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The contiguous Kotre Basantpur and Pachmo (KBP) coal blocks in the Hazaribagh District of Jharkhand State in east India are being developed by Tata Steel Limited (Tata Steel) to supply coking coal to a new steel mill at Kalinganagar in Orissa.The planning challenges are many. The multiple coal seams range in thickness up to 6 m and extend to nearly 500 m depth, with dips up to 25¦ and highly variable quality. Several normal faults with throws up to 150 m intersect the deposit. There is little room for waste dumping on the lease, several large nalas (seasonal creeks) cross the blocks, and the KBP leases are not contiguous with Tata Steel's existing mining operations at West Bokaro. Geotechnical conditions, while not well defined at this stage, are largely unfavourable. There are several villages on the blocks, and extensive paddy fields. In 2009, Adelaide Mining Consultants Pty Ltd (AMC) completed a Detailed Project Report (DPR) for a production level of 8 Mt/a. A terrace mining system was proposed using 28 m3 hydraulic excavators and 185 t trucks working horizontal up-dip slices. Subsequently the viability of in-pit crushing and conveying was assessed, but the full results were not available for this paper.It is planned to extract a total of 147 Mt of raw coal at a strip ratio of 5.2 bank cubic metres per tonne (bcm/t). The planned maximum pit depth is over 300 m.The project includes a washery, a 2 + 25 MW fluidised bed power station to utilise all the coarse washery rejects, and a railway spur line to carry the washed coal to the railhead some 7 km distant.

Dec 6, 2010

By James M. Spear

The U.S. Bureau of Mines conducted a mineral survey of the Domeland Addition (5207) and Woodpecker (5206) RARE II areas during the summer of 1979. These study areas were examined to determine the presence or absence of mineral resources and reserves and where possible, to estimate values. The study areas are 9 air mi northeast of Kernville, California, and encompass 47,400 acres of primarily granitic rocks of the Sierra Nevada batholith with some scattered exposures of older metasedimentary, volcanic, and metavolcanic rocks. These other rock units partially surround the exposed batholith in the Domeland Wilderness and consist mostly of late Paleozoic quartzites, mica schists, marbles, and meta-volcanics, Mesozoic quartz diorite and gabbro intrusives, and local Tertiary basalt and andesite flows.

Jan 1, 1981

By Hal W. Hunt

Steel and concrete piles and power-actuated hammers have developed almost entirely within the past 100 years. Prior to that time, piles were mostly timber, driven with a drop hammer or a maul. The Engineering News Formula ? for timber piles driven with a drop hammer at a factor of safety of six ? was promulgated by Wellington in 1888. Steel com­panies supplied fabricated and rolled shapes for piles in the early 1900's. The thin shell and then uncased concrete piles originated about that time. Now leads have become sophisticated to accurately spot a pile at any required batter. Hammers have grown to phenomenal size and vibratories are being accepted at full value.

Jan 1, 1984

By M. Hopf

The use of water-cooled copper components as sidewall elements of submerged arc furnaces and other pyrometallurgical applications has become increasingly common. The high cooling efficiency of copper has made it possible to increase the service life of furnace refractories when compared to conventional refractory linings. However, even the self-healing effect of ?freezing? worn areas of the lining does not necessarily protect the copper coolers against wear or corrosion completely. In order to avoid furnace explosions, various methods have been used to monitor the wear of coolers. Unfortunately, these have not been able consistently to identify localized wear. Thos Begbie (South African) and SAVEWAY (German) jointly developed technology to embed a line sensor into the copper cooler during the casting process. This system allows an exhaustive monitoring of the copper cooler. A SAVELINE sensor is placed inside the copper-cooling panel between the water-cooling passage and the hot face of the panel. The sensor follows the meandering shape of the cooling water channels. In the first instance, the sensor provides analogue information as the thickness of the copper reduces. Secondly, this wear signal will be confirmed by a signal of interruption if the sensor is washed away. Because of the structure of the sensor, a self-diagnosis is possible and indications can be confirmed (double proofed).Subsequent to the manufacture of some test pieces, coolers for a large submerged arc furnace were manufactured. The sensorized coolers have been installed at the intermittent surface (slag line) where the largest amount of corrosion has been encountered. The system has been operating since December 2005 in what is considered one of the largest submerged arc furnaces in South Africa. Keywords: Pyrometallurgy, furnace, copper coolers, freeze lining, monitoring, Saveway

