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By Saad Elias Kaskah

"The Box-Behnken Design (BBD) is used to model the sacrificial Cathodic Protection System (SCPS) to find the factors effectiveness behaviour. For protection potential assessment the BBD receives (resistivity of environment, sacrificial anode alloy, distance between anode and cathode and surface area for the structure to be protected) as input and gives the protection potential as output. By applying BBD with their analysis tools we get many results. The important results which are the factors individual effectiveness on the sacrificial cathodic protection (SCP) process are the resistivity which has the greatest effect on the potential protection (rank=l) followed by sacrificial anode alloy type (rank=2), surface area for structure protected required (rank=3) and distance between anode and cathode (rank=4). The interaction of sacrificial anode alloy and cathode area {X2X4 ) has significant effect on CP process with the limits which are used in this work while the other factors interaction (X1X2, X1X3, X1X4,X2X3, X3X4 ) has insignificant effect on the limits which used in this work.IntroductionFor carbon steel in seawater the normal corrosion potential E '°""_is in the range -550 to -600 mV vs. Ag/AgCI [1]. The most effective method to overcome the corrosion is cathodic protection {CP) which represents a control method in the steel wall corrosion. Cathodic protection has been used in several areas including marine and underground structures, storage tanks, and pipelines [2]. Sacrificial anodes system generates protective current which depends upon the inherent potential difference between the anodes and the structure to be protected. If the structure is made of iron or steel, any metal that is more active in the electromotive force series can theoretically be used as anode material [3]. There are many factors influencing on cathodic protection like resistivity (NaCl content), chemical composition of sacrificial anode alloy, distance between anode and cathode, surface area of cathode, temperature, humidity, velocity of solution, dust, impurities, bacteria and etc .. The present work studied four factors: NaCl content, resistivity), chemical composition of sacrificial anode alloy, distance between anode and cathode, surface area of cathode) with different three levels of values for each one. Then this work will find the optimum value from the factors levels that tacked to investigated there influencing on sacrificial cathodic protection system."

Jan 1, 2013

By Djalma Souza, Felipe Perissé Duarte Lopes, Frederico Muylaert Margem, Sergio Neves Monteiro

The development of composite materials is a combination of distinct materials, with applications in various areas, such as: aerospace, automobile, etc. Regardingmechanicalresistance,composites reinforced with a dispersion phase in a fiber form is more relevant. The green idea is use composites with natural fibers instead offiberglass, especially in non-structural applications. The Fique fiber has occupying an important place at Colombian agricultural and agribusiness sectors. Epoxy matrix composites reinforced with 1–6 Fique fabric layers were tested and the results indicated that thetensile properties improve with increasing theamount of Fique fabric layers. The fiber/matrix interaction was analyzed by scanning electron microscopy.

Mar 1, 2018

By Wen-long Zhan, Chun-en Zhu, Xiao-dong Du, Yong Zhao, Keng Wu

In view of the traditional evaluation index of sintering basic character- istics ignoring process information, several high temperature characteristic num- bers, which contain process information, were used to evaluate the sintering basic characteristics more comprehensively in this paper. The evaluation model of iron ore properties was established based on the high temperature characteristic numbers with employing fuzzy mathematics. Then, with the constraint of sinter properties and the raw materials, the ore blending model was built, whose target was to obtain the lowest cost and the best sinter properties. A multi-objective fuzzy linear pro- gramming was used to solve the model in order to get the best ore matching schemes. The ore blending model was then applied to the practical production, which was proved to be dependable.

