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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 Carlos Maurício F. Vieira, Lázaro A. Pizatto, Marcus Paulo Cardoso, Sergio Neves Monteiro, Joao Victor C. Nunes, Gustavo S. R. Matheus, Frederico M. Margem

The interest in composites with natural fibers is due, among other factors, to the growing worldwide concern with the preservation of environment and renewable raw materials. The natural fibers have many particular properties that make them an attractive alternative to traditional synthetic fibers. The advantages of using these fibers are: low cost, renewability, biodegradability, low toxicity, abundance and specific strength. The searching for new suitable, economically viable and technologically advanced materials justifies the accomplishment of this work that aims at comparing the mechanical behavior of polyester matrix composites with epoxy matrix composites reinforced with hemp fibers Izod impact tested. The specimens with dimensions: 10 63 12.7 mm, made in different volume fractions of fiber: 0–30 vol%. The samples were tested at PANTEC pendulum model XC-50 located at LAMAV/UENF. With this research was possible to analyse the mechanical properties of these two new materials.

Mar 1, 2018

By John R. Howell

"SUMMARYThe process of producing a new cast component requires significant design and development by both the design engineer and the foundry engineer. This effort strives to produce a high quality component at minimum cost. To assist in this development, an analysis system, consisting of several computer programs, has been developed to simulate the metal casting process. This system incorporates analytical geometric solid modeling, finite element analysis, results display, and an innovative technique to model the casting mold with surface boundary conditions.The simulation has produced excellent thermal results and work is in progress to develop techniques to enable use of this data in additional analyses to predict porosity and residual stress. Research is required to produce working parametric formulations of material properties. Software development is required to develop good fluid flow analyses for large. 3D models to simulate filling of and convection in molds.Integrating this system of programs is difficult due to proprietary database structures used by software developers. However, an acceptable means has been accomplished' to move data from one program to another. Further software development is required to facilitate this task. INTRODUCTIONThe process of producing a new cast component requires significant design and development by both the design and foundry engineer. This effort strives to produce a high quality, reliable component at minimum cost in a timely manner. The design engineer needs to know the physical and mechanical properites which can be expected in the actual part at critical areas. This will enable him to design a part with minimum material while fulfilling the performance required. The foundry engineer needs to produce a sound, quality casting with a minimal amount of material In risers, the feeding system and machining stock. This must be done with a minimum· investment in tooling and development time and maximum productivity of labor and capital employed. This task Is continually being made more difficult because of increased competition in the marketplace and the use of castings in more severe service. This has strongly influenced the need for high quality castings.The task of developing a new casting is difficult for both the design and foundry engineer. To assist in this development, Deere & Company has been engaged in the development of an analysis system to simulate material processes. A major portion of this program involves simulation of the metal casting process. This analysis system has evolved into a package of computer programs which simulates casting solidification and subsequent cooling through the finite element method"

Jan 1, 1986

By Bin Du

In recent years, concurrent product design and process is gaining popularity and will become a norm of the industry of the future. Forging has been a critical manufacturing process for production of components with superior tensile strength, toughness and grain flow. This paper describes an expen system which is being developed for forging die design and forging process analysis in concurrent engineering environment. Rules and guidelines pertaining to forgeability are formulated and incorporated into the knowledge-base in building the system. The system is built using an object-oriented paradigm. The object-oriented approach and hierarchical rule structure paradigm are briefly discussed. Finite element analysis packages (ALPID-2D) were incorporated into the program to give the simulation result of the forging process. The system can automatically produce a competent design and recommend a set of processing parameters for a given product. The designer can modify the design according to the result of the simulation.

