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By James S. Browning

Mica mining in the United States is confined largely to pegmatites and schists in a few well-defined areas. The largest region extends from central Virginia southward through western North and South Carolina, northern Georgia, and east-central Alabama. 1, 2, 3 Whereas in western North Carolina these pegmatite dikes are weathered to only a shallow depth, they are deeply weathered in the Carolina Piedmont and in Georgia and Alabama. Particularly in Georgia and Alabama, mica is found in the decomposed slates and schists adjacent to the pegmatites, and in deeply weathered granites. Most flake mica is obtained as the major marketable product by crushing and milling pegmatites.4 To a lesser extent, mica is produced as a byproduct of feldspars and spodumene.6 Past research by the Bureau of Mines has developed two methods for mica flotation. One method utilizes acid-cationic flotation for recovery of mica." This method requires thorough desliming of the ore with consequent fine mica losses. The other method utilizes an alkaline-anionic-cationic process for recovering fine size mica from pegmatite ores after desliming sufficiently to remove clay materials but not so drastically as to remove the fine mica. 8, 9, 10, 11, 12, 13 The latter process has also been successfully applied to a micaceous schist ore from California.14 This report summarizes the results of these research studies. Both of the flotation processes developed by the Bureau of Mines have been adopted by the mica industry and are being commercially utilized separately and in combination for flotation of mica from weathered pegmatite ores.

Jan 1, 1969

The Bureau of Mines has studied 260 underground coal mine fires which occurred from 1970 through 1989. Every fire had the capacity to be hazardous to life and property, however upon closer examination some were found to be inherently more dangerous than others. Our research involved reviewing and recording specific information contained in published Mine Safety and Health Administration fire accident reports. The objective was to determine if degrees of hazard relative to fire source or location could be construed from information contained in the reports. We specifically looked at the propensity for fires to cause injuries and fatalities as well as the need to seal the area in order to extinguish the fire. Relative to all underground locations, this review found that fires occurring in main haulage-ways were most likely to cause injuries and fatalities as well as require sealing of at least the immediate area to extinguish.

Jan 1, 1993

By A. J. S. Spearing, T. Kostecki, D. Benton

The use of paste backfill in room-and-pillar coal mines in the United States needs to be fully investigated. This paper discusses a series of physical tests that were conducted to examine the support benefits of theoretical paste backfill regimens in Illinois Basin room-and-pillar coal mines, which necessarily included consideration of weak floor conditions. The series of tests included those simulating strong floor conditions, weak floor conditions, under-confined scenarios, and testing of actual coal-based paste backfill samples. The testing indicated that a paste backfill regimen utilizing a minimum backfill strength of 22 psi at a minimum fill height of 50% of pillar height could significantly increase the longterm stability of coal pillars in the Illinois Basin. Considering typical coal wash plant recoveries, 50% fill would be feasible.

Jan 1, 2014

By William R. Yernberg

The Fifth International Conference on acid rock drainage (ICARD 2000) was held May 21-24, 2000, in Denver, CO. The three-day conference consisted of about 150 oral presentations and poster sessions that described the state-of-the-art of acid-rock-drainage (ARD) science and technology. The conference also featured a trade show. It included representatives from consulting companies and government agencies with interests in ARD, as well as other environmental issues related to mining. The conference also included field trips to ARD treatment sites and short courses on acid rock drainage issues. ICARD 2000 was planned and promoted by the ICARD 2000 Organizing Committee and the Society for Mining, Metallurgy, and Exploration, Inc. (SME). Financial support was provided by Barrick Gold, BHP Copper, Homestake Mining, Noranda, Phelps Dodge, PlacerDome, the US Bureau of Land Management, the USEnvironmental Protection Agency and the US Geological Survey. Since the original ICARD was held in Roros, Norway, in 1988, knowledge has improved of the behavior of mine wastes as have methods of environmental mitigation. The ICARD 2000 presented the latest advancements in the field of acid drainage.