Mar 1, 2018

By Run Huang, Xuewei Lv, Songli Liu, Chenguang Bai

"Titanium alloy was prepared from titania-bearing blast furnace slag (Ti-BF slag) by aluminothermic process in an induction furnace. The effects of aluminum amount on the titanium silicon yield and titanium recovery ratio were studied. The phase transformation and chemical composition of the prepared alloy were investigated by X-ray diffractometry (XRD) and X-ray fluorescence (XRF) respectively. It was found that the mass fraction of silicon and aluminum increased with increasing the aluminum amount, however, the mass fraction of titanium increased first and then decreased with increasing the aluminum amount. Furthermore, both the titanium alloy yield and titanium recovery ratio increased with the increase of aluminum amount. The main phases of the alloy were TixSiy and AlTi3. The titanium alloy samples prepared in various conditions had a composition (wt.%): 38–50% Ti, 29-34% Si, 4-11 Al%, 1.6-2.2 Mn%.IntroductionPanzhihua and Xichang regions in the southwest of China are rich in vanadium-titanium magnetite containing iron, vanadium, titanium and gangue. According to the characteristics of the resource, iron and vanadium are successfully recovered with a blast furnace process and a converter process. However, most content of titanium are entered in the blast furnace slag with TiO2 22% -26% and metallic Fe 2%–6% called Ti-BF slag. Due to the dispersed distribution of Ti in various fine grained mineral phases with a complex combination between Ca, Al and Si, it is difficult to recover the Ti components[1]. This slag is generated at a current rate of 3.6 million tons per year, which adds to the existing 70 million tons of slag produced so far[2]. The slag has had to be piled as large as the mountains, which not only waste of resources but also cause a pollution of the environment. Therefore, the study of integrated utilizing Ti-BF slag has become very significant."

Jan 1, 2012

By C. S. Griffith

Lithium Australia NL (ASX:LIT) and ANSTO Minerals have been working together since 2015 on the development of halide accelerated leaching for the extraction of lithium from lithium-bearing micas, spodumene and clays. This technology has been termed SiLeach® process. The driving force behind development of the SiLeach® process, initially, was to develop a hydrometallurgical process to extract lithium from micas and spodumene without the need for the energy intensive, high temperature processing conventionally applied to lithium extraction. This driving force remains today and continues to hold promise in realising the value of previously under-utilised lithium resources. A comprehensive understanding of the technology and its applicability to the processing of micas and spodumene currently exists, and the flowsheet has been rigorously piloted. Production of battery grade lithium carbonate has been demonstrate

By Meifeng Zhi

Separation of uranium and molybdenum in the alkaline leach solution of a U–Mo ore was studied. A process of acidification-solvent extraction-precipitation uranium and molybdenum was determined. The influences of solution acidity and phase ratio of acidic scrubbing on separation of uranium and molybdenum were examined. The molybdenum extraction equilibrium isotherm was drawn. The results show that the separation of molybdenum and uranium can be achieved by acidifying the alkaline leach solution, solvent extracting molybdenum using trialkylamine at equilibrium pH 2.5, and scrubbing the loaded organic phase using sulfuric acid solution. The strip solution can directly precipitate ammonium molybdate. Uranium can be directly precipitated from the raffinat

By Vinicius Alves Gomes, Jean Igor Margem, Thallis Cordeiro, Frederico Muylaert Margem, Roberto Faria Jr., Sergio Neves Monteiro, Marina Rangel Margem

Natural fibers are attracting the interest of engineering sectors owing to specific advantages such as lightweight and lower cost as well as for their inherent condition of being renewable, biodegradable, recyclable and neutral with respect to CO2 emission. In particular, the fiber extracted from the malva plant stem is nowadays recognized as one of the strongest lignocellulosic fibers. However, the thermal properties of the malva fibers have yet not been fully investigated. The present work had as its objective to investigate, by photoacoustic spectroscopy and photothermal techniques the thermal properties of diffusivity, specific heat capacity and conductivity of a pressed malva fibers sample. The results revealed that these fibers showed a superior thermal insulation capacity.

Jan 1, 2015

By Yungang Li, Hui Li, Ramana G. Reddy, Jinglong Liang

High solid corrosion protective coatings were prepared by the dust of the converter with an average particle size of 59.33 μm. The effect of different amount of benzyl alcohol diluent on the performance of high solid anti-corrosion coatings was studied. With the increase of the amount of diluent, the viscosity of high solid anti-corrosion coatings reducing, the film apparent bubble content decreasing, and film resistant to salt water corrosion ability decreased, while acid corrosion capacity enhancement. When the dosage of diluents is 15%, the coating film is more resistant to acid corrosion.

