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By Tristan H. Jones

Beginning in 1987, miniature dataloggers approved by the Mine Safety and Health Administration (MSHA) were publicly available for sale. The principal among these was the model CR21XQM, manufactured by Campbell Scientific, Inc. These dataloggers had been tested and were deemed permissible by MSHA and thus could be installed in the return air of an underground coal mine. In 1996, production of all permissible Campbell Scientific dataloggers ceased due to lack of sales. Data collection with these dataloggers has been a staple of ground control research in the United States for decades, and, without them, or a replacement, the capability to monitor ground behavior is severely impacted. Since that time, any party requiring a permissible datalogger has needed to borrow one that was purchased during the production years. In order to fill this technology gap and ensure its own data-gathering capabilities, the National Institute for Occupational Safety and Health (NIOSH) has developed and refined its own miniature data acquisition system (MIDAS). On February 16, 2010, MSHA deemed the MIDAS to be permissible and approved it for use in the return air of an underground coal mine. The MIDAS is an intrinsically safe, 16- or 24-bit datalogger, compatible with a wide range of resistive, single-ended, and differential-type instrumentation. It contains enough data storage memory to operate for over a year with typical data rates and is efficient enough to do this on a single C-sized alkaline battery for that entire period. It is menu-driven and requires no programming knowledge to operate. It supports wireless or hardwired communication for datalogger setup and data download. This paper describes the design, field and laboratory testing, and capabilities of the MIDAS datalogger. While not as fully -functioned as the CR21XQM, it is the only new permissible datalogger available, and there is intent to make it available to the mining industry for purchase.

Jan 1, 2012

By L. Echeverri

Research studies have shown that the flow within feedwells displays a vortical structure and high velocities at the locations where standard tangential inlets force its way into the feedwell swirling flow, producing high local shear rates and flow non-uniformities. These hydraulic deficiencies can be attributed to the discrete feeding through a few entrances, usually one or no more than a few tangential feedpipes, which practically project jets into the vortex within the feedwell. The main consequences are unequal flocculation with aggregates subjected to different amounts of shear and a non-uniform discharge from the feedwell. This paper presents results on the application of CFD and small-scale models to develop a new design that overcomes these problems by using an involute shaped inlet that converges around the feedwell. The result is a new feedwell with enhanced hydraulics that perfectly couples with the FLSmidth E-Duc® Feed Dilution system by protecting the flocculated aggregates that have been carefully produced upstream, and that favors uniform sedimentation conditions within the thickener thanks to a uniform discharge, while maintaining a practical and trouble-free geometry with excellent turndown.

Jan 1, 2012

By Robin J. Hickson

El Abra is one of the world’s premier copper de-posits. The project is located in northern Chile, 140 km (87 miles) inland from the Pacific coast. It has the same geologic age and structural setting as the world-class Chuquicamata copper mine located 42 km (26 miles) to the south. The current development plan for El Abra extracts798 Mt (879 million st) of high-quality oxide ore. This will require building a solvent extraction/electrowinning(SX/EW) facility that can produce 225 kt/a (248,000stpy) of cathode copper. This will make El Abra the largest SX/EW copper operation in the world, and the world’s seventh-largest copper producer.

Jan 1, 1996

By W. M. Shaver, W. R. Dengler, F. A. Edwards

INTRODUCTION The Macassa Division of Lac Minerals Ltd. is a high grade gold mine that has been operating in Kirkland Lake, Ontario for the past 51 years. It produces approximately 120,000 tonnes of ore per year, averaging approximately 18.7 grams per tonne (0.45 ounzes per ton) of gold. Over the years, the ore body has been developed to a point where mining takes place below the 1,220 m (4,000 feet) elevation and 1,830 m (6,000 feet) west of the original shaft. The mine is currently serviced by two surface and two winze shafts. (Figure 1). The ore body extends below the 1,930 m (6,400 feet) Level which is the bottom of the existing mining operation. An ambitious underground exploration program has substantially increased these reserves. Concurrent with the discovery of greater reserves, has been rapidly escalating mining costs, particularly labour which constituted 66% of the total cost in 1981. These costs continued to escalate as the major proportion of mining was carried out to the west, far away from the existing hoisting systems. This required three lift hoisting for men, materials and ore. I n addition to the increased travel time and ore handling expense, increased humidity and temperature and ventilation and compressed air losses have added to the inefficiency of the operations. As a result, studies were initiated in 1980 to assess the future of the Macassa operation.