Jan 1, 2006

By C. A. Komar

The Bureau of Mines conducted oil-displacement tests in the laboratory with three water-in-oil and five oil-in-water emulsions that were created with ultrasonic energy at a frequency of 20 kHz and an acoustic intensity of approximately 100 watts per cm2. Emulsions of either crude oil or kerosine, brine, and 112 to 2 percent emulsifier were formed during 30 seconds of acoustic irradiation. Results indicate that ultrasonic energy induces greater and more uniform dispersion of one liquid in another in the presence of small amounts of chemi¬cal emulsifiers. When the emulsions were injected as a buffer slug before waterflooding, recovery of the oil-in-place was 8 to 22 percent greater than with conventional waterflooding in the test specimens, regardless of the con¬tinuous phase (oil or brine). The emulsions do not appear to be applicable to the Appalachian area; however, because the oilfields are too "tight," the clays in the formation remove the emulsifier from the displacing fluid, and not enough additional oil is produced, compared with recovery using conventional waterflooding, to warrant the increased operating costs.

Jan 1, 1969

By Qingwei Wang

Heavy metal-containing wastewater from hydrometallurgical processes of lead-zinc was treated by biologics in a 200 m3/h industrial scale experiment. The result shows that Zn concentration declined from 50.28 mg/L~240.81 mg/L to 0.21 mg/L~1.98 mg/L, Pb from 1.00 mg/L~13.47 mg/L to 0.083 mg/L~0.71 mg/L, Cu from 0.24 mg/L~2.38 mg/L to 0.059 mg/L~0.40 mg/L, Cd from 2.12 mg/L~23.47 mg/L to 0.011 mg/L~0.071 mg/L and As from 0.50 mg/L~6.00 mg/L to 0.005 mg/L~0.10 mg/L. The concentrations of the above heavy metals in the treated water were lower than that in Integrated Wastewater Discharge Standard (GB8978~1996) in China. Furthermore, the treated wastewater was recycled and reused in smelter plant. Zinc content in hydrolytic sludge reached up to 34.04%, which indicates that this sludge can be used to recover valuable metals.

Jan 1, 2010

By Bryan Buchholz, N. Kumar Kittusamy

Previous studies indicate that operators of heavy construction equipment are afflicted by musculoskeletal injuries of the arms, shoulders, neck, and lower back. These injuries appear to be due to excessive periods of sitting (static posture), work intensity, whole-body vibration, high resistance levers, repetitive motions, and awkward postures. (2-5) Although numerous studies have shown an association between operation of heavy construction equipment and symptoms of musculoskeletal disorders, very little research has been performed that systematically characterizes operating engineers' exposure to ergonomic hazards. The objective of this study was to systematically characterize the ergonomic hazards associated with excavating operations. As such, the following were performed: (1) vibrations were measured at the operator/seat interface (X, Y, and Z axes), and at the floor of the cab (Z axis); (2) psychophysical ratings of whole-body vibration (WBV) level and overall seat design were obtained; and (3) postural assessments of the job were made. Methodology This study evaluated an inexperienced female operator performing excavation, utilizing two different pieces of equipment. The operator was 37 years old, 162 cm tall, and weighed 80 kg. She had approximately 15 hours of operation time (experience) on the equipment evaluated. The two pieces of equipment used were: a Case Super 580E (1986) backhoe/loader, and an Insley H-2000 excavator (1975) (see Figures 1 and 2). More evaluations were performed on the backhoe/loader than on the excavator. The following evaluations were performed on the Case equipment: 1) vibration levels at the seat and floor; 2) psychophysical ratings of the overall seat design and vibration levels (for the task duration, and for an 8 hour duration); and 3) postural assessments. For the Insley equipment, all of the evaluations were performed except vibration measurements. When the evaluations were conducted, the following environmental conditions were noted: the temperature was 31°F, and soil and terrain conditions were rough and frozen.

By B. P. Watson

Several large falls of ground occur annually in the narrow, tabular stopes mined in the Bushveld Complex. These falls comprise safety risks and cause substantial production losses and compromise efforts to increase productivity. Underground observations in conjunction with instrumentation sites were used to establish the strategic parameters required to describe the rock mass behaviour of shallow-dipping stopes on the Bushveld platinum mines. Existing rock mass rating systems were evaluated using the observations and instrumentation results. None of the current systems adequately described all the relevant geotechnical conditions. Thus a hybrid of several current systems was developed, and the proposed system is discussed in the paper. The new rock mass rating system is termed the ?New Modified Stability Graph? system and follows the method originally described by Mathews et al.1and revised by Hutchinson and Diederichs2.Changes have been made to some of the tables provided by Barton3and to the stress analysis suggested by Hutchinson and Diederichs2. In addition, the logistical regression analysis has been applied to databases, formed using the suggested analyses, for three support resistances and risk levels established.

