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By Wang Yingmin, Xu Zhuyun

There are 3 steps in the process of forming a mine ventilation system, (1) selecting a reasonable ventilation pattern (included pit shaft arrangement); (2) optimizing of the ventilation network and (3) computing and outputting the flow splitting results of the network with the optimal ventilating equipments selected. In the past, the first step was relied on artificial decision-making. In order to design a common ventilation system, some ventilation experts were needed to participate or do some examinations. Even so, the design made was reasonable only for those experts. If there is a mistake in the first step, then even the followed 2 steps are best done, the losses are very difficult to retrieve. So that, the first step is very important. The development of expert systems provided an efficient means and tool for all engineering fields. This paper presents an expert system of selecting mine ventilation pattern and pit shaft arrangement. After testing many times, it is shown that the system can perform the first step of designing a mine ventilation system, and can help the experts doing their study works more efficiently.

Jan 1, 1991

By S. K. Kawatra, R. A. Seitz

Nonpolar hydrocarbon oils are commonly used in the flotation of minerals to fulfill a number of roles. These roles include reducing overall reagent costs by replacing part of the collector addition, improving coarse particle recovery without reducing selectivity, as well as several others. This paper will cover the types of oils which are available, their physical and chemical characteristics, and the effect of these characteristics on the function of hydrocarbon oils in flotation. In addition, techniques for improving the behavior of oils will be discussed.

Jan 1, 1986

By B. J. Arnold, C. D. Harrison, R. A. Lohnes

More than 544 Mt (600 million st) of coal are handled annually for use by this country's coal fired power plants. Coal is transported in various ways: overland conveyors, railcars, trucks and barges. It can travel short distances or thousands of miles, picking up moisture, freezing or drying. When the coal is received at the power plant, environmental problems with fugitive dust and further handling problems can arise. To ensure that power plant availability is not jeopardized by coal handling problems, the Electric Power Research Institute's (EPRI) Coal Quality Development Center (CQDC) developed a research program aimed at addressing utility coal handling problems. The program has identified key areas, and is investigating the cost and cause of coal handling problems as well as the solutions to these problems. The ultimate goal of the program is to develop a "handleability index" that utilities can use in their coal specifications or hardware for a utility's sampling system to predict handleability and determine if a coal shipment should be accepted.

Jan 1, 1993

By Norm Steenson

Rapid excavation includes rapid support and is the central theme of this paper. Over the last few years, enormous strides forward have been made in the excavation and material handling aspects of underground excavation. However, the technology necessary to support these rapidly created openings has lagged behind the other aspects. This paper would attempt to bring you up-to-date on the progress made in bringing ground support using shotcrete into the same productivity rates as the other cyclic operations. Shotcrete has become an acceptable material for temporary and permanent support for undergound openings. However, coarse aggregate shotcrete has been an expensive construction material. It has been confined in the main to difficult ground conditions where conventional methods of support have proved to be even slower and more expensive than shotcrete. There are two main factors influencing the productivity of shotcrete equipment. (1) Structural shotcrete as opposed to gunite requires 40% to 45% rock minus 3/4" in the mix design. The equipment to handle such aggregate content has been difficult to develop on a volume basis owing to the attritional nature of the material which causes intense wear problems on

Jan 1, 1974

By J. Boisvert, E. Daniels, C. Deutsch

"INTRODUCTION Conventional mine planning is performed on a single resource model at a selective mining unit (SMU) scale deemed appropriate for the deposit and mining method. Estimation methods such as kriging and inverse distance, commonly used to construct a single model, are susceptible to histogram smoothing (Rossi & Deutsch, 2014). This can be mitigated by limiting the number of composites per estimate, therefore correctly reproducing the distribution of estimates (Boisvert & Deutsch, 2012). Search limiting techniques remedy histogram smoothing at the cost of introducing a problematic conditional bias (Isaaks, 1999) and introduces even greater spatial smoothing. Localization is an alternative, offering histogram reproduction through post processing of more robust probabilistic modeling techniques. A single localized model at the SMU scale is desirable. The correct histogram can be reproduced and a single model allows for the use of conventional mine planning and resource evaluation techniques. Despite the advertized benefits of localization, the necessary reliance on a larger panel scale as a middle step in the localization process yields unsightly “edge-effect” artifacts (Boisvert & Deutsch, 2012). Two approaches to artifact reduction are presented here. The first is a straight forward optimization approach designed to minimize an objective function that penalizes artifacts including panel edge discontinuities to generate a model free of panel edge-effects. The second approach redefines a panel in a less conventional fashion as a randomly chosen set of SMUs throughout the domain. This method produces a model void of any regular panel shape resulting in an artifact free model. Artifact reduction minimizes the obvious “edge-effect” issues of localization but local precision issues described by Boisvert & Deutsch (2012) persist. Localization is not a replacement for quantified uncertainty for comprehensive risk analysis and resource evaluation. LOCALIZATION Initially developed with Uniform Conditioning in mind, localization collapses a distribution of local uncertainty at a panel scale to an SMU scale model for mine planning (Abzalov, 2006). This process has been extended to Indicator Kriging (Hardke, 2011), Sequential Gaussian Simulation (Boisvert & Deutsch, 2012) and MultiGaussian Kriging (Daniels and Deutsch, 2014). The localization process is performed in a similar fashion regardless of which technique is chosen to create the prior model of uncertainty. Methodology There are three scales of importance considered in the localization process. The point scale, otherwise known as the data scale, is the smallest and is the scale at which experimental data is collected. The SMU or block scale is the familiar scale at which mine planning and resource evaluation takes place. Lastly, the panel scale is larger and contains a number of SMUs. Each of the three scales is illustrated in Figure 1."

Jan 1, 2015

By Andrew J. Neale, Brian C. Flintoff

A review of the current literature, combined with the authors' knowledge of the western Canadian coal industry, indicates that the development and implementation of process control in coal preparation, particularly in flotation applications, is significantly lagging behind that seen in mineral processing. The reasons for this include the lack of inexpensive and reliable sensors, incomplete understanding of the flotation process, limited experience of process control in the coal preparation industry and depressed coal prices, all of which have combined to hinder plant automation. This paper illustrates the benefits of process control in coal flotation, provides a general discussion of the control problem and concludes with two examples drawn from Australian experiences.

Jan 1, 1989

By T. T. Chen, J. L. Jambor, J. E. Dutrizac

A reconnaissance study of the neutralization potential of 30 diverse minerals, 28 of which are silicates and aluminosilicates, has shown that most of these minerals contribute minimally to the neutralization potential (NP) in standard static tests. Feldspars in particular give low NP values and would not be expected to attenuate the acidity to any significant extent in acid rock drainage settings. The BET-determined surface areas of the minerals vary considerably, and the large surface areas of some of the pulverized samples have clearly affected the NP values even though the standard static-test protocol was used for the preparation of the samples. The low NP values of most silicates and aluminosilicates are in general agreement with the laboratory-determined slow dissolution rates for these minerals. The results suggest that, in the prediction of whether rocks will be acid-producing, the most realistic measure is that of the carbonate content. In mine wastes from metalliferous ore deposits, the contribution to the NP by the non-carbonate gangue assemblage is unlikely to be more than a token amount until well after the establishment of an acid rock drainage situation.

Jan 1, 2000

By V. E. Ross

A model has been developed that describes the behavior of mineral particles and water in the cleaning zone of flotation columns. The possible detachment of particles from their sites of attachment at the bubble surfaces is related to the flux of bubble surface area with increasing distance from the interface between the collection and cleaning zones and the late at which floated particles are transported into the cleaning zone. The drainage velocities of floated and entrained particles are calculated from the drainage velocity of water and the properties of the particles. The effects of wash water and inhibited drainage in the froth are also explicitly accounted for.

Jan 1, 1988

By P. M. Sandgren, H. Al-Dabbagh

Saudi Company for Precious Metals (SCPM) is jointly owned by the Saudi Arabian state organization Petromin (The General Petroleium & Mineral Organization) and Boliden of Sweden. The company operates the Sukhaybarat gold mine in the Saudi Arabian desert and produces some 80,000 ounces of gold per year by agitation and heap leaching. The discovery, development, and operation of this mine is a success story. After the first drill hole intercepted a gold mineralization in 1983, it took the partners only 8 years to delineate the ore reserve, locate water sources, prepare pre-and final feasibility studies, obtain permits, design, and construct the facilities. Sukhaybarat, which is an open pit mine, started off with a carbon-in-leach agitation plant only, but a heap leach facility was added in the beginning of 1995. Since start of operation in the middle of 1991, a total of 300,000 ounces of gold has been produced in the first four years of operation at a very competitive cost.

Jan 1, 1996

By Balesh W. Konda, Andrew B. Cecala

Face ignitions occurring during longwall mining are increasing each year and are expected to continue to increase as deeper and gassier seams are mined. Effective methane monitoring strategies are needed to supplement techniques developed either to control the ignition sources or to dilute the gas to an acceptable concentration. Present monitoring strategies do not always detect dangerous concentrations as rapidly as they should. In a number of instances, dangerous concentrations have been observed at the shearer, but are diluted to acceptable levels when measured at the tailgate monitoring location. To effectively monitor and control methane concentrations, methane liberation and emission patterns must be identified. This need has led to a joint research effort between the Canada Centre for Mineral and Energy Technology and the United States Bureau of Mines. By combining the knowledge and experience of both organizations, the methane hazard facing underground longwall operations can be addressed more effectively. A comprehensive plan was developed to monitor methane levels throughout the panel and for an entire longwall mining cycle. In June-July 1986, a case study was performed at the Cape Breton Development Corporation's Lingan colliery in Sydney, Nova Scotia. This initial study was performed on two advancing longwall panels. Methane concentrations and flow patterns from this study are described in this report. A similar study is planned on a retreating longwall panel.

Jan 1, 1987

By W. Petruk

Imaging is a fundamental requirement when characterizing minerals, ores and related products. Images are used for presentation, texture analysis, characterization, image analysis, identification, etc. The image mode that is utilized is dependent on the application, mineral properties and available instruments. Different instruments produce images that display different features. In order of increasing complexity they are: hand specimens, a non-polarizing microscope, polarizing optical microscope, scanning electron microscope (SEM), low vacuum SEM, microprobe, secondary ion mass spectrometer, staining, cathodoluminescence, tomography and others. Image analysis uses images produced with either an optical microscope or a SEM, but the SEM images are superior in this application. Key words: Mineralogy, Imaging, Mineral characteristics, Scanning electron microscopy, Optical microscopy, Cathodoluminescence

Jan 1, 2003

By J. G. Henning, R. Edrissi

This paper describes a practical methodology, based on numerical modeling, for the prediction of progressive failure of underground-mine stopes having cable-bolt support. A case study of the 40-761 scope at the Kidd Creek mine, Timmins, Ontario, Canada is presented. Scope 40-761 was mined by blast hole open sloping in 1986 and was a lead scope within a mining block located between levels 36-1 and 38-2. Initially designed to peak at level 38-2, the scope back caved upwards =40 m towards level 36-1. After caving began, cable bolts were installed above the stope from level 36-1. The stope eventually stopped caving when the falling rock mass encountered a sufficiently high cable density. This paper provides details of the geomechanical data and modeling results of the case study. Numerical modeling of cable bolts around the mine stoke was carried out using a finite-element modeling software. The software, known as e-z tools, was developed by the first author.

Jan 1, 1996

By R. V. Ramani, W. Miola

The MSHA prescribed method for the determination of quartz in airborne respirable-dust samples from underground coal mines is the P-7 method, a combination of low-temperature, radio-frequency ashing (LTA) and infrared analysis (IR). There is no prescribed procedure for quartz analysis in bulk samples of coal and host rock. Dispersive infrared (IR), Fourier-transform infrared (FTIR) and X-ray diffraction (XRD) methods are most commonly used for the analysis of quartz in powders. Several aspects of the experimental procedures, such as the preparation of the analysis sample from bulk samples, ashing techniques, scanning procedures, peak measurement location, calibration techniques, sample amounts, size consist and data interpretation, affect the results from each of the methods differently. Significant differences in analytical results obtained from X-ray diffraction (XRD) and infrared spectroscopy (IR) on the same samples are reported. All studies point to the need for reliable quartz analysis methods. In a recent research program, a procedure for preparing bulk-coal and host-rock samples for quantitative quartz analysis was developed. Further, the results from X-ray diffractometry and infrared spectroscopy for quartz content on identical samples were compared. Calibrations with pure and mixed standards were used to assess the influence of particle-size distribution, matrix and calibration on the analytical results. In this paper, several issues concerning the measurement of quartz in the samples of coal, host-rock and airborne respirable dust from mines are outlined and quantified.

