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By C. G. Clifton

The Oatman District produced approximately 2.2 x 10 6 ounces of gold and 0.8 x 10 ounces of silver between 1897 and 1942. A total of 3.8 x 10 tons of ore averaging 0.58 O/T gold and 0.17 O/T silver was extracted from eight major orebodies and a number of lesser deposits. Oatman lies at the center of a trachyte-latite-rhyolite volcanic complex which contains at least one resurgent caldera. The orebodies are typical epithermal quartz-calcite + adularia lode deposits which are very deficient in sulfur. Ore deposition has occurred within dilatant zones on faults which radiate from a common point within-the complex. Fischer-Watt Mining approached the Oatman District with an integrated exploration program utilizing four basic procedures to define the characteristics of past productive areas the results of which were applied to unexplored portions of the vein system. These procedures, listed in their order of usefulness, in defining known and prospective mineralized zones are: vein contouring, detailed alteration mapping, fluid inclusion temperature determinations, and geochemical sampling.

Jan 1, 1980

By E. R. Bauer

The ground control aspects and occupational safety concerns of extended depth-of-cut mining are presented in this U.S. Bureau of Mines (USBM) report. The scope of extended cut use and typical face operations while extracting extended cuts is reported. A comparative review of roof fall fatalities and a statistical analysis of accidents and injuries for both extended and nonextended cut mining is included. The views and opinions on extended cutting from a series of interviews with mine workers in five states are summarized. In addition, some of the problems and safety concerns of this extraction system are mentioned.

Jan 1, 1995

By F. M. Doyle

Ion flotation shows great promise for recovering and removing metal ions from dilute process streams, either for environmental compliance or to recover values. This technique uses an ionic collector to concentrate non-surface active colligend ions of the opposite charge from a bulk solution at the solution?vapor interface. With a sufficiently large solution?vapor interfacial area (provided, for example, by sparging gas through the solution), the colligend can be concentrated and removed along with the collector in a foam phase. A key limitation on using the technique in the minerals industry, where many process streams contain a variety of ions and have relatively high ionic strengths, is the need to control which ions are interacting with the collector. Here the effect of three different chelating agents, namely dodecyldiethylenetriamine (Ddien), ethylene diamine tetraacetic acid (EDTA) and triethylenetetraamine (Trien), on the selectivity of copper, nickel and cobalt, or copper and alkaline earth metal ions, is reported. The results are discussed in terms of their implications for adoption in the minerals industry.

Jan 1, 2009

By N. P. Widodo

The ventilation measurements by tracer gas method at Pongkor gold mine show that effective diffusion coefficient, E, at straight airways indicated a similar range of measured one by the laboratory experiments which can be estimated by Taylor equation. On the other hand, E of the curved airways in the mine was estimated as larger than that of the straight ones (1.5 to 32 times than that obtained by the Taylor equation and these have been compared with the data measured in Kushiro coal mine, Japan). The curved mine airways, with small curvature against airway radius and complex velocity profile, possibly give concentration ? time curves with long tailings, thus those airway conditions could make larger E. Laboratory experiments of gas diffusion by a pulsed injection of small amount gas, into straight and curved airways, have been conducted in order to investigate a range of E in mine airways. The plots of E against Reynolds number show that the present laboratory results of straight-long airways are almost close to one calculated by Taylor equation. On the other hand, the values of E measured at curved single-direction airways were smaller than that of the straight airways, which may be due to effects by secondary vortexes flow in the curved airways.

