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By S. W. Mao

Hydrologic and economic criteria figure in many obvious ways in water resources development, but they are rarely linked quantitatively, and most of the applications are pertinent only to the case-in-point. In the preparation of the Regional Plan for the massive program of ground water development in the Punjab, situations have arisen where the choice among two or more alternatives was made by analyzing the economic implications of critical hydrologic parameters. Two of these situations which are of more-or-less general interest are described herein. The first involves basic development policy -- whether ground water development should be based on the demand of the economy, or the conservation concept of safe-yield. The analysis demonstrated that mining of ground water is clearly indicated for areas where alternative supplies are unavailable. The second problem involves integrating hydrologic data into an economic model to determine optimum well design, From an analysis of all pertinent factors, a simple nomograph was derived which can be used to determine well specifications on-site during construction. The nomograph can be modified for use in any alluvial terrain.

Jan 1, 1967

By S. E. Khalafalla

A method for preparing ferrochromium alloys containing less than 2 pct carbon has been devised in a single vacuum furnace reactor. This method can conserve chromium and should reduce the capital and energy requirements relative to chromite electrothermal reduction. Reduced products containing less than 2 and as low as 0.01 wt pct carbon were obtained by reacting pellets of chromite and carbonaceous reductant mixtures at pressures of 0.1 to 1 ton and temperatures of 1,230° to 1,320° C. The extent of reduction increased with increased temperature and decreased pressure; however, operating conditions were limited due to the onset of significant chromium vaporization at higher temperatures and lower pressures. Foundry coke, anthracite, and carbon black were found to be superior to graphite as reductants. The reduction of chromite to metallics was found to proceed via the carbide intermediates Fe3C or Cr3C2. Lime accelerates the. rate of solid state reduction of chromite and can shorten the furnacin1r time at 1,3000 C under vacuum from 13 hours to less than three hours. Additional lime and silica are added to the hot reduced chromite after releasing the vacuum and raising the furnace. temperature to 1, 700° C. Soaking the charge for about 20 minutes gave a button of low carbon ferrochromium alloy beneath a well-defined slag layer.

Jan 1, 1985

By Stephen C. Tadolini, Robert Hawker, Peter Mills, Colin Grubb, Tom Meikle

"In unfavorable strata conditions, it is often necessary to install additional long tendon support as part of a primary support cycle. Although these support systems provide the required additional stability to the roadway installation does have a significant effect on the rate of development. To overcome the slow cure time of Portland cement-type grouts, the use of two component resin systems, such as polyurethanes and urea silicates, have become favorable. However, concerns over low modulus and creep properties has led to the development of a two-component grouting medium that displays the properties of traditional cable grouting materials with the rapid reaction times of pumpable resin systems. This paper describes product testing, application, surface trials, underground trials, and full-scale applications of the Tekthix System in a dynamic underground environment. INTRODUCTION Single-component cement grouts have been used to anchor long tendon supports for many years. They range from high- to low-slump Portland cement and can be slow-setting to fast-setting grouts. However, current cement grouting systems, which includes the grout and equipment, have some disadvantages: 1. Low-slump grouts require pumps that can handle a thick, high-viscosity grout, so choice of pumps is limited. 2. Pumping distance is limited with current cable bolt grout pumps; operators often tend to add water to allow pumping long distance, which adversely impacts the quality and strength of the material. 3. Fast-setting grouts tend to cause issues with pump and line blockages due to the reduced working life of these single-component materials."

