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By S. Pastor, S. Hahn

"As the concept of autonomous haulage systems (AHS) moves from prototypes to production-ready applications, the operating performance of the haul road will become critical to the overall success of autonomy in mining. Deterioration in road performance will require remediation, human intervention and significant, albeit temporary, changes to operating procedures, to accommodate road maintenance. With autonomous trucks comes the opportunity to reduce road formation and operating width. This will, therefore, generate potentially significant reductions in stripping ratios and improvements to mine economics, but only if the design of the road, and its associated deterioration rate, is predictable and manageable, based on the materials used to construct the road and the maintenance interventions to be carried out on the road.This article presents the assessment of a digital photogrammetric approach to the characterization of a mine haul road surfacing, or wearing course material. Design and maintenance parameters for these roads are currently determined partly from physical particle size distribution (PSD) assessments of ‘in-road’ material. However, this approach does not accommodate the need, nor leverage the benefits from, AHS. The digital imaging approach is assessed in this article, using two standard digital analysis software tools, together with in-service mine haul road wearing course samples and images that are analyzed to determine the applicability and reliability of the approach to deliver a real-time assessment of haul road surfacing conditions and thus to identify the road maintenance interventions required to address deterioration.Enhancements in mine road design, construction and management for the past 20 or more years has largely been focused on short-term tactical needs. These improvements have not been matched by advances in the fundamental technologies that underpin mine road design and management and, although the quality of mine roads have probably"

Jan 1, 2015

By J. Kim, H. Cho

The objective of the experiment was to investigate the efficiency of hindered-settling column in recovering carbon from anthracite. Two types of Korean anthracites were prepared for feed materials. Each sample was crushed and classified by size, and washability analyses were performed. Separation efficiency was evaluated under various operating conditions using a laboratory scale hindered settling column. Results showed that the carbon recovery was higher for the smaller sizes, but the purity of the product was better for the larger sizes. In, overall, 2-0.21mm particles of 40-45 % ash could be processed into about 20 % ash products.

Jan 1, 2002

By K. N. Panigrahi

India bestowed with 6000km of the coastal belt, contains some of the richest and largest placer deposits with a mixture of heavy minerals like ilmenite, rutile, leucoxene, zircon, monazite, sillimanite and garnet. Each of the minerals is having economic value due to its inherent characteristics for industrial use in fields of paints, metallurgy, refractory, abrasive and so on. The reserves of titanium bearing minerals (ilmenite, leucoxene, and rutile) in the country is around 378 million tonnes. More than 90% of the titanium based minerals produced worldwide are utilised for making value added products in the pigment industries. Approximately 8 million tonnes of monazite reserves are available in the country from which several rare earth elements like cerium, neodymium, lanthanum, yttrium etc. can be extracted for use in several industries. The country contains a deposit of about 20 million tonnes of zircon, which is used in foundries, refractories, ceramics and chemicals. India has a reserve of 107 million tonnes of garnet and 131 million tonnes of sillimanite required for the abrasive and refractory industries respectively. Keeping in view the multifarious uses, the beach sand minerals are being exploited to have the economic growth of the nation. Although the process adopted for the separations are simple, the equipment involved are specially designed because of the nature of the material of construction. Starting from the spirals to magnetic separators, all equipments are manufactured outside India, which is not only costly, but the availability also takes much time for fulfilling the import formalities. Unlike open cast mining, beach sand mining is a environment friendly mining because dredging is implemented to cut and pump the loose sand through a slurry pump causing less damage to the surface topography as both mining and backfilling takes place simultaneously. Therefore all out efforts are made to explore the beach sand placer deposits in an economic manner to emerge as a leader in the global mineral industries.

Jan 1, 2005

By T. D. Parris

At the Frood Mine of International Nickel, tests were begun in March 1966 to evaluate the use of low profile diesel Load- Haul-Dump equipment in cut-and-fill operations. In December 1966, this test was extended to drawpoint loading of caved ore at the Creighton Mine. The results of these tests conclusively demonstrated the effectiveness of this equipment in the operations at International Nickel. This paper describes the equipment used, the operation of the equipment, production data and operating details. Also discussed in the paper are other trackless equipment which works with the Load-Haul-Dump carrier. Production and Safety comparisons are made with the slusher method in bulk mining, giving the reasons for replacing the slushers at the mines of International Nickel Company of Canada, Limited, Ontario Division.

