Search Documents

By Liguang Zhu, Yihua Han, Qingjun Zhang, Xiaoyan Wu, Pengcheng Xiao

The evolution of chemical composition, size, proportion, and morphology of the Al-Ti-Mg-O inclusions during the steelmaking process of Interstitial Free (IF) steel from the RH to the Continuous Casting (CC) slab were investigated by means of Auto-SEM. Results showed that many of Al2O3 and MgO-Al2O3 type inclusions are modified by TiOx, while most of their shapes are irregular due to the high melting temperature. The composition evolutions and melting characteristics of Al-Ti-Mg-O inclusions under different contents of [Al], [Ti] and [Mg] were estimated by using thermodynamic software Factsage 7.0. Results showed that estimated results are in good agreement with the analysis results of industrial samples. Both the Ti alloying and spontaneous enrichment would make a high Ti concentration environment that was in favor of the TiOx existence. Moreover, more TiOx component can modify MgO-Al2O3 spine inclusion into inclusions with a lower melting temperature.

Mar 1, 2018

By David Hoadley, Kenneth R. Maser, Ashok B. Boghani, James E. Billar, D. Randolph Berry, Mackenzie Burnett, Robert H. Trent

APPENDIX E REFUGE CHAMBER LEAKAGE ANALYSIS Variables p 0 = pressure outside of chamber (psi) p = pressure inside of chamber (psi) i q = leakage flow rate (cfm) Q= total leakage (cu ft. ) V = chamber volume (cu. ft. ) t= time (minutes) p= nominal atmospheric reference pressure (14.7 psi) A= chamber leakage coefficient (cfm/psi)

Jan 1, 1976

By Animesh Jha

"Fine ceramic powders (<500 nm) exhibit exceptional physical and mechanical properties in engineered structural ceramics. The production of fine powders, in particular the non-oxide ceramics, via a cheaper route than the organic solvent route has been rather elusive. This paper examines the physical chemistry of sub-oxide vapour-phase reduction reaction for the nucleation of non-oxide ceramic phase. Well known vapour species eg SiO and BO in the production of technical ceramic powders (SiC, BN) are particularly discussed for understanding the nucleation process of SiC and BN ceramic phases respectively. The regimes of partial pressures and temperatures are particularly 'identified. The calculated nucleation rate as a function of the temperature is compared with the experimental results on powder morphology. The production of amorphous and nanocrystalline h-BN powders is discussed in the context of substrate structure and thermodynamic parameters.IntroductionThe physical and mechanical properties of ceramic components are strongly dependent on the powder particle size and morphology used for their fabrication. For example the strength (Os) of the structural ceramic components increases with decreasing average grain-size (d) in accordance with the Hall-Petch relationship: Os = 0""0 + k/(d)1/2. Here k is an empirical constant which can be established from the graphical relationship. However as the particle size approaches submicrometer-size range, the dependence of strength on the particle size becomes more complex [1]. The design of ceramic components based on nanometer-size particles have recently become an important field which can offer ceramic materials with properties comparable to their metal counterparts. Several materials based on these concepts have been developed and reported by Niihara [2]. For example, the Al2O 3-SiC nanocomposite, having average B-SiC grain size 0.3-2um with intragranular SiC particulates of 5-10 nm has unusually high strengths (1100 MN/m2) at low and elevated temperatures combined with enhanced fracture toughness (> 4 MN-ml.5) which is an unusual combination in structural ceramics. Besides mechanical properties, as the particle size of ceramic powders approaches the nanometer-size range, the charge transport properties also improve by many times. The effect of particle size on the electrical conductivity of Si3N4-TiN composites has been well documented [3.4]. The size of ceramic particulates without doubt plays a pivotal role in determining the properties of ceramic components."

