprobar que este cumple los parámetros de seguridad indispensables para garantizar la estabilidad de la excavación en el tiempo. En este sentido, el texto señala el uso de SDT(software) como aplicación informática decuada para el cálculo de sostenimiento en túneles y galerías mineras que suministra una respuesta a las necesidades de proyectistas e ingenieros mineros. Dicho software se basa en cerchas metálicas con capacidad de deslizamiento (perfiles THN), cerchas de perfil HEB, pernos de anclaje y hormigón proyectado en túneles y galerías mineras que utiliza el método “Convergencia – Confinamiento”, procedimiento de referencia en el cálculo y diseño de sostenimiento en excavaciones subterráneas, con las premisas de sección circular, presión sobre el sostenimiento uniforme y el campo de presiones hidrostático.

Jan 1, 2016

By L. D. Haig

"The Texada Mill is a unique iron operation producing High Grade sinter iron concentrate and a by-product copper, gold, silver concentrate. The plant is complex and extremely flexible to handle the many varieties of ore. Two iron concentrates are made and blended. A coarse iron concentrate from primary grinding and a fine concentrate after rougher flotation to remove all the sulphides.All the tailings from iron processing are collected, dewatered, reground and floated for additional copper recovery.The entire milling operation has been carried out in all sea water for seven years and mixtures of sea, fresh, and reclaimed water for ten years prior to that.A very stable float results from the use of sea water at the natural pH8. Reagent Consumption is lower and Metallic Corrosion of mill liners and grinding media is actually less than local fresh water or mixtures of fresh and sea water.Marine growth in pipe lines can be periodically removed by violently bubbling high pressure air up through the water filled mains.Location:Texada Mines is located on tide water on the west side of Texada Island 100 miles northwest of Vancouver, B. C.The Island is served by a 30 car ferry, tug and barge and a scheduled air service from Vancouver to a company maintained air strip near the mine.The climate is moderate with about 30 inches of rain during the winter and relatively dry summers."

Jan 1, 1974

By Tao Chunhui

The seabed deposits type and distribution are very complex at the hydrothermal field. In this paper, we provided an approach to study the seabed deposits classification at the Precious Stone Mountain hydrothermal field (PSMHF) using MultiBeam sonar data . The PSMHF was found in the Galapogas microplate at the Leg 3 of the Chinese COMRA 21st Cruise. Using this approach, the seabed deposits at the PSMHF are mainly classified into three types, which are rock, breccia and sediment, respectively. We can find the distribution of the three types of seabed deposits according to the sonar backscatter data. The rocks are mostly distributed around the hydrothermal vent. The breccia are located at the foot of the vent. Most sediments are distributed at the southwest to the vent due to bottom current. Combining with seabed video, TV-Grab sample and the backscatter data, we draw the map of the seabed deposits distribution at the PSMHF.

Sep 14, 2011

By Henrik Schiellerup, Irene Zananiri, Johan Nyberg, Thomas Kuhn, Luis Somoza, Teresa Medialdea, Maria Judge, Pedro Ferreira, Gerry Stanley, Javier González

