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By P. L. Woolf

An investigation was conducted to evaluate the use of a formcoke as the total fuel in the Bureau of Mines experimental blast furnace. The formcoke performed very satisfactorily, and comparisons made with a metallurgical coke showed that the performance with the formcoke was somewhat superior under the experimental conditions used.

Jan 1, 1966

By A K. Bayer

When the human eye fails in the evaluation of quality parameters in the extraction of minerals the use of laser-induced fluorescence analysis (LIF) can supply more detailed information on the composition of rocks. On the basis of measurements of selected raw materials engineering concepts for the use of this method in the mining industry as an innovative system for horizon control of mining machines will be described and the most important analysis parameters, influencing factors and interference variables are presented.

Jan 1, 2003

By Richard W. Cannon

INTRODUCTION The authors, by means of this paper, will attempt to show the role of Induced Polarization and Resistivity surveys in the discovery of the orebodies of Gibraltar Mines Limited (N.P.L.). In this paper, we will also attempt to show the importance of conducting large enough surveys in order to properly evaluate the results obtained from these surveys. LOCATION The orebodies of Gibraltar Mines Limited (N.P.L.) are located on the western slope of Granite Mountain, central British Columbia (52°30' north, 122°16' west) (See Fig. 1). The property lies approximately 28 miles north of Williams Lake, B.C. and can be reached by way of 10 miles of newly improved road from McLeese Lake, on the Cariboo Highway. The area in and around Gibraltar Mines has a moderate topographic relief with elevations between 3,500 and 4,100 feet. {EARLY HISTORY AND GEOLOGY The present Gibraltar Mines property before amalgamation consisted of the Pollyanna property (Duval-Canex) and the Gibraltar property (original Gibraltar Mines) as well as some Coast Silver and McLeese Lake Copper claims (See Fig. 2). The Pollyanna property was first described in the 1917 B.C. Minister of Mines Report which referred to it as the "Rainbow Group". The development at that time consisted of several open-cuts on copper bearing quartz veins.

Jan 1, 1972

By Cary Moffat, John Kita, Rick Walker

The Lac des Iles Mine, in an isolated area of NorthwesternOntario is a relatively new open pit platinum and palladium mine. They were encountering problems with the equipment and production scheduling when ramping down to begin production on the subsequent benches. A co-operative effort between Lac des Iles Mine operation people, ICI Explosives, and the mines drilling and blasting contractor - Consbec Inc., resulted in a decision being made to use full depth sinking cuts to provide access to the next bench.

Jan 1, 1996

ALABAMA Auburn.-Brown, R. L. Battelle.-Green, G. G. Bessemer.-Abbott, C. E. Dobbs, G. G. Ferguson, V. Birmingham.-Aldrich, T. H. Aldrich, T. H., Jr. Allen, A. W. Bonnyman, J. Bowron, J. Crawford, G. G. Crockard, F. H. Ellis, E. E. Fairbairn, C. T. Gambrill, G. T., Jr. Geismer, H. S. Hiller, E. McCormack, G. B. Maben, J. C.

Jan 1, 1917

By Pentti Niskanen

"The ventilation system of the Pyhasalmi Mine is described. The mine is located in an area where the annual atmospheric temperature may vary from +30°C to -30°C. Natural ventilation causes serious difficulties because the underground mine is connected by drifts and finger raises to the bottom of the 120 m-deep open pit.The natural ventilation tends to make the ventilation net unstable. The paper describes how the instability characteristics of the ventilation net can be studied and how they have been taken into account when automating the control of the ventilation. In addition, the software, hardware and costs of the system are described. The system consists of 12 automated ventilation doors, two mine fans, 8 elements for sensing the air flow and temperatures, a control panel and a process computer."