Jan 1, 1996

In the Broken Hill South mine tile practice of issuing to the miner a quantity of fuse and a box of caps from which he made up the &quot;rods&quot; required for a particular blast, has been abandoned. Instead, capping stations have been established, and the miner can now obtain, from the magazines, fuses cut to accurate lengths with the detonators attached.Various types of fuse-cutting machines and crimping devices are available, but only those used by the Broken Hill South Mine Ltd. are described in this paper.The fuse-cutting machine, designed by the engineering staff, is an electrically driven unit fitted with a gear box for the purpose of adjusting the rate at which the fuse is fed to the cutting device, thereby enabling fuses of various lengths to be accurately severed from the main coil of fuse.The machine in question is designed to cut 4, 6, and 8-ft. fuses, but no difficulty should be experienced in designing a machine to cut fuses to any required lengths.

Jan 1, 1932

By Daoxin Wu

Originated from(C4H9O)4Ti, nano--rutile TiO2 was synthesized by low temperature hydrolysis process in this paper. After being prepared by decomposing ammonium tungstate and covering on the surface of TiO2, TiO2/WO3 were characterized by means of X-ray diffraction(XRD), UV--vis difuse reflectance(DRS), fluorescence spectrum (FS). Results showed that with the increase of the supported concentration of WO3, the reflectance of DRS and the fluorescence spectrum intensity of TiO2/WO3 decreased accordingly, which indicated the powder?s increase in light absorbance and the decrease in luminescence respectively; with the increase of calcined temperature, the reflectance of DRS increased.

Jan 1, 2009

By J. H. Swisher

The solubility of graphite in CaO-S2O2-Al,O3 slags was measured by equilibrating slag samples with graphite crucibles and CO gas. Carbon contents as high as 2 ut pct were obtained in CaO-saturated, CaO-A1,O3 slags, and 1.3 wt pct in slags of the composition CaO.Si0,. Although the observed conditions for Sic formation were in agreement with those predicted from thermodynamic data, CaC, was found to form at a lower temperature than predicted frotn thermodynamic data. From measurements of the equilibrium carbon content as a function of CO Partial pressure, it was found that carbide ions dissolve in CaO-A12O3 melts with a valence of minus two. The carbon content increased with CaO concentration in Ca0-Al,O3 melts and increased with SiO, content along the CaO&apos;AlO3-CaOSi0 join in the ternary system. When solid CaC2 was added to CaO-A12O3 and CaO-SiO2-A12O3 slags, it was found that one of the oxides in the slag was reduced by the carbide (Al2O3 in the forrner and SiOz in the latter). In electric furnace steelmaking, a double-slag practice is frequently used to meet alloy specifications. Initially a flush slag, which is oxidizing in nature, is used to remove phosphorus and carbon from the steel bath. Later in the refining period, the flush slag is replaced by a highly reducing carbidic slag. When calcium carbide is formed in or added to a finishing slag, the slag is effective as a desulfurizing agent and also permits alloying elements such as chromium, vanadium, and tungsten to be added to the slag in the form of oxides. The oxides are readily reduced by calcium carbide, thereby minimizing the use of expensive ferroalloys. More work has been done on the thermodynamics of silicon carbide in slags than on calcium carbide. Baird and alor&apos; and Kay and alor&apos; determined the free energy of formation of Sic by measuring the partial pressure of CO in equilibrium with solid silica, silicon carbide, and graphite. Using a similar technique, they determined SiOz activities in CaO-SiOz and Ca0-Si0,-A1203 slags. Rein and chipman3 also determined the free energy of formation of Sic using slag-metal equilibrium measurements. A literature survey has uncovered only one experimental study of the behavior of CaC, in slag systems. Shanahan and cooke4 report the results of some preliminary experiments on the solubility and stability of CaC, in a CaO-A1,03 and a Ca0-Si0-A1,03 slag at a temperature of about 1500". The carbon solubility as CaC, in a slag containing 50 pct CaO and 50 pct A1203 was reported to be 0.6 pct. They also review earlier work on the binary CaO-CaC, system. A eutectic exists in this system, but various investigators disagree on the eutectic temperature and composition. eal has given an explanation for carbide furnace erruptions in terms of the thermodynamic properties of CaC,; his analysis is not based on experimental data, but on compiled data for the free energies of formation of CaC, and CO.&apos; , These data for steel-making temperatures are all extrapolated from the results of low-temperature measurements. In the experiments described in this paper, slag samples were equilibrated with graphite crucibles and with mixtures of CO and argon or with CO gas at 1 atm total pressure for measurement of the carbon solubility. Most of the work was done on Ca0-A1203 binary slags, although in some experiments CaO-SiO, and Ca0-Si0,-A1,03 slags were used. EXPERIMENTAL Slag samples of the desired composition for the solubility measurements were obtained by blending pre-fused master slags. The master slags were prepared by fusing mixtures of reagent-grade CaC03 with either A1,03 or Si0, in a graphite crucible. The master slags were crushed, then decarburized in air in a muffle furnace at 1200O C. A schematic diagram of the apparatus is shown in Fig. 1. The source of carbon for the solubility meas-

