Search Documents

By Mark J. Schultz, William J. Francart, Gary J. Wirth

Atmospheric Monitoring Systems (AMS) utilizing carbon monoxide sensors have demonstrated their superiority over thermal type fire sensors for early fire detection in underground coal mines. After proving their capability and dependability throughout the 1980's, systems are now evolving and applying new technologies to enhance their effectiveness and reliability. The use of AMS in coal mines which utilize diesel equipment presents unique obstacles. Exhaust gases from diesel equipment not only raise mine ambient CO readings, but also cause numerous nuisance alarms. Both of these conditions reduce the effectiveness of the AMS. New technologies, such as discriminating devices, smoke detectors, and time delays, as well as administrative controls, have been developed and are being utilized to help reduce nuisance alarms produced by the diesel exhaust. This paper will discuss these technologies and administrative controls which are being utilized in coal mines to enhance the effectiveness of the Atmospheric Monitoring Systems. Reference to specific products does not imply endorsement by the Mine Safety and Health Administration.

Jan 1, 1995

By Steven Keim, Steven Stansfield, Kevin Andrews

Geotechnical, geological, and hydrogeological fieldwork and data collection for the mining industry is often conducted by younger, less-experienced staff members. In many cases, fieldwork personnel are recent college graduates or are otherwise relatively new to the mining industry. Due to busy schedules, staffing shortages, project budgets, and in some cases, poor management, new fieldwork hires often do not receive thorough training. In the past and the present, many workers in the mining industry learn(ed) by “doing.” While this is still considered to be the most practical approach and the easiest way for a company to determine the skill set of an employee, there is always some risk involved in the “feet to the fire” method. The reality is that field personnel are often collecting data on which major operational decisions will be made or on which regulators will base enforcement decisions. Inadequately trained or inexperienced field personnel may collect inaccurate data or fail to recognize key conditions that may influence decisions made by regulators, design engineers, mine managers, and corporate leaders. Even the best engineers may come to incorrect conclusions if they are starting with poor input data. Decisions based on inaccurate data often result in delays, budget issues, unsafe conditions, or even worse consequences. This paper provides numerous mining industry examples of incidences where inaccurately collected field information did, or could have, resulted in major adverse consequences. The paper also offers some simple approaches to minimizing the potential for such problems.

Jul 1, 2023

By David J. Brown, Richard C. Fountain, Marc V. Hurst

The Central Florida Phosphate District, one of the most productive phosphate districts in the world, has been mined principally within Polk and Hillsborough Counties, Florida. Recent development is extending the district southward into Hardee, Manatee, and DeSoto Counties. This area is known as the Southern Extension. The combined area of these two phosphate-bearing areas encompasses about 2,000 square miles. Structurally, the district and its Southern Extension lie at the southern end of the Ocala Arch and are flanked by the Hillsborough High to the northwest. South of this area is the South Florida Embayment. The Osceola Low lies to the east. The phosphorite within the Central Florida Phosphate District generally dips very gently (<0.1°) to the south. The boundaries of the central Florida Phosphate District are generally defined by thinning of the phosphorite due the adjacent structurally high areas to the north, west, and east, and by increased clay, CaO, and MgO content reflecting lithologic differences to the east and south. The Bone Valley Member of the Peace River Formation and reworked sediments of more recent age were the primary ore-bearing horizon in the Polk-Hillsborough County area. As those reserves are depleted, the less desirable phosphorites of the Peace River Formation are being exploited in the Southern Extension.

