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By Will S. Pettitt

Fracture Network Engineering (FNE) is the engineering design of rock mass disturbance through the use of advanced techniques to model fractured rock masses numerically, and then correlate field observations with simulated fractures generated within the models. Microseismic (MS) monitoring is a standard tool for evaluating the geometry and evolution of the fracture network induced during a hydraulic treatment, principally by source locating MS hypocenters and visualizing these with respect to the treatment volume and infrastructure (Figure 1). The integrated use of Synthetic Rock Mass (SRM) modeling of the hydrofracturing with Enhanced Microseismic Analysis (EMA) provides a feedback loop in which the SRM is constrained by the information provided by the MS data and the in-situ behavior of the fracture network is better understood, leading to informed decisions on future field operations. This paper discusses the technologies used in FNE and some of the developmental challenges we face in order to provide a more efficient and robust application of the approach. One particular challenge is the accurate representation of MS source data within the models (locations, magnitudes and mechanisms), and the ability to correlate these data effectively with field results. This challenge is being overcome by the development of more efficient numerical modeling algorithms, providing simulations in three dimensions at reservoir scale, combined with validation of these algorithms using laboratory and field case studies.

Jun 1, 2012

By AIME AIME

MINING geology was granted two sessions, Wednesday morning and afternoon, Feb. 17. The morning session, at which H. Foster Bain presided. first considered Paul M. Tyler's paper, "Economic Notes on Steel-making Alloys." The elements used in these important alloys are chromium, manganese, molybdenum, nickel, phosphorus, silicon, titanium, tungsten and vanadium. Edward Sarnpson and C. K. Leith asked whether chromite concentrates could be used, Mr. Tyler replying that they could if not too high in iron. G. W. Pawel said that they were used at Niagara Falls, nlixecl with coarse ore. In reply to a question asked by A. O. Hayes, Mr. Tyler said that molybdenum had not affected the price of tungsten. After this discussion, E. S. Moore's paper on nickel was considered. H. Foster Bain thought that nickel is well controlled and in good hands, technically and politically. The popular stainless steel in America is the 18:8 Cr-Ni metal. In Germany a Cr-Mn steel has possibilities. It is easy to make, cheaper. has better workability, will stand 85 per cent reduction between heats.

Jan 1, 1932

By Harold L. Rhodes

The Bureau of Mines has developed a quantitative method to determine water vapor in helium in the range of 0.1 to 15 ppm by volume. This method uses the quantitative chemical reaction of H20 with CaH2, which produces 1 mole of hydrogen for each mole of H20 in the sample. A gas chromatograph is then used to determine the concentration of hydrogen in the product. The precision of the H20 analysis is ±0.05 ppm at a concentration of 1 ppm. This method is used to calibrate a commercial platinum-phosphorus pentoxide (Pt-P205) electrolytic water vapor analyzer that has an improved inlet system and digital voltmeter readout.

Jan 1, 1981

By K. D. Plants, J. H. Holden, L. F. Willmott

Pulverized high- volatile A bituminous coal was gasified with oxygen and superheated steam in a pressure - gasification pilot plant equipped for steampickup feeding . The pilot plant operated satisfactorily at relatively high steam- to - coal ratios , but steam- to - coal ratios could not be reduced much below 0.5 lb / lb without condensation of steam or softening of the coal . Carbon gasified , gas composition , and coal and oxygen requirements were essentially the same as for a pilot plant equipped with a fluidized coal feeder . Average results from the pilot plant equipped for steam- pickup feeding were coal requirement , 37.3 lb/M ( 1,000 ) scf of CO + H₂ produced ; oxygen requirement , 358 scf /M scf CO + H₂ produced ; and carbon gasified , 87.7 percent .

