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By W. R. Reed, G. W. Luxbacher

As directed by the MINER act of 2006, the NIOSH Office of Mine Health & Safety Research (OMSHR) has annually awarded contracts to enhance mine safety and health. OMSHR has a history of research that focuses on both respirable coal mine dust and respirable crystalline silica (or quartz) dust, and contracts have been awarded since 2010 in support of our intramural research efforts. In 2018, a National Academies of Science consensus study report recommended expansion of respirable dust research. As a result, beginning in 2018 through 2021, eighteen contracts were awarded focusing on this area. These contracts can be grouped in three topic areas: characterization of coal/dust, development of real time monitors, and improvement of respirable dust controls. This paper summarizes the outcomes of completed contracts and the progress of current contracts.

Mar 2, 2022

By Fred N. Kissell

This U.S. Bureau of Mines report is a guide for the control of air contaminants during tunnel construction. Topics discussed are calculating air quantity requirements, types of ventilation systems, planning ventilation systems, control of methane gas, control of dust, control of diesel emission, ventilation to remove blasting fumes, measuring airflow, and measuring gases. This report does not provide detailed design information, but seeks to answer practical questions on air contamination issues.

Jan 1, 1995

By G. A. Smyres

A GaC12--B2 l-eachtng procedure and meEal-recovery method for treating an arsenical Cu-Co sulfide concentrate was developed by the Bureau of Mines as an alternative to smelting, which is no longer considered an environmentally acceptable method for treating arsenic-containing ores. The procedure involved leaching in a CaC12 solution with CaC03 for 96 h at 26 pct solids (concentrate and CaC03), 1150 C, and a pressure of 50 psig (345 kPa) with oxygen. More than 98 pct of the cobalt and 97 pct of the copper were extracted, and 99.98 pct of the arsenic and 99.9 pct of the iron remained in the leached residue. A filtration rate of 2.9 gal/(ft2.h) [118 L/(m2.h)] and a cake formation rate of 36 Ib/(ft2.h) [172 kg/(m2.h)] were obtained by filtering reacted pulp at 1000 C. More than 99 pct of the copper in the pregnant solution was extracted as CuCl2 by golvent extraction with a new copper extractant. Copper was stripped from the loaded organic with a sulfate-chloride solution, which was used as the anolyte for electrowinning of copper in a membrane cell. Copper plate produced was more than 99.99 pct pure and requi.red 0.81 (kW'h)/lb Cu [1.78 (kW·h)/kg Cu]. Cobalt sulfide was precipitated at pH 3 with Ca(HS)2.

Jan 1, 1986

By K. C. Dean

The Bureau of Mines, following passage of the Solid Waste Disposal Act of 1965, was authorized to conduct research on methods for utilizing, stabilizing, or reclaiming mineral wastes. This report summarizes laboratory research conducted by the Bureau and cooperative field studies made with the mineral industry to reduce the environmental impacts of air and water pollution deriving from mineral wastes. Utilization research showed that both dry-press and steam-cured building bricks and ceramic tile could be made from copper mill tailings and other discarded mineral wastes. Sponge iron was produced from steel mill and amination industry wastes, and valuable mineral products were extracted from such diverse sources as flue dusts and uranium tailings. Mineral wastes were combined with agricultural and/or sewage wastes to make artificial soils that have the potential of resolving several disposal problems by production of a useful commodity. Physical, chemical, and vegetative stabilization methods were evaluated, singly and in combination, for reclamation potential on copper, uranium, lead-zinc, and asbestos tailings. Suitable methods were developed in the laboratory for overcoming major adverse conditions of these wastes such as salinity, heavy metal toxicity, acidity, basicity, lack of nutrients and organics, and unstable surfaces. Field testing of these methods was performed on a variety of mineral wastes. Costs for the various stabilization and utilization-procedures developed were also determined.