Jan 1, 1969

By W. J. Li, L. Kong, G. L. Li, X. M. Xi, J. Qiu

"A novel hydrothermal method was applied to prepare the precursor of LiMn2O4 using pre-treated electrolytic manganese dioxide (EMD) and lithium hydroxide as the main raw materials. The precursor was subjected to heat treatment between 400 and 900ºC to obtain spinel Li1.05Mn1.95O4 and Li1.035Co0.035Mn1.930O4 positive materials for lithium ion batteries. The structure and morphology of the obtained powder materials were studied in detail by means of X-ray diffraction (XRD) and scanning electron microscope (SEM). It is found that the precursor has an amorphous structure and a high reactivity, which is easily transferred to spinel structure during heat treatment, obtaining a positive material with an uniform structure and good performances. The XRD patterns reveal that single phase spinel Li1.05Mn1.95O4 can be obtained from the precursor after heat treatment at 600°C in air. The final Li-rich Li1.05Mn1.95O4 product obtained showed a well-defined stable spinel structure and distinctive crystal faces with particle size between 200 and 300 nm. The as-prepared Co-doped spinel sample exhibited a excellent electrochemical performance with an initial discharge capacity of 113.0 mAh/g and 93.8% of its original value was retained after 100 charge-discharge cycling at 0.5 C.INTRODUCTIONThe increasing demand for portable electronic devices and hybrid or full electric vehicles is driving the development of cheap, efficient, compact lightweight and environmental friendly rechargeable batteries systems (Chung et al., 2002; Scrosati, 1995). Lithium ion secondary batteries have satisfied this demand to a greater degree than other battery systems. The cathode material plays a critical role in the performance of Li-ion batteries. The high cost and toxicity of cobalt compounds for the cathode material of LiCoO2 has prompted a search for alternative materials. LiMn2O4-based spinels offer a potentially attractive alternative to LiCoO2, due to its abundance, low price, ease of preparation, environmentally friendly characteristics, better thermal stability, and its effortless recycling (Tarascon et al., 1991; Yabuuchi and Ohzuku, 2003; Amatucci et al., 1999; Tsai et al., 2003). Some achievements have been created to meet the requirements (Guo et al., 2010; Kang et al., 2005; Park et al., 2008; Takahashi et al., 2006; Lee et al., 2001; Yoshio et al., 2001; Arumugam et al., 2008). However, the largest obstacle encountered in the practical applications of LiMn2O4 is its fast capacity fading during long term cycling, which is due to Jahn-Teller distortion of the [MnO6] framework, the electrolyte decomposition at high potentials and manganese dissolution into the electrolyte (Fey et al., 2003). The electrochemical performance of LiMn2O4 is also strongly dependent on its morphological properties, such as crystallinity, phase purity, surface area, grain shape and particle size distribution, etc. All these morphological properties are closely related to the material synthetic routines and heat treatment processes (Huang et al., 2000; Myung et al., 2000; Takada et al., 1998)."