The GeoERA Co-Fund action is a joint contribution of 48 national and regional Geological Survey Organisations from 33 European countries “Establishing the European Geological Surveys Research Area to deliver a Geological Service for Europe (GeoERA)”. This is an ERA-NET action under Horizon 2020. The aim of GeoERA is to fund transnational projects contributing to the best use and management of the subsurface, addressing the following four themes: Geo Energy, Ground Water, Raw Materials and Information Platform. The European Commission recognises the significance of raw materials through its Raw Materials Initiative (RMI), the European Innovation Platform on Raw Materials (EIP-RM) and Horizon 2020 funding, specifically through Societal Challenge 5 – Climate Action, Environment, Resource Efficiency and Raw Materials. The GeoERA Raw Materials Theme will contribute to research and innovative developments for minerals inventory, minerals yearbook, exploration, mapping, modelling, metallogeny and critical raw materials in the pan-European framework including the sea. A major element in Europe’s long term economic strategy is to ensure security of supply for strategic and critical metals as part of the Blue Growth Strategy developing sectors that have a high potential for sustainable jobs and growth as seabed mining. The project MINDeSEA results of the collaboration between eight GeoERA Partners and four Non-funded Organizations at various points of common interest for exploration and investigation on seafloor mineral deposits. The Geological Surveys of Spain, Germany, Greece, Ireland, Norway, Portugal, Sweden and Ukraine are organisations with responsibility for coastal, marine geological investigation and mineral resources studies and mapping in their respective countries. The Non-funded participants: the Instituto Português do Mar e da Atmosfera; the United States Geological Survey; the All-Russia Scientific Research Institute for Geology and Mineral Resources of the Ocean; and the Geosciences Institute, host important databases, they have an international reputation for excellence in both science and technology, and are internationally-known experts on seafloor mineralisation and hydrothermal systems. This project addresses an integrative metallogenetic study of principal types of seabed mineral resources (hydrothermal sulfides, ferromanganese crusts, phosphorites, marine placers and polymetallic nodules) in the European Seas. The work program includes all the regional seas around Europe comprising the Atlantic Ocean, the Mediterranean Sea, the Baltic Sea and the Black Sea (Fig. 1). The MINDeSEA working group has both knowledge of and expertise in such types of mineralisation, providing exploration results, sample repositories and databases to produce innovative contributions. The importance of submarine mineralisation systems is related to the abundance and exploitation-potential of

Jan 1, 2018

By W. A. MacDonald, C. M. McGibbon, J. H. Reynolds

This paper traces the development of the Seaboard Power Plant, which plays such an important role in the industrial life of Nova Scotia. It also shows the involvement of the plant in the siting of a heavy water production facility in Cape Breton. The paper concludes with an outline of the new installations which the Nova Scotia Power Commission has undertaken as an extension to the Seaboard Plant.

Jan 1, 1966

By N F. Fraser

Seafield ResourcesÆ offshore placer gold project covers c.10 000 km2 of the Westland continental shelf between Karamea and Jacksons Head, from the low-water mark out to the 120 m isobath (Figure 1). De Beers Marine (DBM), the marine diamond subsidiary of the De Beers Group, will carry out the project with geological input from Placer Solutions (PSL). DBM bring a wealth of expertise and advanced technology to the project, developed during their 20 years of exploration and mining of diamond placers on the Atlantic shelf of southern Africa, where they have also maintained a strong environmental record.   Glaciers and high-energy rivers emanating from the Southern Alps have transported substantial quantities of gold bearing sediment onto the Westland continental shelf during Pleistocene glacial periods, when fluvial gradients are steeper, sea level is c.120 m lower and most of the shelf is exposed. These deposits have been extensively reworked by the advancing shoreline and marine processes during interglacial marine transgressions, and most are now buried beneath a variable thickness of post-glacial marine sand, silt and mud. DBM will use side-scan sonar, swath bathymetry, Chirp sub-bottom profiling and a magnetometer to map the sea floor and sediments beneath it, guided by PSLÆs predictive geological model for gold distribution on the shelf. Cactus grab and vibro-core samples will be used to ground-truth the geophysics and provide stratigraphic, sedimentological and gold distribution data for incorporation into the geological model. Areas of interest identified by the geophysical and sampling data will be investigated in more detail, with closer-spaced geophysics and Mega-drill sampling to a maximum sediment depth of 20 m beneath the sea floor. These samples will be raised to the ship with air-lift suction technology, processed onboard for mineralogical and grade information, then returned to the sea floor. Environmental baseline data will be gathered from Van Veen grab samples of seabed sediment taken throughout the area during the prospecting programme.

Jan 1, 2005

By M. E. Williamson

In September 2005 Williamson & Associates, Inc. delivered the BMS2 remotely operated seafloor coring system to the Japan Oil, Gas & Minerals National Corporation (JOGMEC). During acceptance trials aboard the JOGMEC research vessel R/V Hakurei Maru No. 2 the BMS2 successfully recovered 7.44 m of rock core in 3377 m water at a site near the crest of a seamount about 500 nm SE of Japan. Hydrogenous ferromanganese oxide crust, basaltic lava, sandstone and volcanic sediments were sampled with near 100% core recovery. The BMS uses rotary rod coring tools to collect samples to a maximum depth of 30 m in water depths up to 6000 m. Depending on bottom type to be sampled, the BMS tool magazine can be loaded with various drilling tools including core barrels with different bit types, drill rod and bore hole casing. The drill has 9 video cameras, a suite of sensors and 60 hydraulic functions powering thrusters, telescoping legs, seawater pumps and all of the standard drilling controls. The BMS provides deep water investigations with the functionality of conventional diamond bit rod drilling currently the mainstay of exploration programs in land mining.