Jan 1, 1969

By S. Pastor, S. Hahn

"As the concept of autonomous haulage systems (AHS) moves from proto-types to production-ready applications, the operating performance of the haul road will become ‘mission critical’ to the overall success of autonomy in mining. Deterioration in road performance will require remediation, human intervention and significant, albeit temporary, changes to operating procedures, to accommodate road maintenance. With autonomous trucks comes the opportunity to reduce road formation and operating width, and therefore generating potentially significantly reductions in stripping ratios and improvements to mine economics, but only if the design of the road, and it’s associated deterioration rate, is predictable and manageable, based both on the materials used to construct the road and the maintenance interventions to be carried out on the road. This paper presents the assessment of a digital photogrammetric approach to the characterization of a mine haul road surfacing, or wearing course material. Design and maintenance parameters for these roads are currently determined from physical particle size distribution (PSD) assessments of ‘in-road’ material. However, this approach does not accommodate the need, nor leverage the benefits from, AHS. The digital imaging approach is assessed in this paper, using two standard digital analysis software tools, together with in-service mine haul road wearing course samples and images which are assessed to determine the applicability and reliability of the approach to deliver a real-time assessment of haul road surfacing conditions and thus to identify the road maintenance interventions required to address deterioration. INTRODUCTION Enhancements in mine road design, construction and management for the past 20 or more years has largely been focused on short-term tactical needs. These improvements have not been matched by advances in the fundamental technologies that underpin mine road design and management, and although the quality of mine roads have probably increased, many of fundamental and longer-term issues have yet to be addressed. With AHS’s evolving from prototype to production applications, any decision to implement these systems in a mine requires a thorough evaluation of impacts, not only operational improvements, but the inter-connectivity of this autonomy technology to other organizational processes. In developing an understanding, the full interactions that may affect autonomous truck behaviour due to changes in various sub-systems or external environments, haul road conditions and operating performance is a key consideration. This is as true in autonomous as well as in conventional mine truck-based hauling systems where the mine haul road network is a critical and vital component of the production process."

Jan 1, 2015

By David Young

This paper presents tunnel design considerations for the SR75/282 Transportation Corridor Project in Coronado, California. The project is managed by the City of Coronado in cooperation with Caltrans and the US Navy and may include a one-mile long twin-tunnel section with two options: a 36.5 foot diameter twin-bored tunnel or a twin cut-and-cover box. The alignment crosses the Coronado Fault, and design provisions were needed at the fault crossing to maintain life safety and prevent rapid inundation of the tunnel in the event of fault rupture. These provisions are discussed along with considerations related to liquefaction and ground shaking. The project is currently in the planning stage with construction to start around 2012.

Jan 1, 2008

By Steve Jones

Minor subsidence damage to the Burgettstown Junior-Senior High School building and grounds near Burgettstown, Washington County, Pennsylvania, prompted an investigation of the site in early 1985 by the Bureau of Abandoned Mine Reclamation of the Pennsylvania Department of Environmental Resources. The investigation determined that subsidence over an abandoned coal mine was occurring and that additional damaging subsidence would occur if reclamation measures were not taken. A Pittsburgh Coal Seam Mine which was abandoned in the 1920's underlies the school at a depth of sixty-five (65) feet. This sixty-five foot section is comprised of five (5) feet of unconsolidated overburden and sixty (60) feet of thinly bedded, highly fractured shale. Approximately five and one-half (5-1/2) feet of Pittsburgh Coal was extracted at the school site. A thin shale binder and one (1) to one and one-half (1-1/2) feet of roof coal were left in place. Within the Contractor's Underground Working Area (See Figure 1) approximately thirty (30) percent of the coal was extracted. It appears that the mine was just being developed in the vicinity of the school when it was abandoned for no known reason. Other nearby portions of the mine show extraction approaching sixty-five (65) percent.