Jan 1, 2004

By John P. Turner

The behavior of tieback retaining walls depends on many factors, including soil properties, groundwater conditions, construction sequence, spacing and stiffness of tiebacks and soldier piles, tieback loads, and others. The primary design considerations for tieback walls are 1) adequate stability and 2) limiting wall movements. Traditional design methods rely on apparent earth pressure diagrams and experience to predict the forces which must be supported by the tiebacks to provide adequate stability. The required soil properties depend upon whether the soil is sand, soft clay, or stiff clay. Design to limit wall movements is more difficult and the usual approach is to design the wall with an adequate factor of safety for stability and then evaluate wall movements during construction through the use of load tests on individual tiebacks and monitoring of wall movements by optical surveying, slope indicators, and extensometers. If excessive movements are likely to occur, it is often not known until construction is well underway. This approach is reflected in the fact that few tieback walls fail due to a lack of adequate stability, while most litigation involving tieback wall performance is related to excessive movements. Much progress has been made in recent years in methods for predicting the movement of all types of insitu retaining walls (Clough et al. 1989, Clough and O'Rourke 1990). These methods are based upon both experience and analytical methods. This paper reviews the methods currently available for evaluating both the stability and movements of tieback retaining walls. Case histories involving excavations constructed in the downtown Seattle area are used to evaluate the applicability of the available methods to Seattle conditions and to illustrate the importance of soil behavior in tieback wall performance.

Jan 1, 1990

By Eric Nordhausen

This report and associated deliverables is the culmination of a comprehensive literature survey, data collection and identification of over 500 metal/nonmetal active mines/mills/smelters (over 50,000 tons per year, TPY, production) in the contiguous 48 states. The main purpose was to compile an inventory of the mine/ mill/smelter waste tonnages, thus forming a data base for future research and development in improving waste management and waste disposal techniques in the metal/nonmetal mining industry. The study specifically excluded sand and gravel, sulfur, granite and any commodity that leaves basically no waste when mined and/or milled. The coal waste inventory is the subject of another report. The study provided for locating, mapping. encodating and digitizing all the mine/mill/smelter information made available throughout the nation as well as the climatological, land use, topographical, ecological and vegetative data. Mine/mill/smelter information also included (where possible) acreage and/or volume, mining methods, primary ore and gangue minerals, waste composition and haulage methods and distance hauled. Finally, a discussion is provided concerning present and potential uses of various types of tailings, as well 8S recommending possible R&D in addressing problem areas in waste disposal techniques and management.

Jan 1, 1981

By C. Hudson, D. Tremblay, A. Frey

"A discussion of the design, challenges and successes associated with the commissioning of the gravity recovery circuit at Canada’s newest open pit gold mine - Atlantic Gold’s Moose River Consolidated Project in Nova Scotia, Canada is presented. An overview of the project, its historical significance and overall flowsheet is provided with special focus given to the design and selection of the gravity circuit equipment including the scalping screen, gravity concentrators and the novel intensive leaching technology selected for the project. The performance of the gravity circuit is benchmarked against the feasibility study process design specifications and the outcomes are discussed. Challenges encountered during commissioning are also presented, including the use of third-party automation and the effects of screen sizing on overall gravity circuit performance. Mechanical modifications made to the Sepro Leach Reactor for the Moose River project are also discussed. A detailed technical review of the mechanical and operational aspects of the Sepro Leach Reactor is provided with key operational data on leach times, recoveries, reagent usage, solid-liquid separation, pregnant solution quality and its influence on bullion purity.INTRODUCTION Atlantic Gold Corporation’s Moose River Touquoy Mill in Nova Scotia, Canada was commissioned in the fourth quarter of 2017 with commercial production declared in March of 2018. The 2 Mtpa process plant uses a conventional, gravity-CIL process. This site was previously mined in the 1870s. Interest waned in the early 1900s but resumed in the 1930s and the mine was brought back into production in 1935 until an underground mine collapse in 1936. This mining district became famous after CRBC radio commenced a ground breaking, around the clock, broadcast of the rescue operations. Over 100 million people listened to the broadcast from Canada, the United States and the United Kingdom. These broadcasts changed radio, transforming it from a medium for music to on the spot, breaking news reporting. The mill was constructed by Ausenco on a fixed price EPC contract in the historic Moose River gold mining district, 95 km north-east of Halifax by road. The mill will process ore from the adjacent Touquoy pit for the first 5+ years of operation; after the Touquoy reserves are exhausted, the mill will process ore trucked 37 km from the Beaver Dam deposit for an additional 5 years."

