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By L. Bloomquist, C. Arnoldi

"This paper describes how Automated Mining Systems (AMS) is evolving the state-of the- art in guidance systems for autonomous underground vehicles. The techniques, tradeoffs, and lessons learned from these systems are described, including the safety regime that has been implemented.First generation autonomous guidance systems for underground vehicles relied on infrastructure for the vehicle to follow. However, there are additional costs associated with that approach.The current generation uses a pair of laser range finders as its only guidance sensors. This system uses a minimum of infrastructure, in the form of a redundant system of location referencing. Advanced steering and drive control algorithms are incorporated into this generation of system.The next generation of infrastructureless guidance systems will be based on a 3D vision sensor, which was originally developed for autonomous Mars rovers and is being adapted for underground mining use. Results of early underground field trials are presented, along with a description of this emerging technology."

Jan 1, 2004

By R. Fuenzalida

Since 2007, a number of Multivariable Predictive Control (MPC) Applications have been implemented on SAG mills, among others, within the Kairos Mining Concentrator Automation Program using ?Profit Controller?? and other tools comprising the ?Profit Suite??. Along this journey, several interesting and challenging issues related to SAG mill operation and control have been faced, which are relevant to be shared with the Mineral Processing community. These advanced control applications have an operational objective whose goal is to increase marginal profit on the concentrator, together with increasing mill stability. In regard to this objective, the issues to be presented and described are in direct relationship with ?Profit Controller? features and the SAG role; they are also stated and linked to get the most of the mill. Some conclusions and findings are also presented, leading to recommended practices on how to use the controller. These findings have also lead us to decide further actions to be taken on new applications to deploy and also on devising and implementing some complementary components to increase robustness of the overall automation solution, as well as reducing the need for operator intervention.

Jan 1, 2012

By Micheal Mitariten

The recovery of natural gas (primarily methane) from coalbed deposits is an established and growing source for the U.S and accounts for over 7% of its total production. The gas from on-purpose degassing is often pipeline quality and requires only compression and dehydration before being admitted to the pipeline grid. However, the raw gas is sometimes contaminated with nitrogen (N2) and/or carbon dioxide (CO2) that can make the gas inadmissible to the transportation pipeline. In general, the N2 must be 4% or less and the CO2 should be 2% or less. In treating gas produced from virgin coal bed or from degassing operations where CO2 is present, amine systems are traditionally used for its removal. Engelhard’s Molecular Gate® adsorption system offers an attractive alternative due to its skid-mounted equipment, low pressure and unattended operation, cost and high on-stream reliability. Natural gas can also be sourced from the residual coal, after the coal has been mined. This source can be the GOB or gas remaining in abandoned coal mines. This source is almost universally contaminated, often with a combination of CO2 and N2. If the source is from air intrusion, the source can also be contaminated with O2. In treating CO2 / N2 contaminated feeds, the Molecular Gate adsorption system removes both of the impurities along with a level of O2 within a single processing step. To date, ten Molecular Gate units are underway with three systems having been installed for upgrading gas from abandoned coal mines. The technology consists of specialty adsorbents and advanced PSA processes that are jointly offered as fabricated packaged equipment by Engelhard Corporation and Guild Associates, Inc. Upgrading requirements, project challenges and project arrangements are discussed in this paper.

Jan 1, 2005

By J. R. Thoenen

In Progress Rerort 1,4/ a number of facto were demonstrated and conclusions drawn from experimental tests and records made during commercial blasting operations at a number of quarries. For example, the tests showed (1) that vibrations received on outcrops were of comparatively

Jan 1, 1938

Much of the coal and gold mining industry of New Zealand is small scale. Funding is tight and mechanisation limited. The country has many well documented small coalfields (some with significant outcropping) and alluvial gold deposits. These are generally remote, difficult to access (physically and otherwise) and of submarginal value (largely a consequence of size when viewed for extraction by traditional techniques). The industry is also burdened by environmental and bureaucratic constraints. The above over simplified setting suggests to the Author, a newcomer to New Zealand, the opportunity to consider some novel concepts based on technology and techniques developed overseas or borrowed from other industry sectors. The objective being to make viable in economic and environmental terms projects that might otherwise be stillborn if considered for exploitation by conventional means. The paper mainly discusses 2 concepts focusing on the application of augers for exposed high wall or outcrop coal and micro-tunnelling augers for alluvial gold extraction. These may be considered high mobility 'container' (as in shipping container) packaged, or 'non invasive' mining systems. It is stressed that these are but concepts and have yet to be subjected to rigorous financial or engineering scrutiny. This could only follow their acceptance by, and input from, New Zealand miners. There will also be brief mention of a new modular conveyor system which might have application within the concepts or existing small scale mineral extraction operations and mention of a project currently in progress to apply tangible 'sustainability' to underground coal mining.

