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By Jean M. Richardson, Steven R. Williams

"Geometallurgical mapping is a new team-based approach that documents variability within an orebody and quantifies the impact of geology (host rocks, alteration and structure) and mineralogy on grinding, metallurgical response and metal recovery processes. The quantitative, spatially constrained database that results can be readily integrated into 3-D block models and mine planning activities. Thus it is an important tool to reduce the technical risk associated with new mine developments or expansions.Normally undertaken during pre-feasibility or feasibility planning stages, the first step of geometallurgical mapping is to review the geology, mineralogy and other critical parameters and construct a geometallurgical matrix. This matrix provides an objective base to then guide sampling and/or compositing activity for physical property and metallurgical testing. Depending on the project, an array of testing techniques can be used to characterize the ore and feed data into the geometallurgical model.While the range and number of tests needed is project-dependant, the geometallurgical mapping approach allows the development of empirical models or interdependent relationships, grounded by spatially-constrained real data. Extensive data sets collected using less expensive testing methods can be meaningfully correlated with results from complex specialty tests to yield realistic metallurgical recovery data.With geometallurgical mapping completed, the resulting database can be integrated into an overall 3-D block mine model. This means that metallurgical response can be used to realistically forecast the recoveries of specific blocks, perhaps sampled only by drilling. Mine planning can then incorporate the forecasted metallurgical response and generate future project cash-flows; opening the door to economic optimization of the mine exploitation."

Jan 1, 2004

This report is the 26th in a series summarizing Bureau of Mines research and technologic work on coal and related investigations and the 8th of these reports to be issued on a calendar-year basis.1 It reviews briefly work in progress during 1961, and it provides references to publications by Bureau personnel during 1961 and also to a few older papers that were not cited in prior reports of this series. Details about some of the researches mentioned may be obtained by referring to the publications cited in the footnotes or in the further list in the Bibliography; other phases of work are reported here for the first time and will be covered in more detail by later publications. The coal program of the Bureau of Mines extends over the wide range of applied and theoretical studies indicated by the table of contents of this report. Applied studies are conducted in connection with the development and evaluation of new mining techniques, and the effective processing and utilization of coal and coal products. Analyses of coal, technical advice, and other assistance to Federal agencies in connection with fuel and boiler-water problems, and health and safety activities are among the practical services handled by the Bureau, Fundamental research such as that on coal structure and on the properties of coal is conducted because it will, over a period of the, furnish an increasing general knowledge about coal; scientists and engineers may use this knowledge in solving problems in mining and utilization of

Jan 1, 1963

To develop more accurate means of measuring low ventilating air velocities in underground mines to facilitate compliance with ventilation standards. The Approach: A commercially available vane anemometer which produces an electrical, rather than a mechanical, output was coupled to electronic circuitry to produce the Bureau's Digital Low Velocity Anemometer (see photo). [ ] How It Works: The experimental instrument has a vane anemometer head which produces an electrical output signal with a frequency directly proportional to the rotating speed of the vane anemometer shaft. The commercially available ABBIRKO FLOWMASTER anemometer head was used in this instrument. In the signal conditioning circuits the electrical signal from the anemometer is converted into pulses, which are counted during either 3-second or 1-minute intervals, depending on the position of the operator's control switch. (Readout is either "instantaneous" or averaged for a period of one minute.) The number of pulses counted is then translated (integrated and divided by a constant) in the logic circuits to get average speed. Average air velocity in feet per minute is displayed in illuminated digits. (See simplified diagram of circuitry.)

