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By Floyd G. Anderson

Bureau of Mines studies show than an electronic counter can be used for determining just concentrations from midget impinger samples collected in bituminous coal mines. A sample correlation coefficient of 0.91 for data obtained using the electronic counter and the Bureau of Mines microprojector procedures indicates a significant linear relationship between the methods. The electronic counter provides better counting precision and reduces analytical time.

Jan 1, 1968

By Fumitaka Tsukihashi

Phase diagrams of the CaO-SiO2-FeOx-MgO, Al2O3 systems are necessary for the analysis of copper smelting reactions and sintering process of iron ore. The effect of MgO and Al2O3 addition on the liquidus of the phase diagram of the CaO-SiO2-FeOx system at low oxygen partial pressure was observed. The liquid phase area changed by the addition of MgO and Al2O3 with a changing oxygen partial pressure from 10-8 to 10-3 atm (10-1 to 102 Pa) at 1573K. The effect of Fe3+/Fe2+ ratio on the melting mechanism is discussed.

Jan 1, 2003

By J. A. Domenico

A safe and precise mineral separation alternative to heavy liquids is being used for mineral sands exploration on large scale orebodies. The separation process, Magstream®, uses ferro-fluids and magnetic and centrifugal forces to produce precise split points over a range of specific gravities from 1.5 to 18.0 g/cc. This paper describes a commercial scale exploration program treating, roughly, 90 samples per day in Senegal (West Africa). Separation results comparing Magstream® and conventional heavy-liquid separation are presented.

Jan 1, 1994

By T. J. Dudek

To be competitive in automotive applications, polymer composites must be processable by high production rate processes like injection molding (IM), reaction injection molding (RIM), structural rim (SRIM) and compression molding. With current fiber reinforced composite materials, performance properties are sometimes compromised to make them compatible with these processes. This is done by decreasing the amount and length of the reinforcing fiber and the viscosity and molecular weight of the polymer matrix. Sheet molding composite (SMC) and thermoplastic polymer blends are examples of polymer composites which are cost effective in many applications and meet the high speed processing requirements for automotive parts.

Jan 1, 1993

By T. Surkova

For the moment reserves of high-grade ores are practically depleted requiring ever-increased involvement of low assay raw materials, such as black-shale ores, in industrial operations. Black-shale ores are constituted of minerals containing such valuable components as vanadium, uranium, molybdenum, manganese, and rare-earth elements (REE). We studied technogenic solutions of black-shale ores processing, after uranium, molybdenum, and vanadium were recovered. Mentioned solutions contain rare-earth elements in substantial quantities (S REE 70-100 mg/dm3) that is very important factor taking into consideration the world demand ever-increasing last years. Higher concentrations of iron and aluminum inhibiting REE sorption and extraction recovery are found in solutions. We propose a method of hydrolytic deposition to cleaning solutions from impurity elements (Fe, Al). Study of hydrolytic deposition kinetics allowed identifying optimal conditions to run this process. Rare-earth elements may be recovered from purified solutions through sorption process followed by their further deposition from eluates in form of concentrates. Keywords: black-shale ores, rare-earth elements, a method of hydrolytic deposition, impurity elements, sorption

Sep 1, 2012

By G. M. Humphrey

It is a great honour and privilege to be here in this distinguished company of the outstanding men in the mining industry and the political life of Canada. I fully recognize that I am so honoured as a symbol of the combination of American and Canadian leaders in industry who are partners in the sponsor-ship of the Quebec-Labrador iron-ore mining development which we are undertaking, and as such I want to express our great appreciation of the co-operation and assistance we have met on every hand in Canada, and the genuine friendliness and never-failing courtesy which we are always accorded. We are quite aware that it springs primarily from the very high regard in which our partner and sponsor, Jules Timmins, and our other Canadian associates are held. Their high standing among you is well known and we quite naturally fall heir to the benefits of the great esteem in which you hold them. Jules Timmins and his long-time associate, John Knox, were the original inspiration for our participation in this venture. It was their enthusiasm and vision which caught our interest and led to our joining with them in the years of exploration and search which have brought us to the threshold of this great development where we stand today. So much has been written of the details of our exploration and plans for future development that it would bore you for me to review them further here, but there is a phase of this development, and an extremely important phase of it, which I think has passed almost unnoticed and which it may be well worth while for me to bring to your attention this evening.

Jan 1, 1951

By J. H. Perkins

The Bureau of Mines has conducted desorption work on fine coal particles at near atmospheric pressure. An apparatus Iris been developed that uses a capacitance manometer to measure desorption of methane from coal particles up to, 2 inches in diameter and pressures up to 1,000 psi. This will make it possible to duplicate the desorption process as it occurs in its natural underground environment.

Jan 1, 1969

By K. C. Dean

Time and motion studies were made by the Federal Bureau of Mines on the hand and machine dismantling of scrapped auto starter motors, generators, and alternators for recovery of copper, aluminum, and iron. The studies showed that an individual with power handtools and convenient access to a hydraulic press, power bandsaw, acetylene torch, and power lathe could, in an 8-hour day, disassemble about 100 starters, or 150 generators, or 30 alternators. The scrap copper yield would be 280, 390, and 45 pounds, respectively, and the iron yield would be about seven times the copper weight. About 100 pounds of aluminum would be obtained from the alternators.

Jan 1, 1976

By H. B. Brunot

A complete list of permissible mine equipment, tested and approved by the Bureau of Mines previous to January 1, 1947, was published as Information Circular 7432.2/ A list of permissible mine equipment tested and approved by the Bureau of Mines during the calendar years 1947, 1948, and 1949 was published as Information Circular 7569. The present list supplements Information Circulars 7432 and 7569 and includes all of 'the equipment approved during the calendar year 1950. Information Circular 7465, which included a list of permissible mine equipment tested and approved by the Bureau of Mines during the calendar year 1947 therefore is superseded.

Jan 1, 1951

By T. D. Murphy

In the fall of 1988 it became evident that the accuracy of sulfur forecasts for Monterey Coal's No.1 Mine needed to be improved. In addition, it became necessary to predict if any individual train shipments during a month would exceed a contract sulfur limit. The challenge was to develop a forecasting process that would take into account the variability of the coal in the ground as well as the difference between laboratory and preparation plant sulfur reduction efficiency, and the effects of mining coal with multiple units. This paper describes how geostatistics and simulation techniques were used to meet this challenge.

Jan 1, 1992

By R. K. Sidhu, N. L. Richards, M. C. Chaturvedi

Nickel base superalloy IN-738LC, strengthened mainly by the precipitation of y' phase, is extensively used in hot sections of land-based and aero gas turbine engines. Fusion welding, which is one of the most commonly used joining techniques for the repair and fabrication of superalloy components, however, finds a very limited application in case of IN-738LC components, as the alloy suffers from HAZ cracking during welding and during subsequent postweld heat treatment (PWHT). The present paper reports on the two methods studied to reduce the HAZ cracking in as-welded and postweld heat treated GTA welded IN-738LC, viz., the use of various fillers during welding, and the use of appropriate heat treatments prior to welding. The results of the microstructural analysis and crack measurements indicated that the HAZ cracking in GTA welds of IN-738LC was significantly reduced by using age-hardenable fillers with Al+Ti concentration less than that in the base metal in conjunction with a preweld heat treatment developed by the authors.

Jan 1, 2006

By L. A. Henry

The island of Jamaica consists predominantly of Carbonate rocks which vary in chemical & physical characteristics. Currently these rocks are used for construction and road aggregate, landfill and as a raw material in the manufacture of cement. Over the past fifteen years the Geological Survey of Jamaica with assistance from a number of international aid agencies and the private sector have identified deposits of high calcium/high brightness limestones which have the potential to be utilized as a high quality filler and a number of other commercial applications. Geologically, these limestones are formed within the Eocene Swanswick Formation, the Oligocene Walderston-Browns Town Formation and to a lesser extent the Miocene Montpelier and Newport Formations.

Jan 1, 1998

By Larry F. McHugh

Current sulfide ore processing methods involving mechanical sizing of ores, froth flotation, electro-winning, solvent extraction, smelting and roasting are quite effective but typically represent a significant energy and environmental cost. This paper is the subject of a recent patent application and development program involving major improvements in sulfide ore processing. This two-step ?looping oxidation? process effectively removes sulfur while producing materials of adequate purity in an energy proficient and environmentally friendly manner. The first step results in a metal sub-oxide and a highly concentrated sulfur oxide off-gas stream. This gas stream can be processed for recovery in a more effective manner regarding both energy and capital equipment costs. In the second step, this metal sub-oxide is further oxidized to efficiently generate energy that can be recovered and utilized without the typical complications of an ?acid gas? stream process. Additionally, a portion of the final fully oxidized product can be looped back to the first step as the oxidizing agent. This process will be described in detail and compared to existing technologies in the area of energy efficiency, and off-gas environment treatment energy requirements.

Jan 1, 2008

By Patrick R. Taylor

Titanium nitride has been synthesized in a thermal plasma reactor from ilmenite ore concentrate using methane and ammonia as the reactive gases. The product has been characterized by x-ray diffraction and SEM. Results show that a high concentration of methane favors the formation of iron, titanium nitride and titanium carbonitride. The formation of titanium carbonitride can be minimized by controlling the concentration of methane. The formation of TiN proceeds by the progressive reduction of the oxides of titanium to titanium, which is converted to titanium nitride.

Jan 1, 1998

By A. Bartkowiak

The lower flammability limit of methane at 0 p.s.i.g. and ambient temperatures is 5.6 volume percent in chlorine, 5.2 in oxygen, and 5.0 in air. The corresponding upper limit values are 70, 60.5, and 15 volume percent, respectively, so that the range of flammable mixtures is greater in chlorine than in oxygen or air. The lower flammability limit of ethane at 0 p.s.i.g. and ambient temperatures is 6.1 volume percent in chlorine, 3.0 in oxygen, and 2.9 in air. The corresponding upper limits are 58, 66, and 12.5 volume percent, respectively. In this instance the range of flammable mixtures is greater in oxygen than in chlorine or air. Generally, the limits of flammability for both methane-chlorine mixtures and ethane-chlorine mixtures widen with increases in temperature and pressure.

Jan 1, 1960

By John E. Litz

The Denver Process is a chemical/metallurgical process for treating radioactive or mixed wastes by extraction and concentration of the radioactive and/or hazardous component(s). The process was developed at bench scale, evaluated at pilot scale, and will be implemented at full scale to remediate a low-level radioactive sludge. Six unit operations comprise the process: feed handling, leaching, solvent extraction, electrodeposition, precipitation, and tailing preparation. Unit operation design may be modified to tailor the process for varying feed stock composition. Radioactive or mixed waste is reacted with aggressive reagents in an aqueous phase, solubilizing targeted components. These components are then selectively extracted and concentrated in subsequent steps. Waste solids and solution exit the process as non-hazardous non¬radioactive waste. Dehydration of aqueous waste by submerged combustion eliminates aqueous discharge.