Jan 1, 2014

By Rustu S. Kalyoncu

Nonoxide ceramics with improved high-temperature properties could substitute for high-temperature alloys and reduce toe Nation's dependence on imports of Cr, Co, Ni, and Mn. To meet this objective, the Bureau of Mines conducted research to synthesize u1trafine reactive boron nitride (BN) powders BN powders were prepared at temperatures ranging from -75? to 750? C. Low-temperature reactions (-75? to 200? C) between boron halides and N compounds led to formation of e1emento-organic compounds that were thermally decomposed to u1trafine (approximately 100-to 150-A particle size) reactive BN powders. BN powders were also prepared through the reaction of a 10w-me1tinginorganic B compound (boric acid, borax) with an organic N compound (carbimide and thiocarbimide) in N2 and/or ammonia (NH3) atmospheres at temperatures between 500? and 750? C.

Jan 1, 1986

By J. U. Burger

The Elizabeth Bay aeolian deposit in Namibia comprises a sedimentary package of diamondiferous grits that have been deposited, reworked and concentrated to various degrees by dominant southerly winds. Diamond concentration in these deposits is highly variable and often unpredictable. The deposit is marginal from an economic perspective and therefore requires selective mining which in turn requires correct sampling and accurate estimation. Three methods of sampling have been used at Elizabeth Bay for mineral resource estimation: (i) pit samples utilizing an excavator to produce a sample 1 to 3 metres deep with a 10 to 20 m2 footprint, (ii)GB50 grab sampling with a 3.34 m2 footprint and (iii) a BG36 bucket auger drill with a 5 m2 footprint. Pit sampling, being easy to execute, has been the most widely used despite a limited penetration ability and, at times, questionable integrity. The GB50 grab sampling tool was tested at Elizabeth Bay and although it had better penetration ability and sample integrity, it struggled with cemented horizons. No sample optimization was conducted prior to the GB50 grab sampling. The latest phase of sampling was conducted using a BG36 bucket auger drill which is capable of penetrating thick overburden, penetrate cemented horizons and provides an acceptable sample support size. Geostatistical simulation methods were applied to establish the optimum sampling parameters required to estimate a mineral resource at an indicated level of confidence. The results show that a 5 m2 sample support size is adequate and that a 50 m 100 m sample configuration is optimal. Sample data obtained from the three methods confirms that the BG36 bucket auger tool combined with the parameters identified in this exercise produce the best results for diamond resource estimation.

Jan 1, 2009

By W. A. Plachner, Schiller E. A., S. P. Santiago

"The Monkman Coal Property is located in the Northeast Coal Block of British Columbia. It is divided into the Duke Mountain Block on the north east and the Dip Slope on the west. Together, these areas cover 39,503 ha of coal licences.The property is underlain by Jurassic and Lower Cretaceous marine and continental sedimentary rocks. Economic coal measures are contained within the Gates Formation. Exploration of the property began in the early I970s, with drilling commencing in 1975. To date, 255 holes have been drilled and nine adits have been driven to recover unoxidized coal samples.The property has a geological resource potential of 2.8 billion tonnes of medium and high-volatile bituminous coal. Medium-volatile bituminous reserves, totalling 68.9 million ROM tonnes at an over-all strip ratio of 6.3:1, have been identified in three pit areas in the Duke Mountain Block.Construction start-up will commence when sales contracts are arranged. The clean coal will be exported via the Ridley Island Terminal at Prince Rupert.IntroductionThe Monkman Coal Property is located in the Northeast Coal Block of British Columbia in the southern port ion of the Peace River Coalfield. The coal field encompasses a strike length of 250 km of Lower Cretaceous coal-bearing strata in which 13 companies have identified several billion tonnes of resources and several hundred million tonnes of reserves. Currently, two companies with contracts are in the construction phase, and are scheduled to produce coal by early 1984. Quintette Coal Ltd. has a contract with Japanese steel mills to supply annually 5.0 million tonnes of metallurgical and 1.5 million tonnes of thermal coal. Teck Corporation (Bullmoose property) has a contract to supply 1.7 million tonnes of metallurgical coal annually."