Jan 1, 1975

By R. Heath Forbes

The route of a new, 4-mile long, electrical transmission line passed through residential neighborhoods and commercial areas of a small town in the South Carolina Coastal Plain. The new line consisted of 54 new poles and a one-mile underground section. Most of the new poles were constructed within 50 ft of existing structures, and in some cases, within 8 ft to 20 ft. A widely-space subsurface exploration consisting of 20 cone penetration test soundings indicated the subsurface conditions along the alignment generally consisted of saturated, loose to medium dense, fine slightly silty to silty sand. The pole foundations consisted of 20 to 30 ft long, prefabricated ?caissons? (essentially an open-end pipe pile with a prefabricated connection system at the top) with diameters of 28 to 56 inches. The steel caissons were installed with vibratory pile hammers. To help prevent damage and defend against possible allegations from nearby property owners, vibration and settlement monitoring was performed during all foundation installation activities. Limited structural condition assessments were also performed before and after foundation installation. For 53 of the 54 foundations, the ground vibrations recorded at distances coincident with the nearest structure locations ranged from 0.05 inches per second to 1.46 inches per second. With consideration of the dominant frequency, the majority of these values were below the commonly used USBM vibration limits. For a foundation installation that was only 8 ft from the nearest structure, a peak particle velocity of 3.06 inches per second was recorded, which exceeded the USBM limits. For all cases, the measured ground surface settlement was negligible (i.e., less than ¾ inch). Several spurious claims alleging vibration-induced damage were made, but the monitoring program provided an adequate defense. One claim involving artwork that fell to the floor during foundation installation at a distance of 8 ft from the house was deemed legitimate.

Jan 1, 2011

By R. Ciccu, P. P. Manca, A. Bortolussi, G. Massacci

Tool performance and the unit cost of cutting depend on a number of operational variables (peripheral velocity, pull-back force, water injection rate, angles of the sections of wire outside the rock) as well as on the geometric features of the cut itself (area and shape). Cutting rate and wire productivity are also influenced by the type and number of diamond beads per unit length of wire and by the characteristics of the rock (granite or marble). A computer program aimed at handling a problem of this complexity has been developed and tested with the use of available field and laboratory data and has been found acceptably reliable. Discrepancies between current industrial data and some of the results suggest future lines of research, while the simulation should also be extended to include different types of rock and tool and a variety of bench face geometries

Aug 1, 1994

By William H. Schiffbauer, Timothy Lutz, Michael R. Yenchek

The National Institute for Occupational Safety and Health (NIOSH) Pittsburgh Research Laboratory (PRL) participated in an experiment to facilitate the remote control of dozers used on coal stockpiles. The experiment consisted of supplementing the normal sensory cues an operator requires to manipulate the dozer from a remote location. NIOSH provided and tested a vision systems intended to give the operator the ability to operate the dozer safely and efficiently from a remote position. This paper highlights the genesis of the experiment, identifies the contributions of Consol Energy and Caterpillar, and details the NIOSH efforts and successful test results. Keywords-remote-control; vision system; stockpiles; safety

By Israel Liebman

The Bureau of Mines conducted an investigation to determine those factors that are significant in affecting the velocity of flames propagating along the boundary separating gaseous fuel and air. In addition the aerodynamic motion of the gases in the vicinity of such interfacial flames was delineated. Parameters in the study included flammable zone thickness, flammable zone concentration of gradient, fuel type, and position of the flame relative to various environmental surfaces. Of all these factors, the flammable zone thickness and burning velocity of the stoichiometric mixture were found to have the most significant effect on the flame speed. Notion of the gases in the vicinity of the interfacial flames was examined by particle track and interferometric techniques. The relative velocity of the interfacial flame with respect to the unburned gas on the central streamline was found to equal the burning velocity of a stoichiometric homogeneous fuel-air mixture. In addition, it was observed that the composition of the lean fuel-air mixture at the boundary of the combustion zone appears to be less than that defined as the fuel's lower flammable limit.

Jan 1, 1968

PERSPECTIVE ?Natural resources exploration, extraction and beneficiation is complex and challenging: ?Input costs rising, complexity increasing, rising stakeholder management needs, regulatory compliance issue, etc. ?With increasing costs and complexity of managing operations are we simply getting less bang for our buck?

May 1, 2013

By R. W. Fedors, S. T. Green, R. A. Hart, D. B. Walter

Computational fluid dynamic (CFD) modeling of a potential nuclear waste repository drift may be an important tool to estimate moisture redistribution caused by natural convection within the drift. To refine and support CFD techniques, a small laboratory cold-trap experiment was developed. Results from numerical modeling of the laboratory experiment show the sensitivity of the bulk air flow rate and average air temperature within the drift to several key parameters, including various boundary condition assumptions and surrounding porous media properties.

