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R. 8. MACPHERRAN, Milwaukee, Wis. (communication to the Secretary): The importance of carbon in pig-iron, as well as the desirability of buying, for some purposes, irons which are high in carbon, has always been recognized. Mr. Summers, I think, has given undue weight to the carbon-determinations. The combined carbon often decreases materially as the center of the pig is approached, with a corresponding increase in the graphite. Even the determination of total carbon, to be of service, must he supplemented by that of other elements. By it alone, the softness of a foundry-iron cannot be determined. Car-wheels and No. 5 iron, for instance, frequently contain 3.75 per cent. of carbon. This is the percentage specified by Mr. Summers for his No. 1 iron, " with the silicon about anywhere the furnace-man wants it." It is true that, other things being equal, the higher the carbon the softer the iron for foundry-use. But to introduce any given percentages of graphitic and total carbon into a pig-iron specification would but make the specification more complicated, without increasing its value in a commensurate degree. Mr. Summers does not believe in the governing of mixtures by the silicon, and, in support of his views, gives several tables. It seems to me that both his conclusions and his tables are somewhat unsatisfactory. He comments on the irregularity in carbon, but fails to note the significance of the irregularity in silicon..The variation of 0.7 per cent. in silicon, for example, is too great to be accounted for by difference in blast. It might better be attributed to bad grading at the furnace, unsystematic sampling, or irregular charging. Deductions drawn under such conditions are of little value. In ordinary work the castings from the same mixture should

Jan 1, 1899

By John E. Wiegand

This study will discuss the AMAX Coal Co., Penndiana Pipeline Project, which was conducted in conjunction with the following parties: AMAX Coal Industries, (U.S.B.O.M.) United States Bureau of Mines, (I.D.O.R.) Indiana Division of Reclamation, Ohio Valley Pipeline, Inc., New Mexico Tech, and ourselves, VIBRONICS, INC., Evansville, Indiana. The purpose of this study was to find a safe vibration level for active gas transmission pipelines near surface coal operations.

Jan 1, 1994

With increasing demand for real-time monitoring of mine parameters, the requirement for appropriate data management in many mining applications is also increasing. This includes atmospheric monitoring in underground coal and metal mines. Although a number of different (real-time) monitoring systems have been installed in underground mines, they all typically share the same systems or sub-systems, where each sub-system may include both custom hardware and / or software components. In addition, monitoring components installed in underground coal mines in the USA should also be intrinsically safe and approved by the US Mine Safety and Health Administration. Real-time analysis adds complexity to the system since data validation and storage should be completed independently of filtering, data reduction operations, or visualization. Real-time processing may include statistical evaluation, trending, cross-correlation, and real-time alarm or warning generation. This paper presents the concept and design of an integrated system under development for atmospheric monitoring in US coal mines.

Jan 1, 2014

By O. A. Ojo, E. Anisimov, A. K. Khan

Electro-spark deposition (ESD) has recently generated a great deal of interest in processing aerospace materials. This is due to its potential for joining and repairing difficult-to-weld precipitation strengthened nickel-based superalloys without having problems of welding cracking that often plaque these materials. The short duration of current pulses involved in the process combined with the intermittent contact results in extremely rapid thermal cycle that produces nearly no heat affected zone in the substrate material. The microstructure of electro-spark deposited superalloy was meticulously studied in this work by scanning electron microscopy (SEM) and analytical transmission electron microscopy (TEM). The results show that in contrast to general assumption, the extreme rapid cooling rates involved in the ESD process did not produce partition-less solidification that is devoid of second phase microconstituents in the material. The secondary microconstituents were found formed along the intercellular regions of the solidification microstructure. The nature of these particles and the possible implication of their formation on mechanical properties of ESD processed material are reported and discussed.

