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By Norihiko Fukatsu, Takashi Iwamoto, Noriaki Kurita, Koji Katahira, Kunihiro Koide, Teruo Ohashi

"The galvanic cell-type hydrogen sensor employing CaZro.9Ino.t03-a. as the solid electrolyte was designed for the measurement of hydrogen activities in molten copper under industrial .conditions. The sensor probe consists of the cap-shaped solid electrolyte with porous platinum electrode on the inside and alumina refractory tube. The gas mixture of the composition 4%H2-0.5%02-Ar was made to flow on the inside electrode. The hydrogen sensor probe was inserted directly into molten copper and the melt was used as the outer electrode. The effect of oxygen activity gradient to EMF was eliminated theoretically by measuring the oxygen activity in the melt simultaneously with an oxygen sensor. The high stability of output and excellent response to the change of hydrogen activity were obtained over the wide range of industrial copper melting conditions.IntroductionIn the metal casting process, hydrogen easily dissolves in molten metals from water vapor in the surrounding atmosphere. Owing to the large difference in hydrogen solubility between liquid and solid metal, dissolved hydrogen becomes a cause of the defects of blowholes in castings or ingots. It is necessary to control the hydrogen content in the molten metals [l]. Using proton-conducting ceramics as a solid electrolyte, high temperature-type hydrogen sensor can be constructed [2]. SrCe03- and BaCe03-based perovskite-type oxides exhibit appreciable proton conduction under hydrogen containing atmosphere at high temperature [3-5]. A hydrogen sensor for molten aluminum using CaZro.91no.103-a. has been developed and widely used in the ·process control in the aluminum melting industry [6,7]. The same type of hydrogen sensor has also been expected in the copper melting industry. .. However, CaZro.91no.103-a shows ·not only proton but also oxide ion conduction in the high temperature and at low oxygen activies like the copper melting· conditions. Then we studied the oxide ion conduction in CaZro.91no.103-a. iit · detail [8]. From the consideration on the EMF of the galvanic cell employing this material as electrolyte, it was shown that the unknown hydrogen activity may be precisely determined from cell potential which is corrected for the effect of oxygen potential gradient And the hydrogen sensor based in this principle was constructed and tested in laboratory-scale [9,10]. We repeated the similar tests in factory-scale and developed the sensor system for practical uses [11, 12]. In this report, the structure and system of the hydrogen sensor for molten copper will be introduced first. The reliability of the sensor will then be demonstrated from the results of experiments for sensor probes carried out in TYK's laboratory."

Jan 1, 2000

By H. R. Babitzke

To develop alloys suitable for use at elevated temperatures, columbium and tantalum were combined with tungsten, hafnium, vanadium, zirconium, and titanium, and the resulting alloys were evaluated with respect to fabricability, hardness, Electrical resistivity, strength at elevated temperatures, oxidation resistance, and bend transition. Of the 23 compositions tested, Cb-2OHf-5W-10Ti exhibited superior high-temperature properties. A recrystallized sample of this alloy was fabricable at room temperature, had a strength of 44,000 psi at 1,200° C, and had an oxidation rate of only 7.7 mg/cm2/hr at 1,000° C.

Jan 1, 1966

By F. R. Jones, B. W. Taylor, A. R. MacPherson, L. J. Lamb

"The Lake St. Joseph Iron Deposit is in Northwestern Ontario. Exploration to date by Steep Rock Iron Mines Limited has indicated an ore reserve of 683 million long tons. Metallurgical investigations have proved that suitable oxide pellets and/or superconcentrates can be economically produced from this ore. Studies of the Lake St. Joseph iron ore deposits have covered the period 1956-71, and have embodied applications of the improvement in mining and processing technology over this period. Market demand in the early 1960's for high-grade oxide pellets as a replacement for natural iron ores for the blast furnace first drew attention to the potential of the Lake St. Joseph deposit. The current market trend toward utilization of sponge iron to replace steel scrap as feed to electric furnaces and cupolas now suggests that the deposit can better be exploited as a prime source of superconcentrates."