Jan 1, 1964

By THOMAS LEONBRD WATSON

I. INTRODUCTION. THE results embodied in this paper are based on a careful field- and laboratory-study of the lead- and zinc-deposits of the Virginia-Tennessee district, begun in the latter part of the summer of 1904 and completed in the spring of 1905, preparatory to the publishing of a State report .on them. A separate description of the individual deposits in Virginia is purposely omitted, since I have already described them in considerable detail in a State report. The Tennessee deposits are described here in some detail for the reason that no detailed record of them has yet been published. Practically, this paper summarizes the results obtained from a study of the geology of the ore-deposits of the district as, a whole. (I had the pleasure of visiting the deposits of Virginia and Tennessee with Dr. H. Foster Bain of the U. S. Geological Survey, in April, 1905. Figs. 21 and 22 are from photographs taken by Dr., Bail.) II. HISTORICAL. . The first authentic records of lead-mining .in Virginia date hack more than 150 years; and the old lead-mines at Austinville, on New river in Wythe county, V a., were the first to be worked. Colonel Chiswell, a native of Wales, and one of the earlier adventurers in southwestern Virginia, was one of the first operators of the Austinville mines. Chiswell's operations at Austinville commenced in the year 1750, and closed shortly after the beginning of the Revolutionary War, in the' year 1776, covering a period of about 25 years. From that time to the present, mining has been carried on almost continuously in the Virginia area. For many years after the Virginia mines were operated, mining was confined exclusively to the lead-ores. The zinc-ores

Mar 1, 1906

ICMM’s vision is ‘a viable mining, minerals and metals industry that is widely recognised as essential for modern living and a key contributor to sustainable development’. The ICMM Sustainable Development Framework provides the basis for achieving this vision by assisting the industry to improve its performance. Two years on from the first SDIMI conference, significant progress has been made in further developing and implementing the Framework. To fulfill their commitment to implement and report performance against the ten sustainable development principles in the Framework, ICMM’s corporate members have committed to report ‘in accordance’ with the GRI 2002 Sustainability Reporting Guidelines and the Mining and Metals Sector Supplement, developed by the GRI and ICMM. While much remains to be done, development of the Supplement and the commitment to reporting mark an important milestone for ICMM and the sector.

Jan 1, 2005

By M. R. Shahan, W. R. Reed

A laboratory apparatus (shield dust simulator) was designed and constructed to simulate the dust generated during the advance of longwall hydraulic roof supports, or shields. The objective of the study was to develop a tool that could be used to test the hypothesis that foam applied to a mine roof prior to a shield advance could be used to reduce the respirable dust generated during shield advances. This paper will outline the design parameters for the development of the system, as well as describe baseline testing of coal and limestone dust. Results show the average instantaneous respirable dust concentrations that occurred during simulated shield advance. Confidence intervals were calculated from the instantaneous respirable dust data to determine the repeatability of the data produced by the device. INTRODUCTION During longwall mining, miners can be exposed to respirable dust that is generated during the advance of hydraulic roof supports or shields. National Institute for Occupational Safety and Health (NIOSH) researchers have conducted numerous surveys of longwall mining operations, benchmarking the operating practices and dust control measures in use. It has been determined that the shields are responsible for 27% of the respirable dust that is generated on the longwall face [1]. The dust generated by the shield advances ranks second, next to the longwall shearer which is accountable for 43% of the respirable dust generated on the longwall face. The respirable dust generated during the advance of the shields can be a significant contributor to the respirable dust exposure of the mining personnel operating at the longwall face, especially since some of this dust is generated in the walkway. Control systems designed to reduce the dust levels generated during the shield advance have the potential to greatly reduce the respirable dust exposures of the personnel downwind of these activities. One control technology to decrease the dust generated by the shield advances would be to apply a layer of foam to the forward shield-roof interface prior to the shield advance [2]. The blanketed layer of foam would interact with the material located on the top of the shield during the advance, preventing a portion of that dust from becoming entrained in the mine air. This layer of foam would be applied using a foaming nozzle located on the longwall shearer body that would spray foam on the roof surface as the shearer passed. Substantial laboratory work has been completed to determine the feasibility of this type of foam application. NIOSH engineers have classified the various characteristics of foaming agents, using foam expansion ratio and drainage as important properties, as well as developed the mechanical systems required to apply the foam safely to the mine roof [2, 3]. The construction of an apparatus that could simulate the mechanical interaction between the dust-laden shield top and mine roof was necessary to adequately test the hypothesis that foam could be an appropriate control. A team of engineers designed and constructed a shield dust simulator system allowing for in-house testing prior to a full-scale field investigation.