Jan 1, 2012

By Forsén. O.

In this ?paper practical solidification of anodes containing nickel, arsenic, antimony and bismuth is compared with the equilibrium? diagrams and kinetic ?factors. In order to clarify the distribution of the impurity elements in the anode the structures were studied after the solidification and also after the electrolysis of anodes. This examination was carried out with optical microscope, scanning electron microscope and electrochemical measurements. All the nickel is remaining metallic in the copper matrix during the solidification and therefore nickel is dissolved in the electrolysis at all oxygen contents, when the nickel content is 0.25 wt-% or less in the anode. The practical .solidification mechanism of the anodes, when the nickel content exceeds 0.25 wt-%, proceeds by the crystallization of nickel oxides. In oxygen containing copper anodes nickel oxide is verified to crystallize together with antimony in certain conditions and to form a micaceous compound (3Cu2O?4NiO?Sb2O5), which may build up a very harmful floating slime in the electrolyte. Arsenic is strongly enriched along the phase boundaries in oxygen free copper anodes. An intermetallic compound Cu3As is formed when the amount of arsenic in the anode. exceeds 0.7 wt-%. This compound is more noble than the copper matrix. This means &apos;that a selective dissolution of copper-arsenic compounds takes place. The copper matrix dissolves more strongly than the grain boundaries. The solidification structures of oxygen free bismuth containing copper anodes show clearly the influence of bismuth. Thin bismuth films which are less .noble than the metallic copper matrix, are formed during the solid1ficatton process. As a result of this the?grain boundaries are dissolved faster than the copper matrix.

Jan 1, 1987

A comparison is made between elementary block estimation techniques and the optimal methods of geostatistics using data from an Australian deposit. Considerable improvement in the estimates are obtained by using the optimal technique in this case.

Jan 1, 1975

By Lee T. J

The area, A, under a gamma-ray log that passes through a horizontal bed given by: A = gl/k. Here is the equivalent concentration of U3O8 in the body, l the thickness of the body, and k the calibration factor or sensitivityof the logger. The area is independent of the logging speed or logger time constant.This relationship, together with the first moment about the maximum of the log and its value there suflicient to determine the thickness, position of the centre of the bed from the log maximum and the concentration of U3O8.Numerical results obtained from artificial and field data show that the computed results arc as good as those obtained by methods such as the inverse filter technique and the iterative method. The present method yields results that arc easier to feed into an ore reserve data base.

Jan 1, 1981

By Charles Maier

PART I DENSITY AND ENERGY CHANGES IN COLD-WORKED COPPER IT has long been supposed that when crystalline materials are com-minuted the energy used in the production of increasingly smaller grain sizes is not entirely dissipated as heat but that a certain portion is "stored" as a part of the internal energy of the material. This portion usually has been called the "surface energy" of the particles. The practical interest of the Bureau of Mines in this subject in connection with the energy requirements of crushing processes has led&apos; to the author&apos;s attempt to measure the "stored" energy in finely divided calcite by heat-of-solution methods1. The experiments on calcite showed that "storage" of energy could not be proved for this material, because fine grinding caused a lack of chem-ical homogeneity evidenced by loss of carbon dioxide and subsequent adsorption of water on the surfaces of the calcite particles. When thermochemical correction was made for composition changes the cor-rected heat of solution was less for fine material than for coarse. Con-tinuation of the experimental work into the problem of comparing work and heat in the deformation of metallic crystals, where the calorimetric difficulties were less, showed, however, that in the case of copper and aluminum a real discrepancy between work and heat could be shown. Similar results had previously been obtained by Farren and Taylor2 and Hort3 and more or less simultaneously with the author&apos;s work by

Jan 1, 1936

By Jae R. Lee

Keywords: Self-propagating high temperature synthesis, AlN, Powder synthesis The particle size and shape effects of starting raw powders on the synthesis of aluminum nitride by self-propagating high temperature technique under high nitrogen pressure were investigated with various AlN diluents and Al reactants. It was found that the structure of beds of the starting raw particles largely affected the pore channels for nitrogen gas infiltration as well as the passages for combustion propagation before and during the reaction, resulting in the morphology and purity changes of the synthesized products. The AlN product of purity over 98% with about 30 microns was obtained.

