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By Jr. Freed

Basic design features, details of the face ventilation system, roof support and Operator protection system, certified lighting, and in-mine evaluation plans are presented for an Automated Extraction System (AES) that has been designed to fill needs which are present in the Mining Industry. The philosophy of design and proposed operation of the machine, as well as the relationships between these factors, are reviewed. The AES is designed to help overcome production problems resulting from the regulation of roof control, clean-up, ventilation, dust suppression, and operator protection required by the Federal Coal Mine Health and Safety Act of 1969. The design permits more continuous operation and greatly improves operator safety. The machine is a full-face drum-type continuous miner which includes self-advancing, continuous temporary roof support and permanent roof support equipment. Onboard self-advancing face ventilation, dust suppression, and air scrubbing equipment are also included in the design. A further improvement over existing equipment is the incorporation of an automatic programmed cutting cycle control system. All mining functions including movements of the roof support system are handled by this automatic system.

Jan 1, 1978

By L. Schernikau, W. H. Smith

Oil, coal, and gas account for approximately 80% of global primary energy, but only a portion of total airborne CO2 eq (approx. 35% at GWP20 to 65% at GWP100), even though they account for 95% of total measured CO2 emissions. The benefits of these energy sources, as well as their related costs, are not all incorporated in current energy policy discussions. Global greenhouse gas policies must include documented changes in measured airborne CO2 eq to avoid spending large amounts of public funds on ineffective or sub-optimal policies. The authors examined airborne CO2, which is less than half of emitted CO2, as well as reported CH4 emissions and the global warming potential of CH4 as published by the IPCC for coal and natural gas. The surprising conclusion is that surfaced-mined coal appears ‘better for the climate’ than the average natural gas, and all coal appears beneficial over LNG. Therefore, current CO2-only reduction policies and CO2 taxes are leading to unintended consequences and the switch from coal to natural gas, especially LNG, will not have the desired impact of reducing predicted future global warming; in fact, quite the contrary. A large portion of anthropogenic global warming is attributed by the IPCC and IEA to CH4, but it must be noted that CH4 emissions from natural sources and from agriculture account for approximately 40% and 25% of annual global CH4 emissions respectively. Energy accounts for about 20% of documented CH4 emissions. CO2 contributes only approximately 35% of annual airborne anthropogenic GHG emissions after accounting for CH4, over a 20-year horizon. At a 100-year horizon, the contribution of CO2 increases to approximately 60%. Energy policies that do not consider all GHG emissions along the entire value chain will lead to undesired economic and environmental distortions. All carbon taxation and CO2 pricing schemes are incorrect and need to be revised. At IPCC’s GWP20 an approximately 2%1 higher loss of CH4 across the value chain prior to combustion of natural gas versus coal will lead to ‘climate parity’ of coal with natural gas. According to public data, natural gas value chains have high CH4 and undocumented CO2 losses. On a global average, using only IEA-documented CH4 data, natural gas emits approximately 15% more CO2 eq than surface-mined coal, over a 20-year horizon. This difference will increase as the use of shale gas and LNG expands. Investors should support all energy systems in a manner that avoids an energy crisis, including intermittent renewable energy systems where they make sense. If CO2 emissions need to be reduced, one of the most effective ways would be to install ultra-supercritical power plants with CCUS technology. However, the undisputed benefits of increased CO2 concentrations in the atmosphere because of its promotion of photosynthesis and plant growth effects (fertilization) need to be considered in energy policy decisions as well. The authors suggest that future research and development should concentrate on reducing net emissions from fossil fuel power plants and providing cost-effective and reliable new conventional power generation capacity, utilizing clean coal and clean natural gas technology.

Mar 2, 2022

By Noan Tonini SImonassi

As fibras naturais extraídas das folhas do curauá estão entre as mais fortes fibras naturais utilizadas como reforço de compósitos poliméricos para aplicações em engenharia. Tais compósitos, até agora, são limitados em relação às propriedades mecânicas e energia de impacto. Assim o objetivo do presente trabalho é de investigar a possibilidade da melhora da resistência à tração bem como a energia de impacto dos compósitos de matriz poliéster reforçados com fibras de curauá com variados parâmetros de processamento. Os parâmetros observados foram a quantidade de fibras com diâmetro fino e pressão aplicada durante o processamento. Utilizando 60% de fração volumétrica de fibras finas (diâmetro médio variando de 50 à 80 µm) contínuas e alinhadas foi possível se obter resistência à tração superior 200 MPa. Ainda, aplicando-se 30 MPa de pressão durante a cura foram obtidos mais de 270 MPa de resistência a tração. Já para resistência a impacto Izod, uma resistência de 340 J/m foi obtido pelos corpos de prova com entalhe feito em sentido perpendicular ao alinhamento das fibras.