Jan 1, 2015

By J. Kennedy

Rare Earths: Understanding The United States complete failure of status and relevance in Rare Earth Oxides, Elements and Alloys. Although rare earth oxides are strategic and critical in their own right, elements and alloys are even more important for the development of "Green Technologies" and advanced weapons systems. America does not have an active domestic source of rare earth oxides. America does not have any Heavy Rare Earth Elemental or Alloy capabilities. The magnitude of this failure continues to become more apparent as the manufacture of REO based electronics and magnetic components moves eastward towards China. China has succeeded in outmaneuvering The United States and the world in its quest to control the Rare Earth Oxides, Elements and Alloys, and the many industries dependent upon REO. What can be done?

Jan 1, 2010

By J. A. Finch, D. Lin

The robustness of the large-sections correction procedure, Hill's fast approximation, Barbery's correction and the PARGEN correction was examined by comparing their ability to reconstruct the true liberation distribution using sectioning data from computer-generated spheres. The results indicate that the flexibility of a correction procedure is related to the assumptions it makes about the continuity of the liberation distribution, locked-particle characteristics and ore texture. Overall, the large-sections procedure appeared to be the most generally applicable. The Hill fast approximation performed well, but this was probably because it partially incorporates the sphere model; the performance of the PARGEN and Barbery corrections varied from case to case.

Dec 1, 1995

By C. R. Fast, G. C. Howard

The loss of fluid to the formation adjacent a fracture governs the areal extent of the fracture and the success of hydraulic fracturing as a production stimulation technique. The three flow mechanisms which control this loss are the result of the viscosity of the fracturing fluid and the permeability of the formation to the fracturing fluid, its wall building properties, and the combined effects of viscosity and compressibility of the reservoir fluid. The effects of these flow mechanisms can be evaluated in terms of a fracturing fluid coefficient, the fundamental concepts of which are developed in the paper. The fracturing fluid coefficient, which may be used in calculating the areal extent of fracturing, affords a direct measure of the effectiveness of fracturing fluids. The area of hydraulically created fractures is in-creased as the coefficient is de-creased. The fifteen-fold variation noted in this coefficient for the commercially available fracturing fluids tested resulted in a six-fold difference m the calculated areal extent of the fracture system.

Jan 1, 1961

By D. Lopez, D. L. Doerr, T. J. Drake

Automated scanning electron microscopy has been widely used in recent years for gold and other precious metals characterization. However, application of this technology is resource intensive and in most instances needs specialized technical personnel to process the samples and information. Newmont Metallurgical Services (NMS) has recently acquired an ASPEX SEM. The ASPEX SEM offers some significant benefits/improvements in sample preparation and sample processing time. NMS and ASPEX have been working together to develop an approach utilizing this technology for the minerals processing industry and specifically for gold characterization.

Jan 1, 2011

By Lyon R. J P

The quartz-cassiterite-wolfram veins at the Aberfoyle Tin Mine, north-eastern Tasmania, form a sheeted zone about 200 ft. wide and 1,600 ft. long in slightly contact metamorphosed shales, slates and greywackes, and are associated with a cupola of aplitic granite whose top is about 1,050 ft. below the present surface. Economic mineralization persists from the surface down to a vertical depth of 1,050 ft. to 1,100 ft., dying away in the vicinity of the cupola. Down to the 9-level there is a progressive increase in wolfram content of the veins, and a decline in cassiterite content, with increasing depth.The veins are banded or zoned, with a seivedge of muscovite on the wall. Cassiterite, wolfram and sphalerite occur inside the selvedges, projecting into a core of quartz of varying width. Other sulphides form the central part of some narrow veins, or occur as clots in the quartz. The general sequence of deposition of the ore minerals was: (1) cassiterite, wolfram; (2) arsenopyrite, pyrite, molybdenite; (3) pyrrhotite (in part); (4) blende-group minerals-chalcopyrite, sphalerite, stannite, pyrrhotite (in part)-as solid solutions; (5) galena, tetrahedrite, matildite, native bismuth, scheelite; (6) marcasite and secondary pyrite, magnetite and hematite. The sequence of deposition of the gangue minerals was: (1) fluorine-bearing minerals-muscovite topaz, apatite, triplite, fluorite-more or less contemporaneous with the cassiterite and wolfram;' (2) quartz-contemporaneous with the earlier sulphides; (3) carbonates--contemporaneous with the later sulphides. The stages overlapped somewhat.The composition of the sphalerite and heat treatment experiments with the solid solutions indicate that the blende-group sulphides were deposited at about 6000 C., and cooled rapidly, so that unmixing of the solid solutions was arrested. This accords with the likelihood that the country rock temperature was not above 2000 C. Annealing experiments at between 3500 C. and 6000 C. led to further precipitation from solid solution at the lower temperatures, and to significant segregation by solid diffusion within, a week, indicating that both deposition and cooling of the ore were rapid processes-completed in a matter of days. Since the mineralizing solutions must have lost some heat during...