Jan 1, 1972

By Árpád B. Palotás, Adel F. Sarofim, John B. Vander Sande, Lenore Rainey Christian, J. Feldermann

"Interest in the fine structure of soots and carbon blacks is motivated by a variety of possible applications. The structure provides information on the origins of the particles and on their adsorptive and reactive properties. This paper describes a method for quantification of the structure of soots and carbon blacks based on direct electron microscopic observation followed by image analysis of these materials. High-resolution transmission electron microscopy (HRTEM) provides a very detailed observation of particle structure. The differences in soot structure, because of its complexity, may not be easily quantifiable with the human eye; therefore, high-level computer software has been used to manipulate HRTEM images. This technique involves the application of fast Fourier transforms (FFT) to single particles and the measurement of characteristic parameters such as interplanar spacings and crystallite sizes from these particles. The methodology and application of this characterization technique are presented here. Results are shown for dif¬ferent samples obtained from soot and carbon black particles selected to illustrate the capabilities of the methodology. Quantitative information can be obtained on structural characteristics, e.g., interplanar spacing, circularity, orientation, elongation, and length distribution of lattice fringes, as well as on the fractional coverage of the extracted pattern. c 1996 Wiley-Liss, Inc.This paper presents a combination of techniques for recognizing and classifying different carbonaceous materials, using their structural morphology. A new method to assess and quantify the parameters which define such structures is proposed and discussed. The technique is based on the use of HRTEM (high-resolution transmission electron microscopy) and computational image analysis.It is well-known that carbonaceous materials like graphite, soots, coals, cokes, chars, etc. possess characteristic structural appearances which can vary from mostly random or amorphous to a perfectly ordered graphitic crystalline structure (Buseck and Bo-Jun, 1985; Buseck et al., 1987). The carbon structure has been variously described as turbostratic (Oberlin, 1989) or as crumpled sheets (Rouzaud et al., 1991) to indicate that parallel layering, reminiscent of graphite, is observed over dimensions of nanometers, but that these planes or crystallites show disorder over larger scales. The degree of order of such structures is strongly dependent on the thermal treatment of the material as well as on the composition of the source of the carbonaceous material. The value of the electron microscope in studying the morphology of such materials has been well-established, and abundant information is available (Ishiguro et al., 1991; Lahaye and Prado, 1978; Buseck, 1992).The use of HRTEM has brought further insight into this matter. Qualitative assessment of the structural order of such materials has been attempted over a long period of time in order to differentiate between various sources or treatments. There is, to date, no successful method available for quantifying the structural characteristics of various carbonaceous materials. This paper presents a technique which is able to recognize dif-ferent materials and to quantify the structural parameters of those materials using HRTEM and computational image analysis, including pattern recognition techniques.In the case of perfectly ordered graphitic crystals, electron diffraction is widely used for obtaining details on structure. Analysis of diffraction patterns can reveal parameters such as interplanar spacing, d002, crystallite size along the c-axis, Lc, crystal size in the plane of the layers, L., mean number of crystallites, Nc, etc.Complicated electron microscopy methods such as defocusing, tilted illumination, axial illumination, etc., often have to be used in order to characterize complex materials such as randomly oriented crystals in soots and carbons. Obtaining the right fo"

Jan 1, 1998

By M. W. Grabinsky, P. B. Tomory, J. Carvalho, J. H. Curran

Many underground mining operations use Split Set friction stabilizer bolts for rock support. Currently, however, little has been done to quantify the effects of various rock mechanics and operational parameters on the capacity of frictional support systems. The strength of Split Sets is usually measured by means of a pull test wherein a jacking force is applied to the bolt and a slip load is obtained. In order to evolve a rational design procedure for this type of support, an extensive database of over 900 pull test results from more than 50 mines through- out North America has been assembled and analyzed. Associated relevant rock mechanics parameters (rock type and quality) and operational details (drilling method, bit size, drive time, time to pull test) were also obtained, as completely as possible, for each test. Analysis of the information has yielded several charts that relate pull-out strength to relevant parameters and simple statistical analyses were conducted where necessary. Quantified distributions for pull-out strength were also produced for several operating conditions. The factors that most significantly affect bolt strength have been identified and specific applications to design are discussed. The information presented will assist mining engineers in designing safer and more economic support using Split Sets.

Jan 1, 1998

By Henry P. Wheeler

H ELIUM (chemical symbol: He) is a member of a family of normally gaseous elements, which, because of their zero valence and corresponding lack of chemical activity, are called the "noble" or "inert" gases. It is a monatomic element with an atomic number of 2, and it exists naturally in two stable isotopic forms-He3, with an atomic mass of 3.0170, and He4, with an atomic mass of 4.0039. With the exception of a trace (10-6 percent) of He3, all of the naturally occurring helium is He4. Two unstable isotopes-He5, with atomic mass 5.0137, and He6, with atomic mass 6.0208-are listed by various scientists, but the existence of He5 is questioned by some of them. He6 is radioactive, with a half-life of 0.8 second. Helium was discovered in 1868 in the gaseous atmosphere surrounding the sun. Although several scientists studied the solar chromosphere that year, it is generally agreed that J. Norman Lockyer of England should be credited with the discovery of helium, which he named, deriving the word from "helios," the Greek name for the sun. It was not found on earth until March 1895, when William Ramsay of London produced a small amount from a sample of cleveite, a uranium-bearing mineral. In 1905, H. P. Cady and D. F. McFarland of Kansas found helium in natural gas produced from a well near Dexter, Kans., and for the first time a large source of helium became available.

Jan 1, 1952

By E. E. Mueser

As Mr. Lundberg has already ably covered the theory of various methods of electrical prospecting, I shall confine my remarks to a consideration of the features which must obtain in an electrical prospecting method in order that it may be useful from a practical standpoint. These remarks I shall make with particular reference to the Elbof method. The successful application of all these methods rests, in the first place, upon the possibility of correlating theory, or empirically established facts, with the field data. Their practical usefulness, however, requires that the technique of making the field observations, and the procedure itself, be such that the method may be applied to large areas, under normal average conditions. The method, therefore, should not involve excessive preliminary labour costs to prepare the ground for actual prospecting work, nor should the prospecting work itself be so slow that its cost, when applied to extensive areas, becomes prohibitive. Moreover, it should be possible to apply the method even under difficult terrain conditions, such as rough topography and dense vegetation. It may be said of most of the methods referred to in the preceding paper, that, while they are interesting and theoretically sound, they fail to meet such practical requirements as I have outlined.

Jan 1, 1926

By J. C. Watts

Monitoring and control of conventional industrial wet grinding circuits is conceptually straightforward. However, since production objectives and operating constraints can vary widely from plant to plant, there is probably no single overall grinding circuit control strategy which is "best" in all cases; in-variably some compromise is necessary between performance desired under ideal conditions and performance achievable in practice. The recent advent of relatively low cost, reliable, high speed small computer systems is revolutionizing daily operations in increasing numbers of metallurgical processing plants. Of special power and capability is a hierarchical computer network like that currently in use at the Pinto Valley Operations of the Cities Service Company. Several satellite processors for key plant areas communicate with a master computer operating under a powerful multitasking real-time operating system. Hardware and software structure is such that downtime on one of the processors -including the master -does not have a major impact on overall system operation. Admittedly, the powerful, core efficient table driven satellite software, which handles process/computer communication, calculation of nonmeasured process variables, and basic Direct Digital Control functions, is difficult to modify. However, important high level process monitoring, report preparation, graphic display, and supervisory control functions -including economic optimization -can be implemented by project engineers at the plant site. Thus, for example, new control strategies can be quickly examined and rapidly evaluated. Such computer monitoring capability also permits use of short duration process pulse tests for approximate dynamic modeling and rapid calculation of controller tuning constants for single loop dominant systems. Following a brief back-ground discussion of the Pinto Valley Project, we present some of the more interesting results and conclusions of our work over the past year.

Jan 1, 1978

By P. D. Laverty

This report describes a processing method developed by the U.S. Bureau of Mines to produce high-quality flake graphite from the steelmaking waste known as kish. The kish produced by current steelmaking practices is a mixture of graphite, desulfurization slag, and iron that is skimmed from the molten iron feed to the basic oxygen furnace. It is estimated that the graphite content of kish discarded by U.S. steel plants is more than sufficient to meet the total U.S. demand for flake graphite. That need is now filled by natural graphite from foreign sources. Kish was treated by a combination of screening and hydraulic classification to produce a concentrate containing greater than 70 pct graphite. Leaching of the concentrate with hydrochloric acid solution gave a graphite product with 95-pct purity. An optional secondary leaching operation with hydrofluoric acid produced graphite with a purity of 98 pet or greater. The flake size of graphite from kish ranged from 10 mesh down. Evaluation of test samples by industrial graphite users indicated that kish graphite is a suitable substitute for the natural material for most uses. A process flowsheet and material balance for pilot plant design are presented.