Oct 30, 2017

By C. H. Lieb

ONE astounding fact in the production of petroleum is the comparatively recent realization by producers that flowing production is the cheapest crude produced. About 1910 or even later, operators actually endeavored to get a producing well to pumping as quickly as possible after completion. A well was not really considered to be completed until it was operating on the pump. Remarkable progress has been made since then. It was not until about 1920 that producers began to take a serious interest in pressures and to think a little about proper methods of handling oil wells. Pressure gauges were installed, and records of pressures maintained, which was quite an innovation. Desultory experiments were made with tubing of different sizes, as well as experiments with placing the bottom of the tubing string at different levels in the well. Probably the first important departure from customary procedure was about 1926, during the Seminole development, when gas lift

Jan 1, 1936

By R. L. Player

"The Copper Isasmelt process has been developed over the past 15 years by Mount Isa Mines Limited (MIM) and the Commonwealth Scientific and Industrial Research Organisation (CSIRO). The first two commercial plants were commissioned in mid 1992.The results of four heat balances on the Mount Isa plant are presented. At a smelting rate of 98 t/hr of chalcopyrite concentrate plus 14 t/hr reverts, the total heat generated was -91MW. Approximately 39% of this energy came from coal, while 50% of the energy reported to the process waste gas. To a first approximation the furnace is near chemical equilibrium.The impurity distribution in the Mount Isa plant was presented. Approximately 91 % As, 85% Cd, 75% Bi, 68% Zn, 60% Sb and Tl, 45% Pb and 30% Te in concentrate was eliminated from the matte.The ""bubble"" frequency of the gas cavity below the foot of the lance was measured at -2. 1Hz. Side bands displaced by -l.lHz modulated the bubble frequency. This was consistent with radial gravity wave motion in the slag bath. The two processes, gas bubbling and wave motion appeared to be coupled together; the bubble frequency was twice the slop wave frequency. IntroductionCopper Isasmelt has been developed over the past 15 years by Mount Isa Mines Limited and the Commonwealth Scientific and Industrial Research Organisation. The process is based on the Sirosmelt lance, invented by researchers at the then Division of Mineral"" and ProcessEngineering ofCSIRO in 1973.The first two commercial scale copper furnaces were commissioned at Mount Isa and the Cyprus Miami Mining Corporation smelter at Miami, Arizona in August and June 1992 respectively.The process concept, the history of the development, and the Mount Isa plant have been described (1, 2, 3).This paper sununarises heat balances obtained on the furnace, the impurity distribution among the output streams and lance injection characteristics."

Jan 1, 1996

By D. H. Garcia

The mining industry responded to public concerns about use of cyanide by developing a voluntary certification to allow companies to demonstrate their commitment. The International Cyanide Code (Code) establishes standards for the manufacture, transportation and use of cyanide. Key concepts in closure planning to comply with the Code are to decommission all facilities related to cyanide operations and to provide a financial assurance mechanism for those activities. Code requirements may differ from state-specific regulations, but requirements are based on closure goals for protection of the human health and the environment. Only issues related to cyanide operations are required to be included in decommissioning demonstrations. For example, the disposal method of cyanide solution holding tanks and the cost must be included in the closure plan, but information regarding closure of roads is not required. Closure costs must be based on a third-party contractor as opposed to internal budgets. Compliance with the closure requirements of the Code allows companies to show their stockholders, lending institutions, and the public that their operations are environmentally responsible.

Jan 1, 2010

By P. W. A. Mayer

"As the push toward the northern regions of Canada steadily increases to exploit the rich mineral reserves, interest is steadily rising in respect to accessibility and climatic conditions and the problems posed thereby. In twelve years of operation, the Iron Ore Company of Canada, and associated companies, have found, through advanced technology, ingenuity and, most of all. need, some of the answers to the running of a profitable year-round open-pit mining operation."

Jan 1, 1966

By Richard D. Miller

This publication contains routine analyses and related source data for 434 gas samples from 16 States. These samples were collected during calendar year 1961 as part of the continuous survey for the occurrence of helium in natural gas conducted by the Helium Activity of the Bureau of Mines. The analyses herein were made by mass spectrometer and Frost helium apparatus. The most important helium resource discovery made during 1961 was the Table Mesa field in San Juan County, N. Mex. This field, Which has an estimated recoverable helium reserve of 850 million cubic feet, is now supplying gas containing approximately 5.4 percent helium to the Bureau of Mines Navajo Helium Plant at Shiprock, N. Mex.

