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By J. A. Stewart

"A common problem in the mining industry involves the overloading of established conveyor systems. This overloading can have a number of causes, such as new production technology or a changing market condition which increases demand. An overloaded system usually spells disaster and leads to clean-up problems, equipment failures and lost production. The Cape Breton Development Corporation's Lingan Mine had a serious overloading situation on its underground coal clearance system, and equipment was being damaged and production was being lost. It was rectified, in part, by increasing the coal clearance capacity through the use of booster conveyors. This paper discusses the problems which led to this situation, the booster concept and the installation of the first unit at the Lingan Mine.IntroductionThe Lingan Mine is a submarine coal mining operation with an annual production of 1.5 million tonnes from three advancing longwalls. Coal is conveyed 3400m up a 13% slope to the surface. Designed and installed in the early 1970s, the system's 820-tonne/hour design initially proved adequate; however, by the late 1970sthe system was handling surge loads of 1640 tonnes per hour due to the introduction of new face equipment.The coal clearance system consisted of three 485-Kw, two 210-Kw and one 105-Kw conveyors. Each conveyor was designed for 820 tonnes per hour using 1050-mm, Type 10 belt with a 35-degree troughing profile.There were many effects of the overloading on the system:• Loading beyond the physical capacity of the belt resulted in spillage along the conveyor, which increased operational and maintenance costs.• Overloading of the drive components resulted in premature equipment failures.• Spillage at the drive pulley often resulted in damage to the belt and pulley lagging and, under extreme conditions, the conveyor would require partial unloading before it would operate. This was a particular problem under wet conditions because the 485-Kw conveyor drives were fitted with single-drive drums."

Jan 1, 1982

By Michael B. Cortie

Mesoporous gold sponge has the unique property of being both metallic and highly resistant to oxidation. It has potential application in catalysis, in bio-sensors, in optical coatings, in analytical chemistry and, as we show here, as the basis for a new kind of ultra-capacitor. Due to the cost of gold, the most probable niche for a gold-based ultra-capacitor would be in the high-power/high-energy regime, a region where gold would compete with devices based on RuO2. A high internal resistance limits the power that can be usefully drawn from existing carbon-based ultra-capacitors, and that this problem can potentially be overcome by gold-based devices. A simple proof-of-concept ultra-capacitor based on mesoporous gold is described and its behaviour during charge and discharge cycles examined. In this work a step change in the input or output voltage of the device was used as the controlling parameter. There was also a residual faradaic current resulting from traces of undissolved aluminium left over from the AuAl2 precursor used to make the sponge, and some charge storage due to polarization of the solution. Deconvolution of these three effects was not entirely accomplished, but an ostensible capacitance of about 7 to 14 mF/g Au was demonstrated. Further improvement from these early results seems likely.

Oct 1, 2003

By Mark N. Savit

It is indeed a rarity for a non-engineer, let alone a lawyer, to even be considered for a mining-related award, especially where that award is for significant contributions to technical progress in the mining and exploration sectors. So, when I was notified that I had received this award, I struggled for a topic that would meld the legal world that I operate in with the engineering driven world of exploration and extraction. The most exciting part of my job has always been the opportunity to absorb the technical details of the cases I work on and, in effect, translate them for a lay audience. Too often, I have found, lawyers, judges, legislators and yes, even regulators who lack a technical background simply give up trying to understand the details of the very conditions or processes that they are trying to describe and simply repeat phrases told to them by their client or by a retained expert.

Jan 1, 2008

By Roy A. Bell

A 200-foot diameter, 72-foot high petroleum storage tank was built in a hillside ravine where a portion of the site contained soft clay fill. Soil-cement piles, 40 inches in diameter and up to 38 feet long, were installed to support the tank shell and ringwall, and a portion of the tank floor by drilling into the stiff to hard underlying soils and weathered bedrock. The goal was to provide a strong enough foundation to resist the seismic tank shell loading and to minimize differential settlement of the tank shell to avoid out-of-round clearance problems between the shell and floating-roof. A cantilevered retaining wall up to 8 feet high was constructed around a portion of the tank perimeter by inserting steel H-beams into soil-cement piles. The cantilever soldier piles for the retaining wall were installed from a temporary earth embankment on the hillside directly over the top of the wall. The temporary embankment was then removed and the tank pad was cut to grade in front of the soldier piles. Some of the soil-cement piles for both the tank foundation and retaining wall could not be advanced to design depth because the drill/mixing tools could not penetrate to the required depth in the hard soils/bedrock. Smaller diameter borings (22 inches in diameter) were drilled through the centers of the short-of-design soil-cement piles to the design depth and then backfilled with concrete.

