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By R. N. Zitter

PRESENT work was done in connection with a program for obtaining a low energy gap semiconductor suitable for photodetection. The inter-metallic compound InSb, which is now being in-

Jan 1, 1959

By C. N. Harman

Steel is the most versatile material which has made the progress in every aspect on this earth possible. There are hundreds of varieties of steel because for each application it has to be made with specific properties to get the most optimum usage. It is well known that the basic constituent of steel is iron. But it is the proportion of other elements in it, which give each type of steel certain specific properties. These elements are added in liquid iron inform of Ferro alloys to get the desired composition and properties. Thus, Ferro alloys are important additives in the production of steel. It can be said that no steel can be made without use of one or more of the several Ferro alloys. They form the backbone of steel. Thus, the Ferro alloys industry is vitally linked for its growth and development to that of the steel industry. Ferro alloys industry in India has never been globally competitive, despite its rich ore deposits and low-cost manpower, essentially due to a) Insufficient availability and high cost of electric power b) Increasing ores and reductants cost c) Non-availability of low ash, low phos. coking coal in the country for the production of desired coke with low ash, and low phos. contents, making import of such coke at a high cost imperative d) High-cost and insufficient infrastructural facilities (both road and rail) for rapid transportation of ore from mines to plants e)Stiff competition from producers and exporters of Ferro alloys in other countries like South Africa, Kazakhstan, China, Russia, Australia etc. due to global trade agreement which has made drastic reduction in customs duty on imports necessary. f) Wide fluctuations in the International price of Ferro alloys depending on demand versus supply. To over come these challenges plus adhering to stringent pollution control norms innovations are inevitable in the process technology, and plant equipment design, along with frequent changes in product mix, to be more cost-effective. An attempt is made in this paper to address the innovations that took place in the past and those that further need to be made, considering the future of this industry.

Jan 1, 2007

By Do-Hyeong Kim, Jong-Jin Pak, Jung-Mock Jang, Min-Kyu Paek

"Thermodynamic relations among Mn, Al and N in liquid iron were studied by measuring the effect of Mn on the solubility product of AlN in liquid Fe-Mn-Al-N alloys in the temperature range from 1773 to 1873 K. The critical Al and N contents for AlN formation were determined by the metal-nitride-gas equilibration technique over wide ranges of melt composition and temperature. The effects of Mn on N solubility in Fe-Mn and Fe-Mn-Al melts containing Mn up to 26 mass% were separately determined in the same temperature range. The experimental results were thermodynamically analyzed using the Wagner's formalism to estimate the critical Al and N contents for the onset of A1N formation. The validity was checked by the observation of inclusion evolution in Fe-20%Mn-1.5%Al-0.6%C-0.3%Si-0.012%N melt during cooling and solidification.IntroductionRecently, high manganese steels such as Twinning Induced Plasticity (TWIP) steels have been developed as next generation steels because of their high formability as well as excellent strength and ductility.[1•2l In these steel grades, a large amount of Mn (15-20 mass%) and Al (1-2 mass%) are added to liquid steels, and such high Mn and Al concentration bring the great challenges to the steelmaking and casting processes. Mn significantly increases the N solubility in liquid iron and the AlN inclusions can be easily formed at such high Al concentrations due to high affinity of Al and Mn with N in liquid steels. Although the AlN inclusion is known to be a dominating and considered as a detrimental phase for the hot ductility of steels,l3l thermodynamics of AlN formation in high Mn-Al alloyed liquid steels was not well known.Moreover, the melting point of these steels decreases down to near 1623 K as increasing Mn content up to 20 mass%. However, most of thermodynamic data has been measured at the steelmaking temperature around 1873 K. Even at steelmaking temperature, there are huge scatters in thermodynamic interactions of Mn and Al on N in liquid iron. The nitrogen solubility in Fe-Mn alloy melts has been measured using the Sieverts' method[4l and the samplinij method[5-7J in the temperature range of 1813 to 1973 K. In the authors' recent study,[8•9 the N solubility in Fe-Al alloy melts was measured using the sampling method in the temperature range of 1823 to 1973 K. However, the simultaneous effect of Mn and Al at high concentrations on Nin liquid Fe-Mn-Al-N alloys is still not known. Also, there remains uncertainty about the temperature dependence of the interaction parameter of Mn on N in liquid Fe-Mn alloys. Therefore, it is worthwhile to check the temperature dependence of this parameter at a low temperature near the melting point of Fe-Mn alloys. There have been few studies on the characterization of non-metallic"