Jan 1, 1996

By Dirk van Zyl

As part of the North American regional activities during the Mining, Minerals and Sustainable Development Project (MMSD) one project focused on the development of sustainability evaluations at the operations level. Engagement was identified as one of the seven important questions to be addressed. Engineers and scientists employed in the mining, minerals and materials production arenas must understand the importance of stakeholder engagement, both within and outside the operations as it is essential in the ongoing activities required to contribute to sustainable development. After developing the awareness that a social license can only be contemplated if engagement is in place, they also have to develop skills in engagement processes. This presentation will present the business case for engagement as well as an approach to motivate undergraduate mining engineers to embrace it. The presentation will also review some recent and ongoing research to improve the engagement process.

Jan 1, 2010

By M A. Knackstedt

Coupling between deformation processes and rock permeability is a major factor influencing the architecture of fluid migration and the localisation of ore deposition in several types of hydrothermal ore systems in middle to upper crustal regimes. Permeability in many hydrothermal systems is controlled by a dynamic competition between deformation-induced porosity-creation processes and porosity-destruction processes. Localisation of deformation within faults, fractures and shear zones leads to flow localisation, with large-scale flow systems forming when active faults and shear zones link to create percolation networks. Numerical modelling techniques are used to explore the growth of fracture networks and evolution of network connectivity during progressive deformation. Initial results indicate that networks reach a percolation threshold at very low strains. Near the percolation threshold, flow is localised along a small proportion of the total fracture population and favours localised ore deposition. At higher strains, flow is distributed more widely throughout the fracture population and may provide reduced potential for production of high-grade deposits. The distribution of mesothermal gold deposits along a small subset of the total population of co-active faults and shear zones in the Archaean Yilgarn Craton in Western Australia indicates that some hydrothermal systems maintain themselves near the percolation threshold for a substantial part of the lifetime of the system. Fluid-driven growth of fault/fracture/shear networks may lead them to self-organise near the percolation threshold.

Jan 1, 1999

By Holger Witthaus

Beside the traditional geomechanical evaluation methods the geotechnical parameters are recognized as important facts of the planning work for multiple seam mining. Standards for applied monitoring and investigation methods for geotechnical determination of drill cores, laboratory rock-tests and observation of roadheadings are the basics for rock mechanics classification and support design. The geomechanical classification is in this context an essential element. The planning procedure, as it is becoming more and more detailed, beginning with the panel layout up to the technical instructions of roadway development and design of roadheading machinery, nowadays uses a lot of geotechnical information that also are expanding to include quantitative determination of more parameters. The current monitoring system includes the description of separation planes using drill cores and roadheading observation as well as laboratory tests of rock-strength and geophysical borehole examinations. This information is analyzed within the geomechanical standard-classification. The re-engineering process of comparison the predicted support success to the actual monitoring results provides the opportunity for continuous optimization of the planning work und support design. This way of empirical analysis is used for basic planning work in Germany for decades. But using the technical standard of information technology and a centralized database now it is possible to reach quick-win effects in implementing research results on the one hand and actual experiences on the other hand.

Jan 1, 2006

By P J. Hommert, D S. Preece

"Commercial development of the United States Oil Shale reserve will require substantial amounts of mining. In fact, even a modest 500,000 barrels per day industry requires a mining effort equivalent to nearly half of the current U.S. coal mining industry. Obviously, mining efforts on this scale will benefit from technological advances. There are a number of areas where advanced technology could impact mining. These include continuous miners, shale transport systems, and blasting. This paperexamines recent developments in computer modeling of blasting and assesses the likelihood of these advances being applied to practical oil shale mining problems."