Jan 1, 1993

By E. R. Spencer, E. R. Bauer, G. P. Cole

Overexposure to hazardous noise has been found in most mining sectors, with up to 100% of the surveyed workforce experiencing a noise dose that exceeds the U.S. Mine Safety and Health Administration (MSHA) permissible exposure level (PEL). As a result, miners show elevated rates of hearing impairment of 70-90% by retirement age. To help manage noise exposures, the U.S. National Institute for Occupational Safety and Health (NIOSH) developed the Determination of Sound Exposures (DOSES) software and implementation guide for use by mine management and safety personnel. This paper describes the development, functions and basic operation of the initial-release version of DOSES. A revised version is being developed to incorporate additional user-suggested functions, and its development and implementation to assess noise control solutions will be described in a future article. The software relies on a time-motion study that profiles the worker’s daily activities. Observations about the worker’s location and tasks or other activities are recorded along with the start and end time, to determine the duration of the tasks so they can later be matched up with the noise data. The software gives the user the option of assessing dose relative to the MSHA PEL, the action level or the NIOSH recommended exposure limit. The software generates a variety of interactive on-screen displays showing where, when and how the worker’s noise dose accumulated. It also can generate customizable printed reports. These outputs can be used to highlight the tasks, locations and times that are associated with the greatest amount of a worker’s noise exposure. DOSES simplifies and streamlines the record keeping and analysis associated with time-motion studies and worker noise exposures, so mine management can make engineering noise control or administrative control decisions to limit the noise overexposure of their workers.

Jan 1, 2011

By P. McGrath

From the mid-1980s through 1997, Echo Bay Alaska evaluated reopening the historic Alaska-Juneau (AJ) gold mine. Their original proposed project underwent numerous modifications in order to minimize the potential for significant environmental impacts. One of the major modifications involved changing .the tailings disposal method from a conventional tailings impoundment to submarine tailings disposal (STD). In 1995, the U.S. EPA began work on a Supplemental Environmental Impact Statement (SEIS) to assess the impacts of the STD proposal. Key features of the STD impact assessment included fate and transport modeling to determine the extent of tailings deposition and the use of ecological risk assessment to predict marine impacts during deposition and ecosystem recovery following STD. A key feature of the SEIS regulatory process included a rulemaking proposed by EPA to exempt the AJ tailings from effluent regulations. Critical to success in moving the project forward was early development of an interactive working relationship with other regulatory agencies and the public.

Jan 1, 1998

By Sakshi Hazuria Anderson, Angela Binder, Oscar Jaime Restrepo Baena, Simit Raval, Sandra Nowosad

As the mining industry faces times of change, new challenges arise to ensure raw material supply for future generations. Different scenarios are currently shaping the way we mine and teach mining engineering. Led by an increasing demand for raw materials, net-zero requirements for improving long-term operation performance, technological advancements such as automation and digitalization, safety improvements, environmental considerations and a need for social acceptance, mining is pursuing to change and adapt to these requirements at a faster pace. Such changing times raise new concerns, one of the most relevant is the lower number of students interested or enrolling in mining engineering and related fields, leaving mining engineering as one of the less preferred career options for students. Nonetheless, it is essential to continue addressing and supplying the skill sets that are suited to the contemporary and future mining industry. To this end, globally, academia is currently undergoing several initiatives such as curricula updates and adaptation, upskilling, improving teaching practices and techniques, including e-learning techniques, enhancing industry-academia and inter-university collaboration, and much more. In countries like Australia, where mining plays a crucial role in the economy, the need for curriculum updates is more pressing than ever. As the mining industry evolves with new technologies and sustainable practices, there is a growing demand for a workforce skilled in these modern approaches. Recognizing this necessity, universities such as the University of New South Wales and Curtin University have taken significant steps to revamp their educational programs. By updating their academic offerings, both universities aim to equip graduates with the necessary skills to drive innovation and sustainability in mining, supporting Australia’s development as a leader in this critical sector. Moreover, the selection of topics that drive curricula update and the focus of the research institutions in mining engineering must extend beyond mere technological and technical aspects to include social and ethical dimensions. In this context, the Universidad Nacional de Colombia, in association with the Colorado School of Mines, has introduced the topic of humanitarian engineering (HE) in 2020. HE is a sociotechnical approach that focuses on developing engineering solutions that promote the sustainable development of communities addressing their basic needs and aiming to improve their quality of life (Menéndez-Aguado et al., 2023; Smith et al., 2023). By focusing on sustainable development, community engagement and equitable resource distribution, HE helps the industry build positive relationships with stakeholders, reduce conflicts and foster social license to operate. As the mining industry seeks sustainable and socially responsible practices, future engineers require training in this area to understand the broader impacts of their work, fostering a mindset that prioritizes community well-being and environmental stewardship alongside technical proficiency. However, developing skills toward humanitarian engineering and sustainable mining among new generations of mining professionals remains a complex task. Integrating the necessary content to prepare future engineers for the multifaceted demands of the industry into a single study program poses significant challenges. To address these complexities, modern educational approaches such as the ones integrated in the mining engineering programs at Clausthal University of Technology can be leveraged to enhance both teaching and learning experiences (Binder, 2024b; Bothe-Fiekert et al., 2023; Nowosad et al., 2024). Innovative teaching methods, such as blended-learning, project-based learning, case studies, scenario simulations and interdisciplinary collaborations, can help bridge gaps by fostering critical thinking, creativity and empathy among students. By embracing modern pedagogical strategies, institutions can better equip future engineers to navigate the evolving landscape of the mining industry responsibly and effectively.