Jan 1, 2014

By D. M. Abbott, H. J. Sandri

The geoscience matrix method has proven useful for valuing metallic mineral properties lacking delineated mineral resources or reserves. However, the method explicitly excludes commodity markets from the factors considered; marketability is assumed. When valuing industrial mineral properties, marketability cannot be assumed, it must considered. Market considerations may also significantly affect the standard weightings of geoscience matrix parameters such as the proximity to known deposits. In some cases, such proximity is desirable but in many cases it is undesirable. Application of the geoscience matrix method to industrial mineral properties therefore requires thoughtful, market-related adjustments to the basic geoscience matrix methodology.

Jan 1, 2000

By J. Chlopas, D. J. Barratt, M. V. Sharp

"This paper describes the modifications made to the Fox Mine copper concentrate bin in order to obtain a continuous flow condition. The design of these modifications is based on test results obtained on Fox Mine concentrate using the flow factor testing machine in the research facilities of Cominco at Trail, B.C.The original design consisted of a cylindrical steel bin on a concrete slab with two slot-discharge openings. Based on predictions of the maximum mass flow hopper angle for conical and wedge shaped hoppers for the concentrate on various potential bin lining materials, Ultra-High Molecular Weight (UHMW) Polymer was selected as a liner.Using the recommended angles for conical and wedge shaped hoppers, the profile of the bin base was changed to suit the existing slot openings.The initial method of fastening the liner resulted in failure of the connections. Subsequent modification to the zinc concentrate bin fastener system proved satisfactory and it has now been in operation for over one year without any separation of the lining material.Utilization of flow testing procedures on concentrate samples has demonstrated that proper design of storage bins or hoppers to achieve continuous flow can be incorporated into the design of new plants."

Jan 1, 1978

By P G. Gaylard

The minerals Industry carries out over US$ 2 billion of R&D annually. The R&D is performed at three levels ? in house research facilities; on a one-on-one basis with a research provider; as syndicated (collaborative) research. The key to a successful R&D programme is project selection. It is suggested that at this time of ?bounty? for the minerals industry the research portfolio should contain some ?blue sky? but potentially long term significantly beneficial projects. This said, the projects should align the technical concepts with the business imperatives. AMIRA has found the ?Road Map? concept has assisted in defining areas for R&D. Examples of this methodology using a Copper Road Map developed by AMIRA for the copper producers operating in South America is presented. The benefits derived from syndicated research are also discussed.

Jan 1, 2007

By Leslie F. Ruppert

The US Geological Survey (USGS) is currently conducting a coal resource assessment of the coalbeds and zones that are projected to provide the bulk of the nation’s resources for the next few decades. The Pittsburgh and Upper Freeport coals are the first two beds in the northern and central Appalachian basin region to undergo fully digital coal assessments. The bed-specific assessments are being carried out in partnership with the state geologic surveys of West Virginia, Ohio, Pennsylvania and Maryland. Comprehensive stratigraphic and geochemical databases have been developed for both of the beds. The extent of the bed with mined areas, structure contour, isopach, and overburden thickness maps for the Pittsburgh coal bed have been released as USGS open-file reports.