Jan 1, 1997

By Brian Khalighi, Massimo Franceschi, Giovanni Giacomin, Gianni Porta

Headrace Tunnels and parts of the Access Adit Tunnels of Kárahnjúkar Hydropower project, KAR-14, in Iceland will be excavated using three full-face Robbins Tunnel Boring Machines (TBM). TBM sizes range from 7.23 to 7.63 meters in diameter and the total headrace tunnel length is approximately 40 km. The crushed rock is transported on conveyor belts to disposal areas near each Adit. The estimated average excavation rate is approximately 25 meters per day per machine. Electricity will begin to flow in April 2007, and the project is scheduled for completion in 2009. This paper is divided into four sections. In the PROJECT OVERVIEW section, a short overview of the scope of the project is presented. In the GEOLOGY section, the geological condition along the tunnel drives is briefly introduced. The TBM DESIGN section discusses the various design criteria and the resulting machine specifications. The paper concludes in the TBM OPERATION section with a case history describing the tunneling operation from start-up to the time of the writing of this paper.

Jan 1, 2005

By Matthias Pulsfort, Markus Herten, Rolf Breitenbücher, Claudia Fierenkothen

"Secant bored pile walls are frequently used as retaining walls in watertight excavations to cut off ground water aquifers and are subsequently exposed to ground water pressure loading in addition to earth pressure loads. To avoid extra loading from ground water pressure in soils with limited permeability, it can be useful to arrange drainage windows within secant bored pile walls by means of single primary piles filled with porous concrete without reinforcement cages, which usually have to be placed within casings in submerged conditions. This concrete may serve as a horizontal arch between the reinforced secondary piles, but it must however enable vertical draining between load carrying construction beams and the bottom of the excavated pit. In the present submission, the results of several material tests with different mix designs of porous concrete with certain admixtures are presented together with first and important experiences with a wellsuited placement technique for porous concrete casings in small- and large-scale laboratory tests. It can be shown that the usual placement technique of employing a tremie pipe is not suited for this type of unsaturated concrete. Instead, pouring with a particular kind of cone and an open conductor pipe has proven successful.Additionally, special testing methods are currently developed for judging the suitability of the desired concrete mix design in preparation for an upcoming real-scale experimental pile installation in Germany.1. INTRODUCTIONRetaining walls are often built as secant bored pile walls in order to cut off aquifers saturated with groundwater against deep building pits. In soil types with relatively low permeability, however, seepage flow may be permitted, because the quantity of groundwater to be pumped is limited, and the range of influence due to dewatering is not reaching far. Thus, the hydrostatic water pressure on the retaining wall can be considerably reduced, leading to a more economic design (see Fig. 1).In unsaturated soils, the dewatering effect can be achieved by means of porous pervious concrete with a uniform grainsize distribution of aggregates typically placed in a borehole under dry conditions. With regard to the use of porous concrete to be placed at the ground surface in road pavement applications, experience is sufficiently available as shown, for instance, by Neithalath et el. (2010). However placing the porous concrete in a bored pile using a tremie pipe under submerged conditions is a challenge and a completely new approach, because there is a considerable risk of segregation of the fresh concrete, separating the cement lime paste from the aggregates when in contact with water and leaving only neat gravel on the one hand as well as a tight cemented area at the bottom of the pile on the other hand. If this concrete placement is successful, additional dewatering by means of extra wells behind the retaining wall can be avoided. Of course the seepage flow in the adjacent soil needs to be regarded seriously."

Jan 1, 2017

By Theo. A. Link

ACCORDING to our office dictionary, geology is "the science that investigates the structure of the earth and its successive physical changes", and a geologist is "one who knows the science of the structure of the earth". No doubt this definition does not suit all of us. Another dictionary would have the definition slightly different. As an example, one dictionary stated that "a geologist is one who practices geology". (Some of our clients told us to quit practising and get to work). There are many different types of geologists engaged in various branches of the profession and some of these are further broken down into subdivisions so that specialization is becoming more and more prevalent. As a result it is, in some cases, doubtful whether or not we are actually dealing with a geologist in the generally accepted sense of the term.