Mar 1, 2017

By G. S. Victorovich

Technical progress in primary smelting has changed the face of the copper industry in the years since the Second World War. Much of this change has resulted from a wide acceptance of flash smelting technology. In addition, research has been directed toward devising converting processes to replace conventional Peirce-Smith converting technology. One major thrust has involved a revival of the old " ", idea of oxygen flash converting of comminuted mattes. This paper reviews the 60-year history of flash converting. Particular attention is paid to Inco's investigations into the processing of white metal containing significant amounts of nickel and, in some cases, iron. Thermodynamic analysis and laboratory experimental results are presented which throw light on the behaviour of nickel and other salient features of flash converting. The possible role of oxygen flash converting in the copper pyrometallurgy of the future is briefly discussed vis-a-vis direct production of copper.

Jan 1, 1993

By T. R. A. Davey

Previous publications on the application of EIETSIM include the modelling of an electrolytic zinc plant and a copper flash smelter. In the present case METSIM has been used to model the desilverising of lead by the reagent zinc, whereby a silver-zinc intermetallic compound is formed, and floats out of the lead. This compound has a variable composition, depending upon the ratio of dissolved zinc/silver in the lead bath. Its solubility in lead decreases with falling temperature. A number of variations and modifications of the Davey Desilverising Procedure are modelled, and applied to a wide range of silver contents in lead bullions at several plants. METSIM uses both feed- back and feed-forward controls to simulate plant conditions, and a logic control to distinguish between different phases in the Zn-Ag system. Use is made of extensive (previously unpublished) fundamental data on the ternary Pb-Ag-Zn system, and of plant data, to establish certain operating parameters.

Jan 1, 1993

By I. Filzwieser, S. Wallner, M. B. Hanel, A. Filzwieser

Whenever thinking about increasing tankhouse performance two major aspects has to be considered, the technological feasibility as well as the economical impact. For meeting the requirement of an increased current density leading to an increased productivity, Mettop has developed the METTOP-BRX Technology, which allows the introduction of fresh electrolyte between each pair of anode and cathode. As an example of a green field approach the installation at Xiangguang Copper Co., Ltd will be described. Since the start up in 2011, Xiangguang Copper Co., Ltd operates one of their two copper refining tankhouse with a current density of 420 A/m2 and a current efficiency above 98% in average. At Montanwerke Brixlegg Ag, as an example of a brownfield installation, the annual production could be increased by 50%. Although for many years a total of two industrial applications are in operation, the successful implementation of this technology that result in significant operational and economic advantages has not been fully accepted within the industry due to misunderstandings, incorrect interpretations and lack of awareness. It is intended with this paper to create a better understanding about the parallel flow technology and help to eliminate worries and concerns.

Mar 1, 2017

By Vasil Kopaleishvili

The bainitic Fe-C-Si alloys with optimum content of retained austenite serve as ?containers? for storing of hydrogen. Both the vacancies of fcc lattice and the possibility of forming hydrides of silicon and other alloying elements will be used. The idea is based on our scientific hypothesis. There is the silicon threshold (Si=0,50%) in "Fe-Si" system and Fe-C bainitic alloys, above which it causes self-organized phenomena: sudden increase of hydrogen solubility and amount of retained austenite in the alloy after ??ß transformation, formation of two supersaturated solid solutions <a??r>, "rejuvenation? and its reverse process. Rapprochement of iron atoms when Si=0,50%, causes appearance of new covalent forces where uncompensated electrons of 3d-subshell are involved and it provokes synergetic phenomena. They ?free? silicon atoms from the previous bonds. After that silicon itself becomes a getter of hydrogen using vacancies (14) of 3P2(6)d0(10) subshell and it results in sudden increase of hydrogen solubility in metal. Simultaneously sudden decrease of iron activity takes place. That in its turn ?releases? the carbon. Thus, its redistribution, controlling the bainitic transformation, is hastened. It stipulates for creation of ?brittle bainite" B[a(C,H)+?r(C,H)] after ??ß transformation. While weathering of metal, "rejuvenating", hydrogen diffuses in ?islets? of retained austenite and ?relaxed bainite? (B[(C)+?r(C,H+H)]) is obtained. When heating austenite ?(C,H) is obtained, and after cooling ?brittle bainite? is obtained, etc. Presented scientific hypothesis explains the available experimental facts ("rejuvenation? and its reverse process, graphitization, weldability, forming of flakes, reaching high strength, etc.) in a new manner, as well as, gives real opportunity for creating of new trends in many fields, e.g. iron based HAA. Provisional data having been obtained are encouraging.

