Search Documents

By D. J. Pyra, J. Kudelko, Korzekwam W.

Polkowice region (Lower Silesia, Poland) is an area, where the copper mining activity started about 40 years ago and new technologies were applied. There are 3 underground mines, 3 processing plants, tailings pond (the biggest one in Europe), pipelines for flotation waste transport, railways. Although new technologies were applied during the copper ore exploitation, the environment in this area were polluted mostly by dust containing copper, lead, zinc and arsenic. Estimated values of heavy metals in polluted soils were compared to the natural contents of this metals. The geochemical background for Polkowice area was defined. The pollution zones occur around mining facilities. Copper ore exploitation and processing is planned for the next 20-40 years depending on market situation. After mines and other facilities closing the most important problem will be sustainable development of this area. To evaluate the scope of revitalization activities the analysis of recent soil environment condition will be necessary as well as forecasts for pollution migration. Geostatistic methods used also in mining will be very helpful for this task.

Jan 1, 2005

By E. F. Adkins, R. W. Douglas

The variation of the spectral emissivity of osmium and ruthenium with temperature can be expressed by the following relations: DURING a study of the sintering characteristics of osmium and ruthenium, discrepancies in the previously accepted melting points of the metals were noted. The melting temperatures had not been measured at the time of the work, but were estimated in the literature as 2700°C for osmium and 2450°C for ruthenium.' A recent investigation by Baird2 has shown the melting temperatures of osmium and ruthenium are 3000" and 2250° C, respectively. In the present work, osmium bars sintered at temperatures as high as 2900° C showed no evidence of melting, whereas ruthenium showed definite evidence of melting at temperatures as low as 2250°C. In view of the apparent discrepancies, the melting temperatures of both metals were determined. The spectral emissivities of both metals were determined as an aid to studies of the sintering characteristics of these metals. MATERIALS AND PROCEDURES The materials used in these studies were metal powders supplied by Englehard Industries, Inc., through the courtesy of The International Nickel Co. Analytical data from three laboratories, although not in complete agreement as to the purity of the material or the major impurity elements, indicated that the maximum impurity levels were 0.5 and 1.0 wt pct in osmium and ruthenium, respectively. The metal powders were pressed to 1/4 by 1/4 by 6-in. bars at 20Tsi using carbon tetrachloride as a lubricant. The pressed bars were presintered 1 hr at 1200°C after heating 1 hr at 400°C. The presintered densities of the several bars of the metals ranged from 65 to 80 pct of ideal density. Specimens were self-resistance heated in a vacuum sintering bell. Temperatures were measured with an L&N, disappearing filament optical pyrometer. True temperatures were read at the base of an 0.30-in.-diam, 0.150-in. deep hole drilled into the center of a presintered bar. Apparent temperatures were read from the surface of the bar adjacent to the hole. MELTING POINT DETERMINATION The melting temperature of the metals was determined as the temperature at which a slight additional increase in current through the specimen resulted in a reduced temperature at the base of the hole. The apparent reduction in temperature is a result of the liquid metal filling the hole, thus altering the black-body conditions. The melting points of osmium and ruthenium, based on three deter-

Jan 1, 1962

By S. Nikolic, O. O. Kehinde-Philllps, O. T. Djamgouz, D. H. Rousell

"A bulk mining method is employed at the Lockerby mine resulting in the formation of large muck-piles. If these muckpiles remain in the stopes for some time they may agglomerate to the extent that the muck cannot be removed by a scooptram. A laboratory investigation was undertaken with sulphide material from the mine in order to detemine the time that oxidation begins and the flowability of the material as a f unction of several factors. The laboratory results are applied to the conditions in the muck-piles.The time of the beginning of oxidation of the material decreases as the sulphide composition, water content and availability of air increases. Oxidation is retarded by the addition of a copper sulphate solution instead of water. The unconfined yield force (strength} of the material increases with an increase in the sulphide composition, water content and time. The material ceases to be free-flowing before there is visible evidence of oxidation and this suggests that oxidation actually begins earlier and that agglomeration is also due to the capillary action of water.Broken ore should be removed from the stope prior to the time a muck-pile ceases to be free -flowing-perhaps as early as two days f or high-grade ore and 5 days f or low-grade ore. In order to control dust, 1.4 weight per cent of a 5 per cent solution of copper sulphate should be added 10 the muck-pile rather than water. This inhibits oxidation and increases the time that a muck-pile remains free-flowing."