Jan 1, 1956

By Bern Klein

Motivation for Improved Energy Efficiency in Mining ? Canada potentially adopting Greenhouse Gas Emissions and Intensity Legislation in 2013 ? BC -Climate Action Plan and Energy Conservation Agreement in 2008 ? BC Energy Plan 2007 -BC Hydro is mandated to save 50% of new load growth ? TSM Initiative -Energy Management, Energy Reporting, Setting Energy Targets, GHG Management BC MOU for Energy Conservation Agreement -MEMPR, MABC, BC Hydro

May 1, 2010

By G. H. Sedahmed, S. A. Nosier, M. H. Abdel-Aziz, A. A. Mubarak, M. A. El-Naggar, E. G. Abdel-Aziz

The performance of a rotating fixed bed reactor in recovering copper from industrial waste solutions by cementation is studied under various conditions. The rotating fixed bed is made of stacked woven steel screens to take advantage of two features of screens: the ability to present large area per unit volume and their ability to promote high turbulence. Variables studied are initial CuSO4 concentration, bed rotation speed, mesh number of the screens and bed thickness. The presence of baffles was found to increase the rate of cementation. The data were correlated by a dimensionless mass transfer correlation suitable for the design and operation of large scale cementation reactors.

By G. H. Sedahmed, S. A. Nosier, M. H. Abdel-Aziz, A. A. Mubarak, M. A. El-Naggar, E. G. Abdel-Aziz

The performance of a rotating fixed bed reactor in recovering copper from industrial waste solutions by cementation is studied under various conditions. The rotating fixed bed is made of stacked woven steel screens to take advantage of two features of screens: the ability to present large area per unit volume and their ability to promote high turbulence. Variables studied are initial CuSO4 concentration, bed rotation speed, mesh number of the screens and bed thickness. The presence of baffles was found to increase the rate of cementation. The data were correlated by a dimensionless mass transfer correlation suitable for the design and operation of large scale cementation reactors.

By Jennifer Riefenberg

Ground control hazards, coal quality, ore reserve estimation, and pollution modeling seem unrelated topics from most mining perspectives. However, geostatistical methods can be used to characterize each of these, and more topics. Exploratory drill core data, and continued drilling and field measurements, can provide a wealth of information related to each of the above areas and are often severely underutilized. Recent studies have led to the development of the Multiple Parameter Mapping (MPM) technology, which utilizes geostatistics and other numerical modeling methods, to generate a "hazard index" map, often from exploratory drill core data. This mapping has been presented for ground control hazards relating roof quality, floor quality, numerically modelled stresses due to mining geometry, and geologic features. A review of the MPM method, future directions with the MPM, and a discussion of using these and other geostatistical methods to quantify coal quality, ore reserve estimation, and pollutant modeling are presented in this paper.

Jan 1, 1996

By Mike Neill, O&apos

? Bypass soft soils near the surface ? Resist uplift loads ? Resist lateral loads ? Bypass scourable soils ? Bypass liquefyable soils ? Mitigate movement of expansive or frozen soils ? "Tune" foundations for vibrating machinery

Jan 1, 1998

By R. Q. Shotts

Factors of geological structure and occurrence of coalbeds, plus the resulting mining conditions, have required more care in preparing coals in Alabama than in most other districts almost since mining Alabama coals began. For this reason, literature on these coals may be interesting to those in areas where prime coals have been mined out, and thinner and less regular beds must now be exploited. This literature review has been arranged in order of subject matter. Some references have been listed more than once, but each separate review is limited to the material pertaining to the subject matter being discussed. For those seeking specific information, the authors have indicated which items repeat material and which items are most complete or specific. Geology, preparation, and carbonization of coal have been reviewed the most frequently.

Jan 1, 1963

By Carl Hendricks

Aquila Mining Systems Ltd., is the world leader in drill monitoring, control and GPS-based machine navigation systems for the mining industry. This paper will review the design and application of AQUILA’s drill monitoring, control and positioning systems currently in use throughout the world and some of the benefits that derive through their use. In 1993, AQUILA became the first company to install a high precision, cm level, real-time GPS receiver on a blasthole drill. In fact, this was likely the first application of GPS on any form of production mining equipment. To date, AQUILA has installed over 90 GPS based drill monitoring systems worldwide. Since 1992 AQUILA has continued to lead in the advancement of new technologies for drilling including real-time geology recognition and automated drilling control systems. The AQUILA DMseries drill systems offer mines the ability to collect and transmit to the mine office; drill production statistics, ore and waste intersections, exact collar elevations, hole positions and depths, maintenance information and consumables tracking. Unique office software developed by AQUILA provides an encompassing Windows environment within which to manage and coordinate all aspects of data communications and information management between the drills and various mine departments. AQUILA and Caterpillar, along with Mincom and Trimble Navigation are partners in a technology alliance that is providing the surface mining industry with vehicle tracking and navigation systems for all mobile production equipment.

