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By Howard J. Handewith

Long used in mine development in England, Europe and Russia, roadheaders are growing in size, features, productivity and application. Beginning with the basics, this paper covers the economic and the technical aspects of the new roadheaders in both mine production and development. The author explains how to choose and integrate roadheaders into ongoing operations as another step in the inexorable march from labor to capital intensive mining. Innovations now on the drawing boards are covered that are the challenge of the future.

Jan 1, 1983

By H. Haselhuhn

Filtration of hematite ore slurries can be a bottleneck in some hematite processing plants due to inadequate filtration rates caused by the dispersion of fine particles. Flocculation of fine particles in the slurry decreases the specific cake resistance of the filter cake allowing for increased filtration rates. CO2 sparging of hematite slurry was shown to increase the filtration rate by altering the pH and the surface chemistry of the particles. It was shown that an increase in filtration rate of 278% can be accomplished by lowering the pH from 11 to 6.5 using CO2. This was attributed to increased flocculation of hematite and silica particles in the ore.

Jan 1, 2012

By R. L. Virta

Six companies mined fire clay in Missouri and Ohio during 2004. Production, based on a preliminary survey of the fire clay industry, was estimated to be 398 kt(438,700 st), valued at $9.81 million. This was slightly less than the production and value figures from 2003. Missouri was the leading producer state. It accounted for more than 70 percent of the U.S. production. Consumption Domestic producers sold or used fire clay primarily for refractory applications. This application accounted for 79 percent of the market. Refractory products made using fire clay include firebrick and block, grogs, high-alumina brick and specialties, refractory mortars and mixes, and saggers.

Jan 1, 2005

By R. Adsero

The volume of data produced by operating mines has increased substantially over the last 10 years. However, the volume of data and analytical capability has been negatively correlated to equipment productivity for at least the last seven years. In simple terms, as the volume of data has increased equipment performance has declined. Table (2010) tells us that ?The calamity of the information age is that the toxicity of data increases much faster than its benefits?. More data does not guarantee improving productivity; but more data is also not the cause of declining productivity. Similarly, when equipment performance does start to improve, (it must ? there really is no option if mines want to remain competitive), it will not be the data nor analytics which causes it; it will be the people using the resources at their disposal; including the data. Data and analytics can help if the toxicity of the data can be managed. The simplest form of business improvement using data is benchmarking. The objective of benchmarking is to understand and evaluate the current position of a process in relation to ?best practice? and to identify areas and means of performance improvement. The application of benchmarking involves four key steps: (1) Analyze and understand in detail existing processes; (2) Analyze and understand the processes of others; (3) Compare your own performance with that of the others analyzed; and (4) Design and implement the changes necessary to close the performance gap(s). There are however, many in the mining industries who have shunned equipment benchmarking because they believe that, ?every mine is a pilot?. In other words, the differences between mine operations make comparisons between them of little value. This paper will present a valid approach to benchmarking equipment performance and reliability, accounting for the differences and similarities between operations, producing a result which can be used to add value to mines around the world.

Feb 23, 2014

By Devin Burns, Saima Ghazal, Michael Owusu-Tweneboah, Kwame Awuah-Offei

Trust in AI systems and the nature and amount of information about the system can influence decision-making. It is, therefore, crucial to understand how AI-powered monitoring systems (e.g., gas monitoring systems) influence miners’ trust and decision-making in emergency evacuation. This work focused on measuring the differences between how participants respond to a simulated underground mine emergency evacuation situation when warnings are represented as coming from a human or AI-based monitoring system. We also manipulated the amount of information participants received about the system, yielding a 2×2 between-participants survey design. The participants received an alert message about rising gas levels in a mine and provided a response on how they would react and reported their perceived safety. We also asked questions to assess their trust in, preference for AI over human-based gas monitoring systems, and whether they are willing to delegate the duties of underground gas monitoring to AI systems. The experiment results show the amount of information had a significant influence on miners’ trust and decision-making. The safety perception of participants based on age, number of children and ethnicity was significantly different from one category to another. This work provides valuable insights as the mining industry deploys AI systems to aid mine safety.

