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By Dean S.

Further discussion at the North of England Institute of Mining and Mechanical Engineers' general meeting held in Newcastle-upon-Tyne, 12th February 1916, with Mr. T.Y. Greener, President, in the chair, of the paper published in Trans. I.Min.E. vol.L, 1915, p.179 and 388. Written contributions to discussion included Mr. Dean's reply to earlier discussion (p.35-44), further written contributions by Tate S. (p.44-54) and Brown E.O.F. (p.54-56), and oral comments by Hare S., Merivale J.H., Greener T.Y. and Tate S. Particularly debated were the causes of the difference in output between American and British coal miners

Dec 1, 1916

By T. V. Simpkinson

Abstract A brief history of the electric arc furnace process of steel-making is given. The greater relative importance of this method of steel manufacture to the Canadian steel industry, as compared with its importance in the steel industry of the United States, is shown. The scope of the process is outlined and brief mention is made of the difficulty of obtaining melting stock low in alloy content. The physical chemistry of steel-making is discussed at length in simple terms, with emphasis on oxidation, de-oxidation, and the role of hydrogen. Carbide-type and silicon-type slags are described and the particular usefulness of each is outlined. The importance of various factors in the melting practice is evaluated on the basis of practical experience. Introduction Although electric furnace steels constitute only a small portion of the total weight of steel used in industrial operations, their importance is relatively much greater than is indicated by comparative tonnage figures. Tool steels, which are vital to all industry, are made almost exclusively by the basic electric arc furnace process, as are stainless steels, valve steels, and the higher alloy types of the class usually referred to as "alloy steels'. For many applications where steel other than electric furnace quality is often used, and when first cost is secondary to performance in service, the extra steel cost of electric furnace quality material is usually returned with interest by consistently longer service life. The electric furnace is pre-eminent in the quality alloy steel field because of the control that may be exercised over conditions of oxidation, de-oxidation, and temperature, the fundamental operations in steel making.

Jan 1, 1948

By Roy J. M. van Lier

In industrial aqueous solutions, germanium generally occurs in trace amounts amid high concentrations of other metals, such as zinc, copper and iron. Separation of germanium from these metals as well as its isolation from gallium and indium pose a real challenge to the hydrometallurgist. After a brief discussion of the aqueous chemistry of germanium, this paper reviews the flowsheet of the Apex Mine in Utah. The Apex property was the only mine in the world to be operated primarily for production of gallium and germanium, but apparently closed due to great operating difficulties. Several process variants proposed for the treatment of the Apex ore, including bioleaching methods, are addressed. Following a more general description of the behavior of germanium in hydrometallurgical zinc processing streams, available technology for its recovery from aqueous solutions is summarized. Precipitation, solvent extraction, ion exchange, electrowinning, ion flotation and liquid-membrane separation are all outlined in terms of the aqueous chemistry of germanium. Finally, the production of high purity germanium dioxide and metal is briefly discussed

Jan 1, 1995

By Clemens Catesby Jones

The substance of this paper, now amended and altered in form for its present use, was the basis of a private report prepared under professional engagement.* A private report is necessarily objective, and deprived of the scope and technicality of a scieintific treatise—which accounts for the prevalence of drawings and succinct mathematical statements rather than full descriptive details in a paper reproduced from data, of which all the original working-notes have been destroyed. In a practical sense the Hudson river valley clay-deposits owe their present existence to the protection afforded by the rock-formations on which they are supported, and, instead of being uniform in depth or continuity, are subject to the irregularities of the rugged masses which preceded and are now concealed by them. The only available information concerning these deposits contained in previous public reports or maps furnished at best a mere photograph of the surface, and as now apparent this was misleading or unreliable. It was the object of this investigation to determine in a practical manner the location, form and extent of all the clay-deposits at present existing in the lower Hudson river valley, and to ascertain with a

Jan 1, 1900

By D. A. Larson

This is the second in a series of Bureau of Mines reports which de-scribe experiments designed to devise an efficient, economic mechanical fragmentation technique for hard rock. The previous study described the development of the ripper cutting technique to successfully cut hard rock with 3-to 6-in-wide drag cutters. This study was conducted to test the ripper cutting technique at full scale using 9-in-wide drag cutters. The experiments were conducted with a special test device that cut shallow, 6-by 6-ft openings in 9,200-lbf/in2 compressive-strength concrete blocks. The tests showed that ripper cutting can excavate large-scale openings of the type required by the mining industry at a production rate that outperforms the conventional drill-blast technique. Moreover, the system can produce openings of various sizes and shapes, is simple to oper-ate and maintain, and produces very little dust or noise during operation. The system appears to meet all of the criteria for a successful hard-rock mining machine.

