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By Harsh Kumar Verma

Blasting off-the-solid is the most commonly used method during development of galleries in Bord and Pillar method of underground coal mining. In this method, only P5 explosives are used with permitted delay detonators in accordance with the safety requirements stipulated by the regulatory bodies. Delay detonators made with pyrotechnic delay compositions have inherent scattering in their delay timings. It is desirable to use precise detonators to achieve better fragmentation, less vibration and noise. Overlapping of delay period is undesirable from production as well as safety point of view.

Jan 1, 2008

By James S. Goff, Stephen J. Navin, Wesley W. Moulton

The White River Shale Oil Corporation (WRSOC), as agent for Phillips Petroleum Company, Sohio Shale Oil Company, and Sun Shale Oil Company, is developing a prototype oil shale facility on Federal Lease Tracts Ua and Ub, located in northeastern Utah and known as the White River Shale Project (WRSP). The Ralph M. Parsons Company (Parsons) has been retained as the design engineer/constructor for the project. This paper covers the successful pregrouting of the Bird's Nest Aquifer in conjunction with the sinking of a 9.2-m (30-ft)-diameter shaft and driving of a 3.89-m by 5.64-m (18.5-ft by 12.75-ft) decline. The Bird's Nest Aquifer derives its name from the ellipsidal solution cavities caused by leaching of random-size nacholite nodules. The sodium bicarbonate nodules occur as persistent bands within a matrix of siltstone and marlstone. The team, made up of the owner, engineer/contractor, and subcontractor successfully grouted the shaft down to an inflow of less than 0.06 lps (1 gmp) and the decline down to less than 0.12 lps (2 gpm) by injecting a total of 213.190 kg (470,000 lb) of Celtite Terraseal, 113,400 kg (250,000 lb) of limestone dust, and 41,730 kg (92,000 lb) of cement into the formation.

Jan 1, 1985

By E. J. Duggan

CLIMAX ore is an altered and highly silicified granite, about half of the gangue being quartz. Molybdenite is the only mineral recovered and most of it is intimately associated with the quartz in fine veinlets. Other minerals are molybdite, pyrite, and chalcopyrite. Although the molybdite may be readily extracted by hydrometallurgical methods, its content is too low to make this profitable. The pyrite ranges from 2 to 5 per cent and the chalcopyrite from 0.03 to 0.05 per cent. There is not enough copper to make its recovery attractive and one of the problems is its elimination, and that of pyrite iron, from the final product. On account of the high degree of dissemination of the molybdenite and the necessity of eliminating the iron and copper, fine-grinding followed by flotation is the only known feasible method of concentration. Two factors, peculiar to Climax ore, have a predominating influence on the metallurgical attack: (1) Molybdenite is one of the most easily floated minerals. High recoveries may be made with pine oil alone if the

Jan 1, 1946

By H Lehtonen, H Mansikkaviita

In primary copper smelters, the received copper concentrate and other materials contain a certain amount of moisture, ranging from six to 14 per cent. Moisture in wet concentrate has a negative effect on the performance of the smelting furnaces when it is fed directly to the furnaces, namely increasing the energy consumption and the off-gas flow. There are several drying technologies available for drying copper concentrate, varying from direct heated rotary dryers and flash dryers to indirect heated steam dryers. Application of steam dryers has changed the drying process for copper smelters. Produced from a waste heat boiler, steam as heating medium enables plant-wide heat utilisation. Fossil fuel used from outside sources to remove water is no longer required and the combustion chamber is not required. In addition special attention has been paid to overcome the known problems of pollution emissions, excessive wear, clogging and frequent maintenance. The Kumera steam dryer is featured with many advantages based on principal improvements in reducing tube element wear and increasing drying efficiency. Thus, it has been considered as the first choice for those smelters where steam is available.