Jan 1, 2017

By John Johnston

When I was honored by being invited to give the Howe Memorial Lecture, I decided to read Howe's book, "The Metallography of Steel and Cast Iron," published in I9I6—that is, about 25 years ago—in search of a text. I found the book written in fine, clear, attractive, yet precise style, as I expected, knowing that his father— Dr. Samuel Gridley Howe, his mother— Julia Ward Howe, and all of his four brothers and sisters had lived in a New England literary atmosphere and had written books. This leads me to suggest that many authors of metallurgical papers and books could well study Howe's writings with a view to the improvement of their own. I failed to find a specific text, but did find a subject, for in reading his book I was struck by the few instances in which time is considered explicitly as a factor in the phenomena examined, and by the fact that many of the hottest arguments would have been settled had time been taken properly into account. Indeed, Howe hardly mentions time except in a rather incidental way, as in a few references to lag; for instance: The lowering of temperature at which the transformation occurs by rapid cooling . . . is a phenomenon of undercooling or lag. It is in part explained by the fact that the transformation itself is a time-consuming reaction which, setting in during a rapid fall of temperature, is naturally protracted till the temperature has sunk far below that at which it is due. He does discuss, quite fully, the iron-clrbon equilibrium diagram, as known at that time, introducing it by stating: As he is a reasonable man who is not deterred from using a hand truck for moving his trunk by the consideration that he has thus to move a trunk plus a truck, so am I reasonable in putting into your hands this useful, indeed indispensable. tool for mastering the ABC of iron metallurgy. Somewhat later, in introducing a discussion of the phase rule, which "it would be hardly proper to pass ... by without an attempt to outline its meaning," for "a clear exposition of its applicability or jurisdiction is needed to restrain the half-initiated from misusing it and the uninitiated from being misled by these misuses," he writes—and I quote his statement because we cannot properly discuss the influence of time on a process until we know the state of equilibrium which would ultimately be reached by the system under consideration: It is a most remarkable and valuable generalization, its conceptions help greatly toward getting a broad outlook on metallography, but its misconception has brought out a flood of obscuring writings. it tells us about the constitution towards which alloys tend, that which they reach when equilibrium is complete, when all tendencies have corrected themselves and have been complied with completely. Its application, in absence of true equilibrium, is like determining density with a telescope or even with a tuning fork; it is like the mad tea party at which the butter put into the works of the watch was the best butter. If the reader learns no more than to beware of attempts to dccipher the conditions of inequilibrium by a law which touches only the conditions of exact

Jan 1, 1942

By John Johnston

When I was honored by being invited to give the Howe Memorial Lecture, I decided to read Howe's book, "The Metallography of Steel and Cast Iron," published in I9I6—that is, about 25 years ago—in search of a text. I found the book written in fine, clear, attractive, yet precise style, as I expected, knowing that his father— Dr. Samuel Gridley Howe, his mother— Julia Ward Howe, and all of his four brothers and sisters had lived in a New England literary atmosphere and had written books. This leads me to suggest that many authors of metallurgical papers and books could well study Howe's writings with a view to the improvement of their own. I failed to find a specific text, but did find a subject, for in reading his book I was struck by the few instances in which time is considered explicitly as a factor in the phenomena examined, and by the fact that many of the hottest arguments would have been settled had time been taken properly into account. Indeed, Howe hardly mentions time except in a rather incidental way, as in a few references to lag; for instance: The lowering of temperature at which the transformation occurs by rapid cooling . . . is a phenomenon of undercooling or lag. It is in part explained by the fact that the transformation itself is a time-consuming reaction which, setting in during a rapid fall of temperature, is naturally protracted till the temperature has sunk far below that at which it is due. He does discuss, quite fully, the iron-clrbon equilibrium diagram, as known at that time, introducing it by stating: As he is a reasonable man who is not deterred from using a hand truck for moving his trunk by the consideration that he has thus to move a trunk plus a truck, so am I reasonable in putting into your hands this useful, indeed indispensable. tool for mastering the ABC of iron metallurgy. Somewhat later, in introducing a discussion of the phase rule, which "it would be hardly proper to pass ... by without an attempt to outline its meaning," for "a clear exposition of its applicability or jurisdiction is needed to restrain the half-initiated from misusing it and the uninitiated from being misled by these misuses," he writes—and I quote his statement because we cannot properly discuss the influence of time on a process until we know the state of equilibrium which would ultimately be reached by the system under consideration: It is a most remarkable and valuable generalization, its conceptions help greatly toward getting a broad outlook on metallography, but its misconception has brought out a flood of obscuring writings. it tells us about the constitution towards which alloys tend, that which they reach when equilibrium is complete, when all tendencies have corrected themselves and have been complied with completely. Its application, in absence of true equilibrium, is like determining density with a telescope or even with a tuning fork; it is like the mad tea party at which the butter put into the works of the watch was the best butter. If the reader learns no more than to beware of attempts to dccipher the conditions of inequilibrium by a law which touches only the conditions of exact