Jan 1, 1987

By E. S. Leaver

Experiments dealing with the dissolution of silver by cyanide from various silver minerals-were reported, several years ago.4/ This work showed that the silver in some silver minerals is completely and readily soluble in cyanide solution, whereas other silver minerals must be given special treatment before or during cyanidation to obtain much dissolution of the silver by cyanide. Flotation as a method for treating silver ores has not been studied much, except in the case of base-metal ores carrying silver, Particularly lead-silver ores. However, many mills now are concentrating gold ores by flotation, and when such ores also contain silver the recovery of the silver by flotation is of considerable importance. Moreover, many mines contain ore in which silver is the principal valuable constituent. Some of these ores are amenable to cyanidation, but the cost of a cyanide plant may be prohibitive because of limited ore bodies or other factors. In such instances the successful application of flotation would mean that the property could be operated.

Jan 1, 1939

By E. S. Leaver

Experiments dealing with the dissolution of silver by cyanide from various silver minerals were reported several yews ago.4/ This work showed that the silver in some silver minerals is completely and readily soluble in cyanide solution, whereas other silver minerals must be given special treatment before or during cyanidation to obtain much dissolution of the silver by cyanide. Flotation as a method for treating silver ores has not been studied much, except in the case of base-metal ores carrying silver, particularly lead-silver ores. However, many mills now are concentrating gold ores by flotation, and when such ores also contain silver the recovery of the silver by flotation is of considerable importance. Moreover, many mines contain ore in which silver is the principal valuable constituent. Some of these ores are amenable to cyanidation, but the cost of a cyanide plant may be prohibitive because of limited ore bodies or other factors. In such instances the successful application of flotation would mean that the property could be operated.

Jan 1, 1939

By Maurice A. Roche

Introduction Most of the Flin Flon ore-body, like many others in northern Canada, was covered by water. The original discovery was made where the ore-body outcropped on a strip of land jutting out into Flin Flon lake. The outcrop could be traced for a distance of 600 feet across the strip of land, but disappeared under the lake on both sides of the peninsula. Following the discovery or location of the property, in 1915, and subsequent to its examination by the H.P. Whitney interests in 1925, an extensive diamond-drilling programme was completed, which proved the existence of an ore-body at least 2,600 feet long and 900 feet deep. In plan, the central part of the ore-body at surface attains an overall width of about 450 feet; including waste horses, and gradually becoming narrower to the south. To the north, it stretches out as a much narrower tongue. The main body is a solid sulphide ore containing gold, silver, copper, and zinc. Adjacent to, and on the footwall side of, the solid sulphide ore-body, there are considerable widths of talcy disseminated copper ore, particularly in the upper 300 feet of the deposit, where the maximum widths occur. The ore-body occurs in a greenstone area, the rock being quite hard on the hanging-wall side, with the footwall schisted, talcy, and much softer. The greater part of the ore-body was overlain by 12 to 15 feet of water and from 15 to 90 feet of mud and clay, this material requiring eventual removal, regardless of the system of mining adopted. The total of mud and clay overburden was estimated at 1,000,000 tons. After considerable study, it was decided to mine the upper 300 feet of the ore-body by open-pit methods; the balance of the ore to be recovered by underground mining . The present paper gives an account of the methods adopted in both operations, and of the problems encountered.