Jan 1, 1994

By Paul W. Richardson

"Introduction And AcknowledgmentsTHIS PAPER outlines the geology and discusses the geological problems of the Mindamar mine. It is impossible to acknowledge the contributions of ideas of all the geologists who have worked in the area. Among the more important contributors are K. DeP. Watson, W. S. James, B.S.W. Buffam, and L. J. Weeks, and John MacPherson, the resident geologist at the mine.A mineralogical and chemical study of the ore and country rock is being carried •on by Dr. Watson at the University of California, Los Angeles.General InformationThe Mindamar mine is on Cape Breton Island, forty miles south-west of Sydney (Figure 1). The nearest railway stations are at St. Peters, which is thirty-two miles southwest of the mine, and at Sydney. Good gravel-surfaced roads connect the mine to the railways.The mine is producing at the rate of 600 tons a day of ore containing zinc, lead, copper, and minor amounts of silver and gold. At the present time the mill feed averages 9 .per cent combined metals, of which zinc makes u:p 7 1per cent and lead and copper each 1 per cent.General GeologyThe ore being mined ,by Mindamar occurs in a shear zone parallel to a northeasterly striking, vertically dipping, series of rocks consisting of rhyolite tuff, rhyolite, minor more basic flow rocks, and diorite (Figure 2). In the vicinity of the mine, these rocks have been termed the Mine Series. They belong to the Bourinot group, which has been assigned by L. J. Weeks to the Middle Cambrian. At the latitude of the mine, the Bourinot group is bounded on the northwest by the Stirling fault and extends eastward for two miles."

Jan 1, 1953

Al2O3,-WC Composite powder for cutting tools was synthesized by self-propagating high-temperature synthesis using A1 powder as a reducing agent. WC, W2C and Al2O3 were concurrently formed in WO3Al-C system. It was found that the complete reaction was achieved with excessive addition of carbon and appropriate processing parameters such as degree of dilution, particle size of aluminum, compaction pressures of green pellets and carbon source. The final product which was leached by 50% HN03+HF diluted solution was consisted of Al2O3-55wt% WC having 2-3um of mean particle size.

Jan 1, 1999

By M. Rafati

In this investigation, the effects of T4 and T6 heat treatments of AZ91 magnesium cast alloy have been studied. The effects of different microstructural details such as morphology, size and distribution of precipitates and their influence on fracture mechanisms were investigated by optical and scanning electron microscopy. The mechanical strength of the alloy after T6 treatment was found to increase in comparison to the T4 treatment, due to the formation of discontinuous precipitates in the grain boundaries. Precipitation in this alloy occurs in two ways: continuous precipitation, which nucleates and grows inside the grains, and discontinuous precipitation, which forms at the grain boundaries. During ageing, the length of the continuous precipitates increases, and, hence, interprecipitate distance decreases. The formation of discontinuous precipitates causes initiation and propagation of cracks at and the weakening of the grain boundaries. This is the principal reason for the reduction of the ultimate tensile strength in T6 heat treatment in comparison to the T4 condition.

Jan 1, 2006

By Mari Yamamoto

Controlled thermolysis of gold(I) complex, [Au(C13H27COO)(PPh3)], at 180 °C for 5 h under an N2 atmosphere affords the new type of monodispersed spherical gold nanoparticles capped by myristate and a small amount of PPh3 ligands (average diameter 23±1.5 nm), in spite of no use of solvent, reducing agent and stabilizer. Much attention has been paid to the preparation and structure determination of transition metal nanoparticles, because of their widespread use in technological applications.1 In general, the chemical reduction of metal salts and organometallic complexes2 by the use of reducing agent is carried out to prepare gold nanoparticles. In some cases, a large amount of solvent and stabilizers such as surfactants,3 polymers4 and ligands5 are used to prevent agglomeration of particles and control the particle size. For instance, Brust et al. reported a two-phase reduction of AuCl4 - by NaBH4 in the presence of dodecanethiol as stabilizer to prepare gold nanoparticles.6 On the other hand, O?Brien et al. recently reported an one-phase preparation of gold nanoparticles by the reduction of AuCl4 - by NaBH4 in the mixture of tri-n-octylphosphine oxide and octadecylamine which act as both solvent and stabilizer, but this procedure also needs reducing agent.7

Oct 1, 2003