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By Run-boWang, Fan-yi Meng, Jian-Liang Zhang, ZheWang

To elucidate the influence of high Al2O3 content on sinter softening and melting behavior, heating-up reduction test under load was carried out. In addition, microstructure study of sinter bed structure change at a different temperature was also made and the mechanism that the effect of Al2O3 content on sinter softening and melting property was discovered. SEM results showed that the increase of Al2O3 content favored the formation of Al2O3-rich slag phase, such as the eutectic (2CaO·SiO2-2CaO·Al2O3·SiO2-FeO) and gehlenite (2CaO·Al2O3·SiO2), resulting in the decrease of sinter Ts temