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By A. Kiziltas, D. J. Gardner, C. W. Mcllwraith, J. W. Bridge, M. L. Peterson

"Dynamic mechanical thermal analysis (DMTA) tests were conducted on high-oil content, paraffin-based wax used in wax-coated granular composites. These composites make up the surface of synthetic Thoroughbred horse racetracks used in North America. The modulus and damping response from the DMTA tests were correlated with the dynamic triaxial shear strength response of the bulk track material taken at two different operational temperatures and at four strain rates. The purpose of these tests is to understand the mechanisms of shear strengthening of the bulk track material as the wax is heated through the first crystalline solid to liquid nominal transition temperature. Previous work using differential scanning calorimetry confirmed that under common operational surface temperatures, the wax coatings undergo distinct thermal transitions. The resulting increase in triaxial shear strength values affects the consistency of the racetrack which, in turn, can potentially affect Thoroughbred racing performance and safety of the track surface.IntroductionSynthetic granular composite materials are being used in nine Thoroughbred horse racetracks in the United States as well as in other tracks around the world. In one case, their use was mandated by the state of California in 2007 due to testimony that these tracks were significantly safer than traditional dirt tracks [1]. Several synthetic tracks have shown substantial reductions in injuries since switching to synthetics; one California track showed a 75% reduction in catastrophic horse injuries during the first year as compared to the previous year racing on a dirt track [2]. The composition of the tracks in the U.S. generally consist of silica sand (>70%), polymer fibers (<5%), and rubber particles (0-15%) all coated with a paraffin-based, high oil content wax [3, 4]. In a recent study of several synthetic racetracks, to include the track location in this study, the oil content ranged from 34 to over 44% by mass [5]."

Jan 1, 2011

By S. C. Dhara

The recovery of Platinum Group Elements from various industrial scraps and spent materials in the form of high and low grade, such as, impure metals, matte, catalysts and other ceramic substrates, etc., has .been described by using high pressure reaction method. Nickel, Stainless Steel, Titanium and glass lined reaction vessels? are used in the reaction process. Primarily, the method involves either direct leaching of the substrates from the metal value or dissolving the precious metal from the substrate. Both acids and alkalies are used along with other reagents in the reaction process. The temperature and pressure of the leaching process are the main criteria for the reaction kinetics.

Jan 1, 1989

By K. Iwami, K. Abe

"Onahama Smelter and Refinery has been operated-since 1965 arid currently produces 243,000 metric tons per year of cathode copper. The Onahama tankhouse consists of conventional-type No.1 and 2 tankhouses with the capacity of 123,000 metric tons per year and No.3 tankhouse with 120,000 metric tons per year, adopting jumbo tank system, using hazelett anode respectively.In October, 1996, for the purpose of improving the - anode verticality, new anode copper body press machine has been installed in No.1, 2 tankhouses; by increasing Walker type anode copper weight by 35kg to 365kg. Consequently, it is possible to raise current density from 191 to 222 A/m2 and the No.1 and 2 tankhouses capacity was increased by 15,000 metric tons per year to 138,000 metric tons per year.At present, the refining capacity is 258,000 metric tons per year in total including No.3 tankhouse.This figure is the largest one in Japan.IntroductionSince the Onaham tankhouse was put into operation in 1965, the cathode copper production has increase with much labor cost saving.The following two cases to increase Walker type anode copper weight by 35kg to 365kg were studied.a) To increase the cathode copper production by raising current density.b) To save the labor cost by prolonging the anode cycle in order to decrease the exchanging time of electrodes.So the electrolytic tests were carried out to confirm· the effect of current efficiency, cathode copper quality and working conditions for space adjustment.As a result, we concluded that it was indispensable to introduce the anode body press machine to keep usual current efficiency and cathode copper quality with same workers, and to be possible to increase cathode copper production.In addition, the high-speed press machine was needed to maintain same working time and which specifications were decided through various investigations. In October 1996, the new anode body press machine made by Kawazoe Machine Works, Ltd. has been installed in No.1 tankhouse."