Jan 1, 1957

By Cosmin Carpinisan, Erich J. Hofmann, Stephen J. Hall

"Since presenting a technical paper regarding their unique capabilities in Forged Steel Mill Gearing at the SAG-2006 Conference, Australian heavy engineering company Hofmann Engineering has pioneered a number of new manufacturing processes and design concepts for components of large comminution equipment. These include: 1. Novel design improvements for HPGR Rolls with forged steel tyres and a unique patented tungsten carbide insert designed to improve wear life, enhance autogenous layer build-up, and to reduce breakage & chipping under load. 2. Development of forged fabricated Mill Heads using rolled & welded high-tensile steel plate as alternatives to cast conical mill heads. 3. Insitu Girth Gear measurements for profile and wear via portable 6-axis CMM. 4. Gear and Pinion designs to AGMA-6114 for SAG mills of 38’-40’ diameter to 24MW and for Ball Mills of 26’ diameter to 18MW. The paper presents case studies from the Australian heavy manufacturing facilities of Hofmann Engineering, combined with news of their new gear manufacturing and gearbox overhaul facility in Canada."

Jan 1, 2012

By R. G. Hamm

A brief outline covering the shovels and draglines in use in the open-pit mines of Western Canada, including British Columbia, Alberta and the Yukon, is given, followed by the procedure for the selection of the correct wire rope for each application. Such fa ctors as wire rope constructions, lay directions and types of cores are mentioned. Once the correct wire rope has been selected, there are variousfactors that can affect the service fife ofthe rope and the reduction ofdown-time during rope change-overs. Factors such as hairpin winding, types of Becket loops, and shovel drum and bail adaptors are described.

Jan 1, 1979

The Golden Grove Project area is located 220 km (137 miles) east of Geraldton in Western Australia (Fig. 1). The project is a joint venture involving Amax Exploration (Australia) Inc. (Amax), Electrolytic Zinc Co. of Australasia Ltd. (EZ), and Esso Exploration & Production Australia Inc. (Esso), each with 31 116% interest, and Aztec Exploration Pty., Ltd. (Aztec), with a 3 1/2% carried and a 3% contributing interest. The venture covers two significant volcanogenic massive sulfide deposits and some 40 km (25 miles) of highly prospective Archean volcanics. During the course of the past 12 years (to 1983), all four companies were responsible for operating the project at one time or another and all influenced the discoveries. The Gossan Hill and Scuddles deposits are typical examples of volcanogenic massive sulfide deposits associated with Archean explosive submarine acid to intermediate volcanic complexes. They are located in the northwesterly trending Yalgoo greenstone belt of the West Australian Archean Shield. Gossan Hill, located in 1972, is essentially a copper deposit with minor zinc lenses; to date, 97 diamond holes have delineated a geological resource* estimated to contain 13 Mt (14.3 million st) of of 3.4% Cu and 13 g/t (0.38 oz per ton) Ag in the main lenses with minor lenses totaling 2 Mt (2.2 million st) of 3.7% Cu and 17 g/t (0.49 oz per ton) Ag and 1.7 Mt (1.9 million st) grading 1.5% Pb, 14% Zn, and 87 g/t (2.8 oz per ton) Ag. Scuddles is a zinc-copper deposit with gold and silver credits. It *Resource estimate provided by Esso for inclusion in Aztec Exploration Pty. Ltd. 1982 Annual Report was discovered in 1979 and, to the end of 198 1, had been delineated with 42 diamond holes. On the basis of this drilling, a geological resource* of 26 Mt (28.7 million st) has been estimated in three coalescing lenses. The lenses comprise 7.5 Mt (8.3 million st) of 2.1 % Cu, 12 g/t (0.35 oz per ton) Ag, and 0.3 g/t (0.009 oz per ton) Au; 7.6 Mt (8.4 million st) of 0.4% Cu, 9.9% Zn, 73 g/t (2.3 oz per ton) Ag, and 0.7 g/t (0.02 oz per ton) Au; and 1 1.0 Mt (1 2.1 mil lion st) of 1.1 % Cu, 9.3% Zn, 8 1 g/t (2.6 oz per ton) Ag, and 1.5 g/t (0.044 oz per ton) Au. Readers are referred to Frater (1978) and Harris et a). (1982) for a more detailed geological account of these deposits.