Jan 1, 1942

By Thomas L. Mell

Continuous processing plants handling liquids have achieved a high degree of centralized automatic control. Many chemical plants are operated from one room, with automatic control of the various process flow rates. These plants know from experience that automatic control can produce higher through-put, better uniformity of product, decreased operating costs and reduction of storage capacity, Plants which process materials in the form of bulk solids have not been able to use control to as great an extent, primarily due to the lack of measuring equipment capable of providing the same types of continuous automatic control available with liquid flow meters. This paper will describe a scale for measuring flows of bulk materials on conveyor belts which is particularly adaptable to remote centralized instrumentation and automatic control, and will also describe some typical control applications. Fig. 1 illustrates the basic method of measurement of this scale. A conveyor belt idler is supported on a rigid carriage which in turn is mounted in two anti- friction bearings on the conveyor stringers. The pivoted carriage is prevented from rotating about the pivot shaft by an electric strain gauge load cell connected between the carriage and a cross support. Increasing load on the conveyor belt increases the moment of the carriage frame about the pivot shaft, and proportionally increases the tension in the load cell. The belt speed is measured by a conventional d. c. tachometer generator driven from a pulley, usually on the return belt. The speed signal from the tachometer generator and the load signal from the load cell are combined to produce a signal proportional to the flow rate of material in tons per hour, or lbs. per foot, or equivalent units, It will be important to remember, in considering various control applications, that the flow rate of material on the belt is composed of these two component signals, namely the weight of material and the speed at which it is moving. The feed rate is then indicated and recorded by a self-balancing potentiometer of the type used for measuring temperature by means of thermocouples. These instruments may also be equipped with integrating mechanisms reading the totalized tonnage over a period of time.

Jan 1, 1958

By Frank Hirthammer

Over the past few years, development and implementation of digital logistics solutions has convinced users of many additional advantages of this technology. Barcode labeling and reading increases the company’s efficiency and safety by reducing handwritten documentation and preventing misinformation. Sustainable information and productivity management is a significant advantage in competition. Since manufacturing information is tracked throughout the whole supply chain until the final consumer, all processes become transparent what ensures efficient risk tracking, correct disclosure to authorities (if required), and the compliance with company rules.

Jan 1, 2018

By Oliver W. Keener

The operation described herein differs from the usual practice in the Tri-State district in two important respects: (1) the ore is loaded into cars which are tramped to the shaft and hoisted on self-dumping cages, and (2) about 30 per cent of the ore is loaded by power shovels. The four-month period covered by the cost data appended at the end of the paper immediately followed a period of about one year during which the mine was shut down, and the expense incident to the resumption of operations is reflected in the costs. The author acknowledges the assistance of C. F. Jackson, mining engineer, U. S. Bureau of Mines, in the preparation of this paper and the compilation of the data.

Jan 1, 1929

Fault detection and identification are major challenges in process engineering and manufacturing and the key component of abnormal event management systems. Timely detection, diagnosis and rectification of abnormal or faulty process conditions can lead to savings of billions of dollars in equipment damage and lost productivity, not to mention the prevention of injury and loss of human life associated with industrial accidents. A major contributing factor to current losses in industry is the reliance on human operators to interpret high-frequency samples from hundreds or thousands of variables simultaneously. As a result, the automation of fault detection and diagnosis is seen as crucial to the successful implementation of abnormal event management, the need for which is becoming all the more urgent given the increased complexity associated with modem industrial plants. In this paper, a methodology for process monitoring that uses support vector methods to extract nonlinear features from data is discussed and applied in the diagnostic monitoring of an industrial liquid-liquid extraction column.