Jan 1, 2000

By T. J. A. Smith

This paper provides an overview of some of the key issues in design of smelter gas handling systems, with particular reference to smelter smelting plants. In both primary smelting and converting, gas handling and treatment systems often represent the major capital cost component. There is also ample evidence that poor system design can be a major cause of smelter down time, lost production and unforeseen high maintenance costs. The paper discusses these issues and offers guidance for improved design.

Jan 1, 1992

By Roland Kammel

In combination with various physical and chemical methods also electrochemical techniques are most frequently used to improve the recovery of metals from aqueous dilute process streams or effluents e.g. in electroplating, metal finishing, mining and metallurgical plants. To insure cathodic metal recoveries with favorable current efficiency and high throughputs per unit of cell volume seve¬ral types of electrolysis cells have been developed comprising extended electrode surface areas and/or intensive electrolyte. agitation. The practical experiences with these units indicate especially for the electrolytic recovery of metals whose values are high, that the treatment cost permits profitable operations with relativly short payback periods for the units. Anodic reactions can be utilized for the removal of undesired anion contents or buildups of impurities. Appropriate combinations of these recovery methods are used to improve the versatility and the overall economy. Industrial applications reveal their potentional as addidtive techniques for existing processes to reduce the metal content of effluents to values that meet the guide lines of environmental legislation whereas integrated in-operation recovery methods are nowadays increasingly introduced to approach nearly close-loop operations.

Jan 1, 1992

By Jamil M. Khalifeh, Shadia J. Ikhmayies, Bothina A. Hamad

"The structural and electronic properties of cubic d -NbN are investigated using density functional theory (DFT) and all-electron full potential linearized augmented plane wave method (FPLAPW). The equilibrium structural parameters are determined by fitting the total energy as a function of volume to the Murnaghan's equation of state. We calculated the total and partial densities of states (DOS) and compared them with those computed by different authors. Our DOS at Fermi level is found to be very close to the experimental value. The band structure is computed, discussed and used to find the characteristic energy separations. Valence electron density contours are recorded and discussed. We deduced the partial charge densities of different bands and binding energies of valence core levels and compared them with experimental and theoretical results obtained by different authors.IntroductionNiobium nitride has been intensively investigated over the last decades because of its interesting physical properties and technological applications (superconducting microdevices, microelectronic, catalytic probes, and hard coatings) [l]. While the group IV transition metal nitrides (TMN) mainly crystallize in the cubic NaCl structure (Bl type), those of group V and VI nitrides occur as different phases. Thus for niobium nitride, many phases have been reported in the literature: cubic fcc d -NbN, tetragonal ? -Nb4N3, hexagonal d -NbN, hexagonal e -NbN, and low nitrogen content hexagonal ß -Nb2N [l, 2].Structural and electronic properties of niobium nitride were investigated theoretically and experimentally by many authors. For example, in 1975 Schwarz [3] obtained the partial density of states for NbC and NbN from APW band structure calculations. In 1975 Kallne and Pessa [4] studied the electronic structure of Nb, NbC and NbN by using X-ray emission. In 2003 Amriou et al. [5] studied the electronic structure and bonding mechanism of NbC and NbN compounds using first principle total energy calculations using the full-potential linearized augmented plane wave method. Also in 2006 Sanjines et. al [l] studied the electronic structure of the hexagonal~Nb2N, hexagonal' d -NbN, and cubic d -NbN thin fihns by using X-ray photoemission spectroscopy. They [l] also calculated the densities of states for these phases and used them in the interpretation of the experimental valance band spectra. Most of these studies are old and there is a need for more recent studies. According to our knowledge, there are little comprehensive theoretical studies on this subject by using FP-LAPW method [5], which proved its ability to give accurate results. In this work we used the FP-LAPW method to study the structural and electronic properties of the cubic (fee) o-NbN (space group Fm-3m, prototype NaCl) crystal."

Jan 1, 2013

By Toshiyuki Hashida, Victor M. Lopez-Hirata

"Small-punch tests and determination of fracture toughness JIC were conducted at 4 and 77 K on new cryogenic JN1, JJ1 and JK2 austenitic stainless steels, after isothermal aging. Equivalent fracture strain ?qf determined by measuring the reduction of thickness in the small-punch test specimen. A linear dependence of JIC on ?qf was found in these new materials. Regression analysis of experimental data produced the following linear relation JIC = 1304.1 ?qf + 8.09 [kJm-2]. An analysis of present work relation was pursued on the basis of material properties and evaluation method of he. Results showed that the slope value has a strong dependence on material yield strength and JIC evaluation method. This linear relation is useful for the evaluation of fracture toughness JIC, measuring the equivalent fracture strain ?qf by means of small-punch test. Thus it can be useful for assessing the degradation of fracture toughness in small areas such as, the heat-affected zone in welded components.IntroductionCryogenic structural materials for superconducting magnets of fusion nuclear reactor are required to possess a good combination of strength and toughness. The mechanical properties are required beyond the capability of conventional austenitic stainless steels [1]. New cryogenic JN1, JJ1 and JK2 austenitic stainless steels were developed by the Japan Atomic Energy Research Institute (JAERI) [1]. The structure of superconducting magnets is constructed by welding of 200 = thick plates of these steels, which are solution treated at high temperatures and then water-quenched to avoid intergranular precipitation. However, the welding process involves heating and cooling [2], which cause microstructural changes in both base metal and weld. In this heterogeneous microstructure, it is important to estimate the fracture toughness of these materials at cryogenic temperatures. Therefore, it is necessary to evaluate the effect of aging process on the fracture toughness behavior of these new steels. To determine the cryogenic fracture toughness, the elastic-plastic JIC value has been co=only used [2]; however, the specimen size is much larger than heat-affected zones in welded components. Small-punch (SP) testing method, employing miniature specimens, has permitted to evaluate the fracture toughness behavior at different temperatures in different nuclear reactor materials [3,4]. Mao et al. [5,6] and Misawa et al. [7] found a linear relation between JIC value and equivalent fracture strain ?qf, determined by SP method in non-ferrous alloys and ferritic steels at room temperature and austenitic stainless steels at 4 and 77 K, respectively. So that, this kind of correlation would be very useful to assess the fracture toughness JICe values by means of SP test in small zones of welded components."

Jan 1, 2012

By Xun Zhang, Huiqing Tang

The inner shape of a blast furnace is of fundamental importance for blast furnace ironmaking to achieve goals of high yield, high quality, low fuel rate and long campaign life. Therefore, it is worthwhile to design better furnace inner shapes. This paper conducted numerical simulations of performance for the blast furnaces with conventional and modified inner shapes. By comparing the calculation results of the two blast furnaces with the same operation conditions, it can be found that there are some certain differences. It is necessary to optimize the inner shape of blast furnace considering the results of simulations. This paper provides references for future blast furnace inner shape design and related technology developments.

Mar 1, 2017

By M Kolbe

Co-Cu exhibits a metastable miscibility gap in the region of the undercooled melt. Specimens have been undercooled and solidified containerlessly into the metastable miscibility gap in an electromagnetic levitation facility (EML) and in drop tube (DT) experiments. Due to the high undercooling the velocity of the solidification front is very high and the microstructure is frozen in instantaneously. The microstructure of samples processed in the EML is influenced by the electromagnetic stirring due to the induction of electrical currents into the melt. A variety of microstructures has been observed. After undercooling below the binodal the liquid melt separates into the Co-rich L1-phase and the Cu-rich L2-phase. Two basic morphologies of the L1-phase can be observed, they can be attributed to the transition in dendrite growth from diffusionally and thermally controlled to only thermally controlled growth. Transient microstructures are observed after solidification in the vicinity of the binodal. Drop tube experiments, which lead to a rapid solidification of a distribution of droplets under reduced gravity conditions, in contrary allow for the observation of the early stages of demixing: the microstructure shows a homogeneous distribution of spherical particles of the minority phase in the droplets. The cooling rate of the droplets and its dependence on the droplet radius has been calculated. The solidification velocity as a function of undercooling has been measured in the EML for the composition Co-lB.Bat%Cu. The data are analysed in the framework of the LKTlBCT model with a velocity-dependent distribution coefficient as well as within a model of Galenko and Danilov using a kinetic growth coefficient of u=0.22 m/Ks.