Jan 1, 1999

By A. T. Visser

"SynopsisAlmost 20 years have passed since the cutting-edge research by Thompson and Visser on the design and management of opencast mine haul roads was conducted in South Africa. This system is based on three principles, namely the structural ability to support the ultra-heavy truck loads, the selection of vehicle and environmentally friendly riding surface, and an appropriate level of maintenance to counteract wear and tear. Obviously, proper layout and geometry are essential.These principles have been implemented worldwide, and it is useful to review the lessons learned. The objectives of this paper are to present a critical review of the status of mine haul road design and management, and the impact that these principles have made on operations, particularly the cost-effectiveness. The paper briefly reviews the principles of the haul road design and management and the extent to which they are applicable. Case studies of a number of implementations are presented to demonstrate that the principles are sound and have been applied effectively. For example, at an international operation the transport cost of coal was 40% more expensive than anticipated in the feasibility stage, and this made the mining operation uneconomic. Correction of this problem resulted in a viable enterprise. Although designed for opencast operations, the principles are equally valid for underground operations, and initial development work will be discussed.The main conclusions are that the research approach is valid and its effectiveness has been demonstrated in a number of applications. The anticipated financial benefit has been derived, and has made the mining operations that used the principles more effective. Of major importance is the application of opencast haul road design principles to the future thrust of using driverless vehicles in opencast and underground mining, where the road quality is not negotiable as there is no driver that can avoid obstacles or severe road deterioration.IntroductionAlmost 20 years have passed since the cutting-edge research by Thompson and Visser on the design and management of opencast mine haul roads in South Africa (Thompson and Visser, 1996a, 1996b, 1998, 1999, 2000a). This system is based on three principles, namely the structural ability to support the ultra-heavy truck loads, the selection of vehicle and environmentally friendly riding surface, and an appropriate level of maintenance to counteract wear and tear. Obviously, proper layout and geometry are essential."

Jan 1, 2015

By W. Hurst

The authors of this paper, in substituting values in a material balance equation associated with a gas reserve and a water drive, cannot find sustainment of what the gas in place should be; therefore, their conclusion is that this type of problem dealing with gas reservoirs is insoluble. They have introduced the word, "cybernetics," based on the work of Norbert Wiener, that further extends this line of reasoning, namely, to the effect that the system is a "black box", and that the gas reservoir and aquifer can take on infinite aspects 'based upon their past performance, to quote the authors. The inference is that this black box is an unknown. which permits in computer programming to subscribe as many variables as possible to observe by adjustment of one to another those combinations of conditions that fit field behavior. This may satisfy those in this discipline whose dedication is to programming, but to the others this is a comparison to the rationalization of the combinational results of the throwing of dice—a probability procedure. In reservoir engineering we are more direct. We learn from the examination of individual we'll and field data exactly what is in this black box. I now come to the impasse that has confronted these authors in their machine calculations. In this I have reproduced from their own production data (Tables 1 and 2 of their paper) pressure vs cumulative gas produced. shown as Figs. D-1 through D-5. A perusal of any of these five plots, for the corresponding fields in the Po Valley, shows the straight-line relation of pressure vs gas produced, evidencing pressure depletion. The point I make is that in their fundamental production data, there is no variance from a straight line that can support a water drive.

The Century zinc-lead-silver deposit has a geological resource of 118 million tonnes averaging 10.2% zinc, 1.5% lead and 36 g/t silver. It lies approximately 250 krn NNW of Mt Isa in NW Queensland, Australia, and is hosted by middle Proterozoic age siltstones and shales of the Lawn Hill Formation. Within the orebody, most mineralisation occurs selectively within black shale units as fine grained sphalerite and galena lamellae with minor pyrite and siderite. The black shale units are separated by weakly mineralised sideritic siltstone horizons. The deposit is unmetamorphosed and only weakly deformed, displaying excellent lateral stratigraphic and grade continuity. The deposit is mostly overlain by younger Proterozoic sediments and later Cambrian age limestone cover and only a small proportion of the mineralisation crops out. Mineralisation has a subtle surface expression without a classic gossan profile, probably due to the low iron sulphide content of the ore. These factors contributed materially to the length of time between the first recognition of lead-zinc-silver mineralisation in the area by prospectors in the 1880s, to the discovery of the orebody by CRA Exploration Pty Ltd (CRAE) in April 1990.   Small scale prospecting and mining continued in the area from the date of the first mining lease in 1887. Post 1950, the deposit area was also included within nine separate regional exploration titles prior to CRAE's title acquisition in 1987. CRAE's original exploration strategy was partly pragmatically and partly conceptually inspired, but the eventual discovery only partly conformed to the original conceptual model. The deposit was found higher in the stratigraphy than the original target position, with unexpectedly low total sulphide content relative to other known deposits.   The discovery soil anomaly was located by the CRAE's first regional orientation traverse line in the area, but was not drill tested for three years. The discovery sequence at Century has strong elements of persistence, technical competence and some luck. It demonstrates that even in well explored terrains (by conventional standards) the exploration story can never be said to be over. The foreshadowed development of an economic resource at Century will hopefully inspire continued commitment to 'brownfields' exploration by mining companies, and demonstrate to external regulators the importance of genuine multiple land use strategies and the need for continued access to land for exploration and mining purposes.