Jan 1, 1996

By Joe Komadina

DOUG HALBE: Our next topic is one that I would think everyone might want to contribute to. I'm sure everyone here has had some experience in this area. If you haven't, I'd suspect you've never really run a mill. This is what we call "Horrible Spill Areas We Had When We Started Up the Plant and How We Fixed Them." Our next speaker has had a really great operating career. He had many years with Newmont in the Carlin area, and now he's executive vice president and chief operating officer of Independence Mining Company: Jim Komadina. I don't have to be nice to the speakers anymore, do I? [laughter] You may wonder why we picked Jim Komadina to give this talk. I was involved many years ago in the start-up of Newmont7s Gold Quarry plant. Jim held quite a responsible position there. I'm not going to say anymore, but I have in the back of my mind this picture of the pump floor and a rowboat and a guy rowing around on the pump floor. [laughter] Jim, was that you? [laughter] JIM KOMADINA: Probably. I wasn't responsible for the design. [laughter] Actually it's amazing. I've seen a lot of these plants and actually had the opportunity to walk around them, so when I say this, "Horrible spills I have seen and done," it's because I've been responsible for more than my fair share of them. But having seen a lot of spills, I will present a little bit of wisdom about how to prevent them.

Jan 1, 1998

By Prof. Dr. T. R. Boulos

The Egyptian marine phosphorite of Sebaiya West, the Nile Valley, consisting of both non-oxidized hard siliceous and oxidized leached friable ore types, is subjected to a roughing-cleaning silica flotation circuit for production of wet-process phosphoric acid concentrate. Operating at its maximum capacity of 268 t/hr, the following were the main problems encountered during the early stages of running the plant: 1. The tremendous amount of slimes generated by scrubbing the crushed ore causing turbidity in the plant thickener after a short time of operation, regardless of the added flocculant. 2. Rod mill choking leading to inefficient performance of all other equipment and poor flotation results. 3. The drastic increase in imported oleic acid price. Pulp density and slurry flowrate measurements at different points of the plant as well as ore microscopy, size distribution analysis, chemical analysis and x-ray diffraction analysis of representative ore samples coupled with Work Index measurements of feed samples showed that the wide variation in the ore's hardness was responsible for such problems. Application of the locally produced non-edible rice bran oil as a substitute to imported oleic acid in flotation resulted in total saving of U.S.$2 million in 1990. The total unsaturated fatty acid content of the oil is high, ranging from 75.2 to 81.5 mole % of which the C18-unsaturated fatty acid content ranges from 72 to 79 mole %.

Jan 1, 1993

By James G. Tilton

Subsidence resulting from mining operations, has been the object of sporadic study for many years. Reports have shown that subsidence has ranged from minor settlement detected only by precise measurements to great slips where buildings are destroyed, roads disrupted, and large fissures opened at the surface. For years, a controversy has raged over the question of whether there is a positive or negative angle-of-draw. None of these questions can be given a flat answer for the variables controlling, subsidence are infinite. Generalizations can be made for various situations and areas but some means of control must be executed.

Jan 1, 1966

By C. Orf. Chukabarah

Acoustic pollution (noise) is a significant mine environmental system problem. The U.S. Bureau of Mines (USBM), Environmental Protection Agency (EPA), Department of Labor (DOL) and other researchers have all performed contributory research on noise in mining environments. The present study addressed the problem of unavailability of a computerized, practical, routine, user-friendly, and user-editable, prose-styled application program with which one can determine (a) the noise exposure indices among mine workers, (b) mine system noise exposure level on time-weighted average basis, and (c) predictive relationships among mine workers' age, prior exposure to abnormal noise levels, prior auditory pathologies and the risk/degree of mining-induced hearing impairment. Results showed that such a program ("NEIL") is accomplishable. Additional results revealed that most U.S. mines operate within the statutory noise exposure levels. Furthermore, the mine worker's age was statistically confirmed to be the main predictive risk factor for mining-induced occupational hearing impairment.