Jan 1, 2002

By M. Demuth, B. Holleis, M. Potesser, D. Spoljaric

"In 2005, Messer Group established a technology competence centre for metallurgy in Gumpoldskirchen (Austria), with the aim to develop oxygen burners which satisfy today's and upcoming standards of legislation as well as customer requirements. With the assistance of the Development Sponsorship Fund (FFF) of Austria, cooperation with the University of Leoben was agreed on. With the long term experience of the Gas-Warme-Institut ""GWI"" in Essen (Germany) and the University of Leoben, different new burners have been developed.The efficiency of industrial combustion processes can be increased in two ways (which can be seen in Figure 1 ), either by preheating the fuel and combustion air or by adding oxygen. Due to the high 79 % Nz ballast in air combustion, only low flame temperatures can be reached. This results in high heat loss in the exhaust gas, caused by the low combustion efficiency. Oxygen can be introduced into the combustion chamber using different techniques:• Oxygen fuel burners• Direct oxygen injection into the fuel air flame• Underlaying of the fuel air flame• Enrichment of the combustion airIn Figure 2, the theoretical flame temperature for the stoichiometrical combustion of natural gas is plotted as a function of oxygen enrichment. Therefore, it can be concluded that even low enrichment values produce higher flame temperatures and result in higher combustion efficiency."

Jan 1, 2012

By Kensuke Sassa, Shigeo Asai, Norihisa Waki

"A new method for separating inclusions from a molten metal using a high magnetic field has been proposed. The principle of this method based on the magnetization force has been confirmed in experiments of separating intermetallic compounds imitating inclusions from molten Al-Si-Mn-Fe and Al-Si alloys. In order to measure a magnetic susceptibility, the Gouy's method has been so modified by using a super-conducting magnetic as to work in a high temperature up to 1473K. A theoretical expression for the magnetization force, which is indispensable to evaluate the magnetic susceptibility, has been derived. The magnetization forces acting on intermetallic compounds which were used in the magnetic separation were measured over the range of liquidous to solidous temperatures and the magnetic susceptibilities of the intermetallic compounds were obtained from measured magnetization forces by use of the theoretical expression.I. IntroductionRecent developments in the technology of super-conducting magnets have given rise to the circumstance that a high magnetic field over a relatively large space is readily available without liquid helium. Then, it has been found that a high magnetic field provides magnetic effects to nonmagnetic substances and various interesting phenomena have been reported in the broad science fields of physics, chemistry and biology1). ""A science related to a high magnetic field"" in which many fields are transversally viewed from the standpoint of a high magnetic field2 ) is going to be established. In particular, new phenomena and functions brought by the science related to a high magnetic field are also useful for Material Science and Engineering so that the creation of Materials Science and Engineering related to a high magnetic field"" has been conceived 3).Now, when a substance regardless of being magnetic or nonmagnetic is put in a magnetic field, it feels a magnetization force, which is familiar to such a force that a magnet attracts iron. The force is in proportion to the product of magnetic field strength, its gradient and susceptibility so that a precipitated substance can be separated from a molten metal based on the difference between susceptibilities of a substance and a melt. This is a basic principle of the magnetic separation. So far the application of the magnetic separation has been limited to the separation of ferromagnetic substances from a nonmagnetic medium. A high magnetic field, however, has enabled to separate nonmagnetic substances from a nonmagnetic medium.In this study, a new method to separate inclusions from a molten metal using a high magnetic field has been proposed. The principle of the method was verified by experimental works and the feasibility on the elimination of inclusions in steelmaking processes has been studied"

Jan 1, 2000

By Annette Revet

Aluminum fluxes have been used for the remelting of secondary aluminum since the beginning of the recycling industry. During the last sixty years, a number of fluxes have been designed, researched and tested at the laboratory and plant scale. Fluxes are primarily a mixture of potassium chloride and sodium chloride with the addition of some other chloride and fluoride containing salts. The conventional Mining methods of potassium chloride and sodium chloride yield products that are not high in purity without costly reprocessing or additional refining. In 1993, Kalium Chemicals, Ltd. began supplying flux mixtures to the aluminum industry. Kalium produces potassium chloride and sodium chloride which are mined and refined by a patented solution-mining process. The salts produced by this process are high in purity with lower concentrations of iron oxide, sulfates, and other impurities. This paper will present the different mining methods used in the production of sodium chloride and potassium chloride. The paper Will address how these mining methods affect the purity of the final product as well as the effect of purity on the performance of the fluxing salt.