Jan 1, 1983

By Steven McCutcheon

As most of us have learned through prior and often frustrating experience, anyone proposing to construct a new or expanded mining-ore processing facility must first contend with a rather complex array of environmental laws and permitting regulations administered by a number of different Federal, State and local agencies. At our lost count, there were about 55 federal enactments affecting base and precious metals projects. Applicable State and local laws will usually increase that number significantly. The time and costs associated with complying with all these various regulatory programs usually constitutes one of the major areas of uncertainty in the development of a proposed project. There are many in the mining industry who firmly believe that these environmental regulation and permit programs necessarily causes significant delays and increased costs in the development of a project. This belief, unfortunately, is probably a result of a basic misunderstanding of how the environmental permitting and regulatory system actually works.

Jan 1, 1984

By L. M. Lopez, J. A. Sanchidrian

This work investigates the performance of some of the measurement techniques used in vibrations from blasting monitoring. Two tri-axial geophones with cases of different size, shape and mass were tested in a shaker table. The geophone cases were mounted in three different ways on a granite slab fixed to the plate of the shaker: freely placed, sandbagged, and anchored. A known horizontal periodic motion of constant amplitude, and frequency from 16 to 200 Hz, was applied to the slab. Two amplitude levels of 5 and 20 mm/s (0.2 and 0.79 in/s) were applied when the sensors were sandbagged or anchored and only 5 mm/s when no holding force was applied. The transmissibility of vibrations from the rock to the longitudinal geophone as function of the frequency (i.e. ratio of response of the geophone to the slab motion) has been obtained for each measuring condition tested. The transmissibility is considered a composition of the transmissibility of the rock-to-sensor coupling and the transmissibility of the sensor’s mechanics and electronics. The transmissibility of the coupling is obtained normalizing the total transmissibility with the transmissibility of the seismographs, obtained by a suitable test to which a coupling transmissibility of 1 is assigned. Geophone-to-rock coupling is a resonant phenomenon that may alter the amplitude of the measured waveforms by a factor of 1.2 to less than 0.6. The most accurate and precise measurements are obtained with geophones anchored to rock. On the contrary, freely placed or sandbagged sensors are non-predictable planting conditions that lead to high amplification or damping in most of the frequency band analyzed. It is also shown that existing acceleration criteria to select coupling methods do not necessary lead to good quality (accurate and precise) vibration data.

Jan 1, 2014

By Fredy Rolando Castillo Peña

El presente trabajo describe el impacto de la crisis financiera mundial en la industria minera y su interrelación con la gestión de las comunidades circundantes al área de influencia de las operaciones mineras y del Estado a través de sus instituciones públicas y locales. Es decir, la crisis financiera internacional brinda a los empresarios mineros la oportunidad de replantear el enfoque tradicional de las acciones de RSE (Responsabilidad social empresarial) y así realizar una redistribución presupuestal adecuada e involucrada en una gestión efectiva con valores estratégicos en los líderes de la comunidad y del Estado.