Jan 1, 1995

By A. Founie

The United States continues to be the world’s leading producer and consumer of diatomite. Production of diatomite in the United States during 2004 was estimated to be 635 kt (700,000 st). This was a 2-percent increase from 2003. The value of processed diatomite in the U.S. was about $164 million in 2004. Production was from six companies with 13 processing facilities in four states. Nevada and California were the principal producing states. They accounted for about78 percent of the U.S. production during 2004. U.S. diatomite exports were about 136 kt (150,000 st). Imports were negligible.

Jan 1, 2005

By Troy Holm, Matthew L. Fuller, Frederick H. Earnest

Virtual Reality Animation Of The Proposed El Dorado Mine In El Salvador Assists Regulators In Reviewing An EIA

Jan 1, 2005

By W. R. Leeder

"The Quintette coal property lies in the Rocky Mountain foothills of northeastern British Columbia (see Figure 1). Quintette and the adjacent Bullmoose property of Teck Corporation are soon to become the first commercial coal mines in the Peace River Coal Field, which is estir1ated to contain 10 billion tonnes of metallurgical coal reserves.Denison Mines Limited acquired the original Quintette coal licenses in 1969 and 1970. Exploration began soon after and the first feasibility study was conducted in 1975. Denison devoted the following six years to extensive planning and feasibility studies of the project. During this period, the provincial and federal governments also undertook studies to assess infrastructure requirements and economic viability of development in this part of the province. Many of the proposed mine sites such as Bullmoose and Quintette were at least 100 to 150 kilometres from the towns of Chetwynd and Dawson Creek, the nearest centres serviced by good highways and a railroad, and a complete network of services would have to be provided if such mines were to be developed. The overall project became known as the North East Coal Development.Concurrently with the feasibility studies, numerous technical and sales missions to Japan were made by representatives of Canadian industry and government, culminating in January 1981 with agreements for Quintette Coal Limited and Teck Corporation to supply a total of 115 million tonnes 8 million tonnes per year for 15 years of primarily metallurgical coal to the Japanese Steel Industry."

Jan 1, 1983

Newmont Gold's methods for deposit modeling vary, depending on geology, mining and processing methods, economic feasibility and availability of historical information. It is argued that successful modeling requires understanding these factors, knowing the strengths and weaknesses of the various modeling techniques and being flexible in selecting the appropriate methods. Newmont is one of the world's largest gold mining companies, with operations in the United States, Peru, Mexico, Indonesia and Uzbekistan. And it is active in exploration worldwide. At the end of 1996, Newmont declared a total reserve of 1.15 equity kt (37.1 million equity oz) of gold and 2.17 equity Mt (2.39 million st) of copper. The gold deposits managed by Newmont totaled 752 Mt (829 million st) of ore containing 1.28 kt (41.3 million oz) of gold averaging 1.71 g/t (0.05 oz/st). In addition, Newmont is developing a porphyry copper-gold deposit that totals 9.1 Gt (1 billion st) of ore containing 380 t (12.1 million oz) of gold and 4.82 Mt (5.32 million st) of copper. (In May 1997, Newmont Gold Co. merged with Santa Fe Pacific Gold Corp., thus increasing Newmont's reserves to 1.72 kt or 55.2 million oz of gold and 2.17 Mt or 2.39 million st of copper.)