Jan 1, 1985

By Gerald T. Homce

A system capable of monitoring mine electrical power systems and detecting impending component failure could significantly improve power system safety and reduce unscheduled equipment downtime. Such monitoring would require a method of evaluating electrical parameters, calculated from terminal values, for indications of component deterioration. The U.S. Bureau of Mines has targeted electrical failure of squirrel cage induction motors and examined the use of mathematical models to aid in this evaluation. The initial stage of this work is complete, and has produced polynomial networks called adaptive learning networks (ALN's) that can detect and quantify winding insulation leakage simulated on laboratory motors. In this modeling process, empirical data from laboratory motors were used to select the electrical parameters most significant for assessing motor conditions, and mathematical expressions relating these parameters to simulated deterioration were formed. ALN's developed thus far can process readily measured motor terminal information and quantify power and current levels of laboratory-simulated leakage to within 1% and 3% of full load values, respectively, for motors in the 10- to 150-hp size range. The next stage of this research is validation of these ALN's for actual motor failures; this stage is currently underway, using accelerated life testing of laboratory motors.

Jan 1, 1993

By John Convey

This short paper deals with the subject of research and its relation to productivity. All who have stopped to even think about industrial re-search and its impact on the nation-al economy take for granted that research and development are pre-requisite to increased productivity. It is another matter, however, to identify and properly evaluate the many factors entering into the relationship between the two. Some studies are currently underway in the United States on the subject, but, so far, nothing much in the way of conclusive data has come to light. In Canada, we have not yet even produced any statistical figures on national productivity, although work is now being done on this subject and information will soon be available. The usefulness of being able to measure the benefits of investment in re-search and development in terms of industrial growth or productivity need not be laboured for the benefit of those interested in research management.

Jan 1, 1964

By I. Bock

Selective Blast Mining (SBM) makes use of milli-second sequential blasting technology to separate the valuable reef material from waste rock in the blasting operation at stope faces in the mining of tabular ore bodies such as exist in the gold and platinum mines in South Africa. The waste rock is cast blast to the back of the stoping area, and the reef material is fractured and deposited close to the stope face. Only the reef material is transported to the surface. A simplified economic model is presented to evaluate the economic benefits of SBM. Although premature, in that adequate experimental demonstration of the validity of the model has not yet been possible, the model is presented since it indicates substantial benefits in the case of narrow reef gold mines. It is suggested that many marginal mines should seriously consider SBM. Benefits can also be realised in platinum mines, but a lot more experimental work is necessary to establish cost parameters more reliably. Some practical experience in the use of SBM in the mining of the UG2 reef is presented.

Jan 1, 1998

By Yuemin Zhao, Wenxuan Liu, Maoming Fan, Zhanyuan Long

"Coal is mainly composed of energy-producing elements carbon and hydrogen. In addition to these elements, coal usually contains many other valuable elements, including iron, aluminum, silicon, rare earth elements, lithium, gallium, germanium, vanadium, uranium, titanium, scandium and phosphorus. These coalassociated elements are significantly enriched in coal combustion byproduct fly ash because the majority of the main components, carbon and hydrogen elements, being removed. Table 1 provides the chemical composition range of the main element oxides in 12 Chinese fly ash samples collected from coal power plants located in Northeast China, Northwest China, Southwest China and Southeast China. It can be seen from Table 1 that the major mineral components of different ashes are similar, but the bulk chemistry of different fly ashes may vary due to the changes of ratios of the mineral components in different coals. The major mineral components in various Chinese coal combustion fly ash are silicates, iron oxides and unburned carbon.Chinese coal fly ash usually contains about 5 to 15 percent of unburned carbon, which are generally chars with irregular shapes and wide particle size distribution. In addition to unburned carbon, XRD analysis of four Chinese fly ash samples from Liaoning, Shanxi, Guizhou and Shandong provinces indicates that the fly ash samples are composed of minerals such as quartz (SiO2), mullite (3Al2O3.2SiO2 or 2Al2O3.SiO2), hematite (Fe2O3), maghemite (gamma form of hematite, ?-Fe2O3) and magnetite (Fe3O4). The mullite and quartz particles are usually present as spherical particles because they are formed by melting clays, feldspars, quartz, calcite and other common minerals in coal during coal combustion. The silicate particles have usually entrapped gas to yield hollow spherical particles because their lower melting point facilitates gas entrapment.The iron oxides are usually spherical also. The magnetite (Fe3O4) is derived from pyrite (FeS2), hematite (Fe2O3), siderite (FeCO3) and limonite (2Fe2O3.3H2O) in the coal. Maghemite (?-Fe2O3) is formed by dehydration of the mineral hydrohematite (?-FeO(OH)) and/or oxidation of magnetite (Fe3O4) during coal combustion. Maghemite (?-Fe2O3) and magnetite (Fe3O4) are strongly magnetic, so they are recovered from Chinese coal fly ash and widely used for coal processing in China (Fan et al., 2005, 2000)."