Jan 1, 1986

By Tassilo Baur

In the motion picture/television industry and to some extent in the entertainment industries in general, there is often a need to use energetic materials to create special effects as part of a production which travels, generally by truck. This can in certain instances create unique compliance challenges given that a production may change its filming location daily or even more often

Jan 1, 2009

By S. M. Moore, J. F. Burr, R. Fernando, D. Snyder

"The Mine Improvement and New Emergency Response Act of 2006 (MINER Act Public Law 109-236) was passed by Congress in response to three major underground coal mine accidents in the United States that claimed the lives of 19 miners. The Act resulted in substantial changes in the underground coal industry relative to the use of technology for mine escape, rescue, disaster response and other areas where the lack of these technologies contributed to the fatalities caused by these tragedies. This year marks the 10th anniversary of the MINER Act, which makes it an opportune time to reflect on the events that led to its passage, the changes that have been made since then, and the work that remains to be done. As discussed below, the last decade has demonstrated tremendous cooperative efforts among mining operators, technology innovators, labor, The National Institute for Occupational Safety and Health (NIOSH), the U.S. Mine Safety and Health Administration (MSHA) and state regulators, resulting in substantial improvement of the technologies used for escape and rescue and noteworthy progress toward meeting many of the goals of the MINER Act. While the MINER Act and this article pertain primarily to coal mining, many of the technologies are equally applicable to any underground mining and have already found some acceptance outside of coal. TECHNOLOGY GAPS TARGETED BY THE MINER ACT The MINER Act addressed several technology challenges: • Problems with donning and switching between self-contained self-rescuers (SCSRs). • Poor visibility in smoke. • No wayfinding assistance for escape from the mine. • Limited breathable air supply. • Inability to locate trapped miners. • Inability to communicate with trapped miners. • Failure of mine seals. The MINER Act had several provisions that prescribed specific safety technologies intended to address these issues. Many of these were directed at post-accident technology requirements — an area in which Congress mandated additional technology investment. Specifically, the Act required mine operators to submit emergency response plans (ERPs) that contained provisions for implementing new or improved post-accident communications, tracking, lifelines, refuge alternatives and breathable air supplies along with training for emergency procedures and local coordination of emergency response. Most of the requirements were to be carried out within three years of the ratification of the MINER Act. In addition to these requirements for mine operators, the Act clarified and expanded NIOSH’s role and authority in enhancing the development of new mine safety technologies and expediting their commercial availability. The MINER Act also required NIOSH to develop research on refuge chambers, mine seals and the use of belt air and fire-retardant belts. Mine seals had to be upgraded and MSHA turned to NIOSH for applied research to establish the new explosion-resistance requirements. Progress toward closing the gaps."

Jan 1, 2017

By Carroll C. Bailey, William F. Boericke

Mine financing, or providing adequate capital for developing and bringing a mining property into production, is an essential requirement for a successful operation. Today it presents a different picture than even twenty-five years ago. The day appears to be gone when a mining property could pay its own way from grass roots to production. The country has been quite thoroughly combed for surface showings from which sufficient initial profit could be immediately garnered to pay for further development and production facilities. The four M's for success in mining-mineral, market, management, and money-are still essential; but doubled or tripled wage costs and steep advances in cost of equipment and supplies throw increased emphasis on adequate capital funds for bringing in a prospect and making it a producer. Consequently, the old picturesque, although seldom rewarding, grub- staking procedure where a single venturesome citizen might advance funds to a prospector on a fifty-fifty basis for whatever discovery he might find, has largely disappeared. Its place, to some degree, has been taken by the small syndicate of venturesome members who band together for furnishing funds to a group of prospectors for the same general purposes. Such a syndicate has a definite organization and is usually assured of sufficient initial funds, or flow of funds, to carry on work for several years. It is headed by an engineer-promoter who has had considerable field experience as well as personal knowledge of his prospecting crews. For the owner of a potential mining property who has ample capital, the problem is to determine (1) justification for the necessary investment in exploration and development, and (2) the economics of the enterprise as to size and degree of integration of the final operating entity. If the owner of such a property has little or no capital, he also faces these same basic problems but, in addition, must be able to present the findings of fact and persuade the prospective investor that the enterprise will produce