Jan 1, 1998

By L. W. Brandt

The Bureau of Mines, as part of its mission to effect pollution abatement, conducted research to study various means of dewatering Florida phosphatic clay wastes and reclaiming mined lands. The work was done in cooperation with 10 Florida phosphate companies. During this work, a novel technique to effectively dewater phosphatic clay wastes was developed. The solids contained in the clay waste slurry are slowly compressed by moving wire mesh screens through the system. In a typical application, the screens were moved downward, compressing solids ahead of the screens. The rate of movement of the screens is an important variable in the process. It is believed that the moving screens distort the gel structure of the phosphatic clay system and cause the release of water. Samples of 18 clay wastes, including a high-grade attapulgite from beneficiation plants of the Florida phosphate field, were studied using the method. Typical samples were concentrated from initial solids of 4.7 and 11.9 percent to 16.8 and 25.2 percent, respectively, in 3-1/2 days. The high-grade attapulgite sample was dewatered from 2.7 percent solids to 13 percent solids in the same period.

Jan 1, 1980

By G. H. Hope

"Pamour Porcupine Mines of Timmins, Ontario operates two 3,000 ton per day concentrators which receive ore from eight to ten mines in the area. The area milling concept was adopted by Pamour in 1971 and has been used successfully since then. The purpose of this paper is to discuss the advantages and the problems of area milling. Pamour Porcupine Mines Limited operates two 3,000 ton per day concentrators which receive ore from eight to ten mines in the Porcupine region. The area milling concept was adopted as the route to survival for Pamour and has worked successfully. HISTORICAL BACKGROUNDProduction of gold from the Porcupine region in Northern Ontario started in the early 1900's and has been continuous since that time. Some of the major operators were companies such as Mcintyre, Hollinger, Dome, Pamour, Paymaster and the list goes on. An underground survey would reveal hundreds of miles of drifts and raises. The main group of mines extends from South East of Timmins to the Pamour Mine, 15 miles to the east. During the lean years of the sixties when gold prices were low, labour costs were rising rapidly, and ore grades were dropping, many of the area mines closed down their operations."

Jan 1, 1981

By Paul C. Schmall, John F. Donohoe, Arthur B. Corwin, Derek Maishman

Ground freezing was utilized to provide complete stability of the excavation face and complete groundwater cut-off for the jacking of the three tunnel boxes for the Interstate 90 / Interstate 93 approach to the Fort Point Channel crossing. Through a wide range of geological conditions and large buried obstructions, the freezing provided complete stability of the face so that a 11.5 m (38 ft) high free standing vertical face could be mined without the need for any additional face support. Obstructions were incorporated into the massive frozen ground matrix, and held in place so that they could be excavated with a minimum of disturbance. The freezing provided an absolute groundwater cut-off, and permitted the work to be done without disturbance to the active rail system immediately above. With the use of instrumentation such as borehole thermocouples, the effectiveness of the freezing was guaranteed and the jacking proceeded with complete confidence and assurance of the ground conditions ahead.

Jan 1, 2001

By Siegmund Babendererde, Jan O. Babendererde

Extruded Concrete Lining combines technological and financial advantages. The tunnel lining is reliably embedded in the surrounding ground as the fluid concrete is extruded at constant pressure directly behind the TBM supporting the exposed surface. Ground deformation from the TBM passage can be compensated and the ground will be pre-stressed by the extrusion process. Developments in concrete technology permit high speed tunneling by use of a slip formwork attached to the TBM. Realised projects in Milano (Italy), Lyon (France), Frankfurt (Germany) and Akima (Japan) will be demonstrated.