Jan 1, 2009

By Jerry D. Pfarr, Gary Loving, David G. McDowall

Introduction The Open Cut is one of the best known landmarks in South Dakota's Black Hills. It is the site of the original discovery of the Homestake ledge, or lead, in 1876. Between that time and 1945, the Open Cut produced about 36 Mt (40 million st) of gold ore, the majority of which was drawn from underground operations. In 1981, a drilling program was undertaken to determine how much ore the old timers left behind. The results of this study indicated an ore body made up of broken and caved ground, and solid blocks in pillars and crowns. Reserves are estimated at about 6.8 Mt (7.5 million st) of gold ore, grading at 4 g/t (0.116 oz per st). Total tonnage of material, including waste, is estimated at more than 60 Mt (66 million st). The mining plan is a combination open pit and underground operations. The bottom 78 m (255 ft) will be mined by the underground panel-caving method. The open pit was designed as a contractor operation up to the expected milling stage or the point of sustained ore production. The pit was designed to avoid disturbance of US Highway 85 near Lead, SD. In 1983, the South Dakota Board of Minerals and Environment approved the mining and reclamation plan. Test mining began in the north of the Open Cut using open pit methods. Upon completion of the test pit, Homestake Mining's board of directors approved an expanded mine plan. They committed an additional $27.1 million to prestrip the ore body that is expected to yield 23 t (750,000 oz) of gold. Project life is estimated at 15 years. Exploration program In early 1980, 10 diamond drill holes were drilled from the surface in the vicinity of the east side of the Open Cut. The reserves delineated by that drilling were too small to justify their development. A continuation of this study attempted to quantify the tonnage remaining in the bottom of the Open Cut in the crushed remnants of old stope-and-crown pillars. This was originally thought to be minable by improved drawhole methods using highly mechanized procedures. By early 1981, however, thinking turned toward surface mining methods. The effort to quantify minable ore tonnage ultimately involved drilling 385 reverse-circulation rotary drill holes. These were drilled from August 1981 to March 1983 in several groups of holes. Each group, or drilling program, had a slightly different immediate goal or purpose. The holes were drilled to various depths using truck-mounted Drill Tech 40 drills with doublewalled 76 mm (3 in.) pipe with 134 mm (5.25 in.) three-cone rotary bits. Initially, wet drilling was employed using a cyclone collection system. Since cutting recovery was not as high as it should have been, all subsequent drilling was dry. The cuttings were collected and deposited by way of a cyclone into the sample bag. The pickup for the cuttings using the three-cone bits was about 50 mm (2 in.) above the bottom of the hole. Overall cutting recovery for the drilling program was estimated at 75%. Samples were taken on each 1.5 m (5 ft) of hole drilled. Each sample was split into three 48-g (1-2/3 assay ton) charges. The accepted value was the straight average of the three charges. Because of the known "nugget effect," assays were nearly impossible to duplicate. Therefore, to validate the regular assays, a series of screen fire assays were run. Based on this method of assays and checks, it was concluded that 10% more ounces would be produced than indicated by mine grade. Test pit The northernmost portion of the mine as planned is known as the Terraville test pit. This portion was mined ahead of the rest and separately. It provided answers to questions on slope stability, reserves correlation, mill recoveries, mining costs, and surface mining conditions in various weather and ground conditions since many boulders and much timber were expected. The mining plan for this portion of the pit was successful. More ore was mined than was expected. Mixing of Open Cut ore with underground ore in the mill feed was successful. Impact on the surrounding communities

Jan 10, 1987

By William R. Yernberg

The 2002 Arizona Conference was held Dec. 8 and 9, 2002, at the Doubletree Hotel at Reid Park in Tucson. The annual conference is organized by the Arizona Conference Board of Directors, which represents SME sections in Arizona and adjacent areas. The conference provides an opportunity for individuals and corporations associated with mining in the region to get together once each year to discuss the status of the industry. The meeting featured a keynote address, a distinguished lecture and about 30 technical papers. As was the case at the 2001 meeting, the economy, the price of copper and foreign competition continue to be the hot topics of discussion among the attendees. The domestic copper industry still faces challenges due to low copper prices dictated by the world market and because of a weakened domestic economy. There continues to be concern about the Arizona region’s copper industry in light of the mergers, downsizing and shutdowns that have occurred during the past several years.