Jan 1, 1989

By Stephen R. Iverson

Manganese deposits exist in the Wonder Mountain RARE II area (fig. 1). The manganese mineral is primarily bementite, a silicate. It occurs with Jasper and manganese oxides in tabular or irregular lenses along the contact between red limestone and basalt. There are about 11,000 tons (10,000 t) of indicated sub-economic resources in the northeast part of the study area. Of this, 10,700 tons containing 27.1 percent manganese is at the Apex Prospect and 300 tons averaging 24.8 percent is at the Brown Mule Mine (fig. 1). Another 1,000 tons (900 t) containing 27.0 percent manganese is at the Steel Creek deposit 0.5 mi (0.8 km) west of the area (Wiebelt, 1942, p. 1, 2). Each of these deposits is subeconomic due to small tonnage and high estimated recovery costs. They are in a regional belt of manganese occurrences trending northwesterly through the area. Pardee (1921) reports that manganese ore was shipped from the Triple Trip (Brown Mule) Mine in 1916.

Jan 1, 1982

By L. Forsbacka, L. Holappa

Viscosities of quasi-ternary CaO-SiO2-CrOxmelts in contact with metallic chromium were measured by the rotating cylinder method up to 1750ºC. Twelve slag compositions were selected in the composition range 20–55 wt% SiO2, 10–45 wt% CaO and 10–60 wt% CrOx. Estimation of the amounts of CrO and Cr2O3was made by regression analysis based on the earlier data. Professor Iida’s (Osaka University) viscosity model was applied and model parameters (0CrO,CrOand Cr2O3) were evaluated. The Iida model gave good consistency with the measured viscosity values.

Jan 1, 2004

By E. E. Cudby

"FOLLOWING the Leduc discovery •by Imperial Oil in 1947, The California Standard Company began to acquire land in the area immediately west of Edmonton and in line with the Leduc reef trend (Figure 1).The California Standard Winter-burn Province No. 1 in Lsd. 10, Section 4, Township 53, Range 25, West 4th, which was spudded, on the basis of a seismic anomaly, in December, 1949, failed to find reef. This well was located on the eastern .edge of a large land block which California Standard and Imperial Oil had pooled as a joint venture, with California Standard a:s the operator (Figure 2).The culmination •of an extensive exploration and land aquisition programme was the drilling of the California Standard-Acheson Province No. 1 well .in Lsd. 13, Section 2, Township 53, Range 26, West 4th. On August 24th, 1950, a drill stem test was run in the D-3 zone which had been encountered at 4,969 feet, and a flow rate of 702 barrels per day •of 36° gravity oil was obtained. Just previously, Imperial Oil had completed a similar programme in the Stony Plain Reserve with the swabbing-in of Imperial Stony Plain No. 1. These two discoveries set off a drilling programme to determine the extent and value of the oil accumulation.Subsequent drilling of wells some successful .and others not by several other companies as well as California Standard bias, .to date, still left much to be determined as to the approximate delineation of the productive limits of the Ache-son-Stony Plain area. However, to August 31st, 1951, there were twenty-one D-3 producers north of the reserve and three in the Stony Plain Reserve."

Jan 1, 1952

Under the Town and Country Planning Act 1977 the Ministry of Works and Development has a responsibility for providing information to local and regional planning authorities on public works and matters of national development and importance, for the exercise of their responsibilities under this Act. One such matter which has recently become a source of concern is the development of South Island lignite. In 1979 the Ministry of' Energy produced a position statement outlining a programme of' research leading to the possible extraction of lignite in Southland or Central Otago for conversion into about 50 per cent of New Zealand's liquid fuel requirements by 1995. Understandably this possibility has caused considerable concern at the local level, expressed particularly by bodies such as Federated Farmers and the local authorities. In the absence of any factual knowledge short of mere conjecture been able to recommend to local authorities is that they limit their planning period to ten years. After this time more information regarding the size, nature, location and certainty of the proposal will permit a more accurate assessment of the implications of the York. While on holiday earlier this year I took the opportunity to visit opencast mining areas in Germany and England to gain an appreciation of the scale of impacts involved and discuss with those concerned the procedures used in planning for such operations. What follows is a brief description of these operations, a comparison with the likely development in this country and the extraction of what may be some relevant principles of' operation for the planning of an environmentally acceptable project. Please note that the views expressed in this paper are mine alone and are not necessarily those of the Ministry of Works and Development.