Jan 3, 2018

By Daniel Ng

The U.S. Bureau of Mines-Michigan Technological University mine ventilation mainframe program was successfully adapted for execution in a personal computer (PC). The hardware requirement can be as modest as 256 kilobytes (33) of random access memory (RM) and two floppy disk drives. A version compiled for a PC possessing 512 Kb RAM has arrays dimensioned to accommodate 512 separate mine airways and junctions, and it contains all the features and capabilities of the original version. It has successfully analyzed all the ventilation networks tested, including a very large commercial mine (404 airways, 237 junctions, and 5 fans). In all cases the PC version produced practically identical results as obtained from the mainframe computer. In all respects, the PC version performed the same as the mainframe version with the exception of execution speed When a numerical coprocessor is employed, execution time can be reduced by more than 50%.

Jan 1, 1989

By K. Drescher

Excavations in deep level hard rock mines show rheological or time-dependent deformation responses to mining-induced stresses. These are generally not as dramatic as those seen in soft rock environments, such as potash and salt mines, but these deformations can nevertheless become substantial in time. It is usual to see total excavation closure at a much earlier stage than predicted by numerical models, and real-time measurements underground have confirmed that closure takes place on a more-or-less continuous basis, with highest closure rates observed after a blast and then slowly diminishing with passing time. This paper describes laboratory tests to determine the time-dependent response of hard rocks to loading, the results of the tests, and then quantifies these effects to explain the time-dependent phenomena observed underground. The primary intention of this work is to help explain the various time-dependent deformation processes around typical deep level hard rock tabular excavations. Three mechanisms were investigated in two typical hard rock types present in the deep level gold mines in South Africa, namely Ventersdorp Lava and Elsburg Quartzite. Uniaxial compression creep studies were done as the first part of the study followed by shear creep studies on discontinuities where crushed lava and crushed quartzite as well as a natural gouge were used as infilling. The last part of the study consisted of triaxial post-failure relaxation tests. The compression creep tests and the triaxial post-failure relaxation tests showed that the amount of energy dissipated by the lava is significantly less than for quartzite. For mines operating at depths greater than 2000 m the implication is that the lava must show a greater rockburst-proneness than the quartzite. Since the lava shows a lower post-failure stress relaxation, it can store sufficient energy for multiple rockbursts, which is seen in the clustering of multiple seismic events in the deep level mines. This study provides the first data available for energy change calculations in fractured rock masses, and provides the first general indications for rockburst intensities ahead of active mining faces.

Jan 1, 2003

By Dimitri Frantzos, Stewart Thompson, Ed Skiba, Hans Tammemagi

On behalf of Acres International we would like to thank Frank Chiappetta of Blasting Analysis International for inviting our organization to participate in this state-of-the-art course on blasting analysis techniques.

Jan 1, 1989

By J. G. Ross

IN the paper entitled Block Caving at the King Mine (1), which was presented at the Annual General Meeting held in April, 1934, at Quebec, it was pointed out that, owing to certain conditions and financial restrictions, it was advisable to provide a temporary shaft. This was raised from the )00-ft. level to the bottom of the pit, and a 45-degree incline track was constructed up the face of the pit to surface. The temporary shaft and incline were within the ore-body, but were to be used only until such time as the new shaft-the subject of this paper-could be sunk and made ready for operation. After a careful study had been made of all available information pertaining to the ore-body, including examination of diamond-drill core records and geological data, a shaft location was selected well outside the ore-body. Further, since the crusher and dryer buildings are located over part of the ore-body, it was necessary to plan the removal of these buildings and to construct a new crushing and drying plant. This, and the new shaft, must operate in conjunction with the present mill and rock storage bin, which would continue robe used as formerly. No part of this programme, with the exception of drifting toward the shaft site, was started prior to 1937. More than usual detail on technical features is given in this paper in the hope that some parts of it may be of assistance to other members of the Institute who have to undertake somewhat similar work. The engineering and operating staff designed and supervised the work, while at the same time carrying on regular production in four mines at the rate of 12,000 tons of rock mined per day, the output at the King mine being at the rate of 140 tons per hour. No additional engineers were required.