Feb 1, 2025

By E. A. Metz

Work related pulmonary diseases are in the top TEN causes of occupational disability and death in the United States. Likewise, it also ranks high inmost of the other industrial countries. It is difficult to know the true occurrence of occupational lung disease because of poor documentation. This is especially true when one examines workers’ compensation claims. Most frequently, silica and asbestos are paramount in our discussion of work related pulmonary disease. Little consideration is given to other “dust-related” diseases, irritant reactions, reactive airway responses, and hypersensitivity reactions. The major classification of occupational lung diseases will be discussed. This includes both acute and chronic disease that arises in the work place, especially, the mining industry. It’s more important to make an accurate evaluation and diagnosis for the prevention of disease among other workers.

Jan 1, 2000

By D. F. Scott

The purpose of this study was to determine if miners are at risk from exposures to chemicals used in the mining industry, and determine the nature and sources of the illnesses and injuries. The authors reviewed the Mine Safety and Health Administration?s (MSHA) Employment and Accident, Injury, and Illness database and identified 2,705 cases of chemical-related injuries and illnesses that were reported to MSHA from 1999-2006, involving 66 different chemicals. The main source (cause) of chemical-related cases was acids/alkalis (about 39%). The primary nature (effect) of chemical-related cases was chemical burns (about 57%). The job classification where workers incurred the most chemical-related injuries and illnesses was cleaning plant operator/media operator/boney preparation plant operator/crusher worker. The number of nonfatal days lost did not change significantly and overall, the incidence rate of chemical-related cases decreased by 36%. Chemical burns accounted for a large number of injuries; mining companies should carefully examine their personal protective equipment (PPE) requirements, training methods, and safety culture to insure that their workers are protected.

Jan 1, 2009

By M. A. D. Azevedo, J. D. Miller, R. Kobler, E. Mutkowska

Up to 3 million tons of automotive shredder residue (ASR) is generated annually in United States. Plastics are the most valuable component of the ASR material making up approximately 25% of the total weight. In order to reuse these plastics, a selective process is required to separate each plastic, with very high purity and favorable economics. One separation technique, which may be able to selectively recover the plastics from ASR, is flotation. The preliminary flotation results have demonstrated that acrylonitrile-butadiene-styrene (ABS) and polycarbonate (PC) can be selectively separated from the model ASR feed, the PC/ABS/PA 66 system, by appropriate control of the surface chemistry.

Jan 1, 2001

By C. C. Clark

The National Institute for Occupational Safety and Health (NIOSH), Ground Control Engineering Branch is investigating the use of shotcrete in weak rock mass mines with the objective of reducing fatalities and injuries resulting from rock fall accidents. When shotcrete is used as part of a multi-element ground support system there is a need to know when the material has developed a threshold early compressive strength of approximately 1 MPa (145 psi) for safe re-entry of miner and machine into shotcreted mine workings. This equates to the material having developed enough strength to be self-supporting and allow for emplacement of the remaining support elements that require drilling of the shotcrete layer without degradation. NIOSH researchers have developed methods and portable test equipment to measure shotcrete strength on-site in the first six hours after application using the ASTM C 116-90 (1990) standard. These advances were demonstrated in tests on five commercially available shotcrete mixes, sprayed as dry shotcrete using the field expedient methods and equipment. The strength values from these tests allowed for real-time identification of the early strength threshold and were consistent with strengths reported using laboratory-type equipment. The findings of this NIOSH research for determining shotcrete early strength can improve mine safety by providing a method for determining initial site specific material property values to be used for design and as a means to conduct on-site quality control and monitoring during production.

Jan 1, 2010

By U. Thorley

Management of mine and tailings reclamation activities by surface mining oil sands operations in Alberta, Canada is experiencing increased national and international attention. Of particular concern is the ability of existing mines to execute and fund reclamation activities. Concern stems from a lack of demonstrated tailings reclamation technologies, perceptions of a poor track-record of reclamation activity by industry, and a lack of transparency with respect to the potential cost of reclamation activities relative to the monies secured in Alberta?s Environmental Protection Security Fund (EPSF). Limited information is publicly available regarding reclamation costs and technologies. Available data typically comes from disparate sources. This paper examines the expected costs of oil sands reclamation activities through a study of corporate Asset Retirement Obligation (ARO) liabilities, the Province of Alberta?sEPSF, and published data relating to reclamation costs.Issues relating to current liability funding are introduced.