Jan 1, 1981

By Yves St-Amour, Vince Luongo

This paper will discuss one of the largest construction projects the City of Portland has undertaken. This phase of the Willamette River Combined Sewer Overflow (CSO)project consists of approximately 18,500 ft of tunnel in soft ground, requiring the construction of six deep shafts and jet grout ground improvement. The purpose of the project is to reduce volume of combined sewerage overflows from the drainage areas on the west side of the Willamette River. Bencor-Petrifond-Pacchiosi Joint Venture was awarded a contract to design and construct six deep circular shafts, jet grout ground improvement for three bridges and jet grout ground improvement break-in/outs for some shafts. Of the six shafts the Pumping Station Shaft was the deepest and largest, requiring a permanent ground support system with a deep jet grout ground water cut-off to 335-ft deep. The joint venture used state of the art methods and equipment to achieve its objectives and build the structures through some very difficult alluvial soils to great depths next to the Willamette River. The paper will provide a general discussion of the shaft construction and jet grout ground improvement installed for this phase of the project. It will also discuss some of the technical challenges encountered while effectively managing risk and costs, resulting in a successful project completed in a timely manner.

Jan 1, 2005

By R. V. Ramani

This report is volume 3 of an eleven-volume final report for a Grant completed by The Pennsylvania State University for the Bureau of Mines to develop a dynamic general purpose computer simulation model for underground coal mining. The simulator developed under the Grant has a wide range of possible applications in the design and evaluation of underground coal mining systems from the standpoints of health and safety, productivity, and mine environment. The Master Design Simulator consists of nine free-standing function-oriented subsystem models linked together into an integrated, comprehensive model of an entire mining system. The subsystems comprising the Master Design Simulator include geology and reserves, methane generation, roof support, subsidence, production, rail haulage, cost, water generation,' and ventilation. This volume of the final report describes the Methane Generator subsystem of the Master Design Simulator. This subsystem is used to determine methane emission rates into the mine environment. These flow rates are then used by the simulator in planning primary and secondary ventilation systems, planning a methane drainage system, and analyzing complex ventilation networks. Both steady state and unsteady state gas flows are included, and have been modeled as second order nonlinear partial differential equations. Finite difference equations are used to obtain numerical solutions to the models using a central differencing scheme. An application of the model is presented. The appendices include derivation of the gas flow equations used in the model as well as a users manual for the computer program.

Jan 1, 1974

Many of the world?s largest existing mines are considering substantial step changes in production volumes, compensating for declining ore grades while trying to address increases in world demand for resources. The natural configuration of coal deposits allows for many mine development openings along the strike to access the ore body and thus increase volume. Similarly, with iron ore the nature of the deposits means that additional capacity can easily be added by opening up new mesas and providing extensions to infrastructure. On the other hand most of the non-ferrous metaliferous deposits form vertically and additional extraction volume comes from increasing depth. Underground mining from the base of the strata allows for large extraction rates, but block or panel caving operations develop at rates dictated by the geophysics of the overlying strata and the need for massive tunnelling developments to establish sufficient extraction points for high volumes. For really big mine production capacity, open cast mining still allows the easiest development of more massive mining techniques. But there remains the question of whether there are limits to how large an open cut mine can become in terms of throughput?

Feb 27, 2013

By Stephen L. Chryssoulis, Daniela Venter, Stamen Dimov

"Comparative surface analysis of floated and rejected free gold grains from a number of full scale benefication plants and from pilot plant testwork, has shown silver (the most common impurity in gold) and sulphur invariably in greater concentration on floated gold grains, implying that they assisted gold flotation (gold activators). Collector loading measurements on individual gold grains from concentrates of staged rougher flotation tests on a cyclone U/F product of a pyritic gold ore, revealed first progressively lower concentrations of the collector monomer on gold from each follow-up concentrate and secondly a direct proportionality between the surface concentration of silver and the collector monomer. These two observations leave no doubt that silver activates gold and that collector monomers play a significant, previously not fully recognized role in gold flotation.INTRODUCTIONGold to some degree is naturally floatable in industrial systems, which means that it can be recovered without collector addition (Marsden and House, 1992). This is due to the adsorption of hydrocarbons and deposition of sulphur, which are dependent on the metallic properties of gold, particularly its high electrical conductivity, which allows surface electrochemical reactions to occur catalytically and selectively. Cyclic voltammetry has shown that gold can be rendered hydrophobic by deposition of a surface layer of sulphur (Sº) from S2- and HS- solutions (Walker et al., 1984). Twenty monolayers of sulphur were required to produce a hydrophobic gold surface.However, no sulphide flotation plant relies solely on the natural floatability of gold for its recovery. Gold hydrophobicity is enhanced by the addition of flotation collectors such as xanthates (X), dithiophosphates (DTP), dithiophosphinates (DTPI), mercaptobenzothiolates (MBC) etc., as used in sulphide mineral flotation (Dekok, 1973: Adams et al., 1986). The mechanism invoked in enhancing the hydrophobicity of pure gold with the aforementioned four groups of collectors is similar to that of pyrite, whereby collector anions are oxidized at the gold surface to form dimers (Groot, 1987; Marsden and House, 1992; Basilio et al., 1992) As an example, xanthate ions are oxidized at the gold surface to form the neutral dimer dixanthogen (X2):"