Jan 1, 1939

During the period 1979 thru 1982. Multi Mineral Corporation conducted a mining research program at the United StAtes Department of the Interior's Bureau vi Mines Oil Shale Mining Environmental Research Facility in the Central Piceance Creek Basin, Rio Blanco County, Colorado. The program consisted of mining, environmental and geotechnical research data and. the results are described in this report.

Jan 1, 1983

By James R. Boyle

The value of Alabama's nonfuel mineral production in 1986 was $405.2 million, a slight decrease from that of 1985. Alabama was second in the Nation in production of bauxite, crushed marble, and ferroalloys; third b fire clay; fifth in masonry cement and lime; sixth in total clays; and seventh in recovered sulfur. Alabama ranked 19th nationally in value of nonfuel minerals produced. Cement, clays, lime, sand and gravel, and stone were the major commodities produced.

Jan 1, 1988

By J. Armanet

THREE MINING colleges are maintained in France; the École Nationale Supérieure des Mines, of Paris; École Nationale Supérieure des Mines, of Saint Etienne; and the École Supérieure de la Metallurgie et des Mines at Nancy. Besides graduates of these schools, a few graduates of the École Centrale des Arts et MIanufactures and of the École Polytechnique are employed as ]nine managers or engineers; however, most of the latter have taken a graduate course at one of the mining schools.

Jan 1, 1939

By Larry Stearns, Lori Tiefenthaler

Remediation of contaminated soil represents a significant market for application of Deep Soil Mixing (DSM). Eighty-one percent of U.S. Environmental Protection Agency (EPA) Superfund Program’s site remedies have involved contaminated soil. Contaminated soil is frequently treated by In-situ Solidification/Stabilization (ISS). ISS treatment of contaminated soil involves mixing binding agents into soil using DSM techniques. DSM is a core business for many DFI members. Members may improve and broaden their services to clients by learning about the recent ISS treatment of contaminated soil at a Superfund site. ISS treatment is part of the EPA-selected remedy for a Superfund Site in the metro New York City area. The property has seen heavy industrial use for more than a century. Soil at the site is contaminated with a variety of volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs) including coal tars and heavy metals, principally arsenic and lead. Beginning in 2017 and continuing through 2018, approximately 150,000 cubic yards (115,000 cubic meters) of soil will be treated by ISS at the case study site. Portland cement and slag cement are mixed into the soil by DSM techniques using GPS guided excavators to immobilize the hazardous constituents within the treated soil. ISS treatment by DSM will contribute to redevelopment of this valuable property. This paper will describe ISS constructability and performance, case study grout mix design with geotechnical results for strength and permeability, and deep soil mixing techniques. INTRODUCTION In-situ solidification and stabilization (ISS) is a deep soil mixing (DSM) technique applied in the environmental remediation field to physically encapsulate, or chemically bind, contaminates of concern such that the impacts to human health and the environment are mitigated. Common remediation applications of ISS include mixing cementitious reagents into contaminated soils to form a monolithic mass with desired performance characteristics, and the installation of vertical subsurface walls designed to control groundwater movement. A key characteristic of ISS is that the contaminated soils are treated in their existing location at the project site and then are left in place after treatment. Typical performance characteristics of the ISS treated soils include improved unconfined compressive strength (UCS), reduced hydraulic conductivity (HC), and reduced leaching potential of soil contaminants. Increased shear resistance of the treated soil may also be a performance requirement where seismic loading is a concern.