Jan 1, 2010

By M. E. Coleman, G. Money

"Clyde Materials Handling is an established customer-driven solutions provider, which utilizes its knowledge, expertise and technologies to transform the production processes of its customers, who operate in the ferrous and non-ferrous metals industries.With over 30 years experience in the process improvement industry, Clyde Materials Handling has helped their global customer base transform the way in which they operate their processes, which has enabled them to generate sustainable economic benefit and maintain their positions as leaders in their respective markets.Clyde Materials Handling has supported operators within the metals market by developing and deploying pneumatic conveying and pneumatic injection technologies. These environmentally supportive and sustainable solutions have been used to transport raw materials within operating facilities, from storage to silo, as well as injecting these materials directly into the heart of production processes.Clyde Materials Handling has worked closely with their customers, such as Codelco in Chile, where their pneumatic solutions have been used to inject a consistent, pulseless and accurate flow of copper concentrate into a bath smelter, which has helped to fuel the operational capacity, availability and productivity.This paper will discuss and highlight the ways in which pneumatic injection technologies, created by Clyde Materials Handling, and applied in partnership with their customers, have helped to improve the operational performance of the production processes of operators across the non-ferrous metals markets with specific reference to applications in the Peirce Smith Converter.Clyde Materials Handling has applications injecting Electronic Scraps, Dusts, Reverts, and other additives to the Peirce Smith Converter. They also have experience of modified PS Units used for Slag Cleaning. There experience with the Codelco Teniente Converter is also directly related to this area of operation."

Jan 1, 2009

By Alessandra Spaghetti

Rolling small-diameter hot wire rods at high speeds with conventional laying head pipes can wear the pipe out frequently and affect quality and consistency in the final product. Laying head upgrades using Sandvik SAF2507LHP™ (UNS S32750) tubes make possible to achieve optimal metallurgical properties, smooth coil formation and easier coil handling. Operators can also avoid unwelcome shutdowns due to frequent worn pipe changes and turndowns. Sandvik have been developing different customers and understand their process needs. The suitable selection materials that are able to withstand high levels of wear better than low alloy and carbon steel grades that are commonly used in industry is very important to improve the quality and increase productivity. UNS S32750 tubes were demonstrably superior to low alloy and carbon steels when used in Laying Head Pipe system regarding tubes lifetime, reducing replacement, production interruptions and increasing reliability.

Aug 17, 2017

By W. P. Yant

[This report describes results of a study bf the carbon monoxide and particulate matter in the air of the Holland Tunnel and metropolitan New York made by the Bureau of Mines (which had participated in the development]

Jan 1, 1941

By E. Allen

Quebec Cartier Mining Company operates approximately two hundred and fifty pieces of equipment in a climate with a temperature that has averaged 27.5°F during the last seven years. The use of special-purpose lubricants, fuels, antifreeze, rubber compounds, and alloy steels have reduced the cold-weather hazards. In some areas, high-cost cold-weather protective heating devices are being eliminated with experience.

Jan 1, 1966

By Harold S. King

TWO summers ago I had the privilege of visiting No. 18 colliery at Glace Bay. Underground, we travelled along the haulage-way behind a powerful electric locomotive. The motor in this locomotive began to smoke badly and a carbon tetrachloride type of extinguisher was used several times during the trip. At the time, I noted a strong odour of phosgene. On my return to Sydney, I spoke to Mr. Harold Gordon, Assistant to the General Manager of the Dominion Steel and Coal Corporation, and warned him of the danger of using this type of fire extinguisher in confined spaces, since it is a well known chemical fact that phosgene, a dangerously toxic gas, is formed by the decomposition of carbon tetrachloride. This danger does not seem to be widely recognized, so it seems advisable that a more general warning be published. Attention was first drawn to the danger by the death of two men in the United States Navy Department subsequent to breathing fumes from carbon tetrachloride used in a fire, and when an employee of the Bureau of Mines also was overcome while fighting a fire with carbon tetrachloride liquid. These accidents led to an investigation of the decomposition products of carbon tetrachloride by a group of workers in the Research Laboratory of the Pittsburgh Experimental Station, U.S. Bureau of Mines, the results of which were published in the October, 1920, number of the Journal of the .Franklin Institute (1). Their experiments were conducted by two methods. The first consisted in applying the liquids to actual fires and -to hot metal in a closed room of 1,000 feet capacity, where the gaseous products, mixed with air, could be retained and analyzed. The second method was to pass the vapour:s in air through heated tubes of iron or quartz, where the humidity of the air and the temperature could be controlled.