Jan 1, 1986

In 2002 the authors updated the MFire model developed by the US Bureau of Mines. MineFire, developed by Mine Ventilation Services, Inc. (MVS), uses the MFire model to perform mine fire simulations on typical mine ventilation networks. The MineFire program is capable of producing visual schematics and other analysis tools for input and output of the MFire model. The MFire model, however, was limited to 500 branches and 10 fans. This paper discusses the newly modified MFire model that is now capable of modeling over 5000 branches and over 400 fans among other expansions and improvements. Given the long history and proven track record of MFire, the expansion did not modify the core calculation methods or results. This paper focuses on a general discussion of the MFire program and issues encountered in expansion of the algorithm. An example large network with simulation results is discussed.

Jan 1, 2011

By T. Klemetti

Moisture deterioration of clay-rich roof rocks causes high numbers of roof falls in coal mines in humid summer months. Rocks with high moisture content are generally weaker and can further deteriorate when subjected to wetting and drying cycles. As a result, it is important to evaluate the moisture-sensitivity of roof rock prior to mining. The National Institute for Occupational Safety and Health (NIOSH) has evaluated three moisture-sensitivity index tests on roof rocks from 23 U.S. coal mines. The three tests were the University of Kentucky Weatherability test (Weatherability test), the Consol Energy Water Sensitivity test (Water Sensitivity test), and the NIOSH Immersion test (Immersion test). Of these three tests, the Weatherability and Water Sensitivity tests are more reliable in classifying the moisture-sensitivity of roof rocks. Disclaimer: The findings and conclusions in this report have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be construed to represent any agency determination or policy.

Jan 1, 2009

By Ann L. Backstrom

The Apex Tunnel is part of the Southern Nevada Water Authority?s proposed Clark, Lincoln, and White Pine Counties Groundwater Development Project. The project is intended to develop unused Nevada groundwater for meeting the water needs of Southern Nevada and would involve over 322 km (200 mi) of water transmission facilities. The Apex Tunnel, as currently conceived by ongoing planning and environmental analyses, would extend 2804 m (9,200 ft) through a structurally complex terrain of Paleozoic carbonate rocks and younger basin fill deposits and will traverse both public and private lands. Several faults cross the tunnel study area, juxtaposing rocks of varying lithology and degree of folding, and creating intervals of differing rock conditions along the tunnel alignment. This paper discusses how the geotechnical program was developed to be flexible and allow for rapid implementation of revisions based on new knowledge that became available during program execution, resulting in more effective decision making and enhanced value from the geologic investigation during the planning phase of the project.

By S. E. Phillipson, P. L. Tyrna

Lineament analysis, a remote sensing application for geological structures, has been criticized for reliance on subjective interpretations. The Mine Safety & Health Administration’s Roof Control Division performs lineament analyses with a technique that removes much subjectivity. Study areas are viewed on satellite images with software that allows examination under artificial sun azimuths and elevations. Extraneous lineaments are removed through successive steps of superposition, resulting in selection of the most robust linear features. Field investigations revealed a strong coincidence of joint and fault zones that were parallel with projected lineaments. The Roof Control Division’s successful identification of lineaments associated with roof falls and highwall failures has prompted some mine managers to incorporate lineament analysis as a mine-planning tool. The identification of potentially hazardous ground conditions will allow mine operators to obviate safety concerns that might otherwise adversely affect miner health and safety.

Jan 1, 2002

By Marcelo de Oliveira, Antoine Allanore, Dennis P. Chen, Davide Ciceri

Potassium fertilizers (potash) are mined in a handful of countries in the Northern Hemisphere. Potash is either expensive or unavailable to the farmers of the Southern Hemisphere. Alkaline alteration of K-feldspar rock (ultrapotassic syenite) in autoclave in the presence of Ca2+ generates a mixture of K-bearing calcium-aluminum-silicate-hydrate (C-A-S-H) minerals that potentially can be used as an alternative local fertilizer. This work investigates the effect of processing temperature (200 °C, 220 °C, and 230 °C) and time (from 0.5 to 3.0 h) on pH, mineralogy, and elemental availability of the C-A-S-H mineral mixture. Increasing temperature results in an increased conversion of K-feldspar and increased content of both the mineral tobermorite (Ca5Si6O16(OH)2·4H2O) and amorphous phase in the resulting C-A-S-H mixture; increasing time results in an increased conversion of α-dicalcium silicate hydrate into tobermorite. The amount of K leached from the mixture is relatively constant across all processing conditions. Hydrothermal alteration in autoclave of K-feldspar-bearing rocks such as ultrapotassic syenite permits the synthesis of a potential potassium fertilizer which alkalinity and mineralogy can be tailored according to soil requirements.