Jan 1, 1992

By M. R. Jolly, J. -C. Gebelin

"A number of different types of so-called ""filters"" are used in the metal casting industries to impart some cleaning effect and flow control on the liquid metal as it passes through them. The filters range from simple planar meshes through extruded channels to reticulated foam structures and they are manufactured from a range of material going from metals to glass or ceramics. It is most common that software packages used in the industry model the filters by a simple pressure drop associated with some area fraction and permeability parameters.Recent experimental work at the IRC in Birmingham [1] has shown that filters of the same type can behave very differently depending upon the casting process in which they are employed. Modelling filter geometries for a range of different casting processes has indicated that the flow of metal and heat losses through the filters are rather complex and should be considered when using filters in the casting processes. This paper will present a number of cases of different types of filters modelled and different processes and indicate some of the sensitivities of the processes to boundary conditions imposed by the process.IntroductionFilters are commonly used in the foundry industry. The real action of the filters on the liquid metal is not really understood. Some filters are claimed to have a chemical action on the liquid metal or to be able to clean the metal by stopping the impurities or oxides that will result in inclusions in the cast part. However, some recent experiment carried out at the University of Birmingham in investment casting and results available on sand casting [2] have shown that the action of filters may be different in these two processes. As the main difference between these two processes is the mould temperature, the hypothesis of a partial solidification of the metal in the filter occurring in the sand casting process during the primary stage of the filling has been advanced, whereas there is little or no solidification in investment casting. In order to verify this hypothesis, and to reach a better understanding of how filters work, a numerical investigation of the flow and heat transfer in filters in both sand and investment casting has started at the University of Birmingham, in the framework of the FOCAST project. The FOCAST project is an EPSRC project aimed to increase the understanding of the investment casting process. Another issue is the way the simulation packages predict the influence of the filters on the metal flow. The filters are most of the time modelled as porous obstacles characterised by a pressure drop calculated from porosity and some surface ratios or proprietary coefficients. This paper will present the preliminary results of this numerical investigation. First, the different models that have been used are presented, followed by the obtained results. A discussion of these results and their perspectives conclude the paper."

Jan 1, 2001

By W. E. Wallace, J. A. Warren, D. Josell, D. Wheeler

"We present the results of experiments and modeling of flip-chip geometry solder joint shapes under shear loading. Modeling, using Surface Evolver, included development of techniques that use an applied vector force (normal and shear loading) as input to determine a vector displacement of the pads connected by the solder joint (standoff height and misalignment). Previous solutions solved the converse problem: fixed displacements used to determine required applied force. Such solutions were inconvenient for applications, where the applied force (chip weight) is known. Also, for geometric and materials studies of solder joint shapes involving multiple parameters, determining the equilibrium displacement from applied force by bracketing solutions could become computationally expensive. Measurements of solder joint standoff height and misalignment as functions of the applied force (normal and shear), solder volume and pad diameter are presented. Experiments were carried out for solder ball diameters from 0.38 mm (0.029 mm3 volume) to 0.15 mm (0.0019 mm3 volume) on pads of diameter 0.64 mm and 0.35 mm. Fitting of simulation to experimental results gave optimized values for the contact angle and surface tension of the solder which were consistent with measured and literature values. IntroductionIn packaging technology flip-chip has become an important method for attaching semiconductor devices to substrates. Generally, the chip and substrate are bumped with solder and then the chip is flipped onto the substrate and the solder reflowed to form conductive interconnects. An epoxy underfill is normally flowed between the substrate and chip to reduce the thermal fatigue on the solder joints. A flip-chip assembly is illustrated in Figure 1.In flip-chip applications, the use of an integrated underfill/solder bump system [1, 2) removes an extra process step, namely infiltration of the underfill. However, the presence of an underfill will retard the self-alignment of the flip-chip. A first step in understanding and predicting this retardation is to develop a model to describe normal and lateral force-displacements curves when underfill material is not present. At this stage it is unclear whether static surface tension theory is sufficient to describe a complete model for flip-chip realignment even without underfill."

Jan 1, 2001

By Junwei Han, Wenqing Qin, Dawei Wang, Fen Jiao, Wei Liu

The removal of iron impurity from zinc calcine was studied by magnetization roasting and magnetic separation. The effects of roasting temperature, magnetic intensity, ore grinding, and leaching pretreatment on iron grade and recovery were investigated. The results indicated that iron recovery increased with the increase of roasting temperature or magnetic intensity, while iron grade was always less than 22%, depending on the fact that the magnetite were not liberated completely. The good liberation was difficult to be achieved by ore grinding but was easier by acid leaching, since the magnetite grains were very fine. After the leaching pretreatment, the recovery of 76.31% with iron grade of 53.24% was obtained by one roughing and cleaning. The SEM/EDS analysis showed that a part of sphalerite, zinc ferrite and other gangues were mixed into the iron concentrate, while some of fine magnetite was reported to the tailing.