Jan 1, 2006

By J Miedecke

A metalliferous mine has operated at Storys Creek from the 1890s to 1979. Storys Creek drains from a pristine catchment and National Park and remains as the most degraded stream from historic mining in north-eastern Tasmania. It has been the subject of public concern since the closure, particularly at times of high rainfall such as existed in 1985 and 1986. The mine is located on the banks of the creek, which flows into a major river, the South Esk River, which is one of TasmaniaÆs largest rivers and important for recreational fishing and water supplies. For much of the life of the of the operations tailings were directly discharged into the creek, and in latter years stockpiled or very close to it. Little rehabilitation was carried out at mine closure. The result was erosion and subsequent deposition on the banks of the creek downstream. Direct emissions of adit water and the consequential emission of contaminated ground water to the creek continue to affect water quality. Contaminant loads discharging from the mine and tailings comprise 70% of the metal load in the catchment and are by far the largest single source. Acidity data suggested that the introduction of systems to introduce alkalinity could be effective in ameliorating the residual acid drainage impacts in the Storys Creek catchment. After a period of investigations and trials which proved their effectiveness, treatments adopted have included the following: relocation of tailings to a constructed and clay capped disposal area and rehabilitation of tailings area; crushed limestone addition to stream flows; crushed limestone addition to creek banks and exposed tailings; sealing of a drainage Adit; and construction of an anoxic drain to generate alkalinity to surface waters draining to old mine workings. These innovative treatments have resulted in a marked improvement in water quality draining from the area. The anoxic drain is believed to be one of the few, if any, which has been constructed to have generated high levels of alkalinity from clean waters and offers a solution to the clogging problems experienced in such drains in the past. Similarly, the use of crushed limestone in an active stream has proved effective in buffering acid drainage and removing metals from solution.

Jan 1, 2003

By Nikhil Dhawan, SHAILA MIR

The emerging problem of electronic waste has promoted the interest in exploring metal recovery from secondary sources under the umbrella of urban mining. This study presents the physical and chemical characterization of various components present in end-of-life laptops to help ascertain the sites of metallic values and develop sustainable and environment-friendly recycling. The recycling potential of a laptop is evaluated by sequential disassembly, separation, and characterization of components such as body (49.8 wt.%), printed circuit board (9.7 wt.%), hard disk drive (4.9 wt.%), and battery (12.4 wt.%). The printed circuit boards comprise metallic values, majorly copper (25 wt.%), tin (5.8 wt.%), and lead (3.1 wt.%). The precious metals (Au, Ag) with an economic advantage are abundantly present in electronic components such as integrated circuits, capacitors, resistors, and processors. Critical elements such as lithium, cobalt, and rare earth elements are detected in the discarded laptops' batteries and hard disk drives. The recycling potential representing the amount of material that can be recycled in various components, depending on the type, concentration, and purity, is determined in the range of 36–100%. On average, a unit laptop contains~ 386 g of Cu (14.45 wt. %), 49.73 g Co (1.86 wt. %), ~346 mg Ag, ~141.2 mg Au, ~650 mg of rare earth elements (Nd, Dy). This study presents a database for investigating integrated and economical recycling techniques from different components of a laptop, and an overall process flow is also proposed.

Jul 24, 2021

By D. W. Hayley

The rapid expansion of exploration drilling with anticipated production facilities for oil and gas in the Mackenzie Delta region of the Northwest Territories has created a demand for granular construction materials. This paper discusses the technique adopted and experience gained by the authors from several major resource evaluation programs in this remote area. The first part of the paper describes a methodology for deposit identification, logistics of helicopter and ground-based drilling operations and the sampling difficulties which are unique to permafrost: soils. The second part describes the exploitation of a large glaciofluvial deposit at YaYa Lake on Richards Island. Granular construction material is sparse in the delta region relative to projected demand. Exploitable sources of granular materials for aggregates or construction borrow are found in glaciofluvial deposits of Pleistocene age or in outcrops of Paleozoic bedrock. Glaciofluvial landforms can be located by reference to published surficial geology maps coupled with airphoto interpretation. Preliminary assessment of these features in a large region is most economically carried out during the summer months with a drill that is transportable by helicopter. Once prospective borrow pit sites are identified, a detailed ground-based winter drilling program must be undertaken to establish aggregate quality and quantity, and to provide information on natural features which could affect development. The glaciofluvial terrain has been highly modified by the formation of massive ground ice within the gravel deposits. This presents some unique pit development problems which are not encountered in a normal bedrock quarry operation.

Jan 1, 1977

Rope guides, consisting of ropes spanning between anchor points at the top and bottom of shafts, have frequently been considered as a viable alternative to fixed guides, comprising buntons and guides. However, their design has generally been based on empirically derived rules, arising from European hoisting practice of 50 to 100 years ago. This paper describes a recent technology development project aimed at defining and quantifying the important forces acting on rope guided conveyances, calculating the resulting displacement of the conveyances and assessing whether the displacements are acceptable or not. The paper describes the derivation of aerodynamic force coefficients based on CFD analyses and other significant forces acting on the conveyance and rope system. The conveyance displacements may be calculated using computer simulation of the mechanical system, or approximately using simplified equations given in the paper. Measurements taken to confirm the suitability of the proposed formulation are described. The combination of displacements and assessment of the rope guide system design are proposed, based on the ratio of design clearances and the predicted displacements.