Jan 1, 2019

By H. Verakis, M. A. Hockenberry, A. C. Smith, J. H. Rowland III

Four different types of fire suppression systems were evaluated in large-scale fire experiments to study the effect of air velocity on their effectiveness in extinguishing conveyor belt fires. The four different types of suppression system were water sprinkler, deluge-type water spray and two different dry chemical fire suppression systems. The large-scale fire tests were conducted with 1.8-m- (72-in.)-wide fire-resistant rubber belt that met the Mine Safety and Health Administration flame resistant requirement specified in Title 30, Code of Federal Regulations, Part 18, section 18.65 (also known as the 2G Flame Test). Each fire suppression system was tested at air velocities of 152 - 168 m (500–550 ft) per minute (mpm) and 411 - 457 mpm (1,350 - 1,500 fpm). Two tests were conducted at both air velocities for each fire suppression system. Both of the water-based fire suppression systems were able to suppress the fire to the point that a miner could extinguish it with a fire extinguisher. However, the amount of water needed to suppress the fire to the point where a miner could walk up to and extinguish any smoldering belting was greater than the current MSHA regulations required. MSHA regulations only require 10 minutes of water supply for a suppression system. In the test setup, neither of these systems would have suppressed the fire had the water been turned off to the system after 10 minutes. The dry chemical suppression systems produced mixed results. Dry chemical suppression system A did not suppress the conveyor belt fire at either air velocity. Dry chemical system B suppressed the fire at 152 mpm (500 fpm) air velocity, but produced mixed results at the higher air velocity. Details are presented on the large-scale fire test setup, arrangement of the fire suppression systems and conclusions regarding the effect of air velocity on fire suppression system design and performance.

Jan 1, 2010

By D. L. Paulson

The Bureau of Mines used 50-and 800-kva electric-arc furnaces to confirm the feasibility of producing ferronickel in electric-arc furnaces from pre-reduced concentrate from the Yugoslavian FENI project. The relationships were established among metallic iron concentrations (degrees of prereduction), ferronickel grades, and nickel recoveries. Smelting the concentrate containing 1.27 wt-pct nickel and metallic iron levels between 2 and 3 wt-pct, produced 15 to 20 pct ferronickel. Higher or lower metallic iron concentrations were compensated by adding oxide pellets or carbon to the electric-arc furnace charge. Over 90 pct of the contained nickel was recovered when up to 20 pct ferronickel was being produced. Data obtained while smelting 16 tons of prereduced concentrate in the 800-kva electric-arc furnace indicated ferronickel can be recovered at an energy consumption of 530 kwhr/ton of prereduced material.

Jan 1, 1977

By D Blair, L Fergusson, G Barros

"The purpose of this paper is to present the findings of a waste rock remediation program conducted at a gold mine in New South Wales (NSW) over a six-year period. The treatment of waste rock dumps included the longitudinal results of one-off applications using: ViroMine Technology, including the application of a chemical reagent called Terra B, which is a benign, clay-like substance derived from processed bauxite and other sources lime and biosolids (added for nutrient value) clay capping and topsoil compared treatment outcomes from these three approaches to a control.Parameters measured in the program included leachate pH, total actual acidity (TAA) and chromium reducible sulfur (CRS), Al, Cd, Cu, Fe, Mn, Ni, Pb, Zn, and tree height and vegetative cover density with data collected at regular intervals over a six-year monitoring period. Findings over the life of the study indicated, for example, that leachate pH in the control area was 4.5 in year 1 falling to 4.0 by year 6; pH in the lime and capping treated waste rock was initially raised to about 5.5 after treatment but fell to 5.0 within 24 months and remained a low 4.7 by year 6; pH in the Terra B waste rock was 6.8 in year 1 immediately after treatment, and actually increased to 7.3 by year 6 with no further treatment. This finding is of relevance because it effectively profiles the acidity curves of waste rock control, lime, and capping applications, and shows that they decline over time, despite an initial æpH shockÆ to the solids as measured by TAA and CRS in the case of lime. Similar treatment curves were observed for heavy metal leachates. Tree height and vegetative cover density indicated that with increasing acidity in the waste rock dump, the lime and capping options did not allow healthy revegetation, but in the Terra B treated areas tree growth and density were comparable to background, undisturbed forest levels.is needed with respect to tailings management, based on a novel integrated research framework.CITATION:Fergusson, L, Blair, D and Barros, G, 2012. Sustainable waste rock remediation and revegetation - A real-world longitudinal study comparing ViroMine technology to standard applications and doing nothing, in Proceedings Life-of-Mine 2012 , pp 249-258 (The Australasian Institute of Mining and Metallurgy: Melbourne)."