Jan 1, 2000

By T. M. Sukel

Engelhard Corporation is one of the leading producers of kaolin based products in the world, having acquired the assets of Freeport Kaolin company in 1985. Much of the production technology used in the kaolin industry was pioneered by Engelhard and Freeport, including Ultraflotation for improving product brightness, delamination to produce kaolin platelet products, calcination to produce ANSILEX® high opacity titanium dioxide pigment extender and pipeline slurry operations to economically transport kaolin from the mine to beneficiation facilities. Engelhard traces its roots back to 1870 when the Edgar family discovered kaolin behind their property in Bonhamtown, New Jersey. Today the company produces the broadest line of premium coating pigments with extensive sales throughout the world. The international scope of the company's business has led Engelhard to evaluate kaolin deposits throughout the world as possible grass roots production sites. Most kaolin products are used in the paper industry -- the largest volume end-user 80% of the total market -- as filler and coating pigments. Lower volume specialized applications include fillers and reinforcements for plastics and TiO2 extender pigments for paints and coatings.

Jan 1, 1987

By R. Miller

Lowering our globe’s emissions is a major effort as we move toward a future net-zero carbon environment requiring significant investment in a new, low-carbon infrastructure, along with key market incentives to change. Industry will play a key part in this transformation, requiring expertise in both energy and emissions. Key elements of the de-carbonization strategy are: energy data, emissions reporting method, governance, de-carbonization project generation and drivers, the MACC, electrification, and the de-carbonization checklist. For a zero carbon future, it will be key for business leaders to understand decarbonization, anticipate technological changes, and implement new business me

Mar 2, 2022

By Dave Ragland

The SDSU tunnel and underground station are the first of these type facilities to be constructed by the Metropolitan Transit Development Board. Because there is no previous experience, and because tunneling activities are associated with some risk, he MTDB has undertaken a very proactive and wide reaching program to identify and control risks during construction. Finally, because the tunneling activity and underground station is on the San Diego State University, MTDB is working closely with their staff to identify construction impacts and mitigation’s, and thus ensure a quality project for both agencies.

Jan 1, 2001

By H. M. Breza

Recovery of phosphate concentrate has received increased attention as the existing mine and plant production capacity limitations of the Texasgulf Inc. Aurora, North Carolina Mine are reached. Improved mining techniques and mineral processing of waste streams offer a potential to increase overall phosphate production without major expansion of the Mining facility. Innovative processes have been or are being identified to maximize pit mining recovery and to minimize losses in waste streams, resulting in more effective use of the valuable phosphate natural resource. This paper will describe the various continuous recovery improvement programs being implemented to achieve this goal.

Jan 1, 1994

By M. Xing, S. Usman, K. Awuah-Offei

"While mines generally focus on achieving operational efficiency, creating shared value for all stakeholders is also a management goal. This includes taking a holistic view of their supply chains and increasing local participation. This paper examines the role of supply chain management in mine management; in particular the effect of a strong local supply chain on regional economic impacts. Using input-output analysis, the impact of a local supply chain on a mining sector’s regional economic impact is examined by increasing local sourcing (increasing local purchase percentage -- LPP) for 10 key commodities. An approach, based on multipliers and excess local capacity is used to identify key commodities. The impacts examined are sales, employment, labor income, and value added. The work is illustrated with stone mining and quarrying in Missouri. Ten percent increases in LPP of the key commodities, in this example, result in $4.1 million additional impact on the Missouri economy. This work can provide insight on how to better create shared value for all stakeholders. INTRODUCTION Little research has been published on improving mine supply chain management (SCM) to enhance regional economic impacts. Although some extensive academic research has explored the importance of an industries’ supply chain, not much is known about how a locally-based supply chain increases shared value in the resource sector. Across industries, traditional SCM is getting more and more complex. This is true of the mining sector as well. However, this increased sophistication is not directed towards increasing shared value for all stakeholders, particularly, the local communities. Further research is required to develop new SCM strategies that enhance local participation. One major point of difference between this work and traditional supply chain management is the inclusion of stakeholders’ shared value as a goal in SCM. Creating shared value has become a business goal in recent years (Porter and Kramer, 2011). The authors use input-output analysis (Leeuw, 2012) to evaluate the regional economic impacts of supply chain decisions, which is not part of traditional SCM. Although input-output analysis has been applied to SCM for decades, most of the research uses input-output analysis as a tool to advance an industries’ own operational efficiency (Accenture, 2014)."