Jan 1, 2005

By P. A. Rona

The first hydrothermal mineral deposits found at a seafloor spreading center were discovered in the Red Sea by multi-national research vessels between 1963 and 1965. At that time, the deposits were considered a special case related to continental rifting and an early stage of opening of an ocean basin. Since that time, examples of almost all major varieties of volcanic- and sediment-hosted hydrothermal deposits associated with basaltic rocks in the geologic record have been found at present spreading centers. Review of over 100 hydrothermal mineral occurrences presently known at oceanic ridges and rifts indicates that a range of deposit sizes from small to large (> 1 x 106 tonnes) occurs at all seafloor spreading rates. However, larger deposits but fewer per unit length of spreading axis appear to form at slow- than at intermediate- to fast-spreading centers based on available data. Larger deposits are more common in sediment-hosted than in volcanic-hosted settings regardless of spreading rate. A spectrum of hydrothermal deposit varieties (stratiform, stockwork and disseminated sulfides; various forms of sulfate, carbonate, silicate, oxide and hydroxide deposits) occurs in almost all of the tectonic settings. High-intensity, ore-forming, subseafloor, hydrothermal convection systems that conserve heat and mass and concentrate hydrothermal precipitates are extremely localized by anomalous physical and chemical conditions relative to nearly ubiquitous low-intensity hydrothermal activity at and flanking seafloor spreading axes at all spreading rates. Two distinct shapes of volcanic-hosted

Jan 1, 1989

By A. F. Marques

The Azores islands are located on a triple junction where the American, African (AFR), and Euroasian (EUR) plates meet. The Mid-Atlantic Ridge (MAR), oriented N-S, represents two branches of the T; an E-W branch defines the EUR/AFR boundary called the Terceira Rift. The nature and structure of this plate boundary, as well as the dynamics of the interaction of tectonics and volcanism remain unconstrained. The Azores plateau is seated on a mantle domain of anomalously low seismic S-wave velocities, and gravity and geoid anomalies, where the apparent thick crust is thought to relate to larger degrees of melting initiated at greater depths [1]. The cause of these anomalies is controversial but many authors consider the presence of an anomalously hot/wet enriched mantle probably supplied by a plume [2]. The geochemistry of the subaerial and most submarine lavas from the plateau reinforces the plume model beneath the Azores [3-4]. The origin, size and present location of the plume is under debate but an area near Terceira is the favoured plume centre [5]. [ ] SEAFLOOR HYDROTHERMAL SYSTEMS IN THE AZORES AREA (36ºN ? 40ºN) More than 150 active and fossil hydrothermal systems are known in the oceanic seafloor [6]. Many more are yet to be found on vast oceanic areas that haven?t been explored [7]. Ever increasing knowledge shows that modern seafloor hydrothermal systems can be hosted in felsic to ultramafic rocks, vary in size and shape and exhibit diverse amounts of sediment cover

Jan 1, 2011

By G. Cherkashov

The geodiversity of seafloor massive sulfides (SMS) deposits at the slow- and ultra-slow spreading ridges is of great variety (Fouquet et al., 2010). Tectonics and magmatism are the two principal factors which control SMS formation and localization. The geological setting of SMS deposits is determined by their position relative to the rift valley and by the types of rocks hosted (Table 1). Depending on the first parameter, SMS deposits could be localized at [ ] the axial volcanic ridge or at the flank of the rift valley. Basalts, deep-seated gabbro, and serpentinized peridotites are distinguished among the hosted rocks. The outcrops of deep-seated rocks are exposed at the flanks of the rift valley. The tectonic mechanism of the lower crust and mantle rocks exhumation process is connected with very large offsets along the detachment faults, resulting in a forming oceanic core complex (OCC) (Smith et al., 2006; MacLeod et al., 2009). The SMS related to OCCs are represented by such ore clusters as Ashadze, Logatchev, Semyenov, and some others (Table 1) and are increasing steadily in number. This fact in combination with widespread OCC formation at the slow-spreading ridges (Escartin et al., 2008) and high grades of metals in SMS related to OCCs has provoked considerable scientific and economic interest in these types of deposits. It could be mentioned in this regard that the first two applications to the International Seabed Authority for prospecting and exploration of sulfides have been submitted for the areas in the spreading centres with wide distribution of the core complexes.