Jul 10, 2012

By D. Harrington

Metal-mine fires in the United States are not of frequent occurrence and relatively for of those that do occur result in loss of life, although many cause heavy property loss or are costly to extinguish. Over a span of years, however, more lives are lost in metal Trines from fires than from any other of the untoward occurrences which afflict metal mining, such as electrical storms, floods, cave-ins, magazine explosions, or strikes. In perhaps more than 90 per cent of the fires. in metal mines' there is no loss of life; hence, the general public, even the general mining public, seldom hears of these fires, though the property loss frequently reaches hundreds of thousands of dollars; on the other end, in some instances the property damage from an underground metal-mine, fire has been negligible and the loss of life comparatively high. In any comprehensive study of metal-mine fires, ventilation is certain to be found a vital factor. The influence of ventilation on fires and the influence of fires on ventilation are of vital importance. In metal-mine fires very few persons meet death from actual contact Pith heat or flame; nearly all fatalities are duo to asphyxiation or suffocation. A well-planned, well-installed, and well-operated mechanical ventilation system is unquestionably one of the best available present-day protections from loss of life and property in case of fire in a metal mine; that this is true is attested by the usual helplessness of mining officials in trying to handled underground fires in a mine that has not had the foresight to install mechanical equipment to control underground air flow. On the other hand, the establishment of high-velocity air currents without sufficient day by day attention to such details as the method of coursing, or controlling, or confining them most certainly tends to increase dangers from fires rather than to aid in the avoidance or elimination of these dangers; the truth of this latter statement is shown by the fact that the greatest, loss of life in metal-mine fires during the past 20 years has been in relatively well-ventilated workings, and in every case the life loss has been due to some more or less trivial or easily remedied defect in the Ventilating system - usually a defect that has had some reference to doors used or supposed to be used to deflect or control air currents.

Jan 1, 1933

By J. M. Singer

Quenching distances for flames of methane-coal dust mixtures were determined with air and oxygen-enriched air. Coals used were Pittsburgh, Sewell, and Pocahontas No.3. Quenching distances were greater for flames of hybrid mixtures of coal dust and methane than for methane flames of corresponding stoichiometry. From the data of quenching distances and methane-coal dust concentrations was calculated the quenching equivalence, which is the increase in coal dust concentration required to maintain a given quenching distance value as the methane concentration decreases. These equivalences could be useful in identifying hazardous methane-coal dust mixtures in mines.

Jan 1, 1966

By H. J. Schulze

From a colloidal science point of view (Schulze 1984, Nguyen & Schulze, 2004) five micro-processes are responsible for successful particle-bubble formation: the approaching of the particle to the liquid-air interface, the thinning and rupture of the intervening liquid film, the expansion of the three phase contact perimeter, the generation of sufficient large capillary force to stabilise the aggregates and the transport process of particles into and within the froth layer. Flotation reagents influence mainly the thinning and rupture of the intervening liquid film between particles and air bubbles, the expansion of the three phase contact after the rupture of the liquid film and the stability of the aggregates against external destruction forces in the flow field. But it exist also a non-negligible influence on the approaching of particles to the bubble surface during the encounter process and on their passing over into the froth layer and the froth stability.