Jan 1, 2005

By Robert L. Frantz

The U.S. Bureau of Mines (USBM) established on August 15, 1983, a Generic Mineral f Technology Center (GTC) for Respirable Dust within the Mining and Mineral Resources Research Institutes (MRIs) at The Pennsylvania State University (PSU) and West Virginia University (WW) in association with participating MRIs at Massachusetts Institute of Technology (MIT) and the University of Minnesota (UMN). The primary goal of the Center is to reduce the incidence and severity of respirable dust disease through researching and advancing the fundamental under- standing of all aspects of respirable dust associated with mining and milling and the interaction of dust and lungs. Other Center activities include the training of engineers and scientists, graduate students and undergraduate students through their respective institutions, and the technology transfer to the industry. The Center also serves as the reference center for publications in the respirable dust area.

Jan 1, 1986

By James Gayley

(Wilkes-Barre Meeting, June, 1911.) THE paper presented to the Institute in 1910, by H. 0. Hofman, on Recent Progress in Blast Roasting,1 has called the attention of the iron industry to the adaptability of these processes to the reclamation of by-products such as flue-dust and blue billy, and the better preparation of concentrates and fine ores for use in blast-furnaces. The waste of valuable iron-ore through the production of flue-dust has increased at an enormous rate, and much of it has in reality been wasted as far as future recovery is concerned. Only in recent years has a possible future value been recognized, and the material stored. The increased use of Mesabi ores, which carry considerable fine ore, is principally responsible for the great increase in the production of flue-dust. The amount of fine material that is carried over depends on the fineness of the material and the velocity of the gases, and also to a very great extent on the regularity or irregularity of the working of the furnace. Attempts to recover a part of this loss have been made by recharging a portion of the production into the furnace, but as this material has been once carried out from the furnace, it is naturally in good shape to be carried out again. A recent practice at some works, is to soak the flue-dust thoroughly with water to give it more cohesiveness, but by many this is considered of doubtful advantage in the furnace, and the gases are in consequence heavily laden with moisture. There are vast deposits of magnetic iron-ores in the United States and Canada that are too low in iron for use at the present time, but which can be economically concentrated into very rich material ; in many cases the fineness of crushing necessary to secure proper concentration has prevented their

Aug 1, 1911

By J. L. Ambs

The U.S. Bureau of Mines (USBM) Diesel Research Program emphasizes the development and evaluation of emission control devices to reduce exposure of miners to diesel exhaust pollutants. Studies by the USBM have shown that diesel exhaust aerosol (DEA) contributes a substantial portion of the respirable aerosol in underground coal mines using diesel equipment not equipped with emission controls. The USBM and the Donaldson Co., Inc., Minneapolis, MN, have developed a low-temperature, disposable diesel exhaust filter (DDEF) for use on permissible diesel haulage vehicles equipped with waterbath exhaust conditioners. These were evaluated in three underground, mines, to determine their effectiveness in reducing DEA concentrations. The DDEF reduced DEA concentrations from 70 to 90 pct at these mines. The usable life of the filter ranged from 10 to 32 h, depending on factors that affect DEA output, such 'as mine altitude, engine type, and duty-cycle. Cost per filter is approximately $40.

Jan 1, 2010

By Neville J. Price

In order that the reader may not be misled, I feel it necessary to comment upon the title of this paper. "Laws of Rock Behavior," one may take as being part of the all-embracing "Law of Nature" and this, according to the Oxford Dictionary, relates to the principles of conduct recognized as being pleasing to God. I feel it would be presumptuous to erect a code of rock behavior on this basis, so turn to a secondary definition, namely that a "Law" is that which is intrinsically reasonable. It is extremely unlikely that any group of geologists, or workers in rock mechanics would be in complete agreement about what could be taken to be "intrinsically reasonable." Therefore, this paper does not present any deified utterances, but rather deals with a few aspects of rock behavior which I consider to be intrinsically reasonable and with which I hope the reader will concur. The mode of behavior of rocks in the Earth's crust covers the range from wholly brittle to completely ductile ; with a deformation time scale which may be measured in milliseconds, for some events such as meteoritic impact, or in millions of years for the tectonic deformation involved in mountain building. A complete survey is, of course, outside the scope of an introductory paper, so I must be both brief and selective in my treatment. Any attempt to establish the mode of rock behavior in the Earth's crust should take into account data and relationships established in laboratory experiments and correlate these with field evidence. Consequently, the first section of this paper presents a brief discussion of the experimental aspects of rock mechanics which are pertinent to the subsequent discussion.