Dec 1, 2025

By Eckl, Martin, Stefan Lemke, Martin Londschien

"Tunnels are built with a design life expectancy of over 100 years. One key component of such a design is the waterproofing system, which must reliably fulfil its function during the whole service lifetime of the tunnel structure. This paper deals with the determination of test criteria for the durability assessment of geosynthetic products in tunnel sealing systems. Hereby the understanding of the individual aging processes is crucial along with the long-term experience with these materials to ensure the transfer of the laboratory results and performance to site practice (test calibration) and vice versa. To verify the results of the new test procedure the material properties of geosynthetic products samples removed from older tunnels are investigated. Based on the presented results of the still ongoing research programs some preliminary conclusion regarding the updating of regulations for tunnel sealing systems are given. INTRODUCTION Watertightness is directly related to the durability and serviceability of the concrete lining. Therefore, modern traffic tunnels and shafts (Figure 1) are generally protected against mountain/ground water and water penetrating through rock fissures by a sealing system, for example with a loose-laid polymeric sheet membrane. Hereby the waterproofing sealing systems must be reliably fulfilling their function during the whole service life of the tunnel structure, regularly of more than 100 years. In consequence, the quality and lifetime performance of the waterproofing materials—beside the correct professional and careful installation in a tunnel infrastructure, is of great importance. The challenge for the industry, owners, operators and designers is ultimately the development of qualification testing and requirements (acceptance criteria) for products to ensure the design lifetime performance. Hereby the qualification procedure is seen as a routine integrated in standards, norms or guidelines, wherein test procedures should cover typical environments for the specific application fields. Polymeric synthetic raw materials are increasingly used in products with long service lifetimes (e.g. in injections, gaskets, waterbars, spray-applied and sheet waterproofing membranes). During service they are subjected to chemical (e.g. oxidation processes) and physical (e.g. changes in morphology) influences from the environment, which affect their mechanical properties—and they age. Hereby organic materials are more affected than inorganic materials. Also, polymers show strongly temperature-dependent properties compared with other construction materials. However, their long-term aging behavior is not given per se and has to be explored extensively by suitable tests, which simulate—under accelerated processes—real exposures and loads. Hereby the understanding of the individual aging processes is crucial along with the long-term experience with these materials to ensure the transfer of the laboratory results and performance to site practice (test calibration) and vice versa."

Jan 1, 2016

By G. A. Campbell

This paper considers the international market trends of the rare earths and how they are strongly influenced by the by-product/co-product nature of their mining and processing. The two main economic minerals for the rare earths are bastnasite and monazite. Monazite is primarily a by-product of mining ilmenite and rutile and is affected by changes in these markets as well as the presence of thorium. Bastnasite is a by-product of mining iron ore in China and a stand-alone product in the USA. The paper will use conceptional relationships and empirical data to delineate the various by-products/co-products relationships and how they determine observed international market behavior.