Jan 1, 1939

By Pengfu Tan

In order to understand and control the formation of dioxins and furans in iron ore sinter plants and to possibly avoid expensive end-of-pipe removal stages, thermodynamic calculations on the stability of PCDD/Fs have been combined with sinter process modeling by means of kinetic simulations and computational fluid dynamics. Three thermodynamic databases of PCDD/Fs, derived using the Group Additivity approach and two computational molecular modeling methods, MNDO and PM3, respectively, combined with the SGTE database have been used to model the PCDDIF formation and the PCDD/F isomer distributions in iron ore sintering. The results show very similar conditions for the PCDD/F formation using the different databases. Concerning the isomer distributions of toxic PCDD/Fs, the calculated data derived from the MNDO method showed optimum agreement with measured values from industrial furnaces. The thermodynamic calculations also proved that the isomer distributions found in combustion processes are equilibrium values, while the concentration ratio of PCDDs and PCDFs in the wind boxes does not represent an equilibrium state. A CFD model of iron ore sintering was developed including the kinetics of 15 relevant chemical reactions with the aim of describing the temperature fields and the gas flow patterns in the sintering bed. On the basis of these information and experimental observations reported in the literature possible pathways for the PCDD/F formation in sinter plants have been identified: PCDD/Fs are formed in the critical temperature region of 250 to 450°C below the combustion zone, are then carried downwards with the gas and condensed close to the bottom of the sinter bed. Transported to the discharge end with the solid mixture, they are again released into the gas phase when the flame front approaches the bottom. PCDD/Fs are also formed in the last wind boxes when the hot off-gases cool down and reach the critical temperature range. Consequently, methods to reduce the dioxin formation reactions are proposed including inhibitor addition to the sinter feed and off-gas quenching.

Jan 1, 2003

By John Nagy, Hylton R. Brown, Irving Hartman

"INTRODUCTION The tests described in this publication were planned to provide information on the explosibility of metal-powder dust clouds. This subject has become increasingly important because of the large quantity and variety of metallic powders now used for military and industrial purposes. To provide the increased amounts of metallic powders needed in the manufacture of munitions and to supply the demand created by the rapid growth of powder metallurgy, existing metal-powder plants have been enlarged, production schedules accelerated, and new plants erected. In some cases new methods of producing metal powders have been developed. This increased production and the development of new manufacturing methods have caused an increase in the number of metal-powder fires and explosions, with accompanying heavy loss of life and property. These have emphasized the need for information on methods of providing protection against hazards inherent in the production and handling of powdered metals. This paper gives results of laboratory inflammability and explosibility tests made to April 1, 1943, and is a progress report. Many descriptive details have been omitted purposely; they will supplied in a later publication, expected to be a Bureau of Mines bulletin."

Oct 1, 1943

By M. Ghamgosar, Erarslan N.