Jan 1, 2004

By Kazuo Magata, Hirohiko Fujita, Masazumi Tashiro, Yoshiaki Sato, Yoshio Shinoda

The Shinkansen of the Japanese National Railways (JNR) presently in operation between Tokyo and Hakata, approximately 1,000 km, was constructed at three stages: between Tokyo and Shin-Osaka opening in 1964, Shin-Osaka and Okayama in 1972 and Okayama and Hakata in 1975. Works on the extension of 400 km from Okayama to Hakata were launched in March 1970. As construction of the undersea Shin-Kanmon Tunnel on the extension was the toughest task, requiring many, many months, the work was undertaken earlier than any other works on the extension. It was brought to its completion in June 1974 at the cost of about 22, 000 million yen. The Shin-Kanmon Tunnel is the third undersea tunnel constructed to connect the main island of Honshu and Kyushu across the Kanmon Straits. (Table 1)

Jan 1, 1976

By H Thanasekaran, L Christodoulou, J Kohmuench

"Column flotation has been successfully applied to iron ore concentration since the 1980s with the goal of reducing silica content and allowing for the efficient production of pellet feed. Since then, columns have been widely used in iron ore processing due to: their lower capital and operational costs when compared to conventional cells their ability to generate higher concentrate grades and recoveries.Currently, more than 100 columns have been installed within Brazilian iron ore processing circuits for rougher, cleaner and scavenger duties. Despite it being a well-established approach, several technological advances have improved column design, accessories and performance. This work presents the performance of some iron ore columns in Brazil and the recent technological developments.CITATION:Thanasekaran, H, Kohmuench, J and Christodoulou, L, 2013. Column flotation of iron ore - status and advances, in Proceedings Iron Ore 2013, pp 479-484 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Aug 12, 2013

By Randal Martin

Recently, questions regarding the influence of atmospheric temperature and humidity levels on airblast levels have arisen at a number of blast sites. Humidity is alleged to have contributed to high levels of disturbance within communities surrounding blasting. In some cases, local regulatory agencies considered adopting guidelines to specify humidity and temperature ranges under which blasting cannot take place. However, it is normal blasting industry practice not to consider humidity or temperature effects, in the absence of inversions, on airblast levels. When blasting is conducted in the vicinity of residential structures, the influence of weather on the propagation and attenuation of airborne noise from the blasting site is always a concern. Sound naturally attenuates in air with distance from the source. A part of this attenuation is attributed to divergence at the airblast wave front, while the remainder of the attenuation is an accumulation of various factors that include temperature and barometric pressure, absorption in air due precipitation and vegetation, wind and temperature gradients, atmospheric turbulence and topography (Beranek, 1971). Wind speed and wind direction, as well as vertical and horizontal temperature gradients can cause airblasts to focus in local regions surrounding blasting operations and may result in air pressures greater than expected. In fact, wind and temperature inversions can actually increase sound levels with distance from the blast site. Close to the blast site, the effects of inversions may be negligible but may exceed 10 dB at 800 m or greater (Davis and Cornwell, 1991).

Jan 1, 2001

By Karel Van Acker

The automotive is a sector where energy consumption during the use phase prevails over the production and the end-of-life phase. Therefore, a lot of research and innovations at replacing classical steel parts by lighter materials like light metals and polymer composites. While composites are very attractive for the use phase of cars, their introduction suffers from the limited end-of-life options for composite structures. An extensive life cycle analysis for a reference car design has been conducted to study the effects of replacement of conventional steel structures by lightweight carbon fibre composite alternatives. The study also takes second order effects in the design of the car into account. The opportunities and treats of the trend towards more intensive use of carbon-fibre composites in car design are identified. A discussion on the potential of other types of composites for the automotive in terms of sustainability considerations is added.