Jan 1, 2005

November 21st, 1871. THE first session of this meeting was held Tuesday evening, in the chamber of the Common Council, the President, Mr. David Thomas, in the chair. Mayor Carroll, of Troy, gave a cordial welcome to the Institute, which was responded to, on behalf of the Institute, by the first Vice-President, Mr. R. W. Raymond. The Council reported the names proposed for membership with recommendation for election. The following named gentlemen were duly elected Anthony, J., - Williamstown, Pa. Babcock, George, - Troy, N. Y. Blake, Theo. A., - San Francisco, Cal. Blossom, T. M., - New York. Boalt, James A., - San Francisco, Cal. Bowman, Amos, - San Francisco, Cal. Chester, Prof. A. H., - Clinton, N. Y. Dewey, C., - Pittsfield, Mass. Dock, Gilliard, - Shamokin, Pa. Emerson, G. D., - New York. Endres, John J., - Pittsburgh, Pa. Firmstone, Frank, - Easton, Pa. Fowle, W. B., - Philadelphia, Pa. Frazier, Prof. B. W., - Bethlehem, Pa. Gardner, George A., - New York. Goodyear, Watson A., - San Francisco, Cal. Griswold, Chester, - Troy, N. Y. Griswold, J. A.,* - Troy, N. Y. Hague, J. D., - San Francisco, Cal. Hahn, O. H., - Eureka, Nev. Harkness, T. C., - Wilkes-Barre, Pa. Harris, Samuel, - Hudson, N. Y. Henry, E. T., - Oxford, N. J. Holley, A. L., - Brooklyn, N. Y. Howe, H. W., - Troy, N. Y. Hunt, Dr. T. Sterry, - Boston, Mass. Jannet, J., - Troy, N. Y. Knapp, John A., - New York. Laughlin, Henry A., - Pittsburgh, Pa. * Since deceased.

Jan 1, 1873

MR. TESCHER (Disaster at Dawson) : I move that you appoint a committee of nine members of this Institute to draft a set of resolutions that we can send out to all members of this Institute, to the mine officials in all four states, that might go towards preventing these disasters; that we reach all men, all mining men, mine officials of all kinds. I think we have enough brains to carry out a few suggestions of that kind. I think you are fully familiar or know men who are fully qualified to act on this committee. The only qualification that I have is to ask that Mr. Harrington be appointed a member of this committee. PRESIDENT WHITESIDE: You have heard the motion, and I believe it was seconded. Is there any discussion? That is a subject that really needs a great deal of thought. MR. LAMB: Things like that can&apos;t be handled in a minute. What Mr. Tescher suggested is all right, but to my mind, going into a great many of these different properties, seeing the conditions, such things hit pretty close to home. I would suggest that you put this off; lay it over until such time as the people who had the disaster have some time to think these things over. It is too soon to offer even a suggestion. Suggestions are all right, but there are no nine living men in the United States who can stand up or sit down and talk it over and give you any reasonable answer, in one hour or six months. First, you would naturally have to go down there and converse with the men who were at the camp at the time. You are all operators; all you operators would -like to talk it over today. You realize that anything that is good for the camp is always acceptable in disasters of this kind. I say, do it gracefully and not by publication. MR. TESCHER: I feel that the men present know these suggestions by heart and they don&apos;t have to discuss them. They know them instinctively and they know they will apply to any mine. It must be understood that if these suggestions are not carried out, they ought to be; and there is a motion before the house. PRESIDENT WHITESIDE: Mr. Murphy, you started to rise to your feet a moment ago. Have you anything to say on the subject? MR. MURPHY: I have just returned from a visit to Mr. Brennan. Mr. Brennan and I have worked together for twenty years. The manager of our company asked me to go down there and express his sympathy. Those things come to all men if they live long enough, in the coal business, and he wanted me to express to Mr. Brennan personally his sympathy and deep regret. What I had in mind when I started to rise, was to suggest that the Institute as a whole express its sympathy to Mr. Brennan. I don&apos;t think there is a man in Utah, Wyoming, Colorado or New Mexico who has done more in safety&apos; lines than Mr. Brennan, and it just seems bad luck that he had this disaster, and I am in hearty sympathy with the gentleman who spoke about not appointing this committee. I believe a resolution to Mr. Brennan would be very much better. JAMES DALRYMPLE: I am in sympathy with this gentleman here. I think it is going to hurt the feelings of those connected with the mines in which this disaster occurred. If you will give me the privilege for a few minutes, I will gladly express myself and the action that has been taken in the past by this Institute, and my opinion combined with a great many other opinions. And what I am going to say is going to be said by the-well, I am going to say it as I see it. I am going to say it not in an unfriendly spirit, but from a spirit of not undue criticism. I happen to be one of the original members who organized this Institute. I did what I could to obtain memberships. I remember very well when we had our first meeting that we had a very large membership. I think I have a photograph of the members which was taken on the steps of the Capitol building at that time. Our membership at that time was composed largely of underground officials. I mean by "underground" officials, the superintendents to some extent, the mine foremen, their assistants,