Jan 1, 2016

By Dany Racine, Daniel Marceau, Denis Laroche, Dmitry Lukovnikov

Carbon base materials play a critical role in the performance of Hall-Héroult cell. The determination of their thermo-physical properties is of primary importance for modeling and designing complete cell systems. However, overcoming the associated experimental hurdles is complex and often underestimated. Of them are the Poisson’s ratio measurements and the continuous oxidation/burning of the materials at temperatures above 200°C. The novel procedure developed in this research is based on the Gleeble® 3800 system. Its vacuum chamber allows test with a chosen atmosphere at temperature of more than 1000°C. Young’s modulus, Poisson’s ratio and the coefficient of thermal expansion values can all be adequately measured using a single test. Cylindrical carbon samples (: 50mm, L: 100mm) were tested in the modified system at temperatures ranging from room to 950°C without any trace of oxidation. The resulting values were also in good agreement with literature data for a specific graphite material.

Jan 1, 2015

By Alaina Mallard, Jannette Chorney, David Hutchins, Grant C. Wallace, Jerome P. Downey

Current commercial processes for producing ceramic carbides require temperatures of 1400–2000 °C and often use extensive milling operations to produce a powder product. A process that could reduce the energy requirements of commercial carbide production could allow for these materials to be implemented in a greater number of applications. In this study, tungstate (WO4 2−) and silicate (SiO3 2−) anions were adsorbed onto activated carbon and converted into silicon carbide (SiC) whiskers and a mixture of tungsten and tungsten carbide (W/WC) crystals via carbothermal reduction using inert and reducing gas atmospheres at temperatures much lower than what is required by current commercial processes (950 °C for W/WC/W2C and 1200 °C for SiC). The adsorption process was statistically-optimized via a central composite response surface analysis using DesignExpert 9. Inductive coupled plasma optical emission spectroscopy (ICP-OES) was used to measure, and optimize, adsorption efficiency while the carburization products were characterized using X-ray diffraction and scanning electron microscopy.

Mar 1, 2017

By Ruixuan Zhang, Yan Li, Shusen Cheng

The high temperature distribution of the blast furnace raceway plays an important role in continuous and steady production. There are a number of techniques which have been developed for flame temperature measurements, but most of them have considerable errors and instability. To obtain more accurate results, an efficient optimization algorithm is necessary. This paper presents a novel measurement approach based on the two-color method and an optimization algorithm using images of raceway flame captured by the RGB CCD (Charged-couple Device) camera to calculate the projection temperature distri- bution. Furthermore, both the back-propagation neural network and the principal component analysis are applied to calibrate the correlation between blackbody temperature and the gray-level intensity. Experimental results obtained from the blast furnace raceway demonstrate that the proposed optimization approach performs well in the measurement offlame temperature compared with the measured temperature.

Mar 1, 2017

By Haibin Wang, Kaile Tang, Chenn Q. Zhou, Guangwu Tang, Zhixiang Cui, Ping Zhou, Armin K. Silaen, Hongjie Yan, Zhi Wang

Bath smelting technology, such as the submerged lance smelting furnace, is used in the modern copper making industry. The first submerged lance smelting furnace developed by Dongying Fangyuan Nonferrous Metals Co., Ltd has shown potential for high productivity and energy savings. In this study, computational fluid dynamics (CFD) was applied to investigate the current design of the furnace. A three-dimensional multiphase CFD model was developed to study the interaction between injected gas and the liquid bath. The multiphase Eulerian model was used for simulating gas/liquid two-phase flow. The flow pattern in the submerged lance smelting furnace indicated rapid flow development and strong turbulent interactions between the gas and liquid phases. The model was validated based on a water model experiment of the mixing process. Mixing times from the simulation results show good agreement with experimental data. Additionally, based on this model, the gas residence time and liquid copper matte splashing phenomena under varying gas flow rates were investigated.

Mar 1, 2017

By Berger. P.

The accepted definition of the function of an edge protector fails to specify adequately the several tasks which it must perform to be functionally effective: detailed analysis of these tasks leads to the reasoned conclusion that they cannot satisfactorily be fulfilled by the conventional types of "edge-strips". The true cost of edge protector failure is cumulative: renewal costs are dwarfed by the increased operating expenses and production losses which result from but partial or incipient failure of the edge-strip; yet, the several supposedly improved types, for use with starter-blanks, generally were "built down to a price", prolonging the agony, as it were. Clearly, a fresh appraisal of the problem was overdue, and more especially so with the advent of "permanent" cathodes. As a result, new methods of edge .protection have been developed, including the so-called "EDGEWISE" system in which the present author as patentee *) has a vested interest-which he hereby declares. Due mention is made of recent progress in protecting the edges of aluminium "Jumbo" cathodes in zinc electrowinning operations, although the present Paper is more concerned with edge protection of starter-blanks and permanent cathodes in copper ER/EW processes, where most of the "old" problems now may justifiably be claimed to have been overcome, Mention is also made - albeit at this time necessarily only briefly, and confined to edge protection - of "rigidized" metal blanks and permanent cathodes: a most recent development**) which may prove to represent a "breakthrough": time will tell.