Jan 1, 1995

By Ma Shao Xian, Li Dong, Li Zhen Guo

"The new type shaft calciner ( SK-10 Serials) is developed and designed by CADRE itself on the basis of the conventional shaft calciner. The actual application in a number of calcinations plants have proven that they are of very good effect. Calcined coke calcining heated by the shaft calciner has a high quality, lower lost by fire. The shaft calciner needs no additional fuel when it is working. Anode Carbon Plant and calcined coke Plant commonly used the shaft calciner in domestic. The waste heat from the shaft calciner can be recuperated to generate electricity and to make the steam for produce. Exhaust waste heat is recovered by 90% or more. The new type shaft calciner's structure is optimized by computer simulation for fire-wall structure, combustion air to fuel ratio, volatile combustion is fully in use, furnace cooling zone structure, the exhaust smoking structure and calciner heat balance. Furnace structure and production operating parameters has been got the best optimized results. This paper introduces the working principle and characteristics of the shaft calciner - the equipment for calcining of the petroleum coke. It also demonstrates measured process parameters of the new type shaft calciner. Through comparison with the rotary kiln and conventional shaft calciner, it proves its own technical characteristics and advantages: higher capacity, high quality products, provides more energy for power generation, equipment operation and maintenance costs lower.IntroductionChina's petroleum coke market is mainly dominated by the delay raw petroleum coke. Rotary kiln and shaft calciner are the main process equipment for calcined petroleum coke. As the shaft calciner burning less, no external fuel, waste heat utilization is high, long service life, the utilization rate in China is more extensive than the rotary kiln."

Jan 1, 2012

By Jun Iwai, Osamu Takai, Yasushi Inoue, Hiroyuki Sugimura

"Infrared reflection absorption measurement was performed during plasma-enhanced chemical vapor deposition of silicon dioxide films at room temperature. Hydrocarbon contaminants adsorbed onto growing film surface are oxidized by oxygen radicals in plasma resulting functional groups which include C=O and C-O bondings. These groups exist only near the surface and are hydrolyzed rapidly after exposure to air.IntroductionRecently low-temperature silicon dioxide (SiO2) deposition has been in a growing industrial demand in pa1ticular, polymelic substrates such as polycarbonate and polyethylene telephthalate, which have poor heat resistance, need low process temperature (near room temperature) in coating of SiO2 which is a suitable material to improve optical and mechanical properties of polymenc products. Plasma enhanced chemical vapor deposition (PECVD) using organosilicon reactants is one of the most promising technique for lowering process temperature, so that it has been extensively studied1-12. In the present; however, hydrocarbon contaminants and a plenty of Si-OH termination in Si-O-Si networks tend to exist in the films, which degrade mechanical, optical and electrical properties of the films. It is necessary to understand the deposition mechanism at, low temperature in order to solve the problems. We have studied the low-temperature PECVD of Si02 by spectroscopic diagnosing techniques such as optical emission and mass analysis6-7, 11- 12Infrared reflection absorption spectroscopy (IR-RAS) has been a well-established technique for characterization of thin films on metals as· well as on semiconductors and insulators13-17. In this paper, we report on' the surface reaction of room-temperature PECVD of Si02by using in situ IR-RAS."

Jan 1, 2000

By Yoshiaki Suzuki

Since 1973, Saganoseki Smelter & Refinery had operated two flash smelting furnaces together to produce 330,000 mtpy of copper. However, in 1990&apos;s, economical situation required the smelter more increased productivity to remain competitive. The program, to integrate two flash furnaces into one was carried out maintaining the same production. Modifications were done on the pneumatic concentrate drying system, concentrate feeding system, concentrate burner and furnace cooling system, etc. to double the, furnace throughput. A new large cryogenic oxygen plant was constructed replacing two old plants. Single flash smelting furnace operation has started in March 1996. This paper describes about details of modifications and operational results.