Jan 1, 1959

By M. C. Manderson

Phosphate rock is a naturally occurring mineral which, in upgraded form, is important to both agriculture and industry. Phosphate rock normally must be upgraded before it can be assimilated and used. Most of this upgrading is now carried out by chemical means, largely through the reaction of a strong inorganic acid (primarily sulfuric acid) with the phosphate rock to remove major impurities and to produce soluble phosphate. A less important but yet still commercially significant conversion method involves the thermal reduction of phosphate rock at high temperature in an electric furnace to produce elemental phosphorus. The elemental phosphorus is then converted to usable end products. This conversion route is a more costly method than the chemical route, but it has the advantage of being able to produce chemically pure phosphorus derivatives. On the other hand, the use of phosphate rock for agricultural application-primarily for use as a plant nutrient ingredient for fertilizer -does not require the same level of purity. As a consequence, the chemical method of phosphate rock upgrading is the predominant technique for producing phosphatic fertilizers.

Jan 1, 1977

By Derek V. Ellis, Jack L. Littlepage

"Marine ecosystem effects ar1smg from the discharge of man-generated wastes to the sea can be schematized as: acute poisoning, chronic poisoning, enrichment, suffocation, temperature effects, salinity effects, toxin bio-concentration, changed production rates and changed species equilibria. A professionally designed site-specific monitoring program to check for such effects can not only safeguard the marine ecosystem from degradation, but it can also protect the industry involved from unanticipated remedial action after expensive construction has been undertaken. Monitoring programs should consist of three steps. Step 1 is an ecosystem survey which should be undertaken prior to final design of the discharge system and submission of applications for permission to discharge, because there can be considerable cost savings in obtaining information at an early stage in development. Step 2 involves location of the effluent field at the time of starting discharge, and analysing its dispersal behaviour. Step 3 consists of ecosystem monitoring with sampling stations and specific tests based on the accumulated prior information."

Jan 1, 1972

By M. Mathiba

High CO2 fluxes associated with reclaimed coal mine spoils pose an environmental hazard where such sites are used for building. CO2 concentrations in excess of 25% have been reported in homes constructed on or down gradient of such spoils. The objective of this study was to investigate the effect of a mitigation trench used at one mine site on CO2 fluxes across the trench using chamber?based trace gas measurement. LI8100 automated CO2 flux system was used to measure CO2 fluxes from 32 sample points located across a deep mitigation trench on June 8 and 9. The maximum recorded fluxes were 7.29 and 8.18 µmol/m2/s, with averages of 4.15 and 5.50 µmol/m2/s, up and down-dip respectively. These preliminary results show CO2 flux is higher up-hill than down-hill at 95% significant level. This work shows that flux measurement can be used to investigate CO2 migration on reclaimed mine land. Further work is necessary to allow geostatistical modeling of the spatial variability of CO2 fluxes over reclaimed coal mine spoils. Knowledge gained would assist mining practitioners and regulators in reclamation planning for envisaged post-mining land uses.

Jan 1, 2010

By Jose Pineda, Abraham Lindo

The Panama Metro System’s Network expansion involves excavating a launching shaft for a tunnel boring machine (TBM) to traverse beneath the Panama Canal. The blasting needed for this shaft construction poses significant challenges due to the presence of concrete walls encircling the excavation. These walls must remain intact throughout construction and the tunnel's future operation. This case study is focused on devising and implementing safe blasting techniques crucial for the shaft's construction, ensuring the preservation of surrounding concrete walls and project equipment. As the interest was potential damage to the concrete walls, an appropriate vibration threshold for this project was also required as an alternative to the traditional U.S. Bureau of Mining RI-8507 limit (USBM RI8507). Blast modeling software was employed to conduct a series of blasting simulations. Parameters like hole diameter, spacing, depth, explosive type, and initiation methods were varied to evaluate their potential effects on wall stability and damage risk. The simulations revealed that smaller diameter holes and reduced spacing between blast holes would effectively mitigate the risk of wall instability. Additionally, utilizing electronic delay detonators and carefully planning the blast hole detonation sequence proved critical in minimizing potential damage. Executing these blasts in the field presented unique challenges, including strict charge per delay thresholds and logistical constraints. Consequently, continuous adjustments to blasting parameters were made and comparative result analysis. Beyond providing a safe blasting strategy for the TBM launching shaft, this study offers invaluable insights into adapting blasting designs to align with environmental and structural safety standards. These findings hold great potential to shape guidelines for analogous sensitive construction projects. They underscore the importance of leveraging prior research as a reference point, engaging with project designers and local authorities, and continually conducting testing and adjustments to ensure project success.

