Search Documents

By W. J. Fene, R. D. Currie

The value of protective clothing in the prevention of injuries has long been recognized in many of the leading industries , but the adoption of the idea into mine safety programs is comparatively new . Once started , however , the idea has grown rapidly and the results already obtained by mining companies have shown that it is fundamentally sound . Both coal and metal mining companies are rapidly adopting these protective measures , and since 1924 many mines have become well equipped with eye , head , and foot protection . At the present time approximately 70 percent of the employees in the anthracite mines of Pennsylvania are provided with safety hats . At many metal mines all employees are provided with safety hats, shoes , and goggles . The Pennsylvania mining law provides that all shaft · workers in anthracite mines shall wear protective hats . In According to a study³ made of the nature of 3,485 temporary injuries and of the parts of the body of underground coal mine employees most exposed to occupational hazards , the head and face were injured 665 times , the hands 856 times , and the feet 565 times . Of 2,555 temporary injuries in metal mines , the head and face received 484 , the hands 788 , and the feet 357 . a similar study4 made by a coal -mining company for the year 1928 , of 556 injuries the scalp received 9 , the skull. 4 , the eyes 47 , the hands 62 , the thumbs 21 , the fingers 141 , the ankle , the feet 51 , and the toes 35 . Probably most of these injuries could have been prevented by suitable protective clothing and equipment . This study also revealed that at least one injury occurred

Jun 1, 1933

By T. H. Patching

This paper provides a review of the available information on the origin and mechanisms of the release of gas from coal seams. With the opening up of new mines in Western Canada and the increased mechanization of underground coal mines, the study of gas emissions is of increasing importance in providing safe working places underground.

Jan 1, 1970

In the past decade, the increased engagement of business in debates around sustainable development has prompted recognition of the importance of biological diversity at the local, national and global scales. Driven by increasing populations that demand rising real incomes, a range of human induced pressures are modifying natural habitats and diminishing their ability to support life. Public policy changes have struggled to arrest the loss of habitats such as wetlands or tropical forests, and the related extinction of plant and animal species. Although conservation legislation and regulation were once the exclusive responsibility of government, new partnerships are now being forged that increase the role of the private sector and non-government organisations (NGOs) in developing and delivering conservation initiatives. Since the mid 1990s Rio Tinto has had to adapt to meet the demands of a rapidly changing conservation landscape. When Rio Tinto adopted its statement of business practice in 1998 The way we work, it explicitly recognised the need to take account of relevant environmental factors in obtaining access to lands, particularly in designated areas of high conservation value. With the revision of The way we work in April 2003, the policy on land access was strengthened through removal of the word ?designated?, thereby signalling recognition of the importance of biodiversity outside of protected areas. In addition, Rio Tinto?s revised land access policy explicitly refers to the use of land that is surplus to operational requirements for habitat protection and biodiversity conservation, subject to social considerations. In late 2003 Rio Tinto further strengthened its commitment to biodiversity with the promulgation of its biodiversity strategy and related position statement, biodiversity principles? (See Appendix 1.1) and technical guidance documents. This commitment is also embodied in a variety of initiatives at the corporate and operational levels, which are reported on annually in Rio Tinto?s Social and environment review. This guide has been prepared to support the practical implementation of Rio Tinto?s biodiversity strategy. The purpose is to provide guidance on how to effectively integrate biodiversity into Rio Tinto?s operations. It is applicable to all Rio Tinto exploration, new development projects and operations, irrespective of whether they have been operational for some years or are at the beginning or end of their operational life cycles. This guidance has been developed to support the Rio Tinto Environment Standards and the Rio Tinto Community Standard and any additional supporting documents as they are developed.