May 22, 2020

By J. A. Organiscak

The National Institute for Occupational Safety and Health (NIOSH) Office of Mine Safety and Health Research (OMSHR) has recently studied several redirected scrubber discharge configurations in its full-scale continuous miner gallery for both dust and gas control when using an exhaust face ventilation system. Dust and gas measurements around the continuous mining machine in the laboratory showed that the conventional scrubber discharge directed outby the face with a 12.2-m (40-ft) exhaust curtain setback appeared to be one of the better configurations for controlling both dust and gas. Redirecting all the air towards the face equally up both sides of the machine increased both the dust and gas concentrations around the machine. When all the air was redirected towards the face on the off-curtain side of the machine, gas accumulations tended to be reduced at the face at the expense of increased dust levels in the return and on the curtain side of the mining machine. A 6.1-m (20-ft) exhaust curtain setback without the scrubber operating resulted in the lowest dust levels around the continuous mining machine, but this configuration resulted in some of the highest levels of dust in the return and gas on the off-curtain side of the mining face. Two field studies showed some similarities to the laboratory findings, with elevated dust levels at the rear corners of the continuous miner when all the scrubber exhaust was redirected towards the face either up the off-tubing side or equally up both sides of the mining machine.

Feb 23, 2014

By C. R. Copeland

Water sprays are a common method used to reduce particulate matter (PM) emissions. Various factors such as wettability, surface area coverage, fine particle engulfment rates, interparticle adhesion forces, suppressant penetration and suppressant longevity have all been suggested as critical factors in achieving effective PM control. However, it has not been established which of these factors are the most important. Experimental work indicated that suppressant penetration is the most critical of these factors. The length of time after application that suppressants were effective was also improved by using hygroscopic reagents that retained moisture to prevent evaporation. Maximizing suppressant penetration and improving suppressant longevity led to an average 86% reduction in PM10 concentrations in laboratory dust tower tests.

Jan 1, 2008

By Carl R. Peterson

The Rapidex continuous drill and blast tunneling concept utilizes a unique spiral blasting pattern that permits efficient performance with relatively small single shots, while at the same time directing major blast fragments at right angles to the tunnel axis. The concept's self-shielding geometry permits the design of a lightly shielded machine that can stay at the tunnel face firing frequent small blasts to provide rapid, virtually continuous advance. This paper describes Phase III of the development program (supported under Bureau of Mines contract H0252047) in which the "front end" of the machine?drilling loading, and shooting components, together with the shield--was fabricated and field tested underground at the White Pine Copper mine, Michigan. One of the major accomplishments of the Phase III effort was to develop a fully remote controlled loading and initiation system in which explosive slurry is pushed, through a hose into the blasthole by a small water-driven piston carrying the blasting cap. The cap is ignited via an induction coil just prior to entry into the borehole, after which a delay permits complete -withdrawal and shielding of the loading hose. The ultimate objective of the present Bureau-sponsored program is to evaluate the feasibility of mechanizing hard rock mining operations, such as development to a point where drilling, loading, shooting, and mucking can proceed simultaneously and result in increased productivity.