Jan 21, 2025

By M Kim, J Park, I-K Suh, E Kim, J Lee

One of the key technologies in developing hydrogen-enriched ironmaking operations is the control of the carburisation, melting, and dripping behaviour of the iron ore burden materials. When a hot compacted iron (HCI) is charged in the blast furnace or the FINEX Melter-Gasifier, iron oxide reduction, the reduced iron’s carburisation, and the melting of iron and slag occur successively. This study investigated the reduction, carburisation, melting and dripping behaviour of HCI under a COH2 gas mixture using the high-temperature X-ray radiographic technique. Under 100 per cent CO gas atmosphere, the dripping temperature was 1410°C. When 5 per cent H2 was introduced, the dripping temperature slightly decreased to 1400°C. Furthermore, the dripping temperature gradually increased as the H2 gas composition increased. As 30 per cent H2 was introduced, the dripping temperature reached 1414°C. The carbon concentration in the drained metal samples gradually increased with increasing H2 composition. It is considered that H2 decreased FeO content in the slag, yielding the increased melting temperature and viscosity of the slag. On the other hand, H2 accelerated the carburisation of the reduced iron by CO gas, enabling the homogenisation of the oxide materials to form a liquid phase. Therefore, it is considered that introducing H2 in the reactor is helpful to increase productivity and energy efficiency by accelerating the liquid phase’s formation.

Aug 21, 2024

This paper describes the development of an approach to sustainable development for application at the feasibility study stage for a proposed bauxite mine near the community of Aurukun, south of Weipa on the western coast of Cape York Peninsula, Queensland, Australia. The general environment for development was complex in all dimensions. In particular, the socio-demographic profile of the Aurukun community (population 1200) characterised it as being amongst the most disadvantaged communities in Australia. The traditional owners of the area, the Wik and Wik-Way people, were at the forefront in the efforts of Indigenous people in Australia to secure land rights over the past 30 years, and they had previous experience negotiating an Indigenous Land Use Agreement (the Western Cape Communities Coexistence Agreement) with Rio Tinto Alcan, the operators of the Weipa bauxite mine. Through this they had shown a well-founded sense of entitlement with respect to the development of resources on their traditional land. The Queensland State Government had recently cancelled an existing mining lease over the bauxite resource as the holder of the tenement had not fulfilled the terms of a development agreement that had been in place for 30 years. The Government was anxious to avoid any future æbankingÆ of the resource, and had decided to offer tenure to the resource on an international competitive basis, subject to the requirements of the Commonwealth Native Title Act 1993. This would require a negotiation process with traditional owners and potentially involve companies with whom the traditional owners had no existing relationship (typically developed during the projectÆs exploration phase) and who possibly had no project development experience in Australia. As well, the State Government envisaged an approach to development that drew on the significant work that industry and other stakeholders had undertaken over the previous ten to 15 years, commencing with the mining, minerals and sustainable development (MMSD) process. This work was aimed at rectifying acknowledged deficiencies with industry recognition of stakeholder interests, in particular with respect to environmental management and socioeconomic development. The approach adopted aimed to define the strategic community interests and sustainable development outcomes to which the development of the resource would be expected to contribute, and to embody these within an easily usable management structure that could be applied to each stage of project development from feasibility study through to mine closure. The logical framework (AusAID, 2006; ICMM, 2005) was the management tool utilised to order the identified interests and desired outcomes. The structure included components aligned with the key areas of development interest expressed by the community, and the initial baseline sustainable development plan (SDP) developed established component objectives, outcomes, indicative outputs and activities for the feasibility stage of the project. This established an objective framework to guide potential bidders when developing their response to the State GovernmentÆs Request for Proposal. The paper will describe the evolution of the competitive process and the parallel process for development of the SDP. While the institutional environment was politically and socially complex, the use of simple visual representations of the environment and the analysis and ordering of issues, objectives and criteria through methods such as stakeholder analysis and the logical framework approach, enable the development of a dialogue on the contribution that the development of a mining project can make to sustainable community development, and for the development of an agreed program of community support to capture the contribution. The use of the logical framework was found to have good functionality for plan development. Achieving plan outcomes though, is highly dependent on the skill of key project personnel in facilitation, team building, conflict resolution and leadership, as well as their ability to influence the behaviour of key stakeholders with the capacity and authority to require the integration of local economic development criteria in to key project development decisions.