Jan 1, 2011

By Gray Mullins

This paper presents results from model and full-scale tests to assess the interface bond between a cast-in-place concrete seal slab and steel H-piles in cofferdams. Three different seal slab placement conditions - fresh water, salt water and bentonite slurry - were evaluated and the results compared against controls where no fluid was displaced by the concrete. Normal pile surfaces were investigated. Additionally, the situation of ?soil caked? piles was also tested. In the model tests, eight 15 cm deep, W6 x 15 sections were used for two different embedment depths of 1.5d and 2d, d being the depth of the section. In the full-scale tests, 16 specimens 35 cm deep (W14 x 90 sections) were tested with the embedment varied between 0.5d-2d. The results show that significant bond stresses developed even in the worst placement condition. Recommendations made for revising current values in specifications have already been implemented by the Florida Department of Transportation.

Jan 1, 2013

By Gray Mullins

This paper presents experimental results from a study to assess the interface bond between a cast-in-place concrete seal slab and prestressed concrete piles in cofferdams. Three different seal slab placement conditions - fresh water, salt water and bentonite slurry - were evaluated and the results compared against controls where no fluid had to be displaced by the concrete. Normal pile surfaces were investigated. Additionally, the situation of ?soil caked? piles was also investigated. Both model and full-scale tests were conducted. In the model tests, twenty eight 15 cm square prestressed sections were used with the embedment depth varied between d-2d, where d is the width of the pile. In the full-scale tests, 16 specimens were tested. The prestressed piles were 36 cm square with the embedment varied between 0.5d-2d. Four of the sixteen piles were cast with embedded gages located at the top, middle and bottom of the interface region. The results showed that loads were transferred to the piles over an effective area, not the entire embedded depth. Significant bond stresses developed even for the worst placement condition. Recommendations are made for revising current values in specifications.

Jan 1, 2013

By J. Oliver, J. Cleason

"With maintenance costs rising and an increasing demand for higher production, the use of sealed spherical roller bearings can reduce maintenance costs while providing increased production uptime. The sealed spherical bearing has increased bearing life by slowing the ingress of contamination. This paper will describe how contamination and bearing wear is reduced by reviewing case histories from coal and metal mines that improved their production by decreasing downtime using sealed spherical roller bearings. INTRODUCTION The spherical roller bearing (SRB) is a robust rolling element bearing that can accommodate high radial loads, low to moderate axial loads, and misalignment with no loss in carrying capacity. (i.e. Figure 1) Because of these characteristics, it is a favorite in mining applications and many other heavy industry applications. Primary applications are the various pulleys on conveyors. Coal and hard rock mines have hundreds of miles of conveyor lines and countless head, tail, drive, and idler pulleys. Maintaining the bearings on these pulleys and replacing bearings that have failed can be a huge expense to a mine in components, labor and downtime. Ideally, the bearings are replaced when the pulley is changed out according to the maintenance cycle, about every 4 years. Reality, however, causes the bearings to be changed out every year, or sooner. These premature bearing replacements can cause production shut downs for as long as 8 hours. Conveyor pulleys have been targeted at many mines as the single biggest maintenance pain point.The primary reason for replacing conveyor bearings is internal wear from fine, solid particle and water ingress through the bearing housing seals. (i.e. Figures 2 & 3) Traditionally, the bearing is mounted in a split pillow block housing (SAF, FSAF, SDAF or SNL are typical industry styles) with only labyrinth seals (LER/LOR) for protection against the ingress of contaminants. The bearings are lubricated with grease. A common way to extend the MTBR is to purge the bearing system with large quantities of grease to flush out the contaminants. If the bearing, and thus the housing seals are not frequently purged with grease, fine solid contaminants enter the housing and bearing through the labyrinth cavities."