Jan 1, 2003

By Robert F. Randolph, Jeffery L. Kohler, David C. Byrne

Multiple versions of an educational message can reach a diverse population more effectively than a single version. For instance, some workers are trained in formal classrooms while others are self-taught. The National Institute for Occupational Safety and Health has developed multiple versions of a hearing loss simulator (an interactive software package, a Web-based module, and an electronic slide show) to show how a single set of information can be readily adapted to different delivery methods. The three versions of the simulator were developed with a minimum of effort and expense compared to a single, less-flexible version. The interactive software is best for training sessions led by a hearing conservation professional, the Web pages are best suited for an individual worker, and the slide show is best for a small, more-generalized, training class. This paper will describe additional advantages and disadvantages of different delivery systems and will show what considerations are helpful in designing content that can be readily adapted to alternate presentations.

Jan 1, 2002

By E. Dendy Sloan

An overview of hydrate properties is given, with emphasis on unusual deviations from ice, the most common solid water form. Reliable sample preparation and reproduction of in situ hydrates provide the foundation for all hydrate science and engineering. Relations are given to connect the three domains in the title: (1) micro-scopic properties measured with Raman, NMR, and diffraction spectroscopy, (2) meso-scopic properties measured with single crystals, and (3) macro-scopic properties measured with pressures, temperatures, volumes, etc. A principal illustration relates micro-scopic and macro-scopic domains. Experiments provides the basis for improving statistical thermodynamics model for these compounds. To date, this model is one of the most commonly used industrial statistical thermodynamics applications, based upon the classical model of van der Waals and Platteeuw (1959). Microscopic measurements and simulations indicate model assumption improvements, resulting in the next generation of the statistical thermodynamics for improved macroscopic property prediction.

Jan 1, 2002

Development of Grindability Tests Based on Direct Measurement of Energy Nowadays, for the characterisation of the grindability different grindability indices - Bond-work index (Wi), Hardgrove Grindability Index (HGI) or Zeisel specific grindability (Wt) - are used. Generally, the grindability tests are carried out under relatively simplified circumstances, in a special dry batch mill with defined feed size material until prescribed conditions are reached at room temperature. However, in the fine- and ultra fine grinding, which is a frequent task (fly ash, tailings, alumina, etc), a fine material (<50 - 200 ¦m) is usually ground down to the few micrometers. The conventional grindability testing methods and apparatuses (Bond-, Hardgrove-, Zeisel-processes) for their determination, although, are not suitable directly to measure the grindability of such fine materials, since the maximal particle size of the feed material (0.5 - 3 mm) to be tested is much higher. One of the important goals of the research carried out in our Institute was to develop the novel grindability testing methods, which are suitable for the fine and ultra fine grinding, and additionally provide the possibility for the fast determination of the grindability. In order to realise the above aim the conventional Bond- and Hardgrove- mills were modified in order to directly measure the grinding work. In particular, the Hardgrove-mill was equipped with a simple torque-meter (load cell). The Bond-mill was rigged with a digital electric power measurer. The systematic experiments were carried out parallel in both mills using the conventional and the developed methods. Finally the results of both were compared. The measuring results have proved that the Bond-work index can be determined based on the developed methods. The new grindability testing methods were applied successfully in several industrial research tasks for the determination of the specific grinding energy and the Bond-work index. These methods can be also used in the industrial practice for the control of the grinding process.

Sep 13, 2010