Jan 1, 2019

By Jens Classen, Martino Gatti

"GENERAL PROJECT DATAThe Sparvo Tunnel is part of the “Variante di Valico” project, a new 65km (40mi) highway link between Bologna and Florence, designed to renew the existing A1 route which connects Bologna and Florence. It is composed of 2 x 2,5km (1,55mi) twin tunnels excavated inside a complex geological context, characterized by the presence of a series of surface landslides and methane gas.The inclination is 2,6 % and the minimum radius is 1.400m (4.600ft). The two tunnel tubes were excavated by a 15,6m (51ft) diameter EPB-TBM from summer 2011 to summer 2013. The internal diameter of the concrete lining is 13,6m (44,5ft), made up of precast concrete segments 2m (6,5ft) long and 70cm (28”) thick, being the largest and heaviest segments ever produced. Excavation went smooth apart from initial problems concerning clogging problems and a main bearing damage of the TBM, which are discussed in a further paper during the congress. No structural damage was observed until the end of the TBM drives.SITE OBSERVATIONS DURING THE POST-EXCAVATION PHASEThe first evidence of the stress state of the segmental lining appeared on November 20, 2013 inside the northern tube (1st drive). Ring No. 884 showed obvious signs of overstress, resulting in spalling and crushing of the concrete, and the subsequent bending of the reinforcement, as visible in figure 1.At this time the tunnel invert was already partially backfilled, and construction traffic was running through the tunnel. First safety measures included closing of the tunnel, and initial measurements of the displacements."

Jan 1, 2016

By A. J. Basu

Geotechnical design plays a key role in mine design. I A proper geotechnical design provides a safe working environment and facilitates efficient mining operation. There are mainly three design approaches I) judgmental, based on observational and experiential facts, 2) empirical, based on empirical design formulae, and 3) analytical, incorporating numerical analysis. Most design applications are based on the design methods one and two as mentioned earlier. However, complexities arise in deep underground mining operations and deep open pit mines. These complexities and difficult geological environment introduce more uncertainties and simple empirical formulae would not be adequate as a design tool. These situations require numerical modelling and analysis of the design problems including interpretation of the results obtained from the analysis. There are several tools available for performing the numerical modelling and analysis. A brief review of the available tools was addressed earlier (Basu and Kuruppu, 1995). The authors selected ANSYS (a general purpose finite element analysis tool) for use in mining geomechanics and geotechnical design. This paper includes several examples demonstrating the applicability of this software in designing structures applicable to mining geomechnics. The authors hope that the design examples will demonstrate the use of the numerical modelling and analysis application in excavation design.

Jan 1, 1996

By B Murphy, A Uliana, P STrgio de Oliveira, G Ara·jo de Souza Franco, T Miettinen

Outotec has performed numerous research and development projects and various surveys in the study of reverse iron ore flotation. Over the past four years their TankCell-70 and TankCell-160 flotation cells at the Germano concentrator of Samarco in Brazil were extensively surveyed. These surveys have revealed some extreme operating conditions in reverse iron ore flotation and are the subject of this paper. Some of the findings include large variations in the content of solids in the various flotation stages. At the bottom of the cleaner cells, the content of solids by weight reached over 60 per cent, whereas at the bottom of the scavenger cell this was less than 50 per cent. Froth carry rates were also significantly different in the various flotation stages. In the case of coarse material, the scavenger cells operated at a froth carry rate of over 40 t/h.m2. With fine material, however, froth carry rates of less than 10 t/h.m2 were measured. High froth carry rates caused significant changes in the residence times at Samarco. In the rougher cells, the fifth cell had more than double the residence time of the first cell. This was even more pronounced with the scavenger cells, where the second cell had more than triple the residence time of the first cell. High froth carry rates also caused losses in iron recovery. As a consequence of such findings, it appears that different rules apply in the sizing of reverse flotation circuits compared to direct flotation circuits. Different operating parameters (mixing intensities and air flow rates) must also be used in the rougher, cleaner and scavenger cells in order to optimise the metallurgical performance. Outotec has also been working on a number of new technologies aimed at improving the metallurgical performance of iron ore reverse flotation circuits by increasing froth carry rate and decreasing fine iron entrainment.CITATION:Miettinen, T, Uliana, A, Ara·jo de Souza Franco, G, STrgio de Oliveira, P and Murphy, B, 2013. TankCell flotation at SamarcoÆs Germano concentrators, in Proceedings Iron Ore 2013 , pp 441-444 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 12, 2013