Jan 1, 2010

By D P. Sainsbury, B L. Sainsbury, A Vakili, H-D Paetzold, P Lourens

The cave propagation behaviour of a jointed rock mass is strongly governed by the unique nature of joints and discontinuities, together with the intact strength of rock bridges that make up the rock fabric. A discrete finite difference (DFD) modelling technique has been developed to allow for the detailed consideration of the rock mass structural fabric at many scales and through many different stress paths that can be used for complex mine-scale analysis. The DFD methodology uses interfaces to explicitly represent large-scale structures and ubiquitous joints embedded within the simulated rock mass matrix to characterise intermediate structures. Through simulated testing of DFD materials, properties such as strength anisotropy and scale effects can be obtained. This paper discusses the successful application of implementing a DFD modelling technique for the back-analysis of caving-induced subsidence behaviour of Lift 1 at the Palabora mine.CITATION:Sainsbury, D P, Sainsbury, B L, Paetzold, H-D, Lourens, P and Vakili, A, 2016. Caving-induced subsidence behaviour of Lift 1 at the Palabora block cave mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 415–426 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By C. C. Hamilton, G. R. Lane

Traditionally, mineral sands are evaluated by preparing several mineral products using a combination of heavy liquid-, magnetic-, and electrostatic methods. Whole-rock assays (WRA) are then conducted on ilmenite, rutile and zircon products in order to determine trace element contents, which may affect project feasibility. Combined methods can be time consuming, expensive and even outdated due to the use of banned and toxic chemicals such as clerici solution. Coupled with large field-sample quantities, these procedures can potentially introduce unacceptable sampling and related errors. Modern mineralogical analysis techniques can provide complete mineralogical inventories on a single THM product, reducing the amount of processing involved in satisfactory characterization of early exploration samples. A small exploration sample can be processed to produce a small THM concentrate using readily available gravity/density methods. In turn, the THM product is submitted for Whole Rock Analysis (WRA) and mineralogical inspection by X-ray diffraction (XRD), and microscopic evaluation. Modal mineralogy and textural data can be determined using optical methods, automated image analysis, and scanning electron microscope (SEM) based systems. Benefits of automation are reproducibility and the capability of rapidly analysing thousands of particles as opposed to manual optical methods. Automated systems include the use of Automated Digital Image Analysis (ADIS), and SEM-based systems such as the Mineral Liberation Analyser (MLA) and QemSCAN. For detailed mineral chemistry, microanalysis techniques ranging from electron microprobe (EMPA) to Secondary Ion Mass Spectrometry and Laser Ablation Mass-Induced Coupled Plasma-Mass Spectrometry (LAM-ICP-MS) are used. Examples of these automated and analytical methods are presented. ADIS at SGS-Lakefield Research uses optical characteristics to identify and measure mineral species in THM samples; rutile, pseudorutile, ilmenite and leucoxene can be distinguished. Analysis of a single THM product provides bulk modal mineralogy and grain size distribution of particles and the individual mineral grains. Textural information is also obtained detailing mineral associations as well as degree of alteration. Where textural and chemical resolution renders mineral identification ambiguous, SEM-based methods offer better resolution. Examples of this ambiguity are shown in this paper, which leads to QemSCAN as the preferred method where within-grain variability is concerned. Sampling and measurement strategies are followed to meet study objectives, providing a value-added framework for a sequential, cost-effective strategy, which will meet due diligence and bankable accreditation criteria. Studying a THM product by electron microprobe and LAMICP-MS may reveal potential fatal flaws related to mineral chemistry. Low detection limits in the range of 200 to 500ppm are possible using electron microprobe analysis for suitable matrixes (U, Th in zircon). For the detection of ultra low level elemental contaminants, LAM ICPMS is the most accurate method of evaluation. Elements including U, Th, La, Ce, Nb, and V in Ti-minerals can be determined down to 50 ppm.

Jan 1, 2005

By Brian P. Stapleton, Bill M. Stewart, Joel R. Warneke, Curtis C. Clark

Of the 28 accident/injury classifications listed by the Mine Safety and Health Administration, handling materials is second only to roof falls in terms of generating the highest number of reportable accidents in active underground coal mines. Two materials-handling activities that cause numerous injuries each year are the categories of “handling supplies or material, load and unload” and “moving power cables.” Mechanization and mine worker activity training are two methods that can aid in preventing these injuries. This paper describes three mechanical methods—the mobile manipulator, the in-mine hoist, and a cable-handling system—being developed and tested at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health. Two of the devices are specifically designed for loading, unloading, and moving supplies and materials, and the third device is for handling trailing cables in the confined spaces of coal mines. Also described are safety solutions developed for underground coal mines geared to showing miners safe and unsafe ways of performing various materials-handling tasks.