Rock cutting includes many unknown parameters which result in different consequences of the different cutting conditions. However, based on the current suggested models for rock cutting, there are some critical parameters that control the fracture initiation and propagation in the rock domain. In general, there are two major cutting tools are used in rock cutting: drag bits and indenters. Different mechanical attacks of cutters result in different fracture models. For example drag bits break the rock parallel to the rock surface, which is called ‘undercutting’ while indenters cut rocks by pressing normal to the rock surface. Both tools cause rock failure by inducing tensile cracks in the rock. However, drag bits induce more tensile cracks compared with the indenters. The full benefits of improvement in rock cutting efficiency will arise from a clear understanding of rock fracture mechanics principles. Therefore, fracture mechanics principles will be applied to the rock cutting as the rock fragmentation process is based on the rock fracturing. The Oscillating Disc Cutting (ODC) has more advantages than drag bits and disc cutters. The forces transmitted back through the cutting head are much lower with ODC. Although ODC attacks rock in much the same way as drag bits, a combination of the oscillating action of the cutter and the undercutting mode produces the lower cutting forces and causes rock fatigue. Fatigue phenomenon in rock has advantages for the rock breaking by applying less effort and energy due to the cyclic loading. The aim of this study is using the Extended Finite Elements Analyses (XEFM) numerical modelling for simulating the ODC cutting with different cyclic loading conditions. An accurate prediction of numerical investigation requires detail laboratory experiments. A series of laboratory tests were performed to obtain the fracture toughness values of our Monsonite rock samples under various cyclic amplitude and frequency values. The numerical results showed different types fatigue damage mechanisms due to the various cyclic loading conditions. Thus, modelling and understanding the crack propagation behaviour depending on different amplitude and frequencies are believed very important for the dynamic rock cutting researches and rock cutting machine manufacturers.

Jan 1, 2015

By J. E. Tiffany

A stick of explosive is a package of stored energy that can be released when needed to blast rocks, coal, and other materials; but, unlike fuels such as coal and gasoline, its potential energy is self-contained, there being enough oxygen within the package to complete the almost instantaneous reaction. When an explosive is ignited or detonated, the solid or liquid materials of which it is composed are converted rapidly into highly heated gases, which, if free to expand, would have a volume many times larger than that of the original explosive. At the instant of explosion these gases occupy only the volume of the shot hole and are therefore produced at a very high pressure, which causes the material that is being blasted to be broken or disrupted. In blasting coal efficiently the proper placement of the shot hole and the confinement of the explosive therein are both of prime importance. When these are not adjusted properly, only a small amount of the energy is expended in bringing down coal, consequently the balance of the energy tends to be expended by the emission of a flame into the working place that may lead to a gas or dust explosion. Permissible Explosives Defined The term "permissible explosive", as applied by the Bureau of Mines to explosives it has approved for use in blasting in coal mines, embraces not only the requirement that the explosive, when used, shall be similar in all respects to the basic sample that passed all the tests necessary for its admission to the published permissible list, but also that the explosive shall be used under certain prescribed requirements.

Jan 1, 1938

By A. A. Berk

In the course of a study of the formation of external deposits on tubes in water-tube boilers it became desirable to determine the sulfur dioxide (SO2) and sulfur trioxide (SO3) in the Due gases. Determinations made by the A.S.M.E. method for SO2 and SO3 in gaseous products of combustion did not give accurate results. It was found that minute quantities of copper, present in the flue gases from the coal in use, caused oxidation of sulfite in the absorption bottle and that the carbon dioxide (CO2) in the flue gases caused high values for SO2. The A.S.M.E. test procedure was revised to prevent oxidation of sulfite in the absorption bottle and to allow for the effect of CO2; subsequent analyses of flue gases produced reliable results. The revised procedure is described.

Jan 1, 1950

By D. B. Dow

"In the natural-gas Gasoline industry, the methods used in determining the amount of gasoline in natural gas are many and varied; they include the specific-gravity test, laboratory tests involving absorption, charge in volume of the gas or in the absorption medium, absorption in charcoal with subsequent distillation, compression of the gas which results in the condensation of the gasoline, and the absorption of the gasoline vapors in an absorption oil, from which the gasoline is distilled and measured. Each of these various tests has advantages, and disadvantages. It is however, conceded in the industry that the tests in which the gasoline is obtained and measured as such are the more reliable.This paper deals with certain factors which should be considered in making absorption tests using ""mineral seal oil"" as an absorbent; this method of testing is widely used not only in the field, but in control work in absorption gasoline plants where the gasoline content of the intake and discharge gas is determined daily. In control work it is frequently found that the plant produces more gasoline than the tests show, which gives the plant the appearance of making more gasoline than is actually present in the gas treated, or in other words operating at more than one hundred per cent efficiency. Obviously then, the tests as made in these cases are in error, and in hope of correcting some of these variances, the following factors have been studied at the U. S. Bureau of Mines petroleum station at Bartlesville, Oklahoma."

Aug 1, 1920