Jan 1, 2003

By K. Webb, M. Hohn

"This paper reviews the evolving Ontario mining regime for mining industry-Aboriginal engagement and its apparent alignment with court decisions, domestic law, emerging international norms, mining industry rules, and mining firm-Aboriginal agreements, drawing on publicly available commentary from government officials, the private sector, and Indigenous communities. This paper provides a preliminary analysis of the potential implications of the new regime, especially for the mining industry and Aboriginal communities and, on that basis, discusses possible future developments.RÉSUMÉ Le présent article analyse le régime minier de l’Ontario pour l’engagement entre l’industrie minière et les Autochtones et son harmonisation avec les décisions des tribunaux, le droit interne, les nouvelles normes internationales, les règles de l’industrie minière et les ententes compagnies minières- Autochtones en se basant sur des commentaires, disponibles publiquement, d’officiels gouvernementaux, du secteur privé et des communautés autochtones. Cet article fournit une analyse préliminaire des implications potentielles du nouveau régime, surtout pour l’industrie minière et les communautés autochtones et, en s’appuyant sur ces données, il traite des futurs développements possibles."

Jan 1, 2016

By Lowell L. Patten

The Federal Bureau of Mines participated with the National Aeronautics and Space Administration and Martin Marietta Aerospace in developing, building, and testing a portable X-ray fluorescence spectrometer for use as an analyzer in mineral-resource investigative work. The prototype battery-powered spectrometer, measuring I1 by 12 by 5 inches and weighing only about 15 pounds, was designed specifically for field use. The spectrometer has two gas-proportional counters and two radioactive sources, 109Cd and 55Fe. Preliminary field and laboratory tests on rock specimens and rock pulps have demonstrated the capability of the spectrometer to detect 33 elements, to date. Characteristics of the system present some limitations, however, and further improvements are recommended.

Jan 1, 1982

In the last five years, new iron ore pellet plants have been built with significantly reduced air pollution levels compared to the older generation of plants. European and American pollution controls are more stringent that in China and Brazil. The recent American plants have successfully employed circulating fluidized beds for sulfur control, baghouses for particulate control, activated carbon injection for mercury and a new design of specialized low-NOx burners.

Jan 1, 2015

By B. D. H. Knights, M. A. W. Bryson

Flotation of PGM ores, specifically UG-2, presents a number of technical challenges. These centre on the prevalence of chromite. Subject to over-grinding, chromite is primarily recovered to the flotation product through entrainment. This is of unique concern as it must be kept below a threshold for downstream smelting, with significant operational and monetary penalties being imposed should it exceed this concentration. A number of strategies have been developed to maximise PGM recovery in the presence of this unwanted contaminant. Specialised flowsheets form a vital basis and advanced control algorithms further enhance PGM recovery while minimising the recovery of chromite. Advances in Mineral Processing Science and Technology Proceedings of the 48th Annual Conference of Metallurgists of CIM Sudbury, Ontario, Canada Edited by

Jan 1, 2009

By I. R. M. Chaston

Abstract. This paper puts forward the concept of 'radial' plant layout where all crushing, milling and treatment operations are preferably concentrated in one central area and these separate stages are connected by radiating conveyors to and from outside storage areas. This system is contrasted to the more customary system of 'linear' plant layout where the crushing, milling and often the treatment operations follow one after the other in separate buildings. The radial system simplifies and improves contral and supervision to a very considerable extent and can lead to a form of continuous plant operation with the separate sectors shutting down in succession for necessary maintenance while maintaining the overall plant operation. The paper is illustrated with example: from past and recent diamond treatment plant practice in South Africa which demonstrate the reduction in plant labour achieved by this system. Previous objection to this type of layout on the grounds that it inhibited plant expansion are shown to be unwarranted. Radial Layout for Increased Treatment Plant Productivity A great deal of time and trouble is spent by highly qualified and experience( metallurgists in developing the right treatment process for a given ore. This process is then often expressed in a treatment flowsheet of the type shown in Fig. 1 which shows a typical diamond plant. This flowsheet, when completed, is commonly handed over to the mechanical engineers who then design the layout of the equipment indicated on the flowsheet and produce the working drawings upon which the detailed construction of the treatment plant will be based. It is an unfortunate fact that the tedious and time-consuming juggling of equipment and inter-plant transportation is often left to hard-working draughtsmen who, however capable' in their field, lack practical experience in the day-to-day operation and maintenance of the treatment plants they design. As a result many plants have been produced which, while they satisfy the requirements of the flowsheet with minimum capital requirements, cost far more than should be necessary to op¬erate and maintain. It is often possible to change individual items of equipment which do not achieve the performance required of them, but it is usually extremely expensive to change the basic layout of the plant if this should be found to be unsatisfactory. It should therefore be recognised that great care and attention should be spent on consideration of the basic layout of any treatment plant and that the views of both designers and operators should be fully regarded before settling upon the inevitable compromise dictated by the varying requirements of process-engineering and economics. It is unfortunate that this important subject receives such scant regard in the standard ore dressing text books and hand-books, being usually dismissed in a few paragraphs.