Jan 1, 1935

By O. P. Hood, G. St. J. Perott, S. P. Kinney

"FOREWORD (By O. P. Hood, Chief mechanical engineer).During the war certain suggestions concerning power production were made by Mr. Walter E. Trent to the War Inventions Board, and at the request of the War Department facilities for experimental work were provided on the grounds of the. Bureau of Standards.The experiments were along the line of controlling the conditions of combustion in a closed space. In order to reduce slag troubles, experiments were carried out for removing ash from powdered coal. After the war, work along this line was continued, resulting in the Trent Process, which agitates or beats together powdered coal, water and oil.A new technology had previously been given to ore preparation by the use of small quantities of oil in water with froth flotation, and although the methods, results and mixtures of the Trent Process were quite different, yet the same physical phenomena of differential wetting used, and the possibility of there being interesting results in fuel technologic was evident. A cooperative agreement was entered into, whereby the Bureau of Mines was to investigate the underlying physical and chemical facts and make them public, and the Trent Corporation was to pay the cost of the investigation.The several reports as made have been available to any one interested, and are now to be published. While the Bureau of Mines felt justified in investigating the physical phenomena so far as might be done in a laboratory, and so far as public interest might reach, no attempt was made to discover the commercial possibilities which development might bring. The question of commercial possibilities must be left for commercial enterprise to answer."

Jul 1, 1921

By T. T. Campbell

This report traces the development of techniques for the preparation of high-purity rare-earth metals. Rare-earth metals, excepting samarium, europium, and ytterbium, were prepared by converting their oxides to anhydrous chlorides or fluorides and reducing the rare-earth halides with active metals such as lithium or calcium. High-purity, anhydrous rare-earth chlorides were prepared by dissolving the rare-earth oxides in hydrochloric acid to form hydrated chlorides and by subsequently dehydrating the hydrated salts in the presence of ammonium chloride at temperatures ranging from 70° to 360° C. while under reduced pressure (50 microns to 1 inch Hg). The chlorides were also prepared by direct chlorination of rare-earth oxide-carbon mixtures. Reaction efficiencies in excess of 95 percent were obtained by either method; however, purer chlorides were prepared by the aqueous ammonium chloride conversion method. Purification of yttrium chloride by high-temperature vacuum distillation proved to be an effective method of separating, oxygen-bearing compounds from the chloride. Yttrium metal prepared from purified chloride contained significantly smaller amounts of oxygen (990 p.p.m. oxygen in yttrium metal prepared from raw chloride and 200 p.p.m. in that prepared from distilled chloride).

Jan 1, 1961

By John Platt, Mark Stephens

"When blasting is required in critical areas and anticipated shot movement and quick cleanup areessential to the success of the project it is extremely important to use the best technology available to achieve the goals expected by the customer. Wampum Hardware was given such a challenge in 2014-2015 when the PA Turnpike and New Enterprise Stone and Lime hired the company to do presplit blasting along the PA Turnpike. The face height averaged 45 feet (13.72m) and the shots had to be controlled to stop within 60-75 feet (18.29-22.86m) of the face or in this situation before they entered the travel lanes on the PA turnpike. In many if not most blasting environments, it is essential in controlling the movement of a blast, to make certain that the face holes are drilled at exactly the right place, with the proper amount and type of burden in front of and to the sides of the borehole. Profiling is an important first step to insure that the holes are drilled at exactly the right place and showing us the correct amount of burden in front of each and every drill hole."

Jan 1, 2016

By R. D. Groves

Laboratory research has demonstrated that high - grade copper powders can be produced under controlled conditions from cement copper products . The technique should enable small producers to prepare a directly marketable product by means other than smelting and electrolytic purification . A continuous drum- type precipitator was the preferred unit for producing fine - sized particles of cement copper that were further processed by chemical digestion in a copper sulfate solution , by reduction and sintering in a hydrogen atmosphere , and by grinding to a powder . The effects of variables related to all stages of the process were investigated . Treatment of leach solutions from three different sources resulted in copper powders containing 99.2 to 99.8 pct Cu , apparent densities of 1.97 to 2.25 grams per cu cm , good powder flow rates , and a size distribution of 54.9 to 60.1 pct minus 325 - mesh material .