Jan 1, 2015

By Ihsan Berk Tulu, Deniz Tuncay, DYKE MARK ALEXANDER VAN, Ted M. Klemetti

Bleeder entries are critically important to longwall mining for the moving of supplies and miners as well as the dilution of mine air contaminants and must stay open for many years. In this study, standing supports in moderate cover bleeder entries were observed, numerically modeled and instrumented by researchers at the U.S. National Institute for Occupational Safety and Health (NIOSH). The measurements of the installed borehole pressure cells (BPCs), standing support load cells and convergence meters, and roof extensometers are presented in addition to the numerical modeling results and visual observations made by the NIOSH researchers in the bleeder entries. The results include the effects of multiple panels being extracted in close proximity to the instrumented site as well as over one and a half years of aging. As expected, standing supports closer to the longwall gob showed the greatest load and convergence. The roof sag appeared generally independent of the proximity to the longwall gob. The BPC readings were driven by both the proximity to the gob and the depth into the pillar. The results of this study demonstrated that the entry roof can respond independently of the pillar and standing support loading. In addition, the rear abutment stress experienced by this bleeder entry design was minimal. The closer the mine development, pillar or supports are to the gob, the greater the applied load due to rear abutment stress.

By Everett H. Dobbs

The Tripoli deposits in the southwest corner of Missouri In Newton County and the northeast corner of Oklahoma in Ottawa County, located in the vicinity of Seneca, Missouri, contains an unusual and peculiar form of silica which has not been found any other place in the world. Its outstanding characteristic is the physical structure of the individual particle, The particle structure of the Missouri-Oklahoma type Tripoli accounts for its market. It is a soft, friable, porous, double-refracting silica of the chalcedony variety, The particle is porous, has a fibrous structure, no sharp edges or comers, ad an average size of less than .01 millimeter, It varies from 90 to 98 per cent Si02 with less than 1 per cent free silica in the form of quartz, 24; has ignition loss of 1 per cent and fractional percentages of iron, alumina, lime, etc.

Jan 1, 1960

By Chee S. Theng

As the 2015 president of the Society for Mining, Metallurgy & Exploration Inc., I am pleased to present the 2015 issue of the Transactions of the Society for Mining, Metallurgy & Exploration Inc., Vol. 338. A significant portion of the contribution that we make as a professional society is the publication of professional and technical papers that accelerate the advancement of scientific knowledge and enable the transfer of technology. Communication within the mining community is the key to a successful society. This technology exchange continues a tradition that dates back to the 1871 meeting of 22 mining engineers in Wilkes-Barre, PA, that resulted in the founding of AIME. Those individuals envisioned that these transaction volumes “would form a most valuable and greatly needed addition to our professional literature.” This volume fulfills that pledge. The 2015 Transactions contains some of the most interesting research and insights from the past year and features an international slate of authors spanning industry, academia and government. Papers include the latest findings from the U.S. National Institute for Occupational Safety and Health (NIOSH) and special-focus articles on gold processing, iron ore processing and coal processing. The 2015 Transactions consists of a total of 67 technical papers, encompassing all 22 papers published in 2015 in the Technical Papers Section of Mining Engineering (Vol. 67) and all 29 papers published in 2015 in Minerals & Metallurgical Processing (Vol. 32). Additionally, this volume contains 15 papers and one discussion that are being published for the first time in this issue. The papers presented in this volume were written by some of the most distinguished professionals in the industry worldwide. All of the technical papers were peer-reviewed. The process of review and publication requires much hard work by authors, reviewers and our publications staff. As the 2015 president of SME and on behalf of all our members, I would like to extend our gratitude to all whose volunteer efforts contributed to the publication of this volume.

Jan 1, 2015

By Paavo Eerola

In May of 1984, it was decided that Outokumpu Oy would design and build a new nickel flotation mill to process ore from the newly discovered Enonkoski mine in eastern Finland. Since there hart peen a number of successful process charges in the existing mills, the design effort included the study and incorporation of several new developments, including all-autogenous grinding, "flash flotation", lane cell roughing, large cell cleaning and a computer-based, profit optimizing, process control system. The paper discusses the background and results of those studies, and a description of the resulting mill which will begin production in 1986.