Jan 1, 1977

By Donald Whittaker

Severe climatic conditions in mines are normally associated with working at depth. More precisely, it is a matter of working in regions of high strata temperature, since, for example, some coal mines in the Ruhr have strata temperatures at 1000 m which are matched only at 3 times that depth in the South African gold mines. In Britain we are perhaps fortunate in encountering strata temperatures in our deeper coal mines some 10-15 K lower than at the same depth in the hot mines of the Ruhr. Nevertheless the problems of high temperatures and humidities in UK mining operations, which in the past have been confined to a few specific sites, have in recent years become more widespread, and there is every reason to suppose that the trend will continue. Clearly strata temperature is not the only .causative factor. Long ventilation circuits serving districts remote from the shaft must also play a part, while the heavy use of machinery and the rapid, rates of excavation of modern mining methods are obviously important. It is necessary to understand the mechanisms of all such factors, and to measure their magnitudes and fluctuations, if remedial measures are to be properly designed or predictions made which are accurate enough to be of use in ventilation planning. This paper presents the results of a long-term (and continuing) investigation carried out in several mines to measure the major sources of heat and moisture on longwall districts and trunk conveyor roadways. The variation with time of these sources is reported, and the resultant effect on the climate is considered. In their investigations of the heat exchanges occurring in a whole mine Oakes and Hinsley (1955-56)1 listed and estimated the magnitudes of a large number of heat sources. Some of these, namely autocompression of the air in the shaft, diesel engines and compressed air mains, do not apply to the present investigations, which refer to longwall districts with conveyor transport and no compressed air supply. Others, such as oxidation of coal and, desorption of methane, have not been taken into account in the measurements, but are discussed later. One other source, the importance of which was pointed out by Gracie and Matthews (1975)2, is the coal on the conveyor, a form of strata heat emission, but one which is strongly dependent on the rate of coal production. The heat emissions measured in the present investigations were the energy consumed by electrical machinery, the heat conducted from the strata and the heat lost by the conveyed coal. Most of the emitted heat was removed from the district by the ventilation air, and was measured by continuously recording the enthalpy of the air at fixed stations. The heat removed by service water, supplied for machine cooling and dust suppression, was also measured. Account was of course taken of the relatively minor changes in level around the districts, in terms of the potential energy gained or lost by the coal and by the ventilation air (autocompression).

Jan 1, 1980

By Francis P. Sinn

IN the zinc smelting industry the year 1947 seems to have been one of putting one's house in order rather than one of any material technical development or radical change in operating conditions. Labor generally has been in better supply but several plants report a scarcity of skilled workmen. Some plants continue to operate on the basis of a six-day week and will probably continue to do so until labor is more plentiful. Only one plant is known to have operated on a curtailed basis because of labor shortage, but here the difficulty was lack of proper housing facilities. Necessary materials and equipment for much-needed maintenance and modernization have been in short supply so these programs have often been delayed. Laborsaving devices of the "Payloader" type have been more generally used for handling materials. Slab zinc production was discontinued during the last months of the year at Danville, 111. and at Langeloth, Pa. Both of these plants used the Hegeler type of furnaces fired with producer gas. It is understood that the rolling mill and possibly the acid plant at Danville will continue to operate. At Langeloth acid will be produced from

Jan 1, 1948