Jan 1, 2005

By Éric Poulin, Simon Gariépy, Mario Paredes Malca

"While the design of a control strategy depends on the available process knowledge, its implementation depends on the available process information. On-line chemical analyzers are today widely spread in the mineral processing industry. A real-time concentration measurement of chemical components is valuable information that could bring control strategies to whole new levels. However, the use of these measures rarely reaches anything more than process monitoring. The reason is simple: the on-line chemical measurements quality is most of the time insufficient to be directly included in control strategies. The choice is then made to let the critical eye of the engineer or the operator appreciates the measurements before making any decision based on it.Data reconciliation through mass balance is a technique today widely used in the mineral processing industry to increase the accuracy and the reliability of plant data, mainly for accounting and survey analysis purposes. Real-time data reconciliation of on-line measurements appears as a natural coupling of technologies that could bring new process optimization trends. Once overcome the technical difficulties, full valorization of the instrumentation investment could be reached.This paper presents the application of real-time data reconciliation for process control and performance monitoring. It proposes a general approach, discusses challenges and illustrates concepts with industry experiences."

Jan 1, 2006

An Integrated Geology-Mine-Plant and Eco-Efficiency Simulator for Anglo Platinum's Evaluation and Operational Improvement Initiatives

Sep 13, 2010

By R. G. Sandberg

The Bureau of Mines investigated a hydrometallurgical procedure to recover gold, silver, and byproduct lead from a complex lead-zinc sulfide ore. A ferric chloride (FeCI3) preleach, at 40° C in 6 h, extracted about 50 pct of the zinc and formed insoluble silver and lead chlorides. Subsequent acid thiourea leaching, for 1 to 3 h at 40° C, extracted about 85 pct of the gold and silver. Lead chloride was solubilized from the remaining residue with NaCI brine solution at 55° C in 1 h. Lead metal was recovered from the brine solution in an electrolytic cell with an anion perms elective membrane at a current efficiency of 95 pct and current density of 100 A/m2. Spent FeCl3 leach solution was reoxidized in the anode compartment at a current efficiency between 75 and 95 pct.

Jan 1, 1986

By Liam Bussey, Graham Speirs

Si bien la automatización de plantas de proceso es quizás la norma actual en la minería, la adopción de esta en la minería subterránea se ha retrasado. En este artículo se compartirán algunas ideas de cómo implementar los sistemas de automatización en la mina subterránea y se explicará cómo la tecnología puede mejorar la operación, de manera que las minas sean más seguras y sus operaciones más competitivas. Se discutirán diversos aspectos tales como los sistemas de comunicación, los sistemas de seguridad, los equipos de producción, los servicios mineros y la gestión de operaciones.

Sep 20, 2019

By Jamsa-Jouneia SL, Lahteenmaki S

Sophisticated control systems require sufficient and reliable information from the process to be controlled. At the Pyhasalmi concentrator two novel measurements, a particle size indicator (PSI) and a mill level monitor (MLM), have led to significant progress in the control of the grinding circuit. The PSI and the MLM measurements have brought additional information from the process. The PSI has been an absolute prerequisite for determining the overall grinding circuit efficiency and the design of the integrated grinding and flotation control system. The MLM measurement has enabled studies on the volumetric filling of a mill to be utilised for maximising the mill throughput. The paper describes the operation principles of the PSI and MLM devices and the additional process information received. The results of a metallurgical pre-control audit are discussed and finally the design of the integrated control system is outlined.

Jan 1, 1993

The simulation study on the process of iron ore beneficiation plant of Essar Steel, Kirandul was carried out. The iron ore fines and slimes generated nearby Bailadila mines of NMDC are used as raw materials for this beneficiation plant. The capacity of the plant is 1400 TPH operating in parallel in two streams. The capacity of the plant was utilized about 60% of throughput capacity. To improve the plant capacity as well as quality performance, the simulation study was conducted to detect the bottleneck of the process. The process samples were collected from input and output of each processing unit operation to generate the data base for simulation study at the feed rate of 400 and 500 TPH of iron ore fines in a single stream. The characteristics data i.e., breakage and selection functions were generated using MILLSOFT package for simulation of ball mills. Then MODSIM package was used to evaluate the performance of each unit operation to identify the bottleneck. It was established by a simulation study that the intermediate thickener draws high current when the feed rate is more than 400 TPH due to high torque drawn by rotating rake because of presence of coarse particles in the input stream to thickener. The problem was sorted out by classification of input stream of thickener to remove the coarse particles. Then the process was simulated at its rated capacity, and experimental validation studies at the plant were also conducted at the feed capacity of 600 and 700 TPH by modification of process flowsheet. The experimental data was almost matching with simulated data. Finally, the processing plant is running with full rated capacity without any bottleneck. Keywords: simulation of ball mill, breakage function, selection function, iron ore