Jan 1, 1985

By X. Song, Q. Zhang

"The development of fracture zones in surrounding rock mass has significant impact on the stability of underground mine roadways. Detection of the fracture zones is of compelling importance for maintaining roadway stability as well as for safe and speedy excavation of the roadways. This paper presents a study conducted at Dong Bao Wei underground coal mine, where the roadways were developed in diabase rock mass. The roadways suffered severe damages, including sloughing and excessive floor heaving. The borehole imaging technique was applied in the study to observe and detect fracture zone development surrounding the roadway openings. Based on the borehole imaging studies, new roadway support systems were proposed to improve the stability. INTRODUCTION At the Dong Bao Wei Coal Mine three main roadways of the west wing were excavated. The three roadways had semicircle arch cross sections and were at a depth of 650 meters, each being about 750 meters in length. The roadways were driven through a section of thick diabase intrusion, which was softened by water with reduced strength and may turn into powder form under weathering. Site investigation indicated that the roadways in diabase intrusion zone were badly damaged due to severe deformation, and very serious roadway sidewall sloughing and spalling accompanied by severe floor heave often occurred.(Figures 1 and 2) In order to ensure the normal use of the roadway, undercuts were excavated. However, this operation seriously affected the roadway construction progress and increased the amount of roadway support operations as well as the roadway maintenance costs. Furthermore, a roof fall accident occurred in nearby drilling site. The investigation indicated insufficient support provided for the roadways which imposed significant safety hazards and would have serious impact to mining production and subsequent mining activities.The support of the main roadways is a critical task and is the focus of the underground opening excavation work at the mine, since more than 40 years of service life is required from these main roadways. For these roadways, large cross sections with high degree of stability and minimal amount of deformation should be maintained. Therefore, providing sufficient and appropriate roadway supports is of significant importance to the coal mine. In this paper, in order to optimize the roadway supporting system, studies were carried out on the geological structures, lithological characters, roof bolt anchoring features and suitable anchoring layers. The studies were aimed at ensuring the stability of mine roadways, reducing the roadway maintenance costs and providing a safe mine passageway for orderly production and progressive development of the mine"

Jan 1, 2016

By Randal J. Barnes

The nonlinear network optimization algorithm developed in this paper solves the following mine ventilation design problem: find the location and size of all fans and regulators which minimize the overall system power consumption while satisfying all physical, legal, and operational constraints. This work includes the formulation of the problem within the framework of mathematical optimization, the development of the computational theory, and the creation of an efficient solution methodology. The algorithm has been implemented on a microcomputer, and a small but representative example is included. The algorithm presented in this paper has four limitations. First, the optimization process is for a single point in time: the dynamic nature of a mine ventilation system in an evolving mine is not directly addressed. Second, the topology of the ventilation network is required input information. The mathematical algorithm does not optimize the size or location of the mine ventilation airways; however, the post optimality analysis techniques can be used to aid in topological decisions. Third, the problem is formulated using volumetric flow; thus, heat and moisture transfer are ignored. Fourth, the capital cost of ventilation equipment is not included in the formulation.

Jan 1, 1989

By L. MacHue

Sulfur containing collectors have been shown over the years to function as strong, selective and non-selective sulfide mineral collectors. Unfortunately, the majority of the widely known sulfur based collectors are of low molecular weight, volatile and subsequently, possess an objectionable odor. Higher molecular weight sulfur based collectors (C9 and higher) are significantly less odiferous due to lower volatility and lower vapor pressures. In this study, a specific proprietary higher carbon number collector, Orfom® MC 37, was blended and used successfully to recover 2-3% additional molybdenum in a laboratory flotation system, when compared to a standard collector blend. Copper recoveries were also positively affected. Further testing is required to give additional conditions favorable to increased copper and molybdenum recoveries, but indications at this time show the proprietary sulfur based collector blend to be a selective collector of molybdenum, while providing a significant increase in copper recoveries.

Jan 1, 2010

By Neal Retzer, Adam Bedell, Nick Cioffredi

The first wagon trail across Loveland Pass was built in 1869 thus starting the struggle between the Colorado Rockies and interstate travel. The 1st Pioneer Bore underneath Loveland Pass at the Continental Divide in Colorado was attempted between 1941 and 1943 and was abandoned due to ground conditions at the Loveland Fault. Construction on the nearby Eisenhower Tunnel began in 1967 and was completed in 1973. Numerous challenges associated with tunneling, including at 11,000 ft were overcome. The purpose of this paper is to summarize the history of investigation and construction challenges associated with the Eisenhower Tunnel to celebrate its 50th anniversary.