By T. A. Muhlare

The use of electrolyte additives to smoothen cathode deposits during copper deposition is practised worldwide. These additives absorb on the cathode surface and take part in the electrochemical crystallization process. However, these additives also affect the quality of the cathodes when they are inadequately controlled. Electrolyte additives used by Palabora are glue, thiourea, Avitone and chloride. Their effects were determined on cathode quality, the size of the current density region that gives the desired compact morphology, and current efficiency. This was done in a small-scale cell. Small cells have different hydrodynamics from industrial-scale cells, which makes it difficult to simulate the operation of industrial cells in a laboratory. The approach used here was to use a rotating cylinder cathode to attain controlled hydrodynamics. The rotation speed was chosen to give a diffusion layer thickness that is similar to that of an industrial-scale cell. It was shown that even fairly small changes in the additive levels can significantly affect the cathode morphology, and the current density range over which this morphology can be obtained. Keywords Copper, electrorefining, glue, thiourea, avitone and chloride.

Jan 1, 2011

By A. C. Fieldner, W. A. Selvig

For purposes of coal classification it is desirable to know the composition and calorific value of the pure coal substance; that is, of the coal free from its ash-forming minerals. Two methods suggest themselves: (1) To free the coal from most of the ash-forming material previous to the analysis; and (2) to analyze the coal as received and calculate the analysis, with certain more or less arbitrary corrections, to the pure-coal basis. Calculation methods are obviously more apt to give correct results with low-ash than high-ash coals. With coals of unusually high ash it would appear preferable to remove, previous to the analysis, as much of the inorganic matter as possible, by float-and-sink or acid-treating methods. Effect of Ignition on Inorganic Constituents of Coal The need of corrections in calculating analysis to the pure-coal basis is due to the fact that the ash, as determined by ignition, is not the same, in either weight or composition, as the inorganic mineral matter in the coal. On ignition a number of changes occur in the coal such as loss of water of hydration of the shaly material, conversion of pyrite (FeS2) to ferric oxide (Fe203) with evolution of the sulfur as sulfur dioxide or possible fixation of more or less of the sulfur in the ash as calcium sulfate (CaSO4), and decomposition of calcite (CaC03) to calcium oxide (CaO). The amount of sulfur from pyrite which remains in the ash as calcium sulfate depends on the amount of calcite and pyrite in the coal. Certain coals high in both calcite and pyrite show relatively large amounts of sulfate sulfur in the coal ash. The determination of total carbon and hydrogen in coal includes, besides the organic carbon and hydrogen, the carbon of inorganic carbonates such as calcite, and the hydrogen of the water of composition of some of the ash-forming minerals. For detailed discussion of corrections proposed for calculations of coal analyses to the " pure "

Jan 1, 1930

By J. Luxford

The last decade has seen an enormous increase in the use of contractors right across the Australian mining industry. So much so that contractors now operate 33 of the 68 underground metalliferous mines around Australia and are making significant inroads into iron ore in the west and coal in the east. Safety used to be a low priority for many contractors. The picture has changed dramatically in recent years as most contractors take a far more professional approach to safety management. This paper examines the changes that have occurred and the requirements for effectively managing safety in a contracting environment.

Jan 1, 2000

By Raymond Chenier

British Columbia (BC) is Canada’s most western province. The landscape in BC is amongst the most beautiful and pristine in the world. Along with its beauty come vast mountain ranges, coastal rain forests, swamplands, deep river valleys, and almost every type of landscape imaginable. These all have, or at one time had, logging roads constructed. Some of these areas should never have had roads constructed due to poor drainage and unstable slopes, but some of the roads could be considered engineering masterpieces. To navigate a vehicle the size of an off-road logging truck down the side of a mountain with an 80°h side slope or greater can be a hair-raising experience. Not to mention coastal rains and/or high elevation blizzards. These factors collectively make logging BC’s most hazardous occupation. People are seriously hurt, sometimes even killed everyday.

Jan 1, 2001

By Martin Pratt

This paper is an overview of deep foundation engineering in Hong Kong past, present and future. The enormity of the subject compared with the space available makes brevity inevitable. Issues of construction and design are covered and some examples of recent challenging projects are given. The content is aimed at those with an interest in foundations generally, but with limited knowledge of the Hong Kong scene. Reference is made to informative publications for further reading on specific topics.

Jan 1, 2000

Review on Some Research Methods of Mineral Crystal Chemistry and Computer Simulation on Flotation

Sep 13, 2010