Jan 1, 1998

By Matti Leiponen

During the last few years Outokumpu Oy has put forth efforts to develop the material handling in the Pori tankhouse. The final objective is full automation including cell loading. The fully automated material handling provides high quality anodes and cathodes as well as equipment and handling systems capable of very accurate cell loading. The new machines and equipment for accurate cell loading and the methods to produce high quality anodes and starting sheets are described in this paper.

Jan 1, 1987

By G. R. Waters

NMR360 is developing a suite of chloride-based metals extraction processes, with the first commercial operation scheduled for commissioning late in 2018. It is critical, therefore, that with the introduction of any new technology, that the circuits do not suffer from mechanical failures which will compromise the operation. Although chloride leaching is at atmospheric pressure and relatively low temperature, the main challenge is preventing corrosion, since the high proton activity makes even a small amount of acid behaves as though it were concentrated. An additional challenge in concentrated chloride circuits is the potential for solids precipitation. In this context, therefore, correct valve selection is crucial, and NMR360 has partnered with CGIS to ensure that the Severe Service Valves (SSVs) needed will perform over and above the definitions of the Manufacturers Standardization Society (MSS) of the Valve and Fittings Industry. This paper outlines what the minimum requirements are for SSVs in chloride leaching applications, drawing on five decades of industry experience from one of Canada’s leading valve experts.

By Muhlis Nezihi Saridede, Burak Birol

"The scraps of high quality steels generally contain expensive alloying elements such as chromium, vanadium, nickel, etc. These scraps are melted in an induction or an electric arc furnace and refined in ESR (Electroslag Remelting) purification process. A significant amount of alloying elements are lost during these processes. In order to avoid these losses, scraps can be utilized directly in ESR by skipping the melting step. In this study, 316L stainless steel scraps were refined in ESR with selected synthetic slags. The products were analyzed by optic emission spectrometry and the effects of slag compositions on the alloying element losses were examined. According to the analysis of the scrap and the products, generally chromium, nickel and manganese losses were encountered. It was determined that the alloying element losses has no connection with electrical conductivity. The slag containing CaF2, Al2O3, and FeO gives the optimum Cr and Ni losses.IntroductionElectroslag remelting (ESR), which is the consumable electrode refining process, finds a wide range of utilization for the production of high quality, low inclusion alloys. This process is based on melting a consumable electrode under a molten synthetic slag containing CaF2, Al2O3, CaO etc. The synthetic slag provides the chemical refining and insulation of molten metal from air which leads to a higher purity and an inclusion-free product. [ 1,2] A schematic diagram of ESR system is shown in Figure 1."

Jan 1, 2011

By Robert G. Robins

Precipitation of ferric arsenate is an effective method for removing arsenic(v) from hydrometallurgical process solutions. The solubility and stability of this compound. FeAs04.2H20, has received some attention in recent years and the reported solubilities of amorphous and crystalline material have varied considerably. This paper reviews previous studies and reports some recent work with a consistent model to explain the variable results. Free energy data for ferric arsenate and its associated dissolved complexes are presented.

Jan 1, 1990

By Yun Soon Han, Joo Hyun Park

Indium (In) solubility in the FeO-SiO2-Al2O3-5%CaO slag was measured under p(O2)=10¯¹¹ atm at 1573 K to clarify the dissolution mechanism of In in FeO-bearing metallurgical slag. The In solubility increased with increasing oxygen partial pressure, whereas it decreased by increasing the activity of basic oxide, viz. FeO. Thus, a dissolution mechanism of In in the FeO-SiO2- Al2O3-5%CaO slag was described by the following equation. In(s)+1/4O2(g)=(In+)+1/2(o2-) The enthalpy change of the In dissolution reaction was negative, indicating that the dissolution reaction was an exothermic reaction. This is consistent with the above reaction mechanism.

Jan 1, 2014