Jan 1, 2003

By Syd S. Peng

University research in the U.S. consists of three components; faculty, funding, and graduate students or postdoctorals. Individual faculty is the unit area of research that is not limited, although faculty normally performs research in their areas of expertise. Faculty can and often do join with other faculty in multidisciplinary research. Faculty research achievements or reputation reflects the standing of the program and university. Therefore, research is highly encouraged and regarded within the university community. Graduate students are the work force of faculty research and doctoral students are preferred for high-quality products. The federal government provides the majority of funding sources, with the remainder coming from industry, state government and others. Compared with other engineering majors, the mining engineering programs in the U.S. are unique in that they: ? Are small in terms of the number of programs, and number of faculty and students in each program. ? Serve a single industry (i.e., mining) and are thus cyclic, reflecting the up and down economic state of the mineral industries. Enrollment statistics during the past 70 years show that a cycle consists of approximately 30 years with the first 10 years up, followed by 20 years down. ? Have curriculum designed to emphasize and thus serve for either the coal, hardrock or industrial minerals industries. These unique features make mining engineering programs hard to manage in university environments. Funding for mining research has relied primarily on the federal government, i.e., the former U.S. Bureau of Mines (USBM) and currently the National Institute for Occupational Safety and Health (NIOSH). The mining industry does not directly perform, nor sponsor research projects. Federal funding provides primarily in-house research. In the last four decades, federal extramural funding was only available when Congress appropriated extra funding in response to mine disasters. For instance, a string of coal mine explosions in the mid to late 1960s prompted Congress to enact the Coal Mine Health and Safety Act of 1969. It provided massive research funding from 1970 to 1983 covering all mining-related subject areas. From 1984 to 1995, federal extramural research funding was minimal, through two generic mineral technology research centers for selected mining engineering programs. In 1995, Congress closed the USBM and transferred the health and safety of miners program to NIOSH. Federally-funded extra-mural research practically stopped from 1995 to 2006. In 2006 and 2007, in response to a series of disasters, including those at Sago, Aracoma, Darby and Crandall Canyon, Congress again appropriated funding for short-term re-search in selected subjected areas such as underground tracking and communication, mine seal and ventilation, and deep cover pillar extraction. Therefore, to develop a meaningful academic mining research program during the past three decades, funding needed to be drawn from other sources such as the mining industries. A ?meaningful? program requires a sufficient amount of consistent funding in order to produce effective results. A review of federally funded extramural research pro-grams shows that a great majority of contractors/grantees are private entities, involving few mining engineering faculty. This, in part, is due to the fact that mining engineering involves so many different subjects. Therefore, a small mining engineering program can only have resources to cover teaching in the core subject areas (i.e., extraction, ground control, ventilation and material handling), at best. In this respect, a successful and meaningful academic mining re-search effort requires strong supporting programs such as geology/geophysics, structural (applied) mechanics, material sciences, compute/software application, etc. Therefore, academic mining research had to rely on private sources such as coal companies, in the author?s case, for sustained funding in the past three decades. Relying on funding from coal companies presents several problems. The projects were small and considered routine consulting projects requiring practical answers in a very short time frame. This is not really suitable for academic research, for which the major goal of research is the training of graduate students. These short-term projects vary with time and mines, most of which are driven by U.S. Mine Safety and Health Administration (MSHA) or U.S. Office of Surface Mining (OSM) regulations. So sustained funding under such condition requires broad experience of coal mining operations, which is also not well-aligned for academic research where faculty tends to specialize in a narrow field. Consequently, under such a funding environment, it is important to keep in mind how to develop long-term academic research objectives from conducting small short-term consulting projects that require quick solutions. In other words, how to look beyond the quick answers and to develop broader and more fundamental theories applicable to other situations that advance the-state-of-the-art. In order to achieve this objective, faculty must act as the connecting link because graduate students come and go. Faculty must know the detail of each project such that they know what are the important unsolved problems, what to assign to specific graduate students and how to guide the next group of graduate students to continue the development and advance the mining science. Under such funding environments, the most effective way to conduct academic mining research and ensure quality products is to maintain a research group consisting of postdoctoral, PhD, and MS students of various rankings such that the senior ranks can assist in guiding the junior ranks, especially the senior PhD students who are experts in their dissertation research areas. A weekly meeting should be scheduled for the group in which problems encountered in the research are discussed or individuals take turns presenting the progress of their projects. During each meeting, the importance of open discussion on scientific issues must be emphasized. Thus, opinions are encouraged, debated, and rejected or accepted. Students are encouraged to listen to and analyze other points of view. In addition to training of this thought process, the meeting also helps identify the strengths and weakness of each individual. As the subject of research expands over time, the group?s and, thus, the faculty?s research experience broadens. With this approach, companies can get the quick answer they desire from expert research experience and the faculty can engage in meaningful applied and basic research that is most relevant to routine mine operations. The end result is that companies will have a high regard for academic mining research.

Jan 1, 2009

Basic parameters affecting the stability of foams have been studied. We used the thin film pressure balance (TFPB) technique of Scheludko and Exerowa (1959) to measure the surface forces in foam films stabilized with various frothers such as pentanol, octanol, MIBC, and PPG. The results were compared with the froth stabilities measured using the shake tests and the film elasticity calculated using the model developed by Wang and Yoon (2006). It was found that the froth stability is controlled by both film elasticity and surface forces (or disjoining pressure), the relative contributions from each changing with frother concentration and type.

Jan 1, 2006

By S. C. A. Franca, M. T. Millqvist, A. B. Luz

Laboratory experiments were performed on a Brazilian diatomite from Bahia State to produce an industrial product for use as a filter aid. Bench and pilot plant tests were conducted consisting of: diatomite desegregation, organic matter and clay removal, filtration, drying and calcination. Calcination temperature and sodium carbonate addition influenced diatomite particle size distribution. Optimum filtration rates for calcined products were obtained at 900°C and 47 min. residence time with 3% (w/w) of sodium carbonate addition, and resultant products met specifications imposed on filter aids.