Jan 1, 1991

By F. G. Clapp

IT is to be hoped that no casual reader will erroneously refer to the latest publication' of the Division of Public Relations of the American Petroleum Institute, as being "Petroleum Facts and Fancies." The facts are so faithfully derived and the figures are so authentically sponsored by the highest sources that no person can read this valuable volume (287 pages and numerous tables) without being convinced that every- thing therein set forth is "the truth and nothing but the truth." Yet, having read the volume from the perspective of the world's petroleum industry and with a critical attitude that comes from years of study of the subjects discussed, I find myself tempted to cogitate and to envisage a few of the fancies that come to mind as a fitting sequel.

Jan 1, 1929

By Ludwig Schmidt

The policy of buying crude oil on a gravity basis , recently instituted by the major crude oil purchasing agencies in the Mid- Continent field , has caused a new and vital interest to be taken in the work of the U. S. Bureau of Mines for preventing evaporation of crude . From the early years of the industry oil men have recognized that the gravity of crude oil is usually an index of the gasoline content , but it has not been so generally known that the gravity of the crude oil decreases if evaporation is permitted . In 1919 the Bureau of Mines began a survey to determine the evaporation losses of crude petroleum in its various stages of handling from the well to the refinery , The results of this study are presented in Bulletin 200 ( Wiggins , J.H. , Evaporation losses of petroleum in the Mid- Continent Field , Bulletin 200 , U. s . Bureau of Mines , 1922. ) and Bulletin 225 ( Wiggins , J.H. , Methods of decreasing evaporation losses of petroleum , Bulletin 225 , U. S. Bureau of Mines , ( In press ) The findings of this survey were so startling that soon after the preliminary report had been published , several tank companies began manufacturing vapor- tight tanks for the purpose of reducing these important losses . Since that time the development of this type of apparatus has been so rapid that today , every oil trade journal carries numerous advertisements of vapor- tight tanks and equipment as well as technical articles dealing with various problems in connection with the elimination of evaporation losses , whereas three or four years ago the subject was scarcely even thought of. The present report has been prepared in response to numerous requests for information on the apparatus actually being used to prevent evaporation losses . At this time oil operators are also extremely interested in holding the lighter fractions in the crude oil in order to prevent a lowering in gravity . The practice of removing the vapors from crude- oil tanks by means of a slight vacuum and extracting the gasoline from them is not discussed here .

Feb 1, 1923

By Ulrich Maidl, Jamal Rostami, Ulf Gwildis

Tunnel Boring Machines (TBM) have more or less become the preferred method of tunneling in various ground conditions and Programmable Logic Controllers (PLC) or microprocessors are standard features on TBMs to monitor and record various sensory systems on the machine providing the possibility for machine automation and control. The data collected from these sensory systems and channeled through PLC is stored for real-time analysis or use by the operators. Based on typical construction specifications, part of the information collected in the process is shared with the project management team representing the owner. Machine data automatically acquired during TBM advance is typically processed by specialized software to offer the project team data visualization and evaluation options. Interfacing with Geographic Information System (GIS), Computer-Aided Design (CAD), 3-D geologic model, instrumentation data bases, and Document Management Systems (DMS) allows for developing Building Information Models (BIM) of the tunnel’s as-built condition. Application of Artificial Intelligence (AI) processes such as Machine Learning (ML) have already been used for analysis of data, including performance prediction of hard rock TBMs, and exhibited the potential of big data analytics in improving the productivity of the operations. This paper outlines anticipated disruptive technological advances with implications on geotechnical exploration, TBM operation, face condition tracking, subsurface risk allocation, and claims management in the future.