Jan 1, 1977

This study was conducted to establish the effects of a diesel particulate filter (DPF) system with sintered metal substrate on the concentrations and size distributions of nano and ultrafine aerosols and concentrations of nitric oxides in underground mine air. The study focused on the formation and transformation of nucleation mode particles in mine air under prevailing test conditions. Experimental work was conducted in the NIOSH Diesel Laboratory at the Lake Lynn Laboratory experimental mine, a facility developed to allow evaluation of control technologies directly in underground conditions. The DPF system was examined for four repeatable steady-state engine modes using a naturally aspirated mechanically controlled Isuzu C240 diesel engine fueled with ultralow sulfur fuel. The engine coupled to an eddy-current dynamometer was operated in the underground drift with tightly controlled ventilation. Measurements upwind and downwind of the exhaust system discharge were used to quantify the effects of the DPF system on the mine air. A baseline was established using a standard muffler. The study showed that sintered metal DPF systems reduced the total mass of aerosols in the mine air by more than ten-fold when compared to a muffler. The nucleation mode aerosols (50dem<40 nm) in mine air were found to be strongly influenced by engine operating mode. The concentration of nucleation mode aerosols was found to be significantly higher for high-load modes than for low-load modes. The muffler and DPF system resulted in comparable total nitrogen oxides (NOx) concentrations. However, the nitrogen dioxide (NO2) fraction of the total NOx was found to be substantially higher for both systems for low-load modes than for high-load modes.

Jan 1, 2009

By S. Agarwal, S. Frimpong

The creation and maintenance of a healthy working environment in surface mining operations require sustained efforts in pursuing advanced research initiatives toward the development and deployment of powered haulage technologies. This paper contains progress summary on a frontier research in truck dynamic control, vision and collision avoidance. This research is required to provide solutions to challenging problems regarding operator visibility in truck haulage in a surface mining environment. The paper focuses on truck control kinematics and dynamics, truck-haul road interactions, intelligent truck sensing, intelligent truck collision avoidance system, integrated system for situational awareness, augmented visualization and operator interface, and field testing and error variance modeling of developed technologies. A sensor suite of four subsystems, including front-side stereo-camera, front-side Doppler radar, close range sonar proximity sensors, and rear-side camera system have been recommended for developing a 360° truck operator vision to allow safe operations. This research initiative is significant because it will provide a strong basis for developing technologies to improve truck haulage safety in surface mines and construction sites.

Jan 1, 2007

By Y. Wang

China is a big mining country with a long mining tradition and history. At present, there are nearly 200,000 different mines and 21 million workers. The total production value of mining makes up 6% of GNP. With the development of economy, the mining industry has played a more important role in our economic market, supplying more than 95% non-reusable energy, 85% of industrial and agricultural raw materials, over 75% of fertilizers and 30% industrial and agricultural water.

Jan 1, 2001

By Richard E. Ray

Conventional concrete block plastered with a cemantitious coating is the most common material used in the construction of perma¬nent stoppings to direct airflow in underground mines in the U.S.A. All mines experience various degrees of strata convergence depending upon depth of overburden, geological conditions, and type of roof support employed. Strata convergence will cause cracks and joint openings in masonry stoppings, resulting in significant air leakage losses. Where strata convergence is severe, complete structural failure of the stopping can ultimately occur. Reconstruction of damaged or destroyed stoppings adds expensive overhead to mining operations, and even greater expenses are incurred from the additional fan horsepower required to overcome leakage losses. Ideally, a stopping should maintain high resistance to airflow while yielding to strata convergence. By properly incorporating "Max-Seal" polyisocyanurate rigid foam material within the masonry block structure, stopping service life can be increased several-fold in mines experiencing strata convergence problems such as floor heave, roof loading, and lateral rib movement.

Jan 1, 1984

By K. J. Stanaway

Major world ilmenite and rutile accumulations reveal similar regional geology and Proterozoic age deeper crustal source rocks. During crustal collision titanium crystallizes as ilmenite and rutile at buried sites of high pressure and temperature rock metamorphism. Hydrothermal activity can convert titanium minerals to rutile, but titanium migration and enrichment seem only local. Many melts crystallize rocks with iron-titanium oxides in solid solution, but titanium enrichment at economic scale takes place in basic intrusive melts often associated with anorthosites and charnokite. Sedimentary placer enrichments have formed since the Proterozoic with water-resistant ilmenite, and rutile segregating by gravity from quartz sands deposited from flowing water. Placers have residual, alluvial, strand and shallow marine variants. Time, organic acids, and sand permeability play lead roles in the leaching of iron from ilmenite during weathering and diagenesis.

Jan 1, 2005