Jan 1, 1964

By Richard D. Miller

This publication contains routine analyses and related source data for 434 gas samples from 16 States. These samples were collected during calendar year 1961 as part of the continuous survey for the occurrence of helium in natural gas conducted by the Helium Activity of the Bureau of Mines. The analyses herein were made by mass spectrometer and Frost helium apparatus. The most important helium resource discovery made during 1961 was the Table Mesa field in San Juan County, N. Mex. This field, Which has an estimated recoverable helium reserve of 850 million cubic feet, is now supplying gas containing approximately 5.4 percent helium to the Bureau of Mines Navajo Helium Plant at Shiprock, N. Mex.

Jan 1, 1964

By John V. Beall

GOING west from Denver on Route 6, the direct road to Grand Junction, one gets the first glimpse of mining a few miles east of Denver near Idaho Springs where the workings of defunct gold mines are visible on the sides of mountains along the highway. One enterprising company is turning a profit by showing tourists through the mine and mill and then selling them gold samples on the way out. We have always known that mining people are ingenious, but this proves it. About five and a half hours fast driving west from Denver brings one to Rifle, Colo., which is the site of the oil shale mine, retorting plant, and refinery of the U. S. Bureau of Mines. As you drive up to the mine, you can see a portal high on the face of the cliff in front of you where the mine surface plant literally hangs by its toenails. Below, the retorting plant and refinery gleam in the sunlight. Up at the mine, Fred Wright will show you how the oil shale is extracted in two benches (a third bench would be used for commercial mining) by the room-and-pillar method. In mining the top level, an underground crew of thirteen men have been able to produce 1500 tons of shale in each eight-hour shift. To do this, the mine is thoroughly mechanized. The mining method is de- scribed in the September issue of Mining Engineering.

Jan 1, 1949

By Markus Reuter, Antoinette van Schaik

In this paper the link between process metallurgy, classical minerals processing, product centric recycling and urban/landfill mining is discussed. The depth that has to be achieved in urban mining and recycling must glean from the wealth of theoretical knowledge and insight that have been developed in the past in minerals and metallurgical processing. This background learns that recycling demands a product centric approach, which considers simultaneously the multi-material interactions in man-made complex ‘minerals’. Fast innovation in recycling and urban mining can be achieved by further evolving from this well developed basis, evolving the techniques and tools that have been developed over the years. This basis has already been used for many years to design, operate and control industrial plants for metal production. This has been the basis for Design for Recycling rules for End-of-Life products. Using, among others, the UNEP Metal Recycling report as a basis (authors are respectively Lead and Main authors of report), it is demonstrated that a common theoretical basis as developed in metallurgy and minerals processing can help much to level the playing field between primary processing, secondary processing, recycling, and urban/landfill mining and product design hence enhancing resource efficiency. Thus various scales of detail link product design with metallurgical process design and its fundamentals.

Jan 1, 2014

By G Stovpchenko, G Jianjun, L Medovar

Electroslag remelting (ESR) today and into the future, will still be the main process for producing high-quality ingots by suppressing segregation, not just refining chemical composition from impurities. This paper analyses state-of-the-art electroslag refining with a focus on ESR with consumable electrodes, and recent technology with liquid metal supply (ESR LM) in view of their refining abilities and development trends, taking into consideration that the size of the ingots required by industry continues to grow, and the composition of new materials sophisticates to withstand increasingly higher mechanical and temperature loads . The yield of suitable metal in large ingots produced by conventional casting is low due to problems of element segregation by height and crosssection. For example, conventional ingots for nuclear powerplant rotors today reach nearly 700 t in weight. Attempts to directly replace such giant ingots with big-diameter ESR ingots weighing approximately 400 t were also unsuccessful because of growing segregation. Modern ESR equipment and technologies produce 200–250 t of ingots of satisfactory quality, reaching 2.5 m in diameter, implementing the change of consumable electrodes during remelting to increase ingot length. Another way to mitigate segregation is to enlarge the smaller diameter ESR ingot by a 500– 800 mm coaxial layer to the desirable diameter by ESR in the current-supplying mould (CSM). Modelling and experiments prove that refining from impurities and non-metallic inclusions at ESR most effectively occurs at the slag bath and liquid metal pool interface because the ESR LM has provided the same desulfurisation. ESR’s special refining capabilities in CSM come from the much longer time of LM residence shown at titanium purification from hard-melting nitride inclusions that are unremovable in vacuum arc remelting (VAR) and electron beam melting (EBM). Implementation of ESR technologies in CSM, especially with LM supply, is prospective to produce heavy enlarged and hollow forging ingots with prevented development of segregation due to dividing cross-section and reducing overheat of solidifying metal.