Jan 1, 1923

The failure of a seal in an underground coal mine can have devastating consequences. Traditionally seals have been constructed as flat walls. Large hydraulic dams, on the other hand, are constructed as concave arches. This paper presents an initial analysis of the potential strengthening of seals by concave construction as well as the impact of additional cost in terms of labor and material. A simple finite element analysis of three-dimensional solids under uniform loading allows comparisons between the strength of a flat wall and a curved arch. The models are examined for reasonable behavior and displacements at 20, 50, 100, and 200 psi loads.

Jan 1, 2007

By Klimpel. R. R.

Acknowledgments I am honored to be named as a recipient of the Antoine M. Gaudin Award, and I would like to briefly single out four groups who deserve a special thank-you relative to this award. The first group consists of Professor Kawatra, the many international support references that he gathered and the Gaudin Committee itself. I know such things don&apos;t come without considerable effort by many individuals, and I&apos;m grateful for their support. The second group consists of the management of The Dow Chemical Company, the managements of various mining companies and, in recent years, the management of G. S. Technologies, all of whom supported me, financially and otherwise, in my grinding, flotation and other particle-processing work. Operations people are the most overworked and under recognized people in the world, whether they be in the mining or chemical industry. Obviously, without extensive industrial support, especially from operating personnel in the mining industry, almost nothing about the work contained in this lecture would have, or could have, happened. The third group consists of a number of coworkers who have played key roles in specifically implementing the new flotation-product portion of this lecture. Of these, Bob Hansen, Don Leonard, Basil Fee, Simon Isherwood, Fernando Cones and Marty Meulendyke deserve special recognition. They have not only been dedicated, but they have been great to work with. Also in this third group are many members of the international academic community, especially those at Penn State. Professor Leonard Austin must be singled out because he took me as a young mathematically oriented chemist and taught me to be an effective process-oriented engineer. Without this experience, I would not have had the over 30-year career as an engineer, which I have loved. In addition, Len planted the size-reduction-research virus in my blood, which I can&apos;t seem to get rid of. I also need to mention Professor Frank Aplan, whose obvious love of mineral processing and froth flotation helped to create my interest in flotation. Thus, for those of you who don&apos;t like my approach to flotation, it&apos;s all Frank&apos;s fault. The fourth, and certainly not the least, group to thank is my wife, Charlene, and our two sons, Richard and Steven. No one could have a more supportive family. In every sense of the word, my wife has been my partner from the beginningwe were married at the end of my freshman year in college. She has sacrificed much for me, and I will never really be able to express the depth of my gratitude for Charlene&apos;s encouragement, loyalty and support over the past 36 years. General comments on froth flotation The industrial process of froth flotation: Where is it going? I&apos;m here to tell you loud and clear that froth flotation is alive, well, and growing. The inherent characteristics of high mineral throughput per unit of capital, low operating cost per unit of feed, high mineral specificity and high operating flexibility have guaranteed froth flotation an important past and a growing future. As with any evolving technology, there are always trends at the industrial level that are primarily driven by economics. The current trends include: •the movement towards larger and larger equipment, •more alternative equipment designs (e.g., the column cell),