Jan 1, 2001

By A. Timur

Fluid flow properties of porous media have long been of interest in such varied disciplines as geology, geophysics, soil mechanics, and chemical, civil, and mechanical engineering. This interest has resulted in numerous models of porous media that have been proposed, tested, and found to be useful under, at best, only special circumstances. A critical review of most of these models is given by Scheidegger. 1 The application of each new tool to the study of porous media has helped to test some of the existing theories and to form new ideas based on the new parameters being measured. In the application of nuclear magnetic resonance (NMR) techniques to the study of the properties of fluids in porous media, the theoretical studies of Korringa et al.2 resulted in a model for the relaxation of spin polarization of protons in a hydrogenous fluid in a pore of a solid. Seevers3,4 verified this model, established a method for measuring the surface-to-volume-ratio distribution in a porous medium, and proposed a technique for determining specific permeability in sandstones. In the present investigation, the uses of NMR methods are extended and a simple model of porous media is developed from an analysis of pulsed NMR measurements. In this model, the pore spaces of a porous medium are divided into three groups on the basis of their surface-to-volume ratios. To evaluate predictions of the NMR model, laboratory measurements of spin-lattice relaxation time, porosity, permeability, and residual (irreducible) water saturation were conducted on more than 150 sandstone samples obtained from four oil fields in North America. Applications are discussed for estimating the volume of movable fluid, ?p, and the specific permeability, k, of sandstone samples. The former parameter, which can be considered as producible porosity, is expressed by ?p = [1 -- (Swr/100)]? , .... (1) where + is porosity in percent of bulk volume and Swr is the residual (irreducible) water saturation in percent of pore volume at a capillary pressure of 50 Psi. Fast, nondestructive laboratory methods are described for determining porosity, movable fluid, and permeability of sandstone samples from measurements with a pulsed NMR (spin-echo) apparatus. Procedures are given for adapting these methods to samples of irregular shape and small size. Theory General In the Korringa, Seevers, and Torrey2 (KST) model the observed decrease in the spin-lattice relaxation time, T1, of protons of a hydrogenous liquid contained in the pore spaces of a porous solid is attributed to an increase in the correlation time for the random motion of the water molecules and to the presence of paramagnetic centers at the liquid-solid interface. This KST model predicts the observed relaxation time of a hydrogenous liquid in a pore of a solid through

Jan 1, 1970

By C. Dorfling, P. Albertyn

"Hydrometallurgical recovery of metals from printed circuit board waste typically involves multiple leaching stages; conventionally, base metals dissolution by mineral acids is followed by leaching of gold using cyanide or halide based lixiviants. Alternative lixiviants for gold leaching can reduce the potential hazardous nature of operation. The aim of this study was to investigate the feasibility of using thiosulfate as lixiviant for gold leaching from waste printed circuit boards. Batch leaching tests were performed to investigate the effects of thiosulfate concentration (0.1 – 0.2 M), ammonium concentration (0.2 – 0.4 M), pH (9 – 10.5), solids content (25 – 50 g/L), and copper content of the feed material on the gold leaching behavior. The concentrations of metals in liquid samples were determined by means of inductively coupled plasma atomic emission spectroscopy, and high pressure liquid chromatography was used to evaluate thiosulfate degradation/consumption. The ratio of thiosulfate to ammonia was found to have the most significant effect on the extent of gold leaching, with the best gold extraction observed at a ratio of 0.5 mole thiosulfate per mole ammonia. The lower pH range of 9 – 9.5 generally produced better Au leaching, while low copper extraction during the first stage base metal leaching stages has proven to be detrimental to gold leaching from the residue. Thiosulfate degradation/consumption increased and gold extraction decreased with higher residual copper in the feed. An optimum gold extraction of 78.5 % from base metal leach residue was achieved with 0.2 M thiosulfate, 0.4 M ammonia, and 0.02 M cupric ions at 25°C in the pH range 9 – 9.5.INTRODUCTION Background and Aim The recycling of e-waste is becoming increasingly important as it provides certain economic benefits apart from the obvious environmental benefits. Printed circuit boards (PCBs) are found in most forms of e-waste and contain especially high concentrations of base and precious metals. Hydrometallurgical processes are often considered for the recovery of valuable metals from PCBs; these processes normally implement several leaching stages to selectively recover certain metals."

Jan 1, 2018