Jan 1, 1984

By J. Y. Murdoch

TAXATION has become a major item in the operation of Canadian mines, and, as such, merits our most serious consideration. I feel it was a splendid idea for the Institute to set aside this time for a frank discussion of this important subject, and believe great benefit will result from a better understanding of the methods and underlying principles involved. Mining, as a great national industry, may quite properly be called upon to pay its fair share of the cost of running the country; and there is no tendency on our part to avoid this responsibility. There is, however, a very definite demand that the proportion be just, and fairly and sensibly applied. I believe that Mr. C. G. Williams, Secretary of the Canadian Metal Mining Association, and others, are giving details of the various Provincial and Dominion regulati6ns, so I shall not touch on that phase of the situation. However, there are some important factors to which I should like very briefly to call your attention. The first is the vital need for stability. As you all know, a considerable period must elapse between the preliminary stages of any mining venture and the time when it comes to production-or is finally abandoned as un-profitable. These early days are fraught with many unavoidable uncertainties. If, to these natural hazards, the apprehension of instability of governmental action be added, the risk becomes so great that capital seeks other and safer fields for investment, and many otherwise promising projects are thus discarded. There probably never has been a time in recent years when so much money was seeking investment as now. Under favourable conditions, the development of our great mineral resources would be a natural and attractive outlet for this money. The amount of taxation which the mining industry can properly absorb is of the utmost importance at this time, and it might be well to consider this question in its relation to the economic stability of our country, for it cannot be too greatly emphasized that direct taxation is only one item in the net return which our governments derive from the mining industry. Indeed, the many indirect benefits are so manifest that it would seem almost unnecessary to enumerate them! We almost invariably think of mine taxation as a direct company tax-overlooking the fact that sales tax, customs duties, acreage tax, income tax on mine dividends, foreign shareholders' dividend tax, and others, must all be taken into consideration. It would seem that the economic value of non-ferrous metal mining in Canada is not sufficiently understood and appreciated.

Jan 1, 1935

By E Westthorp

Final mine sealing of BMA’s Crinum North mine, near Emerald, Queensland was undertaken in December 2015. Due to the benign atmospheric environment at Crinum North, the Queensland Mines Rescue Service (QMRS) Górniczy Agregat Gasniczy (GAG) unit was utilised to reduce oxygen levels throughout the underground atmosphere as part of the final sealing process.The GAG was utilised by way of a vertical borehole from the surface to seam to successfully reduce oxygen levels throughout the underground mine workings. Application of the GAG unit enabled the underground mine to be classified as stable and inert within days of the GAG operation, and subsequently cease gas monitoring at Crinum North. The data and information obtained from this activity provides valuable information to the underground coal mining industry on successful application of the GAG in realistic situations.This paper discusses the strategy used for sealing, the assisted inertisation and the results obtained from the application of the GAG unit. It discusses both the overall results and gives a detailed review of the gas monitoring data obtained via the tube bundle and real-time system, both during and following the use of the GAG unit.Gas monitoring results obtained and the strategy used are critical to share with the industry to obtain a better understanding of how the GAG unit works, and how it can be applied for emergency preparedness, emergency response or planned inertisation.CITATION:Westthorp, E, 2017. A review of the strategy and gas monitoring results obtained during the use of Queensland Mines Rescue Service GAG unit at Crinum North mine, in Proceedings Australian Mine Vent Conference 2017, pp 309–318 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 28, 2017