Jan 1, 1970

By Tassos Grammatikopoulos, Gary Pearse, Massoud Aghamirian, Charlotte Forstner, Stephen Mackie

"SGS Minerals Services (Lakefield, Ontario site) has conducted a number of developmental and pilot programs that examined methods for the beneficiation, extraction and recovery of lithium from a variety of spodumene containing hard rock sources. An overview of the beneficiation programs is presented separately by Aghamirian, Mohns, Grammatikopoulos, Imeson & Pearse (2011). The focus of this discussion will be the hydrometallurgical steps involved in producing a high grade lithium carbonate (Li2CO3) sample from the spodumene concentrate. SGS has applied the standard Li2CO3 hydrometallurgical flow sheet to a number of spodumene concentrates and has determined that all of these samples respond in a similar manner to the process and produce a final product having a Li2CO3 grade of >99.5%. The standard process is sufficiently robust to accommodate the observed variability in the concentrates that have been tested. Advantage of one spodumene deposit over another will thus be gained through process optimization and innovation. Optimization at the beneficiation stage and at the hydrometallurgical stage must be considered. Some aspects of the process optimization of the hydrometallurgical flow sheet will be presented.INTRODUCTION The current activity in the exploration, development, and mining of lithium based minerals is due in large part to the key role that this metal plays in the rechargeable battery industry (U.S. Geological Survey, 2011). Lithium battery technologies are widely applied in a range of portable electronic consumer products. The expanding development and production of hybrid and fully electric vehicles has contributed to the increased interest in finding and developing new lithium sources in order to meet the expected demand from the lithium battery industry. Lithium may be sourced from continental brines (sub-surface salars), hard rock minerals (pegmatite, spodumene), hectorite clay deposits, geothermal brines and oilfield brines. Currently the majority of the lithium products are produced from Li brines. The four major lithium producing countries are Chile, Australia, China, and Argentina (U.S. Geological Survey, 2009; Roskill, 2009). These countries accounted for 97.6% of the total lithium produced in 2010."

Jan 1, 2012

By Don Stevens

The Denali Prospect (147° 08' 20" W, 63° 08' 50" N) is located on the south flank of the Alaska Range in the Clearwater Mountains in south central Alaska. (See Figure 1). The mineralization was discovered in 1963 and surface explora¬tion began the following summer. Surface trenching and diamond drilling were used to locate and sample the mineralized zones. In 1969, an adit totalling approximately 1400 feet was completed. In 1970, a -15% grade decline approximately 1800 feet long was completed. Further diamond drilling was done along with both underground programs. Although much work remains to be done to properly evaluate the prospect, results from all the work to date are quite encouraging. This paper will consider the geology of the prospect and the surrounding area, some- aspects of the geochemistry of the sulfides, and the origin of the sulfide deposits. This paper includes data from this writer's Ph. D. dissertation, "Geology and Geochemistry of the Denali Prospect, Clearwater Mountains Alaska" from the University of Alaska and subsequent work.

Jan 1, 1972

By E. Herrera Alarcón, L. Mariscal Samaniego

The Teniente Converter (wet charge type) was commissioned in august 1995 and was designed to smelt 744 tpd (metric tons per day) of dry copper concentrates. Its products are white metal (73% Cu) that is sent to the Peirce Smith converters, slag that is cleaned in Reverberatory Furnaces and the process gases that are sent to the Sulfuric Acid Plant. Since its start up, the Teniente Converter smelting capacity was increased 1.6 times, from 800 tpd to 1,280 tpd using 33% oxygen-enriched air, and reaching an operative availability of 97%. By the other hand its campaigns have reached a record duration of 530 days without hot patching tuyeres and a partial refractory lining repair in the last four campaigns. This paper describes the most relevant improvements, as well as the strategies that had been used to reach these achievements.