Jan 1, 2011

By P. S. Hettinger

Land Application Discharge (LAD) is a useful method of disposing of waste water from mining operations and in certain climatic regimes, stormwater runoff. LAD systems function under the premise that metals, salts and nutrients in water are dispersed over a large area and are effectively assimilated into the soil profile. Depending on the soil structure, migration or mobilization of dissolved metals through the soil profile can be Substantially reduced. Land application of treated effluent from sewage lagoons or waste water plants was probably the first general use of land applied water. LAD has gained popularity with the mining industry as a means of disposing of waste water and process water. In addition, large volumes of snow meltwater and stormwater are often placed in storage in Montana during spring, and Land Application Discharge has shown to be an effective method for disposing of stormwater during the dry, summer season. LAD can also provide an alternative to recycling or treating waste water at on-site waste water treatment plant&. Application of stormwater or process water can result in little or no change to the background concentrations of metals in baseline water quality samples. One cautionary note about LAD: high salt concentrations and pH values are associated with process water from heap-leach facilities and are known to cause burning of local vegetation. Some pre-treatment of process water may be necessary to prevent such environmental problems.

Jan 1, 1994

By S. Mishra, C. Shon, D. Saylak

Only 40% of fly ash generated by the power plants in US are recycled and used for commercial applications. Of these, the high lime, Class C ash had been preferred. Systematic laboratory and field-scale studies have shown that, by including calcium chloride in the mix design of stabilization of roadbed materials, both Class C and Class F fly ashes can be effectively utilized. Test data reveal that the addition of calcium chloride to the system accelerates its curing rate, thereby increasing early strength and long term durability of the constructed road. For road construction, a preblended Class F fly ash–CaCl2 system tends to be more forgiving than the Class C fly ash–CaCl2 system. The former system produces more durable roads. The role of calcium chloride as an accelerator in these systems is discussed along with a mathematical model developed for fly ash- CaCl2 stabilized roadbed systems.

Jan 1, 2007

By Muhammad Azeem Raza, Samuel Frimpong

Underground mining environments are inherently hazardous and can lead to emergencies where effective rescue and self-escape become critical. Missouri University of Science and Technology is pioneering new technologies for effective self-escape. The rescuers and miners need to be trained in these new technologically driven environments. Previous research in fields like aviation, medical surgery, and oil and gas drilling has demonstrated the effectiveness of virtual simulation training, but the mining sector has yet to fully adopt advanced tools such as eye-tracking and immersive training modules. This research proposes a comprehensive training infrastructure incorporating these technologies to enhance situational awareness and decision-making during emergencies. The novelty lies in the application of advanced miner escape and communication technologies, specifically designed to monitor and enhance cognitive responses in high-stress situations. By leveraging these technologies, the proposed training infrastructure aims to prepare the next generation of underground miners and operators, by equipping them with the necessary skills to manage emergencies effectively.

Feb 1, 2025

By Raymond F. Moran

The history and development of the FMC Coke process has been reported in numerous presentations over the past 10 years (1, 2, 3, 4, 5, 6) but a short review is desirable, especially regarding the aspects that are influenced by the coal to be used. F'MC has been developing this process in pilot facilities since 1956 and in a modest sized plant in Kemmerer, Wyoming since 1960 (Figure I). This plant produces strong uniformly sized coke briquettes from a completely non-coking coal, namely Elkol, a sub-bituminous coal of the Adaville seam. Since operating commercially, over 300,000 tons have been produced, 90% of which has been used in electric phosphorus furnaces and some 10% of which went for trials in iron blast furnaces. We believe that this commercial use of non-coking coals is a unique experience in the history of coke manufacture.

Jan 1, 1975

By William Hodder, Ehsan Alavi, Nader Ghasempour, Daniel Cressman

The Don River & Central Waterfront Coxwell Sanitary Bypass Tunnel (CBT) Project in Toronto will extend approximately 10.5 km from Ashbridges Bay Treatment Plant west under Lake Shore Boulevard, north under Bayview Avenue and east through the Don River park area to the Coxwell Ravine Park. The tunnel is currently being mined by using a shielded dual-mode tunnel boring machine (open and close) capable of operating in EPB mode and lined by using a precast concrete segmental tunnel linear with an internal diameter of 6,300 mm and external diameter of 6,900 mm. The CBT is expected to be excavated mainly through shale bedrock of the Georgian Bay Formation, at approximately 50 meters deep. The tunnel crosses a buried bedrock valley in two locations, in the southern portion of the alignment, adjacent to the Don River, and at the northern portion of the alignment approaching the CX-1 shaft. In these two locations, the bedrock cover is expected to be less than 6 meters. The risk of encountering weathered bedrock, significant ground water inflows or surficial soil deposits through these buried valleys was identified during the design phase. The contract required the TBM to be designed with the ability to probe drill ahead of the TBM and convert to EPB mode if necessary, to cross this area. This paper will discuss the additional exploration that was performed by the contractor to identify the extent of this buried valley, the plan going into the zone of potential weathered shale, and the actual conditions encountered.