By D Porta, E Grigolato, K Behrens

################

Aug 12, 2013

By Christopher C. Woomer

Cyprus Shoshone Mine uses the longwall method to extract a deep, thick, pitching coal seam in the Hanna Basin of South Central Wyoming. The immediate, and main roof rock consists of weak, thinly-bedded, silty mudstones with weak, interbedded fine-to medium-grained sandstone. Tailgate ground control has been a critical factor impacting productivity at the mine. A gateroad condition mapping program for the 11 left longwall gateroads indicated potentially severe ground control problems for the tailgate. It was predicted that the existing, secondary support pattern of wood cribs would not provide adequate support capacity. As predicted, severe deterioration of the tailgate occurred in the form of a roof cutter, sloughing ribs, and failing wood cribs. Productivity was affected and additional support was required. Shoshone personnel evaluated several options for providing the additional support needed in the tailgate. The additional support system and placement method had to satisfy several requirements with respect to access, materials handling, placement method, set-up time and support capacity. Approximately 6,000-ft. of deteriorating tailgate had to be supported. The initial wood crib support system left a 6-ft. walkway for access and construction of the additional support. This access was further reduced as the roof loaded the wood cribs. This eliminated the possibility of mechanized material handling to the construction locations. All materials would have to be transported by hand. The additional support system had to be placed quickly to stay ahead of, and keep pace with, the required longwall advance rate. It had to incorporate the existing wood cribs and provide at least 500 tons of extra support capacity. And most critically, the system could not affect longwall ventilation. Longwall coordinators and engineers made the decision to use a low density, pumpable cement known to the industry as TeksealTM, to provide the system required. A 200 psi ultimate strength mix was decided on to provide the required load capacity. The existing cribs were formed with 1-in. by 6-in. boards and brattice cloth to provide the containment. To overcome the access limitations, three boreholes were drilled from the surface to the tailgate on 2,000-ft centers. A mobile pumping station was established on the surface and the TeksealTM was pumped 900-ft. down the boreholes through a 1.5-in. steel pipe, then as much as 1,800- ft. along the tailgate entry through 1.25-in. miner spray hose. The materials required for the TeksealTM supports could all be carried into the construction locations by hand. As a direct result of incorporating relatively new methods of pumping high yield, low density, cementitious grouts, the Shoshone Mine reduced downtime due to tailgate ground control problems by approximately 70% in comparison with previous Longwall panels. The longwall set three monthly production records while mining the 11 left longwall under the deepest cover, steepest pitch, and most extreme ground control conditions ever encountered at the mine.

Jan 1, 1995

By Jana Dobrovska

The paper deals with new approach for measurement and evaluation of chemical microheterogeneity of elements in polycomponent metallic systems (i. e. steels, Ni-alloys). The method is based on the original mathematical model for determination of distribution curves of dendritic segregation of selected elements and on the original mathematical model for determination of the effective partition coefficients of these elements in the structure of analyzed alloy. Application of the method at research of chemical heterogeneity of continuously cast steel slab is also presented. The original results of measurement of dendritic microheterogeneity of eight elements (Al, Si, P, S, Ti, Cr, Mn and Fe) in structure of nine zones of a transversal section of slab are given.

Jan 1, 2006

By Robert Hopler

DESCENT INTO A COAL MINE From “The Playbook of Metals, including Personal Narratives of Visits to Coal, Lead, Copper, and Tin Mines,” by John Henry Pepper. Published by Routledge, Wa rne, and Routledge, London, 1862 ENGINEERING NEWS New Yor k January 22, 1903 THE BEGINNING OF THE END OF DYNAMITE. In another part of this issue we have reported the results of some test results made upon one of the safety powders. It will pay every c o n t r a c t o r, miner, or user of explosives in any form to carefully re a d the article re f e r red to. Dynamite has done a gre a t work in the service of man, as did black powder before it; but its i n h e rent dangers are admitted by all and are proved by the long list of deaths and injuries, and destruction to property which annually occur through its use. Why should we continue to use an explosive that annually kills and maims hund reds of men, when others are available which are equally powerful, no more expensive and far less liable to accidental discharg e ? Dynamite when first manufacture d is pure and comparatively safe; but most unfortunately it does not always stay pure; it “rots,” and then it is exceedingly dangerous. More than this, the explosive part of dynamite is a liquid, nitro - g l y c e rine, which is absorbed or soaked up by sawdust, wood pulp or the like. So long as this liquid nitro - glycerine remains pure and remains “soaked up,” or absorbed t h e re is little danger. It has been found, however, that the nitro - g l y cerine leaks under certain conditions. During thawing it fre q u e n t l y leaks out of the stick, or if it becomes wet the water causes the n i t ro-glycerine to leak out. In either case free liquid nitro - g l y c e r i n e escapes, and in that free state it may be exploded by any very slight shock. Nor is this all, if a stick of frozen dynamite be bro k e n a c ross it has been found by tests that the frozen nitro - g l y c e r i n e w h e re thus broken is very sensitive to shocks afterward .