Jan 1, 1987

Two pilot-plant investigations were conducted in which strong-base resins were compared with activated carbon for the extraction of gold cyanide from leached pulp from the Golden Jubilee Mine. The results show that gold can be recovered with carbon, but that the extraction efficiency is poor, probably because high concentrations of humic and fulvic acids are. present m the pulp. .However the extraction of gold cyamde from this material with strong-base resins JS very effo:1ent, and the overall efficiency of extraction is better with resin than with carbon, even when the concentration of resin is one-third that of carbon, and the flowrate of resin is one-third that of carbon. The results of the pilot-plant campaign reported in this paper led to the conversion of the Golden Jubilee plant from carbon-in-pulp to resin-in-pulp in February 1988.

Jan 1, 1989

By Binxu Zhaug, Mark Jolly, Xiaojun Dai

"In conventional investment casting process of aluminium alloys for the application of the aerospace industry, to assure the quality of the final casting, usually the foundry uses large runner system which results in low yield, high energy consumption and high GHGs emission. In one case of this investigation, the yield is between 5 ~ 10% which means that the current casting process wastes large amount of energy and generates lots of scraps. By applying a new casting method, the bulky runner system and the melting/holding time are significantly reduced, the quality of the casting is improved, and in the meantime the related energy consumption and GHGs emission are significantly decreased. In the investigation, the energy efficiencies and GHGs emission between the current and traditional processes are calculated and compared.1. IntroductionAs one of the conventional casting process, Investment Casting Process (ICP) and its applications can be traced to thousand years ago [l]. In current casting industry, ICP still plays an important role in the production of small and precious castings with high quality requirements in automobile and aerospace industries. Both casting quality and manufacturing costs which mainly consist of energy costs have crucial effects on the competitiveness of castings in the market. In the production of aluminium alloy castings using ICP, the energy cost and energy efficiency of a casting facility depend mainly on the efficiency of its melting and heat treating performance. In association with the two performances, more than 60 % of the total process energy costs are symbolised in a typical casting facility [2]. Additionally, in conventional ICP of aluminium alloys for the application of the aerospace, to assure the quality of the final casting, typically the foundry uses huge runner system including big risers/feeders which cause low yield, creates lots of scraps and generates high energy consumption. Consequently, there are huge opportunities for casting industry to choose the best practices for potential energy saving. Furthermore, the reasons such as the stringent limitation of environmental legislation in Europe and the pressure of the rising energy price force the casting industry to reduce the energy consumption and greenhouse gases (GHGs) em1ss10n."

Jan 1, 2012

By Ajit Kumar Jaiswal

"Electric Arc Furnace (EAF) being a power-intensive equipment, EAF based industries are highly dependent on scarce electric energy. This is the reason Government of India is highly concerned about this and laid emphasis on the conservation of electric energy.This paper highlights factors contributing to reduction in specific electric energy consumption in EAF and suggests measures not only for power saving, but also for productivity improvement. To name a few, these are proper sealing of furnace, introduction of oxy-fuel burners, foamy slag practice, increased usage of hot metal/DRI, post-combustion of CO gas for preheating of scrap, improved selection & design criteria of electrics, power demand management, and process automation. Few cases also have been cited, where the above measures have helped in reaping significant benefits.IntroductionFor a long time, Government of India had focused on increase in energy supply, in particular, through electricity generation. Now the emphasis of Government of India has shifted from electricity generation to its conservation for following two reasons:??Power plants have become very cost-intensive??By saving energy, more of it can be delivered at lower cost to the consumersPower generating units, transmission & distribution agencies as well as consumers all have roles to play in the area of energy conservation. By energy conservation, we mean curtailing energy requirement by reducing energy wastages and taking up measures to improve energy efficiency of electric equipment/appliances. In almost all cases, this would be economically beneficial.India’s cost-effective energy conservation potential has been estimated by the Planning Commission at 23 per cent of total commercial energy generated ?1?. A national movement for energy conservation can significantly reduce the need for fresh investment in energy supply systems in coming years. It is imperative that we make all-out effort to realize this potential. Whether a household or a factory, a small shop or a large commercial building, a farmer or an office worker, every user can and must make this effort for his own benefit and for the nation’s benefit as well."