Jun 19, 2024

By Leo Panian

Over the last decade, drilled and post-grouted micropile foundations have come to be increasingly relied upon for resisting seismic loads in building foundations on the West Coast. Micropiles have been successfully deployed in a range of soil conditions, in vertical as well as battered configurations, to support a variety of structural systems difficult soils. Their high load capacity in tension as well as in compression, their ability to be installed in confined spaces with minimal overhead clearance, and their ability to be directly tested in an installation have made them indispensable for seismic strengthening of existing structures. More recently, growing industry experience along with improvements in design guidelines have led to wider acceptance of micropiles among engineers and building officials. The increasing availability of the specialized materials, coupled with growing familiarity with drilling technologies among design-build contractors has made micropiles more cost-effective and competitive. For the first time, micropiles are finding applications in the construction of new buildings, where they are combined with shallow footings in hybrid foundations to efficiently resist seismic loads. These new applications rely on more intensive engineering analyses to evaluate the performance of micropile foundation systems and develop detailed requirements for design and construction. This paper describes the design approaches and the analytical methods for the seismic design of hybrid micropile foundations, and provides examples of recent construction projects that demonstrate the application.

Jan 1, 2010

The 29th annual American Mining Hall of Fame Awards Banquet and Fundraiser sponsored by the Mining Foundation of the Southwest (MFSW) will be held at the JW Marriott Star Pass Resort, Tucson, AZ on Saturday, Dec. 3, 2011. Each year, one living inductee, two recipients of Medals of Merit, and up to five honorees from mining history are chosen by the MFSW for their outstanding contributions to the mining industry. Chilean Minister of Public Works and former Minister of Mining, Laurence Golborne Riveros will be the guest of honor, featured speaker and inductee into the American Mining Hall of Fame. Golborne Riveros was instrumental in managing the rescue of the 33 Chilean miners in October 2010 and in the coordination/management of the ?townsite? for family members, rescue support and the media. His engineering background and executive management skills made him ideally suited to assist in both a technical and managerial role in this emergency.

Jan 1, 2011

By Edward F. Fries

The U.S. Bureau of Mines is conducting research that will lead to computer-assisted mining equipment. This research will facilitate improvements in safety by relocating workers from dangerous areas and will increase production by providing more accurate control with less downtime of equipment. A Bureau-developed microcomputer network enhances this research by permitting a group of diverse computers to interact with a mining machine as well as with each other over a common data link. The network is composed of specially integrated off-the-shelf hardware and industry-standard operating system and programming languages. Using the network, researchers can conduct various experiments with the mining machine using a diverse group of sensors, computers, and micro controllers. This report gives a brief background on the Bureau's work in computer-assisted mining, followed by discussions on the network hardware and architecture and the network packets, and an analysis of network operation.

Jan 1, 1992

By Victor R. Eyzaguirre

Cerro Verde is one of several large porphyry-type copper deposits in Southern Peru. The copper occurs as primary sulphides, with a significant oxide capping. The exploitation of the deposit has been correspondingly divided into two stages, the first consisting of copper production from oxides, and the second from sulphides. Minero Peru successfully started the Stage I plant in June of 1977 with the first production of electrowon copper cathodes. This paper is essentially devoted to a description of the Stage I process, which can be summarized as follows: Ore is trucked to the primary crusher, where it is crushed to 225 mm and conveyed to a coarse ore stockpile. Ore withdrawn from the stockpile is secondary crushed to 65 mm, conveyed to a truck loadout bin, loaded into trucks and driven to the leaching pads. Ore is placed on the pads in lifts and sprayed with sulphuric acid solution to dissolve the copper. Copper-bearing solution forms a pond behind a dam at the lower end of each pad and is pumped from there to the solvent extraction plant. Copper is extracted from the leach solution into an organic phase and is then stripped from the organic phase to form a purified concentrated copper solution suitable for feed to electrowinning. In electrowinning, the copper is finally recovered as cathodes suitable for sale as refined copper.