Jun 13, 2021

By William R. Wayment, David E. Nicholson

A modified percolation - rate test is proposed for use in determining flow rates through hydraulic backfill ; in contrast to the conventional test , a percolation- rate versus void - ratio relationship is established . requirements and a detailed test procedure are described . Equipment Results of a conventional test are compared with those of the proposed modified test . The proposed modified test method yields more accurate , realistic , and usable percolation- rate ( permeability ) data . The significance of obtaining accurate percolation rates for use in analyzing waterflow through hydraulic backfill is discussed .

Jan 1, 1964

By R. E. Mitchell

Environmental Impact Assessment (EIA) is the accepted method for evaluating proposed mining and other industrial projects to obtain regulatory approval and to help companies plan for responsible development. Another evaluation system becoming increasingly more common for proposed projects is the Environmental, Social and Health Impact Assessment (ESHIA). An ESHIA differs from an EIA for its more comprehensive and inclusive approach to evaluate potential impacts on public health, and its ecosystem services approach to assessing biodiversity impacts. An ESHIA may also be required by certain lenders for financing major projects. Conducting an ESHIA for a proposed mining development is not without its challenges, with costs, scheduling, regulatory concordance and other constraints to be considered. This paper examines some benefits and challenges of ESHIAs and summarizes lessons learned using a case study approach.

Jan 1, 2012

By W. T. Wertman

LABORATORY research has been started at the Bureau of Mines Morgantown Petroleum Research Laboratory, Morgantown, Va., to investigate the possibilities thermal-recovery methods for producing crude oils of high API gravity found in oil reservoirs of the eastern United States. This bibliography on thermal methods of oil recovery was compiled as a part of the work. Crude oil discoveries to December 31, 1958, in the United States were estimated to exceed 270 billion barrels. Cumulative production of crude oil through 19.55 was about 60 billion barrels, and the American Petroleum Institute estimates that an additional 30.5 billion barrels are economically recoverable by present methods. On this basis, about two-thirds of the oil that has already been found can be classified as economically unrecoverable for lack of a satisfactory method. The rap icily rising costs of proving new deposit; of domestic petroleum, the lack of new discoveries of large oilfields in the united States, and I he growing demand for crude oil have caused an acceleration of research to develop new or improved methods fur producing "unrecoverable" oil in known reservoirs.

Jan 1, 1960

By B S. Utting, W J. Cowie

The alluvial gold industry of New Zealand is based on the placer deposits in Otago and on the West Coast. Production from these since discovery in the 1850s has been an estimated 480 t (15 Moz) of gold. Annual output has expanded continuously since 1980 and is expected to be over 2 t of gold for 1989. Following a historical review, the characteristics of typical operations, which use hydraulic excavators and mobile trommel units are discussed. Descriptions are then given of alluvial activities in Otago and on the West Coast.

Jan 1, 1990

By D. Ofstie, B. Kargutkar

BIM, or Building Information Modeling, is transforming the way metallurgical facilities are built, operated and maintained. BIM provides a digital representation of the facility, complete with all physical and functional characteristics - enabling collaborative planning, concurrent design, construction simulation, sustainable operations and predictive maintenance through a connected information model. Building on experience gained in other industries, Hatch is aggressively applying the BIM process to the mining & minerals processing industry to address inefficiencies inherent in traditional document-based information management. Intelligent 3D models support real-time quantity forecasting and cost trending by commodity type and construction work package. By linking procurement and schedule data, material availability and constructability reviews are visualized to verify construction critical path, ensure work front safety and minimize craft downtime. The BIM digital information model connects engineering, construction, commissioning and vendor data, aiding timely asset-centric handover to plant operating and maintenance systems.

Jan 1, 2015