Jan 1, 2006

By Zhengde Pang, Xue-wei Lv, Guibao Qiu, Chenguang Bai, Zhiming Yan

The viscous behavior of molten slags has played an essential role in determining the performance and productivity of the ironmaking process. In this paper, the viscosity and free running temperature in CaO-SiO2-Al2O3-9 mass% MgO-TiO2 slag has been measured at different content of Al2O3 and Al2O3/SiO2 ratio. In addition, the slags viscous activation energy has also been calculated. The results show that the TiO2 as a basic oxide content from 1 to 5 mass% can reduce the viscosity and free running temperature, and moderate content of TiO2 in high alumina blast furnace slag remains effective for reducing viscous activation energy and free running temperature.

Mar 1, 2018

The viscosity of high magnesium content FeO-Fe3O4-SiO2-CaO-MgO slags at nickel flash smelting conditions was investigated using a commercial rotational viscometer. The studied parameters were compositions of slag and temperature. The viscosity of these slags was measured as a function of CaO, MgO, SiO2, FeO. Fe3O4 and Fe/SiO2 in temperature range from 1473K to 1723K. These slags contained 5.81 to 10.59 pct MgO, 0 to 10.37 pct CaO, 28.21 to 36.21 pct SiO2, 39.40 to 55.42 pct Fe and 1.1 to 1.5 Fe/SiO2.

Jan 1, 1999

By E. Charles Abbey

Manganese in electrolyte has both beneficial and detrimental effects in Zn electrowinning. Mn oxidizes to form MnO2 on Pb–Ag anodes, cell walls and pipes. MnO2 reduces anode corrosion but also leads to short circuiting and maintenance issues. MnO2 is thought to interact with chloride ions and produce oxidized chlorine species. The interactions between Mn and Cl are not well understood. Therefore, two sets of 45+ day bench scale experiments were conducted to investigate the effects of the manganese to chloride ratio on anode corrosion rate and electrolyte chemistry using rolled Pb–Ag anodes. Daily manganese and chloride losses from the electrolyte appeared to be correlated. Increasing the average Mn/Cl− ratio from ∼7:1 to ∼11:1 reduced the anode corrosion rate. Increasing the ratio above 11 did not reduce the corrosion rate further. Anode scales produced with Mn/Cl− ratios at and above 11:1 contained some γ–MnO2 while scales formed with ratios less than 11:1 did not.

By M. Bugdayci, Onuralp Yucel, K. C. Tasyurek

This paper is a contribution to the theory and quantitative understanding of the processes for the production of magnesium, calcium and strontium metals by metallothermic process. In the present study, effect of reductant type was investigated. Thermodynamic simulation of system was made by Fact Sage 6.4 program. In order to produce magnesium metal, effects of reductants “FeSi, Al, Si and CaC2” were investigated. To understand Calcium-oxide reduction system, effects of Al and CaF2 addition were investigated for different temperatures. In the last simulations, SrO reduction parameters were simulated. Al used as main reductant and BaO, CaO, CaC2 were added to green mixture as a functional additive. Finally probable phases and minimum reduction temperatures are determined.