Jan 1, 1964

By Ralph T. Buscarello

For practical purposes, the terms "natural frequency," "resonance" and "critical speed" are synonymous. A part passing though its "critical" or "critical speed" may also be said to be "resonant" or "resonating." The vibrations of a precisely balanced part can be magnified by the structure in which it is assembled. Anyone who has driven an automobile knows that it will vibrate more at a certain speed than at others. According to the formula for centrifugal force, vibration should increase steadily with a rise in rpm. What happens instead is that the vibration not only in- creases with r m. but suddenly rises at a much higher rate through the critical speed, and then apparently smooths out as the rpm passes beyond it. To visualize what happens, consider a simple flat spring with a weight mounted at one end. When the spring is deflected by pulling down on the weight and then letting it go, the spring will oscillate, and the spring-and-weight system will vibrate at its natural frequency. If the timing or direction bf the impulses imparted to the spring did not coincide with its natural frequency, the result would be an irregular vibration that would not build up. If, on the other hand, the timing and direction of the impulses did coincide with the spring's natural frequency, the result would be a larger and larger amplitude. If the impulses were continued indefinitely, the amplitude of the spring's vibrations would go on rising [while its frequency stayed the same] until the spring broke or the amplitude of the vibrations reached an equilibrium [because frictional or other forces would tend to damp it]. Resonance magnifies the amplitude of vibrations in a relatively undamped system between 100 to 200 times over that of nonresonant vibrations. Frictional or viscous damping often reduces the magnification [from 10 to 20 times], but even with this reduction the amplitude would still be large enough to cause excessive wear, and sometimes even fractures. For example, a blower might show only 0.001 in. of vibration on the manufacturer's test stand. Installed, the blower could pass into its critical speed [the speed at which the frequency of the vibrations caused by the rotor coincides with the supporting structure's natural frequency], and the 0.001 in. of vibration could be resonated to 0.010 in., or as much as 0.020 in. The cure for such a condition would not be to lower the vibration of the blower by further balancing or better alignment but to separate the two frequencies by at least 20 to 30%.

Jan 1, 1970

By D. Parks, A. Miller, M. McNinch, R. Jacksha

Each year, hundreds of mine workers are involved in machinery-related accidents. Many of these accidents involve inadequate or improper use of lockout/tagout (LOTO) procedures. To mitigate the occurrence of these accidents, new safety methods are needed to monitor access to hazardous areas around operating machinery, improve documentation/monitoring of maintenance that requires shutdown of the machinery, and prevent unexpected startup or movement during machine maintenance activities. The National Institute for Occupational Safety and Health (NIOSH) is currently researching the application of Internet of Things (IoT) technologies to provide intelligent machine monitoring as part of a comprehensive LOTO program. This paper introduces NIOSH’s two phase implementation of an IoT-based intelligent machine monitoring system. Phase one is the installation of a proof-of-concept system at a concrete batch plant, while phase two involves scaling up the system to include additional sensors, more detailed safety/performance metrics, proximity detection, and predictive failure analysis.

By R. A. Ynchausti

In January 1993, Pyramid Resources began implementation of a supervisory expert control system at a U.S Cu concentrator. The objective of this control system was to improve plant profitability through unit operation optimization and integration. This paper documents the key aspects of the project, including: economic and associated benefits, system architecture, concepts of implementation, process control strategies, practical aspects of implementation and conclusions. The implementation of expert control at this concentrator has resulted in an estimated benefit of $50,500 per day. This is a net result of improved tonnage, reduced reagent consumption, improved concentrate grade and reduced energy per ton produced.

Jan 1, 1995

By W. J. Long

As a part of the strategic mineral exploration program, examining engineers of the Bureau of Mines collected samples of ore from four manganese properties in Yavapai, Yuma, Maricopa, and Mohave Counties, Ariz. As all of the ores were too low in grade to be acceptable by manufacturers of ferromanganese beneficiation studies were made to determine the amenability of the ores to concentration.