Jan 1, 2007

By Jamal Rostami, Wei Hu

Efficient performance of EPB TBMs in clayey ground is primarily dominated by the flow capability of the excavated muck in the cutterhead and screw conveyor. Currently, Consistency Index approach is used to evaluate clay clogging potential, but it does not include the effects of surcharge pressure on clay behavior. In this paper, a macro-scale soil rheometer is introduced to assess the clogging potential under various water content and surcharge loading conditions. The results show that, in addition to water content, surcharge pressure has clear impact on clay clogging too. In practice, Consistency Index chart can be refined to incorporate the impact of face pressure to better simulate the EPB tunneling conditions.

Jun 13, 2021

By B J. Andrew, M R. Daley

Mount Isa Copper Mines is a world-class mining operation producing approximately six million tonnes of ore per annum. With over 50 years of mining history and over 76 million tonnes of underground resource remaining there are many challenges facing the mine technical team today and into the future. The mine consists of nine distinct areas: the Hangingwall Lens, Footwall Lens, 1100, 1900, N1100, N1900, 3000, 3500 and N3500 orebodies. Each of these areas have different characteristics, requiring varying methods of mine design and ground control for safe and efficient orebody extraction. Each of the areas operate with an independent sequence whilst interacting with the entire underground operation. Within the first five years after graduating mining engineers tend to orient their careers in either a technical or operations direction. Engineers working towards a specialised technical career will often be working as mine planning engineers, whilst others more focused in the operations stream occupy roles such as operations or project engineers. At this stage of a mining engineerÆs career they are not yet categorised into one stream or another, but career decisions made now can generally focus their ultimate career path in one direction or the other. Due to the size of the Mount Isa operations there are many opportunities for engineers pursuing both career path and plenty of room for growth forthose as yet unsure.

Jan 1, 2005

By K. K. Kelly

METALLURGICAL thermochemistry of titanium is a broad subject and (if data were available) could include a wide variety of topics. The present report is restricted to extractive metallurgy and to substances and reactions that bear upon the magnesium, sodium, and hydrogen-reduction processes employing titanium tetrachloride. The aim has been to present enough data so that the reader not only can check: the calculations for the reactions discussed but also can conduct related calculations if he so desires, without recourse to other compilations of data. The subject matter divides naturally into two parts-the selection of the data to be adopted and the application of these data to pertinent metallurgical reactions.

Jan 1, 1959

By David Mast, Amanda Foote, Mina Shinouda

The Michigan DOT’s I‑75 Modernization Project, Segment 3, is a 30-year, $1.2 Billion design-build-finance-maintain project in Southeast Michigan. The scope includes building a nearly 4-mile long, 14.5-foot ID stormwater storage tunnel. The tunnel and pump station are being built concurrent with new roads and bridges, requiring multiple levels of design and construction coordination. Underground risks include the poten‑ tial for encountering granular soils, groundwater, and explosive gases. The new tunnel will be mined by a new open-face TBM and lined with a one-pass steel-fiber-reinforced precast concrete segmental lining. Shaft construction began in early 2020 and tunnel mining in July 2020.

Jun 13, 2021

By M. C. Flemings, S. B. Brown

"Metallurgy, as all of material science and engineering, rests on the intellectual foundations of processing-structure-property-performance relationships. Today it is widely recognized that processing has been too long neglected and presents exciting opportunities for exploitation. New processes, many of them already in the laboratory, will be exploited in the year 2000 and beyond, for near net shape forming and for achieving-new metallurgical structures and composite structures. Process modelling will alter the way we think about process and product design. Processes themselves will increasingly be automated and controlled by computers, altering the nature of the workplace and the tasks of the metallurgical engineer of the future. IntroductionInnovations in metal processing is hardly a new phenomenon, with the field thousands of years old. Nonetheless, the next few decades offer particularly important opportunities to improve our ability to process these materials. We appreciate today the variety of processing paths available to us, including vapor-, plasma- and electro-deposition, multiple phase and casting technologies, and non-equilibrium processes, and how these affect structure at the atomic level and at higher levels of aggregation. We understand the basic physical mechanisms involved far better than even before and have remarkable new abilities to predict, control, and simulate the kinetics underlying processes, and the processes themselves.The following sections describe these new opportunities in greater detail. First, we examine developments in the modelling of metal processing. We then consider some implications associated with process control and automation. Finally we present what we consider to be particularly promising metal processing technologies, and conclude with a few summary comments."

Jan 1, 1988