Sep 14, 2009

By Nicholas J. Grant, William H. Ferguson, Bill C. Giessen

Ta-lr alloys have been examined over the complete range of compositions using metallographic and X-ray techniques. The terminal solid-solubility limits, solidus temperatures, and intermediate phases were determined. There are four inter-mediate phases: o, tetragonal, analogous to a (Fe-Cr); 0,. orthorhombic; az, tetragonal; and a TaZr,, cubic, AuCu, structure. Of these, o and a, melt peritecticaLly, a, decomposes peritectoidally, and a TaIrs has a congruent melting point. Three peri-tectic and one eutectic reactions occur. 1 HE Ta-Ir phase diagram has not been treated in the literature. Intermetallic phases and terminal solid solubilities have been described and estimated.'-4 The previous findings have been confirmed in this work. A complete diagram with additional phases and solidus curves is presented. EXPERIMENTAL METHODS Starting materials were tantalum powder of 99.8 pct purity, supplied by the National Research Corp., Cambridge, Mass., and iridium powder of 99.9 pct purity, supplied by the Bishop Co., Malvern, Pa. Both powders were -200 mesh. Table I lists the analyses as given by the suppliers. A standard procedure was employed in making the alloy buttons, which was described in detail in Refs. 5 and 6, and which included repeated arc-melting of powder compacts and determination of the composition by the weight-balance method. This is especially justifiable due to the similar vapor pressures of tantalum and iridium. In the critical parts of the diagram, a spacing of 1/2 at. pct was used, based on premelted master alloy material. The observed structures and X-ray spectra were consistent with the composition sequence of the alloys. Table II lists the final alloy atomic percentages with the calculated percent error of composition. Cross sections representative in grain size and composition were selected for the study, as described in Ref. 5. Based on prior experience, no contamination from the tungsten electrode was considered. Temperature measurements were obtained using a Leeds and Northrup optical pyrometer and have been described extensively in Refs. 5 and 6. All heat treatments were made in the high-vacuum tantalum tube furnace mentioned in Ref. 5. Samples annealed in tantalum containers cooled from 1800" to 1000"~ in 5 sec; those annealed in ceramic crucibles cooled over the same range in 15 to 30 sec. The thermal treatments are listed in Table 111. All specimens were homogenized at 1735°C for 24 hr. Tantalum-rich compositions were treated in tantalum buckets. Iridium-rich compositions were annealed in tantalum buckets below the eutectic temperature of 1950°C; up to 2200°C, tungsten-lined tantalum baskets were used; and above 2200°C thoria crucibles were used. It was found that refractory oxides (in early stages of the investigation alumina crucibles were used up to 1800°C and thoria crucibles were used to 2400"~) give off minute amounts of oxygen and thereby influence the microstructure considerably, or react directly with the alloys.

Jan 1, 1963

By Raymond Henn

Yes we have also used some however, again because of the nature of the maintenance window where we have that two hour (at best) window every night and due to the numerous other crews that are wanting to get in to do the other types of maintenance activities, we don't know if we are going to be getting into that same area from one night to the next. So even with the dormancy additives that one can add to cementitious grouts (that are good up to 72 hours) we don't know if we are going to get back in to the same locations from one week to the next. That's why I use the term "the forgiving nature of the acrylamide". It allows us to ream out the hole allowing us to use the exact same hole without having to re-drill a new hole. The program started in 1997 and we have a budget between labor/materials and equipment of 4.5 million dollars on a year to year basis. For the next few years that is going to come down drastically because the program is going to be more of an ongoing maintenance program. The program started in 1997 and we have a budget between labor/materials and equipment of 4.5 million dollars on a year to year basis. For the next few years that is going to come down drastically because the program is going to be more of an ongoing maintenance program. Up to the end of 2001 we were just over 1.7 million liters of between AV100 and AV118 grout. Of that, approximately just under 200,000 was AV100 and the remaining balance was AV118.

Feb 10, 2003

"In 1989, improved milling and recoveries resulted in a record production of 7 722 200 Ib Nb2P5 at the Niobec Mine. At the beginning of 1990, proven and probable reserves stood at 11 952 000 tons grading 0.65% Nb205. This year, the world steel market has slowed and as a result, niobium consumption is down. Consequently, production at the mine dropped 14% for the second quarter.IntroductionThe Niobec Mine is located approximately nine miles northwest of Chicoutimi, Quebec, (Fig. I). After ten years of production, the Niobec Mine is the only operating niobium mine in North America and the second largest producer of niobium in the world after Brazil.The Niobec Mine is a joint venture held equally by Teck Corporation and Carnbior. Teck Corporation operates the mine while Cambior is responsible for marketing and selling the niobium pentoxide concentrate (Nb2P5).The deposit was discovered in 1964 following an airborne radiometric survey in search of uranium. However, mining of the deposit did not begin until 1976. The initial production capacity of 1500 tons per day was increased several times to the present capacity of 2450 tons . The deposit is considered as an ample source of pyrochlore concentrate for at least 15 years at the present production rate.Niobium, also known as columbium, is a greyish-white metal used primarily as an alloy in various steels and other metals. The use of niobium in alloys heightens tensile strength and improves corrosion resistance while at the same time reducing the weight of the alloy. Niobium is also used in the fabrication of steel for the aerospace, automobile, and oil and gas pipeline industries. Although substitutes for niobium exist, their use often results in diminished performance and net cost increases."

Jan 1, 1990

By Werner Wenzel

Whisker growth during the reduction of iron ores The phenomenon of whisker growth can be observed in a number of solid-state crystallisation reactions, which, apparently, appear in6 the first instance as though they are two independent processes. From such reactions, one can find the whisker type of crystallisation on solid bodies. These examples show, that the whisker growth is neither due to certain crystal forms with predetermined temperature and pressureranges, nor to parameters, which, ad hoc, are necessary for the crystallisation. In all cases the whisker formation seems to depend on nucleation and the availability of crystallizing material in direct environment of such a nucleus, under given parameters of a system. One can generally state, that the research of whisker growth with the aim of establishing proper physical laws, to determine the foundamentals of whisker formation and whisker growth, is at present under active study. We can conclude that, although a great number of hypothesis have been proposed; no concluding theory has yet been arrived at. In the institute for ferrous metallurgy of the technical university of Aachen, research works are undertaken to find an explination to various metallurgical phenomena through help of whisker growth which was observed under varying conditions of iron ore reduction. This was possible by using refined microscopic techniques through which the whisker growth on solid oxyde substrates is detected. This refined technique combines the latest methods of surface examination with the help of stereo-scan-electron-microscope and proper and carefull preparation of surface to be stereo-scanned.

Jan 1, 1971

By S. Ramachandran, R. A. Walsh

Many investigations have shown that the manganese enhances the deoxidation power of silicon. Here it is suggested that this phenomenon could be explained in terms of the formation of impure silica. Data of Hilty and Crafts on the Fe-Mn-Si-O System has been evaluated on the basis of the reaction S_i + 20 = (SiO2) where (SiO2) denotes silica of variable activity. The activity of silica in this system is a function of aMn/aSi and the temperature, and can be described by the equation 12700 l°gaSiOz = -6.85+ - - 0.5 log aMn /asi PRACTICAL melting experience has shown that it is helpful to maintain a certain range of Mn/Si ratio in deoxidizing quality alloy steels. Herty,1 as early as 1932, reported a strong association between manganese and silicon as did schenck2 and Korber and Oelsen3 in later work. More recently, Hilty and crafts4 have studied the solubility of oxygen in the Fe-Si-O system, both with and without manganese. Their study confirmed the marked ability of manganese to increase the deoxidizing power of silicon. This phenomenon has remained unexplained in the liter,ature5 since it has been shown that manganese has virtually no influence on the activity coefficients of silicon or oxygen.= In this paper, an explanation for the role of manganese is suggested and equations are devised for quantitatively describing this influence. DISCUSSION Hilty and crafts4 equilibrated their melts under an argon atmosphere and the system established equilibrium with a self-generated slag which was not always the oxide of lowest free energy. Drawing on the early work of Korber and Oelsen,3 it was reasoned that the formation of complex Fe-Mn-silicates