Apr 1, 2005

By E. J. Kloos, R. H. Schutz, B. I. Ferber

To Assist users in the selection of reliable and satisfactory respiratory protective devices, the Bureau of Mines has established five schedules of minimum performance requirements for the approval of respirators . The current revisions of these schedules include 13D for self-contained breathing apparatus, 14F for gas masks , 19B and the amendments to 19B for suppliedair respirators , 21B for dust , fume, and mist respirators , and 23B for chemical cartridge respirators . Copies of these schedules may be obtained from the Bureau of Mines, Publications Distribution Section, 4800 Forbes Avenue, Pittsburgh , Pa . , 15213 . Approval tests on respirators are performed only at the request of the manufacturer of the respirator and at his expense. If the device meets the approval requirements , a certificate of approval is granted on the complete respirator. This certificate states that as long as the respirator is manufactured as originally approved, or in accordance with any changes covered by an extension of the original approval, the manufacturer may advertise and sell his respirator as being approved by the Bureau of Mines. Many industries and regulatory agencies require that respirators approved by the Bureau of Mines be used where respiratory protection is needed. The Bureau of Mines, however, has no regulatory power over the use of the respirators that it approves. It acts as an impartial testing agency to insure the availability of suitable and safe respirators. At frequent intervals, the Bureau of Mines purchases approved respirators and replacement parts on the open market. These are examined for conformity to the approved status, and are checked to insure that the manufacturer's production facilities are maintaining a satisfactory quality control .

Jan 1, 1966

By D. C. McLean

Early studies in the carbonate leaching of uranium ores led to the investigation of pressure leaching as a method to enhance the dissolution of the metal values in this system. The initial investigations conducted at the University of British Columbia supplemented by the work done by the group at the A.E.C. Grand Junction pilot plant, all established the higher efficiency and better economics of the alkaline pressure leaching system. This work was conducted either in laboratory autoclaves using oxygen overpressures, or in pilot plant sized horizontal autoclaves with air as an oxidant. Both of these testing vehicles utilized agitation provided by relatively high speed impellers (300 to 700 rpm), which apparently enhanced the oxidation of the uranium to the hexavalent state. The installation of vertical autoclaves on a production scale, which through design considerations require relatively slow agitator speeds (68 rpm), led to the studies of the utilization efficiency of the air addition and the use of catalytic type oxidants to effect a greater usage of the oxygen added through the aeration system. In addition to investigating the effects of the chemical additives, studies were also conducted on the effect of different impeller configurations on the extraction of uranium, which in itself is a measure of oxidation efficiency. The material presented in this paper was compiled in the Ambrosia Lake district of New Mexico, and the majority of the data was obtained in the Homestake- Sapin Partners mill, located at Grants, New Mexico.

Jan 1, 1960

By Dean. R. S.

The work of the copper metallurgy section during the year was devoted to laboratory studies of sulphur recovery from smelter smoke and combination smelting of copper and manganese. Both of these subjects were new this year. Combination Smelting of Copper and Manganese According to published work, the affinity of manganese for sulphur is greater than that of iron for sulphur, so that if a suitable mixture of com-pounds of iron, copper, and manganese be smelted to form a matte and slag, manganese should concentrate in the matte, together with copper.

Jan 1, 1937

By Hewitt Wilson

[ ]

Jan 1, 1927

By Robert S. Warfield

Eight samples of high-volatile bituminous coal, each large enough for a study of its coking properties by the Bureau of Mines, were obtained from a location along the Kukpowruk River, Arctic Northwestern Alaska. Bench scale and pilot plant carbonization studies with several patterns of coal blending were conducted. The data from these tests were compared to data from similar tests on a coking blend used by the Kaiser Steel Corporation at Fontana, Calif. The majority of the samples representing the 20-foot seam was found to have significant coking properties, and produced coke approaching metallurgical quality when blended with selected coking coals. Although oxidation effects were evident in the samples representing upper portions of the seam, it appears that the whole seam could be used.

Jan 1, 1966

By Jr. Gabler

Because of concern over the availability and reliability of an uninterrupted supply of manganese and other materials, the U.S. Congress requested that the U.S. Bureau of Mines (USBM) study the /low of strategic and critical materials in the economy to delineate and quantify the production areas where metal values are lost. As a result, the USBM developed a generic computerized commodity flow model that is readily amenable to updating. The original model developed for cobalt, with slight modifications, was used to track the flow of manganese. This report follows the flow of manganese through its metallurgical and chemical applications and highlights areas where significant losses occur owing to downgrading, export, or disposal. The study indicates that materials containing 695,000 short tons (st) of manganese were consumed domestically in 1990. Scrap recovery specifically for manganese recycling was insignificant. However, considerable manganese was recycled through processing operations as a minor component of ferrous and nonferrous scrap and steel slag. The major loss category is manganese lost in steel processing, 323,156 st or 46 pet of the 1990 apparent consumption. Most of this loss reports to steelmaking slags. Recovery from slags is technically feasible, but is not economically feasible.