Sep 1, 2012

By C. Gravel, A. Fathi, P. Rivard, G. Ballivy, Z. Moradian, M. Quirion

Numerous schemes have been proposed in the past to evaluate the shear strength of rock discontinuities based on in situ and laboratory testing. Due to scale effects, in situ testing is the most reliable way to assess the shear strength parameters. However, practical reasons often impede this kind of testing. This is unfortunate because advances in theoretical rock mechanics are still dependant on qualitative experimental works. This paper presents a mobile high capacity shear apparatus developed for in situ direct shear testing of discontinuities along with testing methodology. The apparatus has the advantage of being simple, although of high capacity, and can be moved to different site locations for other tests. The in situ test was performed on a natural rock outcrop of schist with subvertical schistosity. A concrete block 50 x 50 cm with a base layer of high strength mortar was cast on the rock surface. Prior to the test, the concrete block was lifted and repositioned to have an unbonded joint but with interlocking asperities. The shear load was applied perpendicularly to the schistosity direction. The test was conducted in a constant normal load (CNL) condition. Both normal and shear loads were applied manually. The instrumentation consisted of two load cells for shear and normal loading, eight displacement laser extensometers for shear, normal, and lateral displacements and fourteen acoustic emission sensors for monitoring evolution of asperities’ degradation during the test. The friction angle obtained is 72° for the peak and 58° for the residual. The high values of friction angle indicates that first-order roughness and good interlocking of the joint surfaces can result in high shear strength parameter values in a rock generally regarded to have low values.

Jan 1, 2015

By Mingchun Lu, Zhijia Liu, Xueqi Zhang, Jianliang Zhang

"In order to solve the problem of shortage of scrap, especially high quality scrap, a new substitute for scrap or DRI has been developed. The decarbonization mechanism of granular pig iron has been analyzed and the technical process and decarbonized granular pig iron have been evaluated in this paper. The research result shows that this new process is superior to direct reduction process in product quality, construction investment, operation flexibility, production efficiency etc. Decarbonized granular pig iron (DGPI) not only can be used as conventional scrap but also can be charged into EAF as high purity .burden equivalent to heavy scrap:IntroductionIn the past years, with the universal application of continuos casting technique in China, the amount of scrap generated inside steelworks has been reducing continually. On the other hand, the EAF steel proportion is increasing and this gives to the obvious change in structure of steel product. At present, the requirement on both scrap quantity and scrap quality is being paid more and more attention. Because China is a country which is devoid of scrap and poor in resource (nature gas and high grade iron ore) for developing direct reduction iron (DRI) so that sponge iron can not be produced cosmically in China and has to be mainly imported. Instead of part of scrap, some cold pig iron in cold state has been charged into EAF in China. However the high carbon content in pig iron has limited its proportion in EAF metal burden. Because the price of pig iron is lower than that of imported DRI in China, the technique of granular pig iron decarboniztion is hopeful to become effective way to produce substitute for scrap or DRI."