Jan 1, 2004

By G. L. Oldwright, F. K. Shelton, W. E. Keck

"INTRODUCTION Zinc must be of high grade to satisfy the present demand. Even when the amount of premium paid is small, the purer metal as the buyers' preference. The following specifications for spelter were taken from the American Society for Testing Materials for 1927, Part I, pane 524. (The specifications for 1930, p. 582, are tile same.)Another specification for zinc of a much higher grade than any of the above has been established lately by the same society. The committee on zinc die-casting (Proc. Am. Soc. Test. Mat., vol. 31, 1931, p. 263) reached the following, conclusions: I. ""That the purest of zinc is necessary to produce stable zinc-base die castings, and as a result requested specifications for zinc spelter .with total impurities not over 0.02 percent."" Their tests showed that the die castings made of the purest zinc had the least elongation and the greatest tensile strength, and exhibited the least changes with temperature.Still more far-reaching claims are made for the properties of zinc containing over 99.99 percent metal. Zinc foil, for instance, may someday be made as a common commercial product. It would seem likely that the demand for zinc of high grades rill continue and that even purer varieties may be desired. This demand fits in with the modern trend in manufacturing plants of reducing the number of variables to a minimum by using pure materials, and of controlling the processing of metals during their various stages of fabrication by mechanical means instead of by expert laborers."

Jun 1, 1933

By Kiseong Hyeong, Young-Tak Ko, Gee Soo Kong

"The benthic environmental impact experiment addresses environmental impacts at a specific site related to deep-sea mineral resource development. For such a purpose, since 2010 we have carried out essential environmental research at both the BIS and a preservation site. We have acquired several tens multi- or box core samples at 32 sites within the BIS especially between 2011 and 2013, aiming to examine the basic properties of surficial deep-sea sediment as the potential source for deep-water plumes.In this study, we present physical the properties such as water content, shear strength and also geochemical properties such as major elements, rare earth elements (REEs), heavy metal contents at the BIS. Such proxies vary distinctly according to the Facies association. The lithology of all core sediments in the BIS corresponds to both Association Ib (Unit I/Unit II) and Association IIIb (Unit I/Unit III) on the basis of the KORDI classification (KORDI, 2004); Unit I is watery mud and dark grayish brown (10YR4/2) to dark brown (10YR4/3). Unit II is highly bioturbated mud and brownish yellow (10YR6/6). Unit III is very dark brown (10YR3/2) to black (10YR2/1) mud. Physical properties of these sediment types show that Association Ib is distinct from Association IIIb. The vertical profile of water content changed more sharply in Association IIIb probably due to compaction; water contents varied from 230 to 300% in Association Ib and changed from 200 to 250% in Association IIIb. The vertical profiles of shear strength are also quite different between Associations; the profile curve in Association IIb is much more gentle due to bioturbation."