Jan 1, 2009

By Jean Igor Margem

Materiais sustentáveis estão sendo investigados para substituir os materiais sintéticos, os compósitos com matriz polimérica têm sido aplicados em componentes, tais como capacetes e blindagem para os quais a resistência em um requisito importante. O presente trabalho avalia a classificação energética de impacto Charpy e Izod da matriz de epóxi compósitos DGEBA / TETA, reforçado com até 30% em volume de fibras de malva contínuas e alinhadas (Urena Lobata, L). Os testes de impacto foram realizados em amostras padronizadas em matriz de epoxi obtidas por aplicação de pressão em molde com cura a temperatura ambiente por 24 horas. Os resultados mostraram aumento significativo da energia de impacto com a fracção de fibras incorporadas de malva. A superfície de fratura foi analisada por microscopia eletrônica de varredura, SEM. O desempenho das amostras incorporados com 30% de fibras, sofreu apenas ruptura parcial devido a dificuldades impostas ao quebrar-se as fibras, e, consequentemente, a natureza dos quais fendas tendem a propagar na interface entre a matriz de fibra / resina epóxi, o que ajuda a absorver a energia do impacto.

Aug 17, 2017

By Jean Igor Margem

Nestes dias materiais ecológicos como compósitos com fibras naturais em matriz polimérica estão chamando a atenção de pesquisadores científicos, devido ao seu bom desempenho na substituição de materiais como madeira, polímeros à base de petróleo e outros. Neste trabalho foram avaliadas as propriedades de tração de compósitos de matriz epóxi reforçados com diferentes espécimes de fibras lignocelulósicas. Compósitos reforçados com até 30% em volume de fibras longas, contínuas e alinhadas de malva, sisal e bambu foram testados em uma máquina Instron a temperatura ambiente. A fratura foi analisada por SEM. Os resultados mostraram alterações significativas nas propriedades mecânicas com a quantidade dessas fibras. Estas propriedades mecânicas foram comparados com outros resultados em compósitos testados em ensaio de tração. A análise da fratura revelou uma fraca interação da interface fibra / matriz, o que poderia ser responsável por um maior desempenho de algumas propriedades.

Aug 17, 2017

By A. E. Lewis

The emphasis of this paper is on the characterization and testing of the slag produced by a secondary lead refinery. This work forms part of a broader investigation aimed at reducing loss of valuable product from the process as well as minimizing the environmental impact of the process wastes. It was this work that led to a critical examination of the standard waste classification tests. Characterization of the slag was carried out using a number of complementary techniques. In the broader context, the slag characterization aided in identifying process deficiencies and thus was a critical tool in suggesting potential for process optimization. For this study, the slag characterization provided a relatively comprehensive picture of the composition and properties of the slag, which facilitated understanding the behaviour of the slag under batch test conditions. On the basis of quantity of hazardous components alone, the slag is hazardous according to South African Acceptable Risk Limits (ARL). However, when both the quantity and the leach potential of the hazardous components is taken into account, standard waste tests carried out by three independent agencies indicate that the slag should not be classified as hazardous according to local regulations. Also, according to United States Environmental Protection Agency (US EPA) limits, which are independent of the quantity of the waste, the slag would not be classified as hazardous. The standard waste tests used by the independent agencies was the Toxicity Characteristic Leach Procedure (TCLP), a test which was developed by the US EPA to classify hazardous wastes. One of the requirements of this batch test is that it should be quick, simple to carry out and that the results should be reproducible. Previously, the applicability of the TCLP test to mineral processing and metallurgical wastes has been challenged on a number of points. Additional testing of the slag was carried out using both the TCLP and the Synthetic Precipitation Leach Procedure (SPLP) recommended by the American National Mining Association as being more appropriate for mineral processing wastes. The particular physical and chemical characteristics of the secondary lead slag highlighted additional limitations of both the TCLP and SPLP tests as standard laboratory batch procedures. Keywords: environmental protection, secondary lead processing, slag, leach testing, TCLP, SPLP, ARL, hazardous waste, batch tests