Jan 1, 1948

By David J. Mack

A survey and critical appraisal of published information about Young's modulus was originally made by the writer because of a complete lack of information about this very important quantity in works on. mechanics, physical metallurgy, physics, and other sciences. It was felt that a comprehensive summary of such information about Young's modulus might be of general interest and may suggest new problems or lines of attack on other problems that involve E. Hence this paper has been prepared even though it is only a review, with no new ideas or experimental data. The references are only those used in assembling the paper. No attempt was made to compile a complete bibliography on the subject of Young's modulus. CalculatioX oP YouNg's Modulus from Theoretical or Empirical CoNsidera-tions Many attempts have been made to compute E from theoretical considerations. The earliest calculations were probably those of Tomlenson (1883) and Souther-land (1891), but Fess'enden4',~ made extensive calculations a few years later and arrived at the relationship: £ = 78.TOw(i)* where V is the atomic volume. In 1923, Peczalski, working from the same standpoint but with more information available on atomic structure, arrived at an identical relationship, which he expressed as: where B is a constant of value about 8 . 107, p is density and mis atomic weight; the atomic volume, of course, being ml p. Portevind4 immediately pointcd out that while the equations of Fessenden and Peczalski were true of the common metals, they gave low values for the refractory metals with high moduli (Fig. I). He showed (Fig. 2) that much better concordance was obtained by means of an empirical equation of the form: F- KT" where K is a constant; T the absolute melting point; V, atomic volume, and a and b constants of value approximately I and 2 respectively. This constant K in the Portevin equation is not necessarily the same for all elements, as shown by Thompson. Other equations for E based upon theoretical considerations have been derived by Honda and Yamada49 and Lasareff.50 The most recent calculations of elastic moduli based upon quantum mechanics are probably those of Fuchs He extended the method of Wigner and Seitz for calculating the lattice energy and compressibility of monovalent metals and computed the elastic constants of lithium, 18

Jan 1, 1946

By S C. Dominy

Grade control programs aim to deliver economic tonnes to the mill via accurate definition of ore and waste. The foundation of a successful program is high quality sampling supported by geology and a suitable data management and modelling system. Underground sampling methods include chip, channel and panel samples; grab/muck pile samples; and drill-based samples. Grade control strategy is related to mining method and orebody type. Sampling protocols must be designed to suit the style of mineralisation in question. Holistic studies focussing on ore mineralogy and gold particle deportment, size and distribution are required for sample collection and preparation protocol optimisation through ‘Theory of Sampling’ application. Where possible, such programs should be undertaken early in the life of a project. Appropriate assaying procedures are also required. Program implementation will require suitably skilled individuals to train and mentor staff, with ongoing Quality Assurance/Quality Control (QA/QC) monitoring and review will allow protocols and staff to be updated as required.

Aug 22, 2011

Effective control of respirable dust is one of the most serious problems associated with longwall mining in the United States. This report describes the development and laboratory testing of dust collectors for use on double drum shearers. Systems tested included: ? High Capacity Flooded Bed Scrubber ? Water Powered Extraction Cowls ? Water Powered Extraction Drums ? Water Powered spot Scrubbers. The systems were tested using tracer gas in a full-scale model of a longwall shearer face. This report provides a detailed description of the test facility, test methods, and system test results.

Jan 1, 1982

By H. S. Duzgun, N. Demirel

Estimating productivity of a walking dragline is of paramount concern to mining engineers and mine planners. Risk based evaluation of the dragline productivity is a valuable tool to estimate the dragline’s long-term availability, to develop preventive maintenance plans and to make future projections about the dragline’s performance. This paper aims to provide mining professionals with an overview of risk assessment methodology for productivity of two walking draglines, Page 736 and Marion 7820, which have been operating in the Tunçbilek openpit coal mine of Turkish Coal Enterprises (TKI) in Turkey. The study encompasses three main stages: (i) acquiring of monthly maintenance records, operating hours, mechanical and electrical failure hours between 1998 and 2009; (ii) reliability modeling using mean time between failure data and (iii) determining hazard rate and consequences to compute risk associated with dragline productivity. The results showed that that Page 736 (15.29 m3) seemed to be more reliable and less likely to fail when compared with Marion 7820 (30.58 m3). The operating hours without failure range from 41 to 51 hours with 50% reliability.

Jan 1, 2011