By J. Jerome MacDonald, Stephen B. Flewelling

"In the base metals industry of today, operations required to continuously improve productivity and reduce unit production costs. Consistent with these goals is the improvement of the muck haulage cycle from open stopes with the No. 12 Mine.Existing haulage from open stopes occurs with LHD units experience at Brunswick indicates that LHD units have a higher unit cost per tonne mucked than loader-truck combinations when the haulage exceeds approximately 150 m.The reintroduction of open stoping at Brunswick made existing loader-truck combinations unsuitable. It was recognized that application of recent continuous loading technology could potentially result in significant unit cost savings and productivity increases.A review of the technology resulted in the testing of the Voest Alpine AL60 loader in the open stopes located on the 1000m Le vel. Testing began in January 1988 and finished in late November 1988. The test will provide experience as well as quantified production and maintenenace parameters f or the purpose of quantifying production unit costs and system productivity, ultimately resulting in a decision to further utilize or not utilize the loader as a primarymucking unit at Brunswick .INTRODUCTIONBrunswick Mining and Smelting Corporation Ltd. produces approximately 10500 tonnes per day from the No. 12Mine located 35 km southwest of Bathurst, New Brunswick Mining is the largest (single mine) producer of zinc in the world having mined over 52 million tonnes since 1964. Many years of production still remain with proven and probable reserves in excess of 90 million tonnes. Reserves grade at an average of 3.65% Pb. 8.99070 Zn, 99g/mt Ag and 0.32% Cu . The operation employs 1446 people with approximately 800underground including operations and maintenance staff.In the No. 12 Mine two major mining methods are presently utilized . The primary method is Mechanized Cut and Fill (MCF) accounting for approximately 6500 tonnes per day from four major areas. The remaining 4000 tonnes per day is produced from open stopes with the majority of 2800 tonnes per day being produced by the 1000 level.The 1000Level contains 30 million tonnes segmented into open stope blocks 30 m high, 15m and 30 m on strike , with a transverse width of 10m to 50 m (Fig. I). Stopes are organized on a primary secondary stope arrangement along strike. Primary stopes are undercut and overcut full size with the back fully cablebolted. All stope and lateral development is driven 4.0 m high. All stopes to date are flat bottom (Fig. 2). Primary stopes are filled with cemented rock- fill , secondaries with conventional rockfill, Haulage from the stopes is primarily with 8-yard LHD units ; mucking is approximately 50% conventional and 50% remote. Haul distance to date has averaged approximately 150m with current stope haul distances of approximately 300m. Haulage is presently to a small jaw crusher situated on the 1000 Level. From August 1989on, haulage will be to a set of ore passes feeding to a large gyratory crusher situated on the 1200 Level. Start up of the gyratory crusher corresponds to an increase in tonnage from 1000 Level to 4100 tonnes per day."

Jan 1, 1989

By A. Duerksen

"Surface coal mining in West Virginia has supplied energy to the eastern coast of the United States for over a century. Over the years, the coal mining industry has been forced to adapt as societal demands regarding health, safety, and environmental impacts have changed. More recent pressure has called for another iteration of change: long-term post-mining sustainability. The research discussed in this paper investigates one potential solution - or component of a solution - to improve the sustainability of surface coal mining in West Virginia: post-mining wind power. The paper begins with an introduction to the Appalachian region of the U.S. and the role that mining has played in its history, followed by a discussion of the need for sustainable mining and how post-mining wind power may help fulfill it. Data processing methodology of field data from monitoring locations is then explained. The results are then used to estimate the electrical output of a wind turbine. This data is then utilized in a case study discussion of one of the monitored sites. The paper concludes with an analysis of the broader implications of the research and a discussion of future work."

Jan 1, 2011

By R. Abela

Heavy mineral sands are usually beneficiated in a spiral concentrator circuit prior to separation of heavy minerals into streams of zircon, rutile and ilmenite. The performance of the spiral concentrators is heavily affected by the presence of slimes in the rougher feed. The paper quantifies the effect of slimes content and discusses the beneficial effect of spiral feed de-sliming. The net effect of inefficient slimes removal can cause significant recovery losses of the heavy minerals present in the feed.

Jan 1, 2003