Jan 1, 2015

Waste areas of a mine should be sealed especially if there is a risk of spontaneous combustion. Leakage through and around such seals can be problematic. Pressure balancing has been one of the favored options to prevent the ingress of air into these waste areas. Balance chambers require maintenance and monitoring to ensure that they are effective. This paper explores the use of inert gas as a means of controlling ingress of air and egress of waste gases as a means of reducing leakage around seals.

Jan 1, 2009

The major coalfields of Australia are almost unique in the occurrence in some areas of CO partly or almost completely replacing CH4,t1e normal seam gas from metamorphism of coal due to time and depth of burial. This CO2 situation has some benefits but mostly it introduces particular safety problems result- ing from the high density of CO2 relative to air, magnifying problems of gas dilution in ventilation, and the greater affinity which coal has for CO2 than for CH4 increasing proneness to gas-dynamic phenomena. The occurrence of most CO2 seam gas can be directly related to igneous intrusion and to its associated pneumatolytic injections. Whilst intrusions locally increase the rank of coal by their contact metamorphic effect, normal coal metamorphism due to time and depth of burial continues after intrusion and injection together with the ongoing metamorph- ic production of CH . This new CH slowly displaces any CO to leave some present-day intruded coals with seam gas with reduced CO2 or even without any significant CO2 associat- ions. The seam gas maps of the Bowen and Sydney Basins and more detailed maps of specific areas exemplify these situations. Mining progress, plus more searching studies of igneous-coal relationships provide improved understanding of the factors involved.

Jan 1, 1986

Studies of the Main Seam in the Rapahoe Sector of Greymouth Coalfield have shown that the proportions of palynomorphs and palynomorph groups vary vertically within the seam, but remain laterally consistent. Subsequent examinations of other seams in the Rapahoe Sector have demonstrated that the changes in palynomorph proportions observed in the Main Seam are specific to that seam, effectively providing a seam 'fingerprint'. Such a characteristic signature may be used to identify the Main Seam where faulting or seam splitting confuses seam correlation between drillhole intersections. Palynomorph assemblages are derived from the original plants which formed the peat mire, and yield information on mire conditions such as climate, mineral matter input and chemistry. These depositional factors influence coal properties such as mineral content, volatile matter yields and coal breakability. Palynological data can therefore assist in development of depositional lTIodels for prediction of coal quality variations. Several other, thiner seams in the Rapahoe Sector have been demonstrated to also contain recognisable palynomorph assemblages, suggesting that other seams may also possess distinct palynomorph abundance profiles.

Jan 1, 1996

By Kot F. v. Unrug

In spite of the extensive research and accumulated experience from mining operations, an appropriate pillar design remains an open issue. Due to the shrinking reserve base, present mining operations move to more challenging conditions. There are usually thinner seams and geologic conditions are often unfavorable. For instance, mine roof and floor are weak or deteriorate rapidly when exposed to moisture fluctuations in mine atmosphere. It is common that pillars of current operations are more- squat than several decades ago when the bulk of pillar research have been carried out in thicker seams. The methods of pillars calculations were developed regionally (in particular countries) to suit design needs for the most important seams, from which the majority of coal production was coming (e.g. Pittsburg or Pond Creek seams in the eastern of US). Most of the pillar formulae use similar approach by assigning weights (using constants) to the influence of coal (seam) strength and pillar widthheight ratio on its final strength. That mechanistic approach has sound theoretical base and good data supporting its validity. However, what seems to be missing is a qualification system of the mine conditions, which are outside of the data base or do not comply with the theoretical model applied in pillar strength formulae. This paper attempts to address that issue in two major categories, first when only a drill core data are available, and second during the mine development observations can be made directly on a coal seam. The composition of a coal seam is also addressed, (which often changes rapidly across the reserve), and discussed its influence on pillar's structural performance. In summary a set of practical design rules is presented.

Jan 1, 2005