Jan 1, 1996

By R. J. Sheets

"INTRODUCTION What is the primary responsibility for geo-engineers in mining? Early in my career, I was asked this question by an experienced engineer. After explaining some various tasks, I was informed that the main responsibility was to monitor. Although this proved true for many cases, I came to understand that monitoring is merely one means to achieve the primary responsibility of a geo-engineer – ensure the safety of all personnel. The potential for groundwater to impact stability allows this responsibility to be shared with hydrogeologists as well. Inherently, we monitor to identify risks; we analyze designs and develop models to mitigate risks; and we are provided opportunities to explain to supervisors the geo-risks to personnel and mine plans that will result from particular courses of action. A couple years ago, I took an opportunity to share experiences from the first several years of my career as a geotechnical engineer with junior geo-engineering staff within my company. The intent was to share situations that were a part of my development, so they could learn and understand their responsibility to the safety of all personnel. Similarly, the purpose of this paper will be to share these thoughts with new geo-engineers in the industry in order to help prepare them for the challenges they will face. WHAT IS OUR PURPOSE? A senior hydrogeologist shared an experience that occurred in their career. The experienced hydrogeologist had spent some time with the hydrogeology staff, most of them relatively new to the mining industry, to understand how they viewed, and carried out, what they perceived as their responsibility at an active mining operation. After a couple months of observing and mentoring, the senior hydrogeologist met with everyone and posed the question above. I am sure that most junior geo-engineers would start explaining different tasks or projects that they must complete. The list would include monitor groundwater levels, track slope movement, evaluate designs, build models, oversee drilling programs, etc. These individuals did as well their supervisor. After going around the room allowing each individual to answer, the experienced hydrogeologist provided them the real answer to the question: SAFETY. If you examine the root intent of nearly every responsibility geotechnical engineers and hydrogeologists have, it is to apply our professional skills to ensure the safety of our workforce. When the objective of safety from the geotechnical and hydrogeology disciplines is achieved, inherently accomplishing the mine plan should follow suit, or it should significantly minimize the impact by gravity or groundwater. The objective of a hydrogeologist is to ensure the soil or rock around an open pit or underground mine is dewatered; this specific objective will reduce pore pressures which could lead to a possible ground failure. They ensure a working bench/UG level is dry, so operations are not dealing with adverse conditions while mining. A geotechnical engineer is expected to use all available information and engineering judgement to provide design recommendations, so that the mine will not catastrophically fail. Additionally, they will implement the monitoring systems to identify hazards in advance in the event that the design is flawed and people need to be evacuated. We all know that safety is important to everyone; however, our particular set of technical skills play a significant role in ensuring the safety of a large portion of the global mining workforce."

Jan 1, 2018

By Tad S. Golosinski

The paper presents the computing stream of the mining engineering curriculum at he Western Australian School of Mines (WASM), a branch of Curtin University of Technology. Learning to use computers begins during the first semester of the initial year of studies and culminates in the Mine Design Project done during the last semester of study. It covers all areas of computing which are judged to be of importance to the graduate.

Jan 1, 1996

By Jerry Dollinger, Levent Ozdemir

An extensive series of laboratory cutting tests using linear and rotary cutting machines were carried out with the objective of investigating the feasibility of achieving very high rates of penetration with TBMs in rocks of low to medium strength. These tests were performed with large diameter disc cuttrs at cutter path spacings and penetrations of up to 12 and 1.75 inches, respectively. A predictor model was also formulated to characterize rock cutting at large spacings and penetrations.

Jan 1, 1987

By W. Keilich

A methodology of subsidence prediction using the Distinct Element code UDEC has been developed as an alternative for subsidence modelling in the Southern Coalfield, New South Wales, Australia. The models have been validated by comparison with empirical results and observed caving behaviour. At this stage, modelling capability is limited to flat lying terrain. It is planned to apply the methodology to areas of high topographical relief to investigate the mechanics of valley closure.

Jan 1, 2006

By J. L. Post, L. Borer

Small seams of fibrous tremolite and actinolite commonly occur in many California counties. A number of larger seams of this fibrous material were mined from 1882 until about 1955. The fibers from these mines were used for making acid filters, battery cases and fire-resistant paint. With increasing population, new residential areas are being developed in the foothill regions, leading to increased contact with seams of fibrous amphiboles. These forms of asbestos can be particularly dangerous to human health. Thus, it is necessary to determine the locations of these mines and adjacent veins and to identify the specific amphibole minerals present.

Jan 1, 2003

By J. I. Schoenherr, T. A. Baloun

Mixed cable waste, which amounts to more than 200,000 tpy in Germany, is subjected to recycling. In most cases cable recycling means only recovering copper and/or aluminum metals. The remaining cable waste contains nearly 3-8% of the reusable materials, and is disposed of in landfills. Aluminum is recovered within copper products and leads to lower product prices. Preliminary laboratory tests show that the use of shaking hydro-tables as well as electrostatic separators result in less than 1 % of metals in the residual material. The products are high in grade at metal recoveries of more than 85%. Furthermore, applying a modified electrostatic separator may also lead to an efficient Cu-Al separation. The separation efficiency amounts to up to 95%.