Jan 1, 1996

By N. Demirel, O. Gölbasi

Draglines are massive machines extensively utilized in opencast mines for overburden stripping. The demanding working environment induces fractures, wear and tear, and fatigue failures in dragline components and eventuates in extended maintenance, lengthy downtimes, and loss of production. The bucket is the main source of external loads on the machinery, since interactions with ground materials take place in this region. This study aims to develop a generic finite element model of the stress on an operating bucket. This entails (i) three-dimensional modelling of a dragline bucket, (ii) analytical estimation of resistive forces in the bucket movement, (iii) three-dimensional simulation of the moving bucket using finite element analysis (FEA), and (iv) sensitivity analysis to examine the effect of formation characteristics on stress variation. Simulation results imply that the drag hitch and digging teeth are the elements of the bucket that are most prone to failure. In addition, sensitivity analysis indicates that internal friction angle of the formation is the dominant parameter leading fluctuations in stress values. Changes in stress level are least influenced by formation density.

Jan 1, 2015

Author&apos;s Note: Since the paper on &quot;All-Flotation at North Broken Hill Limited&quot; was read and discussed, the metallurgical results obtained have conclusively justified the adoption of the All-Flotation treatment.At present the shipping grades of lead concentrate produced from North mine ore range between 74% and 75% Pb, carrying approximately 43 oz. Ag and 4.5%-5% Zn. The lead recovery in lead concentrate is recording 95%-96% of the lead content of crude ore, and the milling and treatment cost on 6400 tons crude ore perweek of 96 hours has dropped to 6s. 3.6d. per ton on ore. With an increased ore tonnage, and with a new mill, considerable further reduction in costs is certain.New flotation machines, with 30 in. vertical depth of overflow (instead of 42 in. depth), are now being tried for the secondary granular treatment, with advantageous results. The treatment to-day is practically the same as that outlined in the paper, excepting that additional concentrate is returned for retreatment in the existing units.(Signed) A. LOWRY.Mr. T. A. READ: The author states (page 356 of Proceedings, No. 79), &quot;The sulphide ore itself was then comparatively coarsegrained, a fact which permitted ready concentration of the galena contents by means of jigs, tables, vanners, etc.&quot;

Jan 1, 1931

By H. Sevim

Three transportation systems in surface coal mines: 1-Truck Haulage, 2-Belt Conveying, and 3-Coarse-Coal Slurry Transportation are compared from the operations and cost point of Views. Computerized design and cost models were developed and cost data banks were compiled for each system. These models can be used to evaluate transportation systems and layouts that are practiced in most of the U.S. surface coal mines. A typical midwestern area strip mine was considered for illustration purposes. Sensitivity analysis on critical parameters such as production rate, transportation, distance, etc. was conducted and the outcomes are presented.

Jan 1, 1990

By Paul Girodo

Government Approval For Foreign Workers 1.Service Canada Work Permit Tasks: i. Prove there are no Canadian Journeymen; ii. Use heavyweight stakeholders; iii. Understand the FWU transformation taking place today. Government Approval For Foreign Workers 2.Provincial Nominee Program (PNP) i. Build relationships; ii. Use heavyweight stakeholders; iii. Continually demonstrate benefits to the Province from foreign Journeymen. Government Approval For Foreign Workers 3.Letter from Union Supporting Temporary Foreign Workers i. Easiest path to approval ?CLAC model

May 1, 2006