Jan 1, 1992

By Pieter Berendsen

Lamproite occurs in two locations in southeastern Kansas that are in close proximity to each other. In both locations, the lamproite is restricted to north- east-elongated, ellipsoidal depressions measuring about 3 mi by 1.5 mi. At the surface and in the shallow subsurface, lamproite occurs as sills that were intruded into Middle and Upper Pennsylvanian rocks consisting of shale, limestone, and minor sandstone. Isotopic age determinations by Zartman and others (1967) indicate that the lamproite was intruded during the Late Cretaceous (88-91 my). Drillholes for hydrocarbon exploration down to a depth of about 1,400 ft (top of the Mississippian) and numerous shallow drillholes (mostly 200-300 ft) by the Kansas Geological Survey in the northern portion of Silver City dome helped to understand the structural complexity and extent of the near-surface sills. Numerous radial faults showing small apparent vertical offsets limit the lateral continuation of individual sills. Concentric faults are believed to mark the edge of the depression. Wagner (1954) mapped the geology of Silver City dome in considerable detail and recognized a northward dipping, 120-ft-thick, lamproite sill exposed at the surface along the northeastern edge of the dome. The upper 40-50 ft of the sill weathers olive-brown and has a soft, clayey consistency in which only the phlogopite mica is recognizable. The weathered material has been mined by Micro-Lite LLC since 1982 from the exposed sill in an open-pit that measures about half a mile extending in an east- west direction. The bulk of the material, about 98%, is used as an additive in mineral supplements for cattle feed.

Jan 1, 1999

By Jeffery Denit, Steve Hoffman, Van Housman

The Environmental Protection Agency (EPA) is in the early stages of developing a national mining waste program. Our goal is to develop a mining waste program that will be state implemented, multimedia in nature, flexible, utilize and enhance existing state programs, and protect the environment. The Agency appreciates the cooperation the mining industry is providing through its participation in the Policy Dialogue committee on Mining and by providing the Agency with technical data. The following is a discussion of what led to the development of a national mining waste program, the agenda initiative to evaluate Toxic Substances Control Act authority in phosphate manufacturing, and the important steps being taken through the Policy Dialogue process to frame and discuss issues. EXTRACTION AND BENEFICIATION OF ORES The Resource Conservation and Recovery Act of 1976 (RCRA) and subsequent amendments created a framework for the regulation of hazardous wastes under Subtitle C and nonhazardous waste under Subtitle D. In 1978, initial regulations were proposed for hazardous waste management units under RCRA. These identified a universe of special wastes that were large volume, low hazard and less amenable to Subtitle C control techniques. EPA noted that waste materials from the "extraction, beneficiation and processing of ores and minerals m fit these criteria. In October 1980, Section 3001 of RCRA was amended. This Bevill amendment excluded solid waste from the extraction, beneficiation and processing of ores and minerals from regulatory control under RCRA's hazardous waste Subtitle C. This was done pending a report to Congress and a regulatory determination regarding the Subtitle C status of these wastes. Thus in November 1980, EPA published an interim final amendment to the RCRA Subtitle C regulations to reflect the Bevill amendment. RCRA requires EPA to perform studies and make reports to Congress regarding the management methods and potential hazards of managing waste. RCRA also calls for a regulatory determination regarding whether Subtitle C (hazardous) or D (non- hazardous) controls are warranted for these wastes. In December 1985, EPA submitted a report to congress entitled, “Wastes from the Extraction and Beneficiation of Metallic Ores, Phosphate Rock, Asbestos, Overburden from Uranium Mining and Oil Shale." In that report, EPA found that some mining wastes exhibit hazardous characteristics, that the range of risk from mining waste is broad, and that waste management practices have caused environmental damage. In July 1986, EPA published a regulatory determination based on information gathered in the 1985 report to Congress and comments from interested parties. In the report, EPA concluded that RCRA Subtitle C regulation of extraction and beneficiation wastes was unwarranted because mining wastes tend to be disposed of in arid climates, waste volumes are high, and facilities and wastes are located in sparsely

Jan 1, 1992

By R. P. Upadhyay

The Deserado Mine, located in northwest Colorado, is an underground coal mine designed to produce 1.225 million tons (1.35 million short tons) of clean coal per year for the Bonanza Plant located in northeastern Utah. Coal is transported to the power plant via a 61 kilometer (38 mile) captive railroad. Most of the surface facilities and the stationary underground equipment is controlled and continuously monitored by the computers located at the surface control room. In addition to system control, the computer also continuously monitors vital environmental conditions using sensors located at various critical locations underground. The system's advantages are increased mine productivity and safety.

Jan 1, 1988