Sep 1, 2014

By Vidal Navarro Torres

El presente trabajo señala el proceso experimental para determinar la transferencia del calor del macizo rocoso al aire en la atmósfera subterránea, dado que a ciertas profundidades cuando la temperatura de la atmósfera subterránea excede el valor máximo admisible por las normas y estándares de confort o comodidad térmica, se presenta el riesgo ambiental térmico. En ese sentido, el estudio comprende tres etapas: la primera etapa fue dedicada al desarrollo de un modelo matemático que establezca la variación de la temperatura debido a la transferencia del calor del macizo rocoso al aire de la atmósfera subterránea; la segunda etapa consistió en validar el modelo matemático en una mina subterránea de cobre, y la tercera fue realizar una aplicación práctica en dos minas con problemas de impacto ambiental térmico. En consecuencia, la metodología propuesta para la evaluación del impacto ambiental térmico en minas subterráneas se fundamenta en procedimientos científicos plenamente sustentados, cuyos resultados indican su aplicabilidad.

Sep 12, 2005

By T. F. Anstett

The Bureau of Mines estimated the potential availability of tungsten from 57 mines and deposits in 19 market economy countries. The tungsten resources of China and the U.S.S.R. were also estimated. This resulted from an evaluation of tonnage-cost relationships indicating the quantity of tungsten available as ammonium paratungstate (APT), artificial and natural scheelite, and ferrotungsten at various average total costs of production including 0- and 15-pct rates of return on invested capital. The evaluated deposits contain 1.2 million metric tons (t) of recoverable WO3, of which approximately 52,000 t of AEYT can be produced at the January 1983 market price of $5.37/lb, 89,000 t of natural and artificial scheelite at a market price of $3.63/lb, and 1,700 t of ferrotungsten at $5.61/lb of tungsten. An annual availability analysis indicates that by the early 1990's new deposit discoveries, development of known prospects, or expansions of producing mines will be necessary to meet projected tungsten demand.

Jan 1, 1985

By Davorin Kolic, Harald Wagner

Conventional ground support in accordance with latest state-of-the-art considers proper preparation of geotechnical investigation, structural design, observation during construction and fair risk sharing documents. Depending on the ground, there are different means and methods, reflecting different experiences. The paper is presenting ground support concepts, as mostly used in Europe during the past three decades. It discusses the use of anchors as well as the use of steel arches respectively combinations. It also discusses different applications of plain shotcrete, respectively fibre reinforced shotcrete. As excavation sequence is a major input to create the ground arch, the paper discusses also criteria to create closed ring conditions. Finally deformation criteria will be presented with case histories in order to control stability of the structure.

Jan 1, 2001

By Dean Lindsay, Inna Dymov, Mariam Melashvili, Jim Smolik, Chris Fleming

"This paper presents results from the proposed cyanide detoxification circuit for Seabridge Gold’s KSM project. The proposed flowsheet uses a two-stage CCD (counter-current washing/decantation) circuit to transfer the flotation products CIL(carbon-in-leach) barren solution to a SART process (Sulphidization, Acidification, Recycling of precipitate, and Thickening of precipitate) to recover copper and free cyanide from the copper cyanide complex. The SART barren solution is then treated by an AVR process (Acidification, Volatilization of HCN gas, and Reneutralization) to concentrate the cyanide that was liberated in SART for recycling to leach. The washed CIL barren pulp (the CCD underflow) is treated with the SO2 /Air process to oxidize residual cyanide.The goal of this complex flowsheet is to recover and recycle as much cyanide as possible and produce a final effluent containing less than 0.5 mg/L copper and CNWAD at the lowest cost. The SO2/air process is capable of achieving low residual CNWAD (<1 mg/L) in the final product, but the persistence of aqueous copper above the target level has been detected in the treated solution in some instances. The expected high concentrations of copper and cyanide in the KSM CIL barren ( >200 mg/L each species) and the difficulties this might create for the SO2 /air process was a key factor in the decision to consider including the washing, SART and AVR steps in the project flowsheet.The target concentrations of CNWAD and Cu were readily achieved after aging the SO2 /air treated pulp, as would occur in a tailing or polishing pond. This suggests no additional treatment will be required to sustain low levels of these species in the final plant effluent."