Jun 13, 2021

By M. Dayne Aldridge

A discussion of the definition of automation in mine ventilation applications is presented. The results of theoretical studies, experiments and practical experience from work in the United Kingdom, Belgium, Poland, the Soviet Union and the United States are summarized. Conclusions are drawn from these efforts and the prospects for the future development of automatic mine ventilation systems are explored.

Jan 1, 1978

By D. M. Abbott, H. J. Sandri

The geoscience matrix method has proven useful for valuing metallic mineral properties lacking delineated mineral resources or reserves. However, the method explicitly excludes commodity markets from the factors considered; marketability is assumed. When valuing industrial mineral properties, marketability cannot be assumed, it must considered. Market considerations may also significantly affect the standard weightings of geoscience matrix parameters such as the proximity to known deposits. In some cases, such proximity is desirable but in many cases it is undesirable. Application of the geoscience matrix method to industrial mineral properties therefore requires thoughtful, market-related adjustments to the basic geoscience matrix methodology.

Jan 1, 2000

By Daniel F. Meyer, William C. Paschen

INTRODUCTION The problems involved with moving millions of tons of rock are being addressed by nationally recognized tunnel contractors who have converged in Chicago over the past 5 years. This wealth of expertise has been needed to meet the risk and challenge of constructing the world's largest network of underground tunnels which in turn has required a dramatic advance in the art and science of tunneling. These pioneers, through innovation, adaptation, and hard work, have eliminated the one major concern of The Metropolitan Sanitary District of Greater Chicago - how to move 8 million tons of rock. The Metropolitan Sanitary District of Greater Chicago (MSDGC) serves 122 municipalities covering 866 square miles in Cook County, Illinois. Of these cities, towns, and villages, 53 have combined sewer systems. On an average of once every four days, these systems overflow about 4 million gallons of combined sewage and rainwater into the area's rivers and canals. The overflows occur at approximately 640 outfall locations of which 10% are owned by the MSDGC, with the remainder of the points belonging to various other municipal bodies. All those who own these "point" sources of pollution are in violation of Illinois State and Federal regulations. To enable its member municipalities to come into compliance with State and Federal law, the MSDGC is implementing its Tunnel And Reservoir Plan (TARP). TARP is a regional solution to the problem of combined sewer overflow in the metropolitan Chicago area. TARP will greatly reduce the pollution of area waterways by intercepting the combined sewage and rainwater carried in the existing sys-

Jan 1, 1981

By B. Cousins

Flotation reagents are critical to the optimum performance of flotation circuits. How a flotation reagent performs within the first few cells of a flotation train is a key indicator of how well it will perform throughout the entire circuit. A method to compare reagent performance was recently developed by Ashland Water Technologies. The procedure involves collecting a timed sample of concentrate from each cell and then measuring the volume of the settled solids. An estimate of the percentage of concentrate collected from each cell can then be mathematically determined, providing an understanding of the recovery changes in each cell. Data from trials at a coal flotation circuit are used to demonstrate the method's validity.

Feb 27, 2013

By C. Restarick, R. G. Robins, R. M. Taylor, I. Ennis

Lime addition to acid mine drainage waters (AMD), possibly accompanied by aeration, has been the basis for their remediation by precipitation of predominantly metal hydroxides. An efficient novel alternative technique causes precipitation of double M(II)-M(III) hydroxy sulfates which readily precipitate and are easily dewatered. When the Fe(II)/Fe(III) + Al(III) ratio of the AMD is appropriate, the Green Precipitate (GP) Process provides a more effective alternative to normal liming/aeration. The process can be adapted to give a continuous in-line treatment by the choice of suitable computer-controlled reactors designed to improve the liming efficiency, reduce scaling and control the rate of treatment. The processes are described in terms of the chemistry involved.

Jan 1, 2000