Jan 1, 2002

By M. Fustic, A. H. Paul

The geology of the Muskeg River Oil Sands Mine is described to demonstrate how geologic modeling aided in resource evaluation and material characterization during the feasibility and construction stages. Bitumen is hosted in the clastic sediments of the Cretaceous McMurray Formation which is informally divided into members representing the fluvial, estuarine and marine environments of this transgressive sequence. Lithofacies mapping of drill core provides further detail to classify materials as resource type, for extraction suitability and for construction suitability. Geologic interpretation provides tools for the engineers to produce effective mine plans and for the operators to execute them during mine development.

Jan 1, 2002

China’s vibrant economic growth is built on coal, the source of two thirds of the country’s electricity. Over 95 percent of China’s coal is mined underground with the average mining depth at 410 m and in-creasing at 10 m per year; today, the deepest Chinese coal mines have exceeded 1,000 m. With increasing mining depths, there are greater challenges including increased methane emissions and spontaneous combustion. According to the government, nearly half of China’s coal mines are classified as gassy (with specific gas content at least 10 m3/mt). Coalbed methane (CBM) is a clean energy source. However, only a small percentage of the methane is captured, and the rest is vented directly to the atmosphere. This paper describes China’s CBM resource, its production and utilization.

Jan 1, 2006

By Laszlo Toth

A feeder is used to control the gravity flow of bulk solids from storage areas, like a bin or a stockpile. For this type of application, it is important to select a proper drive that can fulfill all of the demands put on it. High starting torque capacity, variable speed and the ability to handle frequent starts and stops are some of the demands that the drive must be able to meet. The following is a comparison of the most common type of drives used today for feeder applications. When a feeder is started, the breakaway torque may reach as high as200% of the running torque. The accelerating torque usually is set to protect the carrying element of the feeder, like the belt for the belt feeder and the carrying chain of the apron feeder (Fig. 1).

Jan 1, 2003

By P. J. Doig

The LCLS project at SLAC will allow new insights into material properties, chemical reactions and biological processes. The project includes half a mile of new underground construction. Excavation in weathered rock is by NATM, using AM 50 roadheaders. Construction began in 2006 and is expected to be completed in 2008. This paper details the construction of the tunnels and cavern on the project.

Jan 1, 2008

By R. L. Loofbourow

SEVERAL categories of storage are used depending on capacity. Operational storage, which is small in comparison with the market, facilitates handling surges of a few hours' or a few days' duration. Seasonal storage, usually larger, permits accumulation of product during sea- sons when demand is low, for delivery when demand is high. In producing areas, large storage may permit production at a uniform rate, without waste or distress sale. Near large markets such storage increases the efficiency of transportation, allows a more extensive or higher grade market to be served, and affords protection against interruption in delivery.

Jan 1, 1959

By M. J. Price

The usage of Geographic Information Systems (GIS) is increasing rapidly throughout the Mining Industry, especially in the Industrial Minerals sector. GIS provides an efficient and robust link between spatial (often CADD) and tabular (database/spreadsheet) components. Mineral economists and corporate planners employ GIS to perform market analyses, to source raw materials, and to schedule and monitor deliveries to customers. Exploration and acquisition groups apply spatial analysis to identify high quality resources that meet economic guidelines. Mining regulators and environmental affairs departments expedite and monitor permitting, environmental compliance, and best management practices reclamation through GIS data management and Electronic Permitting. Operations staffs monitor overburden removal, material extraction, quality control, and stockpile volumes with GIS. This paper summarizes the many aspects of GIS in Industrial Minerals. It also introduces and addresses issues and concerns commonly encountered during a mining GIS implementation.

Jan 1, 2001

By SH. Shahsavari, H. Akbari, M. Noaparast, M. Oliazadeh

Mejel valley zircon ore in Iran is located in north part of Iran and was sampled to evaluate its concentration. The aim of this project was to define the mineralogy of this zone and separating zircon from other minerals using gravity concentrators and magnetic separators. It is constituted of various valuable minerals, mainly zirconium, niobium-tantalum, titanium, rare earth elements particularly cerium-bearing minerals namely zircon, sphene and rare earth elements oxides. We used statistical method for designing of experiments. Yates method used for analysis of basic experiments results. The grade of zircon in primary sample was 1.1%. Different experiments were designed to optimize all required parameters. The final concentration with 75% zircon was produced and final recovery was 79%. Finally, lab-scale based flow sheet was prepared using experiments results.