Jan 1, 2009

By Andreas Orth

Outokumpu Lurgi Metallurgie has developed a process for the calcination and reduction of laterite nickel ore tines where the reduction of iron and nickel to the wustite/metallic states respectively, is performed in a fluidized bed reactor using reduction gas generated very cost effectively from natural gas in an autothermal catalytic reactor. As an option coal can be used as reductant as well as additional fuel. The process of reduction and calcination is very energy optimized. It uses the off gas from the fluidized bed reduction reactor, which still contains energy, to dry and calcine the nickel ore fines in a primary stage circulating fluidized bed (CFB) reactor. The product shows high metallisation of nickel and iron oxides reduced to the wustite stage. This results in considerable energy savings in smelting the prereduced product to ferro-nickel. Alternatively the product can be leached to produce nickel. Laboratory tests showed very high recovery of nickel and cobalt. Keywords: Fluidized Bed, Prereduction, Calcination, Ferro-Nickel

Jan 1, 2004

By Yuanbo Zhang, Zhixiong You, Zijian Su, Bingbing Liu, Guanghui Li, Guang Yang, Tao Jiang

Sodium stannate is widely used in the electroplating and tin alloy industry. But the traditional processes for sodium stannate production are characterized by long flowsheet, high production cost and strict requirement for the equipments, etc. In this study, a novel process for sodium stannate preparation from cassiterite concentrate and sodium carbonate via roasting in CO/CO2 mixed gas then followed by leaching was developed. The effects of roasting parameters on the Sn leaching efficiency were conducted. A Sn leaching efficiency of 77.2% was obtained under the optimal conditions. Sodium stannate (Na2SnO3·3H2O) with a purity of 95.8% was produced by the new process, which is better than that specified for the industrial first-grade product.

Jan 1, 2014

By J. E. Klein

Bench scale tests using a stack of ten whole SAES St909 pellets, 6 grams, to crack methane have been completed with pure methane feed. Test conditions ranged from 600 to 800°C at 101 kPa (760 ton) with a methane feed rate of ten sccm. Methane reformation tests, test where hydrogen was passed through a St909 bed after cracking methane, were performed to determine if and how much methane can be generated under "reformation" conditions. Phase structure determinations of St909, composed of a ZrMnFe alloy with aluminum used as a pellet binder, after methane cracking were complicated by the number of materials that can be formed by the elements in the St909 and the carbon from methane cracking. It was determined that the aluminum not only alloys with the Zr, Mn, and Fe in the St909 alloy, but also forms aluminum transition metal carbides in addition to ZrC as the carbon content and the temperature of the St909 increases. Some A14C3 was also found in some pellets. Passing hydrogen over St909 pellets after methane cracking formed methane at various rates in the temperature range of 600 to 800°C. Temperatures of 800°C gave the best methane cracking performance and efficiencies decreased rapidly with temperature.

Jan 1, 2002

By Markus A. Reuter, Jacob Wood, Robert Matusewicz

Over the last 20 years, significant improvements in copper smelter productivity have been realized through the advent of continuous smelting processes. This progress has until recently however, not been carried through to copper converting. Peirce-Smith converting has been widely used by the copper industry for 100 years but is limited by its batch nature in achieving large scale of production. A logical next step is therefore copper converting on a continuous basis with its inherent environmental benefits. A number of continuous converting technologies are currently in use or being developed within the copper industry, the majority of these operating with calcium-ferrite slags. A notable exception however is the Ausmelt Continuous Copper Converting (C3) technology which has focused on operation with ferrous-calciumsilicate or loosely called olivine type slags. This paper discusses the merits of the Ausmelt C3 process and the advantages offered in terms of operational flexibility and process control arising from the use of lime modified iron silicate slags. It also examines the effects of key process variables pertinent to continuous copper converting from both a theoretical and experimental/operational perspective.

Jan 1, 2009

By Zhigan Deng

Ni–Mo ore is a black shale containing amorphous colloidal sulfides which have highly active. The oxygen pressure leaching behavior of nickel from black shale in aqueous media is presented. The effects of agitation speed, temperature, oxygen partial pressure and particle size on the rate of nickel leaching were determined. The results indicate that at low temperature hydrothermal and excess oxygen presence, the amorphous sulfides are easily oxidized to sulfuric acid and sulfate, and leaching nickel. The mathematical analyses of the experimental data for various experimental conditions indicated that the dissolution process was controlled by the chemical reaction during the early stage of dissolution, and was then controlled by liquid-film diffusion. In the initial stage of leaching, the reaction depends on oxygen partial pressure.