Jan 1, 2015

By C. A. Cole

This work consists of research in cable fault location and the construction of four field-test units based on the research. Swept-frequency sounding of mine cables with RF signals has been the technique most thoroughly investigated. The swept-frequency technique is supplemented with a form of moving target indication (MTI) to provide a method for locating the position of a technician along a cable and relative to a suspected fault. Separate, more limited investigations involved high-voltage time domain reflectometry and acoustical probing of mine cables. Particular areas of research included microprocessor-based control of the swept-frequency system, a microprocessor-based fast Fourier trans-form for spectral analysis, RF synthesizers, transmit-receive switches, RF receivers, cable dispersion-compensation techniques, low-voltage multielement display systems, and techniques for injecting or recovering RF energy through cable walls in support of clamp-on fault locators.

Jan 1, 1982

The following paper deals with a method for the&quot; Proximate Analysis&quot; of Chloridized Ores, which are free from arsenic, antimony and lime. When these are present the analysis is rendered far more complicated, and many of the methods which I am about to describe could not be applied. Sufficient scope is therefore offered for discussing the analysis, when these metals are present, in a separate paper, which I hope to contribute at a future date.I am fully aware that this method is far from being perfect. No doubt many, modifications and improvements will suggest themselves to my readers, and I trust that this paper will be the means of giving a certain impetus to the study of Proximate Analysis which at the present time is practically dormant. For the benefit of my readers who are not initiated into the details of ordinary estimations, I have briefly described well known methods, which, however, will be found fully described in most text-books of analysis. Assuming that the ore contains. sulphates and chlorides of soda and magnesia, sulphates, sulphides, chlorides and oxides of copper, lead, iron, zinc, manganese and silver chloride, the analysis would be conducted as follows. The first compounds to estimate are the chlorides and sulphates of soda and magnesia.

Jan 1, 1901

By D. E. M. Plaumann, B. S. Fee, R. D. Hansen, R. R. Klimpel

"The steps from experimental curiosity through to commercial product can be slow and tortuous in spite of the quality of the technological advances offered by the new development. Data generation and interpretation need to be done in lab tests as well as full-scale evaluations and, in each, the advantages of the new reagent must be clearly identifiable and measurable.The Dow Chemical Company has patented a novel new collector for the flotation of zinc. Fl (2-hexylthioethylamine hydrochloride) has several unique structural features that suggest atypical mechanisms for zinc collection. Laboratory data have demonstrated significant flexibility with respect to grade and recovery balance at dosages lower than those typically used for xanthates.In mill trials, the same phenomanon is evident - the choice between high grade and high recovery allows one to select the desired quality of zinc concentrate. One trial in particular was run over a three month timeframe and Fl gave improvements in recovery of 2.5% and a reduction in lead levels with less than 0.5% loss in grade. The dosages of other reagents in the flotation circuit were also reduced.Data demonstrating improved recovery and grade in lab trials will be discussed. Extensive data from the mill trial will illustrate how Fl works in both rougher and cleaner circuits."

Jan 1, 1990

By David Hake, David Salisbury

The Drainage Services Department (DSD) of the Hong Kong SAR Government commissioned the design and construction of the West Kowloon Drainage Improvement, Stage 2, Phase 2, Kai Tak Transfer Scheme (KTTS) project in 2000 to relieve potential flooding in Mong Kok caused by the insufficient capacity of the existing storm water drainage system. The KTTS involves construction of a 1.5km,4.4m drainage tunnel and a 450m long box culvert, running from Waterloo Road near Hereford Road to the existing Kai Tak Nullah in San Po Kong. This paper describes the design and construction of; the bored tunnel through both hard rock and soft ground using a slurry Tunnel Boring Machine (TBM), six associated access shafts, a connection structure at Waterloo Road and the box culvert connecting the bored tunnel to the outfall at Kai Tak nullah. Details will be provided on the contractor’s alternative designs adopted during the contract including the use of fibre reinforced shotcrete as one-pass temporary and permanent support for three of the shafts and modifications to the Engineer’s design for the box culvert structure.

Jan 1, 2005

The Development of a Non-Roasting Technology for Polymetallic Gold and Silver-Bearing Sulfide Concentrates Treatment

Sep 13, 2010