Jan 1, 2000

By W. Vorster

Bateman Engineering Project's acid-plant track record goes back to 1977. Bateman Engineering can design sulphuric plants based on gas from sulphur burners, metallurgical off gas as well as pyrite roasting systems. Bateman Engineering has a technology marketing agreement with NORAM Engineering Ltd of Canada to provide state-of-the-art, well-proven acid plant technology, and also has access to roaster technology from several sources, including Chinese technology. Utilising the Noram technology agreement, Bateman was awarded the Engineering and Procurement (EP) contract for the Ambatovy Nickel Project, Sulphuric Acid Facilities in 2007. This is the first Greenfield sulphuric acid plant Bateman has designed for many years, producing a combined 5,500tpd, and is one of the largest sulphur burning acid plants in the world. This paper gives an overview of the sulphuric acid plant for the Ambatovy Nickel Project, advantages of Noram?s unique technology on offer, an overview of work conducted on a recent study of an pyrite roasting acid plants as well as a new technology currently being developed by Bateman for the direct combustion of solid sulphur to form sulphur dioxide.

Jan 1, 2009

By E. T. C. Spooner, Ioannou S. E.

"Abstract- The Dixie Zone Au-Ag deposit is a low sulfidation (adularia-sericite) epithermal system located 1.4 km from the producing Ken Snyder mine (7.0 M oz Au equivalent reserve/resource), Midas Mining District, north-central Nevada. This WNW striking, steep south dipping, fault system is hosted by mid-Miocene (17 Ma to 14 Ma) felsic volcanic rocks that were erupted from a vent(s) to the northeast. The system was mineralized by approximately 250 ± 20°C (n = 86), near-neutral pH, ascending fluids of predominantly meteoric origin [volatile corrected salinity = 0.52 ± 0.35 eq.wt% NaCl (n = 86)]. Bulk analytical fluid inclusion gas chromatography identified a mineralizing fluid volatile composition of 99.68 ± 0.18 mole % H2O, 0.16 ± 0.09 mole % CO2, 0.11 ± 0.05 mole percent N2, 0.05 ± 0.04 mole % CH4, and 0.01 ± 0.01 mole % CnHn+i (n = 7). Sulfur species were not analyzed due to absorption within the chromatography system; however, a H2S concentration of 16 ppm to 160 ppm molar is estimated. The volatile content contributes approximately 50% of the microthermometrically measured freezing point depression. Cl- concentrations up to approximately 9000 ppm suggest an additional, probably magmatic, fluid component.Ascending fluids were channelled along approximately NW striking faults related to the same primary extension (17 Ma to 14 Ma) responsible for Nevada basin and range physiography. Boiling induced by CO2 effervescence led to precipitation of Au and Ag over a 150 m vertical interval. At the time, this interval was about 460 m below the water table (approximately 38 bars), but because of erosion, it is now within 90 m of the surface. A Ag:Au ratio of 25:1 has been calculated for the Dixie Zone."

Jan 1, 2000

By Wilhelm Knickmeyer, Johannes Henneke

PREFACE For about 1 year Bergbau-Forschung GmbH, central research institute of the German Coal Mining Industry, undertakes full size tests for waterjet assisted tunnel¬boring in German coal mines (Fig. 1). These tests are performed with a tunnelborer of 2.6 m diam in an upper [ ]

Jan 1, 1979

By Frances H. Clark

DEVELOPMENTS in powder metallurgy have been disappointing in 1943. If any new part has gone into large-scale production, knowledge of it has been restricted by considerations of national security. Nor have any outstanding papers appeared to advance the theory of the subject during this period.

Jan 1, 1944

By Ricardo Gaviria, Vincinte Acosta

There are major blast design and field procedures differences between conventional blasting in horizontally bedded coal seams and blasting underneath coal seams in a multi seam deposit with seam inclinations of 14 degrees or more.

Jan 1, 1995

By Stephen C. Tadolini

The U.S. Bureau of Mines has developed ultrasonic measurement instrumentation capable of measuring strains and elongations on tensioned and untensioned mine roof bolting systems. This report evaluates the pulsed-phase-lock-loop and pulse-echo systems. The pulse-echo systems measure time of flight of a signal through the bolt. The ultrasonic instrument converts the measurement into elongations or stress. The most recent Bureau instrument development converts travel-time measurements directly into elongation, load, stress, and torque by simple data manipulation from the keyboard. Bolt preparation and instrument calibration are described in detail.

Jan 1, 1990