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By Cushwa, C. C.

AT the Park Utah Mine, labor costs of stoping A have been reduced from 30 to 40 per cent. by the use of double-drum hoists and scrapers. The application of scrapers varies with the methods of timbering. In stopes, which must be timbered with square-sets or stringer sets, one method is used; another is used in wide orebodies that can be held open until filling is introduced; and still another in narrow flat veins. Nearly all the oreshoots at the Park Utah lie at less than 50" from the horizontal, and most of the ore is difficult to handle through flat chutes. Proper care is probably the most important requisite for successful scraping, as serviceable equipment can be obtained from several manufacturers. One capable mechanic, therefore, was put in charge of the scraper hoists. He visits every stope daily, oiling hoists and tail1 blocks, inspects all equipment, splices cables and changes "set-ups" when necessary; his pay has been a good investment. The Park Utah now has in use ten double-drum Turbinair hoists, and one Sullivan double-drum a. c. hoist of the same capacity and outside design as the air hoists. The electric hoist is slower than the air hoists and does not pass large boulders easily; it is, however, a very effective machine. The air hoists are fast, powerful and

Jan 1, 1925

By Donald Koch

The project investigated regional impacts of mining on the ground water system of the Powder River Basin by: 1) establishment of a regional ground water monitoring network, and 2)development of , set of digital computer models to simulate ground water flow and quality, ground water contributions to surface water flow and quality (i.e., baseflow), and watershed run-off and recharge. Over 100 wells were monitored for physical and chemical parameters. Data were used as input to the model; and for the development of a comprehensive data base. The basin was modeled on a regional and subregional scale using a finite -difference model employing an alternating difference technique. Two water-shed models were evaluated for their ability to provide runoff and recharge inputs to the basic ground water model. Application of the regional and subregional models using conservative mining scenarios showed that drawdowns may extend west from the mines as far as ten miles but that impacts would be insignificant on a regional scale. The watershed model could be effectively applied to small watersheds only.

Jan 1, 1982

By P. Varona, L. Lorig, M. Board, E. Chacon

Geomechanical factors at the mine are important and will become even more relevant as the pit expands and deepens. To address these demands a team was assembled to collect geomechanical information and perform numerical analysis. The west wall is the largest and flattest of all the design sectors in the pit and rigorous studies were carried out on this wall. The wall behaviour is controlled mainly by a set of steeply dipping joints within the slope in the Fortuna Granodiorite and a weak zone, the Zona Plastica, that extends vertically near the pit bottom. These features lead to large toppling displacements in the upper portions of the wall. Two numerical models were used to reproduce the general features of failure observed in the wall. The modelling indicated that a toppling mode of failure results from shear on the steeply dipping joints. The toppling leads to slumping or landslides whereby the west wall flows slowly downslope as the Zona Plastica compresses

Apr 1, 1996

By Qingwen Shi, Brijes Mishra

Laminated rock can delaminate and fail under certain stress states. Delamination-caused roof fall and cutter roof failure is a common failure mechanism in roadways in Pittsburgh coal seam due to the existence of laminated shale roof. Two-dimensional numerical models were developed at laboratory scale based on the bonded particle method in order to simulate the delamination with particle flow code. In these models, an assembly of bonded particles and parallel weak planes represents the laminated rock. This model calibrated the micro-parameters of the bonded particlematerial and weak planes with laboratory data. The mechanism of fracturing and delamination in a laminated specimen was investigated using unconfined and confined compression test and unsupported roof compression test. The numerical results show that, under a constant horizontal stress, delamination occurswhen the stress is much lower than its compressive strength. The confined compressive test indicates that delamination is restrained by applying confining stress since delamination-caused failure does not occur during any stage of the confined compressive test. Unsupported roof compression tests showed propagation of cutter roof failure with initiation of cracks and delamination at the intersections of the roof and ribs. An outer failed zone and inner failed zone form separately. The separated zones connect and form an opening in the roof. The presented numerical results provide additional insight into process of delamination.