Jan 1, 2018

By D. O. Kennedy

"INTRODUCTION During the recent war attention was directed to prevent the destruction of American industries by sabotage. By Executive order of Lay 19, 1942, the Bureau of Mines was required to conduct investigations and make recommendations that would prevent loss of production of essential war minerals. The Health and Safety Branch of the Bureau of Lines was able to extend its activities with minimum loss of time to include security surveys of the important mineral facilities in the United States.A Mineral Production Security Division was established in the Health and Safety Branch with funds appropriated for that purpose by Congress in April 1942. From July 1942 to July 1945 engineers of this division, under the direction of D. Harrington, Chief, Health and Safety Branch, and J. J. Forbes, Chief, Mineral Production and Security Division, conducted investigations of 1,560 metallic and nonmetallic mines and associated facilities in accordance with the requirements of the Executive order.PURPOSEAn analysis of losses in the production of minerals shows that failure or destruction of equipment either from deliberate or accidental causes produces essentially the same result. Maximum production is insured by the prevention of subversive activities, fires, and industrial accidents."

Sep 1, 1946

By J K. Wright

In recent years the production of steel from directly reduced iron ore pellets has expanded rapidly. However, continued growth will depend on an adequate supply of suitable raw materials for the various commercial gaseous and solid reductant processes now in operation. Although at present Australia does not produce pellets primarily for direct reduction, there is an increasing awareness of Australia's potential role as a supplier of high grade ores for export and/or domestic use. The properties and quality requirements of iron ore pellets made specifically for direct reduction (DR) are reviewed and the laboratory techniques and test methods used at the CSIRO Division of Process Technology for the evaluation of potential DR feedstocks are described. At the present time most of the evaluation tests for DR pellets are extensions of those designed for existing blast furnace (BF) burdens. In the case of some physical parameters such as cold compression strength, abrasion index and cold strength after reduction this extension is quite satisfactory. In the measurement of parameters such as reducibility, swelling and sticking tendency, however, it is necessary to develop meaningful standardized tests so that ores and pellets can be ranked for DR performance. To do this, data from the laboratory tests and from operating plants must be correlated.

Jan 1, 1980

By S. C. Langvik

The presentation named 'Dewatering of fines by Rotary Vacuum Disc Filters' has an opening why the filtration process is important to the Iron Ore Industry. It goes on to describe the various types of dewatering machines which have been used in this industry in the last 30-40 years, and where the vacuum disc filters now dominates. It presents also the most important design changes which have been made during this period to enhance performance. Further are discussed the principles of filtration and the factors and parameters which influence performance and operating costs. As a closing is presented today's ideas and thoughts about what can be foreseen of design modifications and improvements in disc filter design in the coming ten years.

Jan 1, 2001

By Joseph Poplawski, Christian O’Keefe, Robert Maron

"Unique and difficult minerals processing measurement situations will be described and the application of passive array-based technology for performing these measurements will be illustrated. Examples of these situations include volume flow measurements in froth lines and flotation feed lines with entrained air, slurry lines with magnetite and other magnetic ore, slurry lines with abrasive or corrosive materials, high pressure lines, and slurry and non-slurry lines exhibiting scale buildup. Other situations include measurement of entrained air levels in pipes and in flotation columns. These measurements are achieved through CiDRA’s patented passive sonar array-based technology. This technology performs two independent measurements – flow rate and entrained air amounts. Two hardware implementations of this technology have resulted in a non-intrusive flow and entrained air meter which easily is installed on the outside of the pipe, and a submersible version for entrained air or gas holdup measurements which is used in flotation processes. Recent developments in extending this technology to solve other unique measurement problems such as valve movement confirmation will be covered.INTRODUCTIONThe minerals processing industry faces many unique and challenging process control conditions and environments. In terms of flow measurements, many of these situations are not being properly served by traditional flowmeters such as ultrasonic meters, magmeters, turbine meters, orifice plate meters, vortex flow meters, Coriolis flow meters, and venturi meters. A new class of flowmeters has been developed that solves these unique situations and flow measurement problems. This new class of flowmeter technology utilizes sonar-based processing algorithms and an array of passive sensors to measure not only flow, but also fluid composition. It does so accurately, reliably and without making contact with the fluid. These measurements are performed on practically any type of fluid within virtually any type of pipe.PRINCIPLE OF OPERATIONSonar array-based flowmeters are ideal for tracking and measuring the mean velocities of disturbances traveling in the axial direction of a pipe. These disturbances generally will convect with the flow, propagate in the pipe walls, or propagate in the fluid or slurry. First let us focus on the disturbances that convect with the flow. The disturbances that convect with the flow can be density variations, temperature variations or turbulent eddies. The overwhelming majority of industrial flows will have turbulent eddies convecting with the flow, thus providing an excellent means of measuring the flow rate as described below."

Jan 1, 2008