Jan 1, 2002

By B. J. Arnold, F. F. Aplan, S. Chander

There is a broad range of chemical reagents of potential use to the coal preparation industry: flotation frothers, flotation collectors (for coal, ash minerals or pyrite) and collector-assisting (conditioning) agents, flotation depressants (for coal, ash minerals or pyrite), pH regulating agents, acid mine drainage treatment chemicals, flocculants, filtration aids, dispersants, dust suppressants (wetting agents and car-top or pile binders), freeze conditioning agents, water treatment chemicals (corrosion and scale inhibitors) and suspension stabilizing reagents (dispersants, stabilizers, biocides). The application of each of these types is discussed with particular attention paid to those of greatest importance: flotation frothers and collectors, pH regulators and acid mine drainage treatment chemicals, flocculants and freeze conditioning agents.

Jan 1, 1986

By Roger B. Jr. Herbert

Surface water samples were collected from water accumulations at the surface of a neutral pH mine tailings deposit in Kristineberg (Sweden) where algal growth and iron hydroxide precipitates were observed. Ferric iron in the aqueous samples was determined by (adsorptive) differential pulse - cathodic stripping voltammetry. The analyses indicated that labile Fe3+ concentrations were in the range <20 to 337 nM, while total Fe3+ levels were much higher at 0.9 to 8.3 uM. The labile Fe3+ levels are more than two orders of magnitude greater than would be expected based on equilibrium with ferrihydrite. These results suggest that iron complexation with strong ligands in the surface water competes with iron hydrolysis, and that these ligands may be of algal and/or bacterial origin.

Jan 1, 2000

By C. DeRossett, K. F. Unrug

Sedimentary rock fractures commonly occur in the vicinity of outcrops. Mine highwalls and highway cuts provide excellent views of these near-surface joint systems. This paper explains the origin, characterization, distribution and extent of the these joint systems with reference to the lithologic composition of the rocks. The practical implications of these joint systems on the operation of a mine are described. Included are discussions of the discontinuous deformation that results from surface subsidence, the stability of mine portals and near-outcrop underground operations, and the stability of highwalls when using highwall miners and strip operations. Some design procedures are recommended to minimize the problems encountered within mining areas having intense joint systems.

Jan 1, 1996

By A. Foscolos

Land reclamation and rehabilitation of depleted coal mines in the wider area of Ptolemais-Amynteon is practiced by the Division of Mines of the Public Power Corporation of Greece in order to conform to the concept of environmentally sustainable economic development of its operations. Detailed chemical and mineralogical studies were performed on reclaimed soils and their crops in order to evaluate the results of land reclamation and rehabilitation while similar studies were undertaken in adjacent, regularly cultivated, soils. Results indicate that trace element concentrations as well as concentrations of elements of environmental concern to be higher in regularly cultivated soils than the reclaimed ones. However, the concentration of the elements in wheat grains harvested from both, regular and reclaimed, group of soils is the same. The reason for this behavior is the very low water solubility, of the elements in the soils, due to their high pH values and the nature of their occurrence. As a result, wheat crops produced from reclaimed-rehabilitated soils developed on depleted lignite mines in the wider area of Ptolemais-Amynteon do not pose any health problem on either humans or animals when consumed.

Jan 1, 2003

By T. N. Singh, M. M. Singh, R. B. Singh

Fly rock is common when blasting shallow holes and during secondary blasting. Although the required quantity of explosives for secondary blasts is less, noise and fly rock can have an enormous environmental impact. This paper mainly deals with field experiments on blast-design parameters and addresses some precautionary measures that can be taken when pop shooting.

Jan 1, 2000

By Arthur F. Moss

Smallbore tunnels in urban environments often present more technical and managerial problems than major large diameter schemes carried out for transportion, water supply and hydro-electric facilities. The 1.8 km Bath scheme was designed for construction in tunnel using the pipe jacking system. Unforeseen ground conditions meant other techniques were needed during construction. The paper describes the problems encountered and how they were overcome.

Jan 1, 1981