Jan 1, 1963

By W. M. Bertholf

To establish the minimum or break-even efficiency of a preparation plant it is necessary to determine the ratio of production costs per ton of run-of-mine coal to sale price per ton of clean coal. This ratio is then divided by the percentage of plant recovery. Assume, for example, that washability data indicate that 80 pct of the run-of-mine coal may be recovered as clean coal selling for $5.50 per ton. If the same plant incurs $4.00 per ton mining costs and $0.25 per ton preparation costs, the cost to sale price ratio would be 4.25/5.50, or 77.3 pct. Since the plant is capable of recovering 80 pct of the run-of-mine coal the minimum plant efficiency would be 77.3/80, or 96.6 pct. If the plant efficiency were increased to 100 pct the limit on preparation costs would be increased to $0.40. Therefore, the washing operation must be accomplished at a cost of $0.25 to $0.40 per ton and the efficiency must be 96.6 pct or higher. By plotting a curve of efficiency vs preparation costs and taking into consideration the plant cost, feed rate, operating costs, and yields of the various flowsheets it is possible to select a financially sound process. Table I classifies preparation processes according to their nature of separation. It must be remembered that what is thought to be ideal does not always prove practical under actual operation. An outstanding example is the work done on the plunger-type jig. It was determined by the law of equivalence that this unit could treat satisfactorily only sizes differing by no more than a ratio of 2. Yet these same plunger-type jigs are successfully treating sizes considerably greater than this ratio.

Jan 12, 1957

By W. F. Carew, F. A. Crossley

The stress for rupture in 500 hr at 1000° F has been reported to be about 13,000 psi higher for Widmanstitten than for equiaxed microstructures for the Ti-7A1-3Mo alloy.1,2 Also, limited data indicated Widmanstatten and equiaxed micro-structures to have approximately the same creep resistance at 1000°F.' Recently, data have been obtained which show Widmanstatten structures to be significantly more creep resistant than equiaxed structures at 1000°F, see Fig. 1. These data represent several ingots and several heat treatments of the solution treat and age type. The thermal history and tensile properties corresponding to the creep data are given in Table I. The creep data were taken from creep-rupture tests. The associ- ated rupture data are given in Table 11. It may be noted that total creep deformations are considerably greater for equiaxed structures. Previous evaluations of stability indicated that all of the structures tested are stable with respect to exposure to stress at elevated temperature.1,2 For a minimum creep rate of 10-4 in. per in. per hr the difference in stress levels is indicated to be about 17,000 psi. Holden,et found an irreversible contraction upon heating three a-ß titanium alloys in the equiaxed condition above their ß-transus temperatures. The alloys were: Ti-6Al-4V, Ti-155 A (5Al-1.3Cr-1.5Fe-1.2Mo), and C-130 AM (44-4Mn). The net contractions in length between the original equiaxed and the final Widmanstatten structures measured at room temperature were: 0.4, 0.4, and 0.7 pct, respectively. The greater creep and rupture resistance of the WidmanstStten structure of the Ti-7Al-3Mo alloy may be associated with the phenomenon

Jan 1, 1959

By J. Wild, M. Ounpuu, G. Chevalier

"The requirements for a finer grind at Heath Steele have resulted in the investigation of agitated milling as a cost effective alternative to conventional tumbling ball mills.The grinding unit is a vertically agitated, or stirred ball mill. Grinding occurs as the result of the motion of a single vertical rotor equipped with protruding pins which impart a stirring action to the ball charge. A comparative evaluation of a 30 kW SALA Agitated Mill (SAM), and a 1.5 m x 2.5 m copper-lead regrind ball mill has been conducted at Heath Steele.An overview of agitated milling as it applies to the reduction of sulphide ore will be the primary topic for discussion. Specific parameters including energy efficiency, media consumption, operating costs, and the mechanical aspects of the SAM operation will be presented.Evaluation of the agitated mill has shown that improved grinding performance at much lower work indices than those of the conventional ball mill is possible. Media consumption has proven to be comparable on an average g/kWh basis, but the mechanical availability of the mill has been low.INTRODUCTIONConventional tumbling ball mill grinding has proven to be an energy inefficient process. Energy losses occurring within the ball mill itself can be attributed to particle friction without breakage, kinetic and potential energy losses, plastic and elastic deformation and the production of heat and sound (Lynch, 1977). It can be generally stated that a certain amount of the input energy will be converted to another form as a necessary by-product of particle breakage. Theoretical interpretation of experimental results indicate that the energy required for breaking the ore particles in a ball mill varies between I% and 25% of the total energy input (SME, 1985)."

Jan 1, 1993