Jan 1, 1978

By J. A. MacLellan

It is the hope of the author that this paper, largely a compilation of observations and opinions built up over 20 years of experience in cold and remote areas may be of some help to others in designing better plants for the future in the north. The north is not as difficult to operate in as the better story tellers make it appear to be. ()n the other hand for 6 months of the year the cold is always there, and it seems to be waiting for someone to make a mistake. The simplest things can shut a multi-million dollar plant down at -4n' F with a 4n M.P.H, wind. It only takes one man door improperly latched to freeze up all the pumps on the bottom floor. Someone can poke a one inch hole in an outside wall in July and six months later while you are having Christmas dinner, a watchman will call up to report that the whole plant is flooded because the main water line just froze up and burst. Basic things to remember in plant design for cold and remote areas are: everything in these areas is more expensive due to long and difficult supply lines. Fuel is expensive and would be a major cost item even if it were not expensive, due to the extended periods of low temperatures. Building volumes should therefore he kept to an acceptable minimum. Service areas on the other hand must he adequate, because maintenance generally has to be conducted inside in a heated area. Supply vehicles for instance have to get completely inside the building to unload. If you try to unload a supply vehicle with the door open at -50° F, you won't be able to find the vehicle for fog and if you take more than 5 minutes half the water lines in the plant will freeze up. People in a remote area are expensive. The capital investment per employee may be as high as $30,000; with fringe benefits per annum costs of an employee will he as high as 812,000 per year regardless of basic wage rate. It

Jan 1, 1971

By M. L. Maniocha

Most magnesia, MgO, whether of natural or synthetic origin, is utilized in its dead burned or periclase form as refractory linings for the production of steel. Continued research in refractory science combined with good refractory maintenance and improvements in steel making practice have resulted in decreased use of magnesia. To make up for this loss of business producers of synthetic magnesia have started to manufacture a variety of magnesium based chemicals that are utilized in many diverse industries and applications.

Jan 1, 1997

By R. A. Friedel

THE IMPORTANCE of infrared and ultraviolet-visible spectrometry in studies of the structure of coal and similar substances is described. Special experimental techniques have been developed for these studies. Thin sections of coal are preferred, but halide pellets are easier to prepare. Information obtained from infrared spectra on chemical functional groups has been discussed; the importance of both intensities and wavelengths of absorption bands has been emphasized. Functional groups assigned include aliphatic and aromatic CH, methylene and methyl groups, hydrogen-bonded hydroxyls, hydrogen-bonded and chelated carbonyls, phenolic structures, minerals, and aromatic structures that are benzenoid or polynuclear. Infrared studies of structures of coal extracts, distillates, and reaction products of various processes, both chemical and physical, are discussed. Coallike infrared spectra of chars of model compounds have been utilized extensively in studies of coal structure. Ultraviolet-visible absorption spectra of coals show a lack of fine structure and low spectral intensities. These results have been applied to the questions of the chemical and physical structure of coal, particularly the question of polynuclear aromaticity of coals. The color of coal is also treated. The physical-chemical origin of the color of coal may be due to free radicals, as interesting correlations of ultraviolet-visible spectra with electron paramagnetic resonance have been obtained. The optical color of coal has been explained and simulation of the color changes observed in thin sections has been carried out, The spectra and structure of coal derivatives and other carbonaceous materials are also discussed. Possible sources of error in absorption spectral measurements are pointed out. Limited measurements of the ultraviolet-visible reflectance spectra of coal are described.

Jan 1, 1967

By Frank J. Perzak

This report describes a U.S. Bureau of Mines study on the hazards of large-scale conveyor belt fires in underground coal mines, as a function of both air velocity and distance from belt surface to gallery roof. The fire hazards considered were smoke obscuration, toxic effects of carbon monoxide (CO), and elevated air temperatures downstream of the fire. All of these hazards scale with the ratio of fire intensity to ventilation airflow. These hazards were all found to be greater at the lower belt-to-roof distance, owing to the greater fire intensities that resulted. The hazards of smoke obscuration and elevated CO levels were greater at lower air velocities. Smoke obscuration was found to be the earliest hazard, reaching critical levels before the stage of belt flame spread. Critical levels of CO and downstream air temperatures were not reached until the later stages of flame spread. Fire growth rates during rapid flame spread were much greater than rates measured during the early stages of belt burning. Data were analyzed to determine the early-warning capability of fire sensors. Smoke sensors provided the earliest warning, followed closely by CO sensors. Thermal sensors did not exhibit any early warning capability.

Jan 1, 2010