Jun 13, 2023

By G. A. Kosick, L. Kuehn

The design of an information management system (IMS) for a mineral processing plant requires prior consideration of many factors, which can be broadly categorized into two domains, process plant considerations and IMS considerations. The process plant considerations include: plant characteristics, management and personnel issues, existing organizational standards and policies, and the level of existing hardware and software systems. The IMS considerations include: system functionality, system sizing and desired performance, hardware components, software components, and system support issues. All of these aspects must be addressed in order to achieve a functionally successful and cost effective system. The purpose of this paper is to lay out these design issues and, in doing so, to provide process engineers with a guideline with which to tailor a system that is best suited to their specific application. The paper is completed by presenting an approach that has been used in two Canadian concentrators. Both of these plants have incorporated MillEX, a software system designed specifically as the central component of a mineral processing IMS.

Jan 1, 1993

By P. R. Wotruba

The Fortitude gold-silver deposit is related to a "wallrock" copper porphyry system developed within Middle Pennsylvanian to Permian Antler Sequence rocks adjacent to a Middle-Tertiary altered granodiorite intrusive stock at Copper Canyon. Gold-silver ores of the Fortitude deposit occur with disseminated and massive sulfide replacement mineralization of skarn-like or calc-silicated limy horizons of the Antler Sequence contact meta-sedimentary rocks. A major, north-trending, steeply westward dipping normal fault was important as a conduit for hydrothermal fluids responsible for the metallization in the Fortitude area. Gold-silver mineralization is best developed near a marble front where retro-grade chloritization and destruction of prograde calc-silicate mineral phases is most prevalent. Fluid-inclusion studies performed on the Copper Canyon system indicate a wide variation in fluid chemistry during several hydrosilicate stages that ranged in temperature from 500°C to 220°C.

Jan 1, 1986

By Irina Melekestseva, Beltenev. Victor, Victor Ivanov

"One of the major problems discussed over the last years is a possibility of mining of seafloor massive sulfide deposits. In spite of the pessimistic points of view on their commercial development, they are still of great interest and continue to be studied (Hannington et al., 2011). Recently, Barriga (2012) paid special attention to the underestimated amount of massive sulfide hydrothermal fields and pointed to the importance of the buried fields and subseafloor mineralization.This study examines the geochemistry of seafloor and subseafloor precipitates collected at the Peterburgskoe (19°52´ N) and Irinovskoe (13°20´ N) hydrothermal fields (MAR) during the 34th cruise of the R/V Professor Logatchev in 2011. These fields were discovered by the Polar Marine Geosurvey Expedition in 2010 and 2011, respectively (Shilov et al., 2011; Beltenev et al., 2012). The Peterburgskoe field, associated with basalts, is located 16 km west of the main rift valley at the depth of 2800-3100 m at the junction of a large non-transform discontinuity with the second rift ridge parallel to the rift valley. The Irinovskoe field occurs at depths of 2700-2850 m and has a northwestern satellite sulfide site, both confined to an oceanic core complex (MacLeod et al., 2009), which includes mafic and ultramafic rocks. The details of geological structure of the fields may be found in the relevant papers.Diverse samples were collected from the hydrothermal fields: seafloor massive sulfides, Fe-hydroxide crusts, SiO2-rich sulfide-bearing precipitates, and subseafloor mineralized rocks (Melekestseva et al., 2014a). Massive sulfides may be subdivided on the Fe-rich and Cu-rich types. The marcasite-pyrite, pyrite, hydroxide-marcasite, and chalcopyrite-pyrite (Fe-rich) mineral types are dominant in the Peterburgskoe field at lesser amounts of sphalerite-hydroxide-chalcopyrite and pyrite-covellite-chalcopyrite (Cu-rich) massive sulfides. The mineralized sulfide-talc-carbonate-chlorite, chlorite-sulfide-quartz, and hematite-sulfide-quartz rocks host stringer-disseminated sulfides including chalcopyrite, covellite, and pyrite."

Sep 1, 2014