Jan 1, 2000

By R. Karl Zipf

A fatal explosion in a sealed area at the Sago Mine in 2006 prompted researchers and regulators in the United States to re-examine the requirements for explosion-resistant mine seals. Seals are used in underground coal mines to isolate abandoned mining areas from active workings. Prior to the Sago disaster, mining regulations required seals to withstand a 140 kPa explosion pressure. Recent research at the National Institute for Occupational Safety and Health (NIOSH)Pittsburgh Research Laboratory showed that pressures from explosions can far exceed this pressure. U.S. mining regulations now require much stronger seals. Current research focuses on understanding the science, engineering and management of sealed areas of coal mines. Scientific efforts seek understanding of how explosive methane-air mixtures accumulate using measurements and models of the sealed area atmosphere. Additional scientific efforts aim to understand the explosion pressures that can develop using a combination of numerical modeling and experiments. Engineering efforts aim to produce design guidelines for seals that can resist the new higher pressure design criteria. NIOSH researchers are also developing guidance for monitoring of sealed area atmospheres and inertization of potentially explosive gas mixtures within sealed areas. This paper seeks to encourage scientific discussion among international peers since preventing explosions within sealed areas is of interest to underground coal operators and regulators.

Jan 1, 2009

Block caving is the lowest cost underground mining method but it has relatively high risks and a high up-front capital and development cost. It has application to large, often lower-grade orebodies where high production rates can provide good returns on the investment. However, it has a range of technical risks that are peculiar to block caving and the usual financial, political and environmental risks that may be exacerbated by the long lead-in times associated with the development of a block cave operation. With initial development costs that may be $100 M to $1000 M when the building of a treatment plant is also required, it is obviously important to minimise and manage the risks. In a greenfield project, commitment to a substantial proportion of the capital expenditure may be required to gain access to the deposit, and the decision to proceed at this stage would be based very largely on interpretations of drill hole data. In established mines the data may be supplemented by geological mapping and past experience, etc. The quality of this data is critical and yet it is frequently degraded through poor techniques and avoidable omissions. The final decision to proceed would be assessed on projected commodity prices, mining capital and operating costs, dilution and run of mine ore grades. The latter will vary over the life of the project and these can be estimated with drawdown or draw control modelling techniques. In this modelling, there are further risks in the assumed modelling parameters or that the modelling technique may not be applicable or appropriate. The paper addresses the most critical technical and operational risk areas and provides some practical precautions that can be taken to reduce these and improve the reliability of the geological and geotechnical models.

Jan 1, 2000

Organization Place Date 1919 American Society of Mechanical Engineers... New York, N. Y. Dec. 2-5 American Institute of Chemical Engineers.... Savannah, Ga. Dec. 3-6 Geological Society of America..: Boston, Mass. Dec. 29-31 American Society of Heating and Ventilating 1920 Engineers New York, N. Y. Jan. Mining and Metallurgical Society of America.. New York, N. Y. Jan. 13 American Institute of Min. and Met. Engineers New York, N. Y. Feb. 16-19 American Ceramic Society Philadelphia, Pa. Feb. 23-26 American Electrochemical Society Boston, Mass. Apr. 8-10* *On Apr. 9, a joint meeting will he held with the A. I. E. E.

Jan 12, 1919

By F. L. Wideman

This report describes the sinking of No. 3 shaft at the Westvaco mine. It is one of a series of publications of the Bureau of Mines on mining methods and practices in the United States. The Westvaco mine is in Sweetwater County, Wyo., approximately 23 miles northwest of the town of Green River (fig. I), There are no permanent habitations in the vicinity of the mine, and employees live in Green River or Rock Springs, Wyo., 14 miles us t of Green River. The mine plant is on a windswept, treeless plain, from which low buttes and flat-topped ridges rise. The altitude at the collar of No. 3 shaft is 6,351 feet. The climate is arid, with temperatures as low as 40° below zero in the winter. Blacks Fork, a tributary of the Green River and a perennial stream, flows near the mine.

Jan 1, 1959