Jan 1, 2005

By Bruce Gellar

For the past six years, the author has made it a priority to attend the Prospectors and Developers Association of Canada’s (PDAC) annual conference. This most recent meeting took place March 10-13, 2002in Toronto, Ontario. In the three years since the author’s last PDAC report, the mining industry has undergone a severe trough. Some the industry’s woes included deeply discounted commodity prices, rampant layoffs, mergers, and overall avoidance by the investment community. However, at each of the PDAC conferences, the author has felt a heightened sense of excitement about the mining industry, more so than at other similar gatherings.

Jan 1, 2002

By Claudio Flores Martinez

The prospect of accomplishing economically and scientifically profitable deep-sea mineral mining within this decade or the next one is of particular interest to the emerging discipline of astrobiology which is concerned with the origin, distribution and future of life in the Universe. Several planetary bodies within our own Solar System such as Jupiter’s moon Europa and Saturn’s Enceladus now appear to be potentially habitable, or life-friendly, in terms of the three prerequisites for life as we know it: a sustained body of liquid water, biogenic elements (C, H, N, O, P, S) and energy sources to fuel metabolic reactions. Europa, for instance, possesses a global subsurface ocean, believed to be up to 100 km in depth, hidden beneath a kilometer-wide ice-sheet. A silicate mantle is directly interacting with a cold, aphotic ocean in which tidal forces might drive geological seafloor activity that results in the creation of hydrothermal systems. These locales are commonly hypothesized to be the cradles for an alternate origin of life on Europa. Especially alkaline hydrothermal springs, as found at Lost City, have been at the center of modeling the prebiological evolutionary dynamics preceding cellular life. Serpentinization-like reactions are also possibly fueling metabolic networks in putative microbial communities found in the oceans of the icy moos. Major space agencies around the globe are planning future space missions aimed at exploring and eventually characterizing potential life forms in these habitats. The technology needed for this exploration effort resembles the requirements for a successful deep-sea mineral mining industry: highly efficient AUVs (also equipped with biologically-oriented instrumentation), swarm robotics, landers, seafloor rovers and general high-pressure, cold temperature extreme environment engineering. Interestingly, science questions of deep-sea mineral mining and astrobiology converge too: the hypothesis of life originating at hydrothermal systems, the biogeographical distribution of species among these environments, adaptations of extremophilic organisms across the three domains of life and adequate autonomous robotic systems to assess the complexity of deep-sea biological communities. This presentation attempts to present a two-fold view of advanced planetary exploration that relates to a sustainable vision of deep-sea mineral mining: charting our oceans and developing technologies least harmful to endemic biology can propel the design and prototyping of future robotic planetary probes bound for aquatic missions on alien moons. Space industry, government and public interest towards a broadened planetary perspective on deep-sea mineral mining is promoted by addressing an astrobiological rationale of this endeavor.

Sep 1, 2014

By J. Gholamnejad

In open pit mine planning and design, push back mine sequencing is widely used for long-term production planning. In push back design, a series of nested pits is generated and then considered as possible push backs with regard to the minimum push back width requirements. These nested pits are produced by parameterizing on one economic parameters like commodity price, mining or processing cost, stripping ratio etc. The most important characterization of these push backs is that the inner most push back has the highest value per ton, the second inner most push back has the second highest value per ton and so on. These nested pits are generated based on the best estimates of grade within a representation of the ore body in a three dimensional matrix form. Therefore, the inherent uncertainty associated with reserve estimation (for our discussion grade uncertainty) is not taken into account when push backs are designed. These methods do not attempt to establish which part of the deposit is likely to be worth most. This paper introduced a new algorithm that incorporates ore grade uncertainty during push back design process. The suggested strategy tries to seek to schedule risky blocks later in the extraction sequence.

Jan 1, 2007

By W. Lee Daniels

Significant deposits (> 4,000 ha) of heavy mineral sands were discovered in the USA Coastal Plain of Virginia and North Carolina in 1989. The majority of these lands support highly productive row crop agriculture, and the development of restoration protocols that would return these lands to agricultural use was deemed to be critical to the long term sustainability of mining operations. Virginia Tech worked closely with all stakeholders to develop appropriate restoration protocols and to coordinate their implementation. Full-scale mining operations at the Old Hickory Project in Virginia were initiated in 1997 by Iluka Resources Inc., and restoration protocols have continued to evolve in response to a variety of economic, technical, and social issues. Approximately 750 ha of land are in various phases of backfilling and final reclamation. Return of these lands to agricultural row-crop production has been complicated by lateral variability in mine soil physical conditions, excessive compaction, and limited topsoil return. However, within the past two years, a series of tailings deposition and soil reconstruction practices have been developed and implemented that significantly improve post-mining soil productivity. Deep ripping and appropriate use of organic soil amendments have been particularly effective at restoring post-mining soil productivity.

Jan 1, 2005