Sep 14, 2020

By Philip G. Burkhalter

Total yield and backscattered electron coefficients were measured in this Bureau of Mines study in an microanalyzer as a function of atomic number and of primary crier: ;y in the 15- to 35-kilovolt range. The electron coefficients were obtained indirectly from measurements of the specimen electron current and the primary beam current collected in a Faraday cage and were measured with a precision better than 0.5 percent. Secondary electron emission was suppressed with opposing potential applied to a screen grid surrounding the specimen. The values of the backscattered electron coefficients agreed with published values within 5 percent.

Jan 1, 1965

Alfred Nobel first invented a practical detonator in 1863 and then the blasting cap in 1865. At that time the detonator was used on the end of a length of safety fuse to initiate nitroglycerine-based explosives. Since then the detonator has gone through a number of changes. The instantaneous electric detonator was the first to allow remote firing. The electric delay detonator followed and allowed for timing between holes. In the mid 1970s the NONEL« Tube was invented. This tube combined with NONEL« detonators meant that many of the safety issues, such as stray current and radio frequency, associated with electric delay detonators were eliminated. This system gave the mining industry a reliable and fairly accurate system with which to detonate shots of any size. Since the early 1980s a large amount of research and development work has been done around the world to create a more accurate detonator for the mining and quarrying industry. After years of research, electronic detonators have emerged as the most accurate and precise initiation system available to the mining and quarry industry today. Electronics provide the user with millisecond timing accuracy. The improved level of timing control allows operations to improve fragmentation, throw and reduce vibration levels. There are now a number of different electronic detonator suppliers on the market today. In 2004 Dyno Nobel formed a joint venture called DetNet with AECI. DetNet has a suite of electronic detonators: DigiDet«, HotShot« and QuickShot«. This paper will focus on the HotShot« system, the first of the three new initiation systems to be released to the market in Australia by Dyno Nobel.

Jan 1, 2005

By George J. Tamara

The urban environment presents special challenges for the design and construction of earth retention systems. Complications arising from difficult subsurface conditions are compounded by the presence of urban infrastructure and existing and prior construction. The proximity of adjacent structures as well as intense prior use can cause special concerns including the potential for archeological artifacts or contaminated ground or ground water. Utilities and structures may be particularly vulnerable to the effects of ground movement, dewatering and vibrations. Difficulty of access, congestion and limited work areas may severely restrict means and methods of construction. Dewatering may be limited or prohibited because of concerns for disposal of clean or contaminated water, depletion of aquifers, drawing of contaminants to the site or dewatering induced settlements.

Jan 1, 2003

By J Koshy, M Ralph, P Foley

Mining in the state of Western Australia (WA) formally commenced in the 1840s, and over the ensuing 180 years has evolved to be the epicentre of the Australian mining industry and a significant contributor to the national economy. The lithology of WA is replete with mineralisation that hosts uranium and ‘critical minerals’ required for the global renewable energy sector. The state’s first uranium mine is under development, and high levels of activity are occurring in the state’s nascent critical minerals sector, with 168 WA-based companies pursuing rare earth-bearing minerals, 51 of which are actively drilling on their tenements. WA’s mineral deposits typically contain levels of the naturally occurring radionuclides (NORs) thorium-232 and uranium-238 that are elevated above the global crustal average. Workers are exposed to NORs during the mining and mineral extraction processes, and radiation doses that exceed applicable exposure standards may eventuate. The research traces the history of worker radiation doses from 1977 to 2020, finding the maximum dose was 163.4 mSv, more than eight times the current derived annual dose limit. Whilst 93.5 per cent of all workers received doses of less than 5.0 mSv per annum, the potential for elevated doses is ever-present as witnessed by 10.3 mSv reported in 2009/2010. The increase in activity coincides with a revision of the dose coefficients (DCs) associated with the intake of radionuclides. The research evaluates the revised DCs and forecasts doses from inhalation of radioactive dusts will nearly double, and lead to workers receiving doses exceeding 5 mSv for the first time since 2009/2010. The research finds that the current regulatory framework is fit-for-purpose. However, inter-agency relationships, and the capacity of the regulator to effectively regulate the current and future number of mining operations is questioned. The mining industry is vulnerable to capability and capacity constraints – but has failed to respond to issues in relation to competent radiation safety officers first raised by the Winn Inquiry (Winn, Mathews and Tough, 1984). Disconcertingly, monitoring of worker exposures to NORs reached a nadir in 2021, raising questions as to the veracity of worker doses reported to the regulatory agency. The research recommends personal dust sampling be prioritised.

Apr 16, 2024

By B. J. Moore

This publication contains analyses and related source data for 269 natural gas samples from wells and pipelines in 18 States. All of the samples were obtained and analyzed during, calendar year 1979 as a part of Bureau of Mines investigations of the occurrences of helium in natural gases of countries with free market economies. This survey has been conducted in the United States by the Bureau of Mines since 1917. In late 1965, the survey was expanded to include foreign gasfields. The analyses published herein were made by mass spectrometer and a special helium analysis apparatus, which are described in Bureau of Mines Bulletins 4862 and 576.3 The results of the investigation of the occurrences of helium are published annually to make the information available as soon as possible to the gas industry and the general public. Twenty-one previous publications have presented tine results of 11,883 gas analyses made prior to 1979. The first three, Bulletins 486,4 576,5 and 617,6 contain analyses and related source

Jan 1, 1980

By F. Dinter, S. A. C. Hockaday, Q. G. Reynolds

The thermal decomposition of carbonate minerals as pre-treatment before smelting reduces the energy requirement for smelting. It can also make the combustion of fossil fuels for heating unnecassary. Thermal decomposition may become important in reducing greenhouse gas emissions when producing ferromanganese alloys while simultaneously reducing electrical energy demand during smelting. A kinetic reaction rate model for the thermal decomposition of manganese ores is presented, based on published reaction rate kinetics for the decomposition of manganese oxides and calcium carbonate. The model was validated against thermogravimetric data for two carbonaceous manganese ore samples and one ferruginous manganese ore sample. The reaction rate model shows that carbonate minerals in the manganese ores are decomposed at temperatures above 900 °C while pyrolusite is decomposed at temperatures from 450 °C to 500 °C. Mn2O3 decomposes rapidly at 550 °C. Braunite decomposition at temperatures below 1000 °C was negligible. The presence of organic carbon in the samples led to further reduction of the samples during thermal treatment.

Aug 3, 2023

By C. Ogasawara

This document describes the direction and progress of the Bureau of Mines Oil Shale Mining Environmental Research Program as of January 31, 1979. It is aimed at focusing the Bureau's role in environmental research supporting oil shale development with respect to the activities of other involved government agencies and private industry. Environmental considerations in oil shale extraction, such as ecological disturbances, health and safety hazards, waste management, and socioeconomic impacts, are discussed along with the type of research known to be planned by organizations to ameliorate these problems.

Jan 1, 1979

By I D. Gregson, A Gandhe, A S. Garcia, K M. MacAndrew

"Falls of ground still cause around one-third of all underground mining fatalities. The recent introduction of mechanised room and pillar working into Indian coalmines is an example of the application of new design by measurement and safety monitoring strategies, which can be used to reduce falls of ground risks in mines.Rock Mechanics Technology, now part of Golder Associates UK Ltd (Golder), is providing rock bolt support and pillar design services to the mines using a design by measurement approach. This involves in situ monitoring to confirm support and pillar designs and pillar extraction sequences.Site examples are given of the support designs determined and the monitoring programs undertaken for both design and safety.Routine safety monitoring of roof movement using telltales is also described. A new auto warning telltale has been developed specifically to warn of imminent caving as pillars are extracted.The approach used by Golder has played a major role in ensuring the success of these projects. As a consequence, mechanised room and pillar working is now firmly established in India, and wider application is planned to help meet future demand for coal.The experience confirms that the design by measurement method for this application has important advantages over conventional design approaches using analytical or empirical methods. Firstly, it measures the design performance or outcome rather than trying to calculate or predict it. Secondly, it provides the opportunity for the design to be adjusted to obtain the optimum outcome. Thirdly, it can do this at a local level, so that the support design can be matched to changing conditions to give the most cost-effective design. Finally, it incorporates long-term monitoring of support performance, again at a local level, so that subsequent change can be identified to enable corrective measures to be implemented in a timely manner and to ensure that ground control safety is maintained.CITATION:MacAndrew, K M, Garcia, A S, Gregson, I D and Gandhe, A, 2014. Application of design by measurement for support and pillar design in mechanised room and pillar coal mining in India, in Proceedings AusRock 2014: Third Australasian Ground Control in Mining Conference, pp 65–76 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Nov 5, 2014

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

Jan 1, 1983

By R. S. Douglas

THE Granby Consolidated Mining, Smelting and Power Company, Limited, is engaged in the mining and concentrating of copper ores, and, incidentally, in the mining of coal and the production of electric power. The Company has been engaged in these various operations both on the mainland of British Columbia and on Vancouver island for the past forty-five years. This paper will attempt to cover their present operations in the Similkameen mining district of southern interior British Columbia. GENERAL CHARACTER OF THE DISTRICT The Interior Plateau in southern British Columbia ranges in elevation from 3,000 feet to 6,000 feet. In the vicinity of Princet0n, a depression in the Plateau forms a well defined basin which is floored with a series of nearly flat-lying Tertiary sediments containing some workable seams of lignite. From this basin, the upland surface rises gradually t0ward the south, from an elevation of 2,000 feet at Princet0n to 4,000 feet at Copper mountain, and 6,000 feet in the upper parts of the Similkameen basin, where it merges into the rugged and diversified t0pography of the Cascade system, with glacier inhabited peaks rising to over 9,000 feet. The valleys of Similkameen river and its tributaries are wide, having flaring sides and gentle slopes, and are separated one from another by subdued rounded spurs, of which Copper mountain is typical. The drainage of this district is taken care of by Similkameen river and its larger tributaries, such as Pasayten river, and Wolfe, Friday, and Whipsaw creeks. The name Copper mountain is applied to a gently arched, nearly flat-topped spur between the deep valley of Similkameen river to the west and the shallower valley of Wolfe creek tO the east. The mountain is appro-priately named from the number of copper deposits occurring on its sides and summit, some of which have been developed int0 an important producer, known as the Copper Mountain mine.

Jan 1, 1943

By W. Dan Walker

In recent years the Federal Bureau of Mines tested and approved four new types of self-contained breathing apparatus and a facepiece designed for use with the McCaa 2-hour self-contained oxygen breathing apparatus. The Bureau also developed and perfected a battery-powered lifeline telephone for use in mine rescue and recovery operations. Some of this equipment is described in Bureau of Mines Information Circular 7413.4/ This publication is a revision of information Circular 7413 and presents pertinent information on more recently developed mine rescue equipment. The breathing apparatus described herein are 1/2- and 3/4-hour sell-contained types of much simpler design than the conventional 2-hour self-contained oxygen breathing apparatus ordinarily used by mine rescue crews; however, it is just as important to select rescue crews carefully and to train them properly in the use, care, and limitations of the newer types of apparatus as well as the older, established types, if the newer types are to be used safely. The Bureau of Mines recommends that 1/2- and 3/4-hour self-contained breathing apparatus be used only as auxiliary equipment in mine rescue and recovery work and that the capabilities and limitations of the apparatus should be well understood by those who wear the equipment.

Jan 1, 1957

This Institute, by nature of its charter, draws on various persons in the mining and metallurgical world of Australasia for its President from year to year, and consequently when the presidential address is given by one of these people the topic. which they generally select is a topic to which they are accustomed and on which they are able to speak with authority.As most of you know, my prime object in life has been concerned with steelmaking, so tonight you can steel yourself to the thought that you are going to be spoken to about steelmaking.Even if that were not the case, and were I not particularly interested in steelmaking, I think it would be appropriate to look at steelmaking in a broad sense on a basis of pure metallurgical interest, because the steel industry is going through as big a revolution today as it went through something over one hundred years ago when Bessemer made a theory become a fact.Bessemer, and as the Americans prefer to think Kelly, separately conceived the idea of blowing cold air through molten pig iron, and, contrary to the then general belief, this did not result in cooling of the metal but succeeded rather in heating it, and in burning out of the rather crude pig iron the impurities which prevented it from becoming a ductile metal.For many years before this, steel had been made in a very small painstaking way by what was known as the crucible process. Benjamin Huntsman is credited with having developed the crucible steel making process to a stage where it could make a reliable and trustworthy product, but he...

Jan 1, 1961

Despite modest improvements in the performance of domestic interest rates and gross national product,1 fixed investment in domestic producers' durable equipment continued to weaken during the second quarter of 1982 and declined at a 12.8 percent annual rate compared with the first quarter.2 Large declines occurred during the second quarter in expenditures on many of the major mineral-consuming industries such as aircraft, computers, agricultural and construction machinery and mining and oil field equipment. These data appear to be consistent with the low level of business investment plans for 1982 reported in the DOC's Bureau of Economic Analysis survey of expenditures on new plant and equipment.3 Domestic and foreign industrial production and mineral industry production activities continued to decline in the most recent period because of weak demand conditions (Tables 1 and 2). The U.S. mining production index declined 7.7 percent between April and June as compared with 1.2 percent for total U.S. industrial production (Table 1).

Jan 1, 1982

By Margaret R. Egan

A series of experiments were undertaken by the Bureau of Mines to determine the emission products of several types of conveyor belting and other combustible materials found in mines. These experiments were conducted under intermediate-scale, simulated mine conditions to determine smoke characteristics and gas concentrations. From these determinations, heat-release rates, particle sizes, obscuration rates, combustion yields, and production constants were calculated. Three types of belts were investigated: chloroprene, also known as neoprene (NP); polyvinyl chloride (PVC); and styrene-butadiene rubber (SBR). The belts were designated as ignitable or self-extinguishing depending on the length of the burning time and the subsequent combustion products. Under these experimental conditions, the SBR belts were the easiest to ignite. The PVC and NP belts tended to self- extinguish within a few minutes after ignition, but were still capable of maintaining a brief flaming period. These conveyor belt combustion results are compared with previous analyses of wood, transformer fluid, and coal fires. Together they form a data base by which findings from future experiments with other mine combustibles can be compared.

Jan 1, 1988

By M. E. Hawkins

This Bureau of Mines report provides information on all of the 329 proved salt domes in the Gulf Coastal States and offshore area of the United States. It includes specific data related to location, depth to the cap rock and to the salt, storage facilities for LPG, and production of salt, sulfur, petroleum, and rock related to or associated with the dome structure in the subject area. Also included is a brief history of the salt, sulfur, and petroleum industries as related to the salt domes. Gulf Coast salt domes were the scene of the first discovery of a large deposit of rock salt in North America, the birthplace of the Frasch sulfur industry, and the location of the first large oil gushers that ushered in the modern liquid fuel age.

Jan 1, 1966

By R. R. French

The industrial minerals industry in the Atlanta, Ga., area was studied in order to better understand problems associated with exploiting mineral resources in and near metropolitan areas. A method for delineating the Atlanta urban area and its component parts was developed so that the factors affecting the location of the minerals industry could be viewed mere objectively in the urban context. Major attention is focused on the area's dominant crushed stone subindustry Demographic and socioeconomic analysis of the Atlanta, Ga., area shows that expansion of the metropolis and its environs will probably eliminate potential mineral resources from the mineral resource base in the area, and that the expanding metropolis will be the primary determinant of future mining sites. Competition for land is accentuated to varying degrees by the incompatibility of wining operations with residential and other environmental requirements. Areas of consideration are suggested to provide maximum development of land and resources for greatest economic benefits it minimum social cost. Further research is recommended to determine market locations in urban areas, optimum operating levels for industrial minerals plants, and alternatives to surface mining.

Jan 1, 1970