Mar 1, 2018

By Ragnhild E. Aune, Mark William Kennedy, Shahid Akhtar, Jon Arne Bakken

"To determine the heating rate of billets using ‘short coils’, an appropriate correction factor must be applied to the theoretical relationship. In 1945, Vaughan and Williamson published a semi-empirically modified Nagaoka coefficient applicable for moderate frequency induction heating processes (10 kHz). Recently it was demonstrated that the method of Vaughan and Williamson gives <10% error in the estimated power when heating aluminum billets at 50 Hz.In the present study, experiments have been conducted on aluminum billets in order to verify an empirical frequency corrected ‘short coil’ equation. Measurements of electrical conductivity (<± 0.5%), current (± 1%), heat (± 1-3%), and magnetic flux density (± 1-2%) have been performed. The results are compared with 1D analytical calculations, and 2D axial symmetric FEM modeling using COMSOL 4.2®. The frequency corrected equation has proven to provide accurate predictions of power (<4% error) within the frequency range 50 Hz to 500 kHz.IntroductionInduction heating is commonly applied to the re-heating of billets before forging or extrusion processes. The resistive heating produced by eddy currents in the solid or semi-solid work piece during this procedure, is driven by the time varying magnetic flux density in the air-gap between the work piece and the coil. The flux in the air-gap is created by the current flowing in the induction coil, i.e. the magneto-motive force. In Figure 1 it can be seen that the currents present in the work piece are concentrated in the outer ‘shell’, or the first electromagnetic penetration depth (dw), and flow in a direction which opposes the magnetic field produced by the induction coil."

Jan 1, 2012

By Rodney Clary

Building on work completed in earlier papers, the current paper presents a techno-economic evaluation of two recently demonstrated technologies for treatment of arsenic containing refractory gold concentrates. Using defined project parameters and inputs, the authors compare capital and operating cost estimates for pressure oxidation (POx), and the Albion Process™. The paper incorporates data now publicly available from the Albion Process™ plant, which has operated at the GeoProMining Gold (GPM Gold) project in Armenia since 2014, as well as recent POx circuits.

By R. W. Charles

The Los Alamos National Laboratory, under the sponsorship of the U.S. Department of Energy; is involved with laboratory and field experiments to assist in development of the Hot Dry Rock concept of geothermal energy. The field program consists of experiments in which hot rock of low permeability is hydraulically fractured between two wellbores. Water is circulated from one well to the other through the fractured hot rock. Our field experiments are designed to test reservoir engineering parameters such as heat-extraction rates, water-loss rates, flow characteristics including impedance and buoyancy, seismic activity, and fluid chemistry. Laboratory experiments were designed to provide information on the mineral-water reactivity encountered during the field program. Two experimental circulation systems tested the rates of dissolution and alteration during dynamic flow. SOlubil ity of rock in agitated systems was studied. Moreover, pure minerals, samples of the granodiorite from the actual reservoir, and Tijeras Canyon granite have been reacted with distilled water and various solutions of NaCl, NaOH, and Na.CO.. The results of these experimental systems are compared to the observations made in field experiments done within the hot dry rock reservoir at a depth of approxi-mately 3 km where the initial rock temperature was 150 to 200°C.

Jan 1, 1981

By T. T. Lin, N. H. Madsen, K. Groom, B. A. Chin

"The objective of this research is to investigate the feasibility of using infrared sensors to monitor the welding process. Data were gathered using an infrared camera which was trained on the molten metal pool during the welding operation. Several types of process perturbations which result in weld defects were then intentionally induced and the resulting thermal images monitored. Gas tungsten arc using AC and DC currents and gas metal arc welding processes were investigated using steel, aluminum and stainless steel plate materials. The thermal images obtained in the three materials and different welding processes revealed nearly identical patterns for the same induced process perturbation. Based upon these results, infrared thermography is a method which may be very applicable to automation of the welding process.IntroductionAutomatic welding is commonplace in industry today. However, most, if not all, involves preprogramming for performance of a repetitive task. These systems are incapable of correcting for perturbations which arise during the welding process. Control of the welding process requires the identification and monitoring of perturbations in a wide variety of parameters. The varied nature of these parameters and the large number of variables involved have thwarted previous attempts at closed loop control of the welding process. The sensor(s) employed by a control system need to meet rather strenuous requirements. First and foremost of these is that such a sensor must be able to identify and discriminate between perturbations that might affect the quality of the weld, including such geometrical perturbations as a change of direction in the seam between the parts being welded, gaps in the seam or a misalignment of the parts being welded. The sensor should also be able to locate and identify contaminants and impurities in the weld puddle and ahead of it while monitoring the extent of the heat-affected zone and the cooling rate of the metal. The sensor(s) should, additionally, be able to perform these tasks in a time frame that is consistent with automatic control of the welding process. This paper presents results that could aid in the assembly of such a controlled welding system."

Jan 1, 1986