Jan 1, 2000

By S. Panigrahi

The SO2-ammoniacal ammonium sulfate leach liquor generated by leaching of manganese nodules, after removal of minor quantities of iron and manganese, contained copper, nickel, cobalt, zinc and (NH4)2SO4. After extraction of copper from the leach liquor with LIX 84I, stripping of ammonia from the Cu-barren raffinate was carried out followed by precipitation of metal ions from the ammonia-stripped solution as sulfides. Leaching of the sulfide precipitate was carried out with H2SO4 to obtain a leach liquor containing 0.58 kg/m3 Cu, 2.67 kg/m3 Zn, 2.00 kg/m3 Co, 24.68 kg/m3 Ni and 10.0 kg/m3 (NH4)2SO4. After extraction of copper and zinc from the sulfate leach liquor with LIX 84I and D2EHPA, respectively, the solution was left with Co and Ni. Extraction of cobalt from the Cu- and Zn-free solution was carried out with 0.1 M PC88A and stripping of the cobalt-loaded organic was carried out with the cobalt-spent electrolyte (pH 1.4). Extraction of nickel from the cobalt-free solution was carried out with 90% neutral 1M NaPC88A followed by stripping of the nickel-loaded organic with 120 kg/m3 H2SO4 solution. Extraction of metal ions increased with increasing equilibrium pH and extractant concentration. The maximum separation factors, with respect to the pH and extractant concentration variation studies, were 3796.7 and 15350.0, respectively. The extracted species for the metal ions were CoA2?3HA and NiA2?5HA.

Jan 1, 2009

By O. V. Suvorova, V. G. Minenko, D. V. Makarov, A. L. Samusev, E. A. Selivanova

"Saponite is a valuable marketable product widely used foundry, metallurgy and construction, in the chemical, food and consumer goods industries, in medicine, and in agriculture.The feasibility of producing of high-quality construction materials with enhanced physical-chemical and decorative characteristics from saponite-containing products has been given a scientific basis and experimentally validated. The compressive strength of the samples in the sintering temperature range of 800-1000 ?? varied between 35 and 80.9 MPa; the bending strength 8 and 26.7 MPa, which is superior to the high-grade ceramic bricks of the M-300 brand. It has been established that the saponite-containing product obtained using the electrochemical separation of process water has a high sorption capacitance relatively the heavy-metal ions such as nickel and copper (40.7 and 99.8 mg/g, respectively). As a result of sintering at 750 ?? the sorption capacity of the sorbent for the nickel and copper ions increased to 194.2 and 212.8. Using the XRD and SEM with energy-dispersive spectroscopy studies, we diagnosed the metal-containing phases and validated the metal sorption mechanism.This study opens up the possibility of practical realization of the saponite-containing product as high-quality building materials and heavy-metal sorbents while addressing the issue of process water treatment. INTRODUCTION The Lomonosov deposit of the Archangelsk diamondiferous province accommodates 10 kimberlite pipes. The anticipated volume of diamond-bearing ore and dump rock to be removed before reaching the open-pit mining limit is 300 mln t (Karpenko, 2009; Bezborodov, etal. 2003). Rock in the deposit is almost completely displaced by clay minerals, predominantly saponite, amounting to 90% in the vent facies (Karpenko, 2009)."

Jan 1, 2018

By Joseph Chalmers, J. S. Desmond, R. Van A. Mills

[Because of the limited space in this volume and the fact that a description covering the oil recovery buildings and equipment (see page 4, Technical Publication No. 144) will be given in a forthcomnig U. S. Bureau of Mines publication, and because the paper was published in detail as Technical Publication No. 144, and is available as a separate at the Institute, it is impossible to include here more than the following brief extract.] Problems Being Studied The selection of the first problems to be studied was based largely upon the following very practical questions asked by several of the largest operators in the Mid-Continent field. 1. What are the causes for the formation of excessive amounts of bad thick oil on properties that are being repressured with compressed air and how can this trouble be prevented? 2. Why, in some areas, does the oxygen in the air injected into an oil sand during repressuring operations apparently change to carbon dioxide? Is carbon dioxide formed by the oxidation of some of the oil in the sand'? How can the formation of inert or low B.t.u. casinghead gas, loaded with nitrogen, carbon dioxide and oxygen, be prevented? 3. What percentage of the oil originally present in an oil sand can be recovered by the ordinary methods of operation when the gas originally dissolved in the oil is the main propulsive agent? 4. What percentage of the amount of oil produced by ordinary methods can be recovered under average conditions by repressuring a so-called depleted oil sand? 5. What are the relative propulsive efficiencies of compressed air and natural gas in repressuring operations? 6. What are the practical advantages of pressure maintenance and early repressuring as compared with late repressuring?

Jan 1, 1929