Jan 1, 1995

By Darold Woodward, Stefan Haydn, Petr Pospisil

Most fatalities in tunnel fires are caused by the spread of toxic smoke. Controlling the spread of smoke is crucial to provide a survivable environment for emergency egress. A properly designed and tuned feedback control loop is required to achieve a target flow that is slow enough to allow pedestrians to escape under different boundary conditions. Feedback control loops are also helpful in optimizing energy consumption under moving traffic conditions. A reliable feedback flow control system requires sophisticated engineering knowhow and experience, careful selection of instruments and controlled variables, and thoughtful implementation from design through field testing and commissioning.

Dec 1, 2022

By Irving Wender

This report describes Bureau of Mines experiments and reviews the work of others on the exposure of coal and coal-derived products to gamma rays and some other types of radiation. Results are presented on tests of three bituminous coals and a lignite that had been pulverized to minus 200-mesh particles and exposed to 1,000 megaroentgens of gamma irradiation from spent-fuel elements of a nuclear reactor. Of about 20 chemical and physical tests in Bureau work, only mass spectrometry of gases evolved during vacuum pyrolysis of the coals to 450° C gave results indicating differences in the irradiated and unirradiated samples. Mass-spectral distribution curves for CO and CO2 evolution showed fewer irregularities (reversals of curvature) for irradiated coals; thus, mass spectrometry appears to be the most sensitive method for determining radio-induced changes in coal. It is concluded that coal is not significantly altered by gamma irradiation owing to the resistivity of its highly condensed ring structure. High-level gamma irradiation, therefore, is unlikely to prove advantageous in coal processing and utilization. Specially treated coals, because of resistivity of coal to radiation damage, may be useful as an absorbent in processing radioactive wastes.

Jan 1, 1968

By Carl E. Bagge

It is easy for a coal spokesman to relate to the theme of this meeting--that the decade of the 1970's is pivotal for the mineral industries. For the coal operator, this period is crucial. The coal industry, according to most energy forecasters, must gear its production machinery to meet a sharp rise in the demand for coal--in this decade to sustain inevitable boosts in electricity output, and in the next to start supporting a big new domestic synthetic fuels industry that is already in the formative stage. The logic of that projection flows from a combination of hard circumstances--proved reserves of domestic fluid fuels are dwindling, the hope for bountiful and cheap nuclear power must be indefinitely deferred, and the threat of long-term fuel imports to the national interests is becoming starkly visible. Only coal, with its assets of abundance, security and versatility, offers the nation an adequate and immediate lift out of its current energy crisis. A hard-won expansion of coal production made the critical difference between local power load-shedding and major area blackouts in 1970, the year the energy crisis went public. Coal will have to play that same key role, not just through this pivotal decade but through the turn of the century. But the logic of fuel demand apparently does not always extend to supply. The coal industry has had a huge production job laid out for it by the energy statisticians, but up to now the energy policy-makers have not followed through with the aids and inducements that the coal operator urgently needs to do that job well and completely.

Jan 1, 1972

By P. Heald-Wetlaufer

Doubly polished sections (i.e., sections polished on both sides) allow insights into complex paragenetic relationships, the interpretation of which is essential to understanding ore-forming processes. Alternate viewing of these optically superior sections in transmitted and. reflected light facilitates the recognition and definition of growth zones in ore and gangue minerals and the interpretation of postdepositional changes, such as hydrothermal leaching and replacement. Many such observations would escape detection by conventional petrographic methods. Our procedure for preparing doubly polished sections has evolved during the past 20 years and incorporates many standard procedures. Studies from such diverse districts as Creede, Colorado, Hokuroku, Japan, and the Upper Mississippi Valley zinc-lead district, southwestern Wisconsin, demonstrate the value of observations from doubly polished sections in constructing genetic models. The advent of doubly polished sections represents a major advance in the study of ore deposits and they should be a standard tool in every ore petrology laboratory.

Jan 1, 1982

By M. E. Coleman, G. Money

Pneumatic Conveying and Process Injection Technologies have been implemented in the metals markets for the last 40 years and have considerably improved the productivity and the performance of many processes. There have been many steps forward in handling technology and this paper seeks to consider those now offered by Clyde Materials Handling who as an established customer-driven solutions provider has turned its attention to supporting the Metals Market. Clyde seeks to utilise its knowledge, expertise and technologies to transform the production processes of its customers, who operate in the ferrous and non-ferrous metals industries.

Jan 1, 2008

By K. V. Raj, M. McNinch, A. L. Miller, J. Wilson, D. A. Parks

Diesel particulate matter (DPM) has been shown to contribute to various adverse health effects on underground miners. In order to reduce worker exposures, it is critical to measure the levels of DPM in the active work settings and in real time. However, the 5040 method, developed by the National Institute for Occupational Safety and Health (NIOSH), which quantifies the mass of elemental carbon (EC) and organic carbon (OC) in the samples, is based on full-shift samples, and can take days or even weeks for results. Use of real-time monitors could significantly reduce the risk of DPM exposure to miners, and available monitors have been shown to quantify DPM, mainly using the EC and other surrogates. The NIOSH Spokane Mining Research Division is conducting research aimed at developing a field-portable DPM monitor that is able to quantify both EC and OC. One part of this work is to understand the effect of OC on currently available real-time DPM monitors. This paper will present the results from experiments that were designed to observe the effect of OC on real time monitors and compare the results with the NIOSH 5040 method. BACKGROUND Diesel engines remain ubiquitous in mining environments and, as such, are one of the primary sources of ultrafine- and nano-aerosols in the mining environment in the form of diesel particulate matter (DPM). As a result of their small size, DPM has longer residence times in a mine atmosphere than the typically larger mechanically generated dust [1]. In addition, the small size enables DPM to penetrate deeply into the respiratory system [1], and exposure to DPM has been shown to contribute to various adverse health outcomes of the pulmonary system [2] and cardiovascular system [3]. Diesel exhaust has been classified as a carcinogen to humans (Group 1) by the International Agency for Research on Cancer [4]. Due to mounting concern about adverse health outcomes, extensive efforts are being made to reduce workers’ exposure to DPM, with the high exposures that often occur in underground mines being of particular concern [5]. New technologies are being developed to reduce engine emissions and thereby airborne DPM levels, including advanced engine technologies, a host of aftertreatment systems [6], and a variety of alternative fuels. The latter have been shown to markedly decrease respirable DPM and other hazardous components of diesel emissions from mining vehicles [7], yet high exposures persist, especially in underground mines [8]. In order to reduce worker exposures, it is critical to measure the levels of DPM in active work settings. In mine settings, exposures to DPM are measured by collecting air samples on filters (usually full-shift samples) and sending them to a lab for analysis using the Mine Safety and Health Administration (MSHA) P13 method, a variant of the National Institute for Occupational Safety and Health (NIOSH) 5040 method. The 5040 method is designed to quantify the mass of elemental carbon (EC) and organic carbon (OC) on the samples [9], which is then used to determine the concentration in the sampled air. MSHA has set a limit for exposure, which is based on the concentration of total carbon (TC), or the sum of both EC and OC. The allowable TC in the air (time-weighted average over the shift) is 160 μg/m3 of TC [10].

Jan 1, 2019

By Claude Bodeving

The present steel economy drastically increases the financial strain on blast furnace operators. As a consequence, the importance of reliable cast floor operations is increasing drastically, which has a direct influence on the required clay mass and tapping equipment performances. When using modern high performance clay masses, pneumatic taphole drilling machines quickly reach their performance limits, which has made fully hydraulic drill hammers a standard in modern cast house operation. Besides the well-established hydraulic TMT hammers with high impact energy, an alternative version with lower impact energy, but high impact frequency was developed by TMT in the past, in order to achieve improved taphole protection. TMT’s recent research has shown that the drilling requirements inflicted by the taphole condition change over the taphole length, which has triggered the development of a new hammer, capable of switching between a high impact frequency mode and a high impact energy mode.

Aug 17, 2017

By Harold J. Bennett

The purpose of this study was to develop methods for the financial evaluation of mineral deposits. This includes the selection of the best alternative mining and processing methods and production rates. This was done by performing a financial evaluation through computer simulation using sensitivity and probabilistic risk analysis. The criterion used to measure the relative advantages of these investment and operating alternatives is the discounted-cash-flow rate of return. Included is a description of the theory and methods used in the probabilistic analysis approach, which is based on the premise that the expression of a range of values in establishing an estimate for a parameter is more realistic than the choice of a single value. Numerous simulations are made using randomly selected values of the input parameters resulting in a frequency distribution of the rates of return and their relative probability of occurrence. The sensitivity analysis method is described and combined with the probabilistic analysis to interrelate mineral reserves, capital investments, operating costs, and production rates. The ability to vary these input parameters on successive runs has permitted the selection of the best alternative mining and processing methods and production rates for a given mineral deposit. For illustrative purposes the evaluation of a mineral deposit was performed using three alternative mining and processing methods at three different quantities of resources and various production rates and prices. The computer program used in this analysis was written in FORTRAN II for maximum compatability and should run without modification on most computers having BK (8,000-word) core memory, a card reader, and printer (120 characters per line).

Jan 1, 1970

By Boyd Guthrie

As the American petroleum industry surveyed its position in early 1937, it had many reasons to be optimistic concerning its future. The industry had emerged successfully from the depression, and for the first time since 1929 it had produced over one billion barrels of crude oil in a single year. The demand for gasoline and fuel oils was up, and reserves of crude petroleum and production capacity seemed adequate for the future. Although production of crude oil dropped slightly in 1938, the oil industry was still in a good position with respect to its supply of raw material, which improved economically in 1939 with the decrease of crude-oil stocks in storage above ground. However, by 1940 a threatening cloud (the invasion of France and its rapid surrender) had appeared on the horizon. This aroused Somme fears as to the industry's immediate future, and these fears were intensified the following year when the United States entered World War II. As the war progressed, more and more ships, planes, and vehicles were produced, and the problem of obtaining enough liquid fuels to supply them intensified. Hearings were held in August 1943 before a subcommittee of the Committee on Public Lands and Surveys of the 78th Congress to determine the advisability of passing legislation to promote the development of synthetic liquid fuels.

Jan 1, 1951

By A. B. Young

T HE smelting industry in Utah is represented by four plants: The Midvale of the United States Smelting, Refining & Mini.ng Co., the Murray of the American Smelting and Refining Co., the Garfield of the same company and the Tooele of the Inter- na.tiona1 Smelting Co. The first two are lead smelters, the Garfield plant is a copper smelter while the last named embraces both a lead and copper smelter. A total daily smelting capacity of over 10,000 tons is represented, of which 4000 tons is lead smelting capacity. With the exception of Tooele, forty miles distant, all of these smelters are within twenty miles of Salt Lake City. Pyrometallurgical operations in this district are con- fined entirely to the production of unrefined bullion, which is shipped east to the various refineries of the respective companies. The smelting industry in this state had its beginning away back in the latter days of the Civil War, many years before the completion of the trans-continental railroad. Ox teams were still bringing their companies of better fixed Mormon emigrants across the plains to the valley of the Great Salt Lake and those in lesser circumstances were still pushing their hand- carts over the same roads to the temporary abode

Jan 1, 1925

By B. Arvidson

Computer-controlled machine sorting may, if properly applied, have a dramatic effect on overall economics of a mine operation. Radiometric and photometric sorters have been used for many years and new developments will be reported, such as a sorter for fine particles and a conductivity/magnetic sorter. Application examples with emphasis on precious metals will be given. Economics for some of the projects will be reviewed and discussed. Sorting underground is shown to be particularly attractive, but machine sorting would be profitable in most cases based on savings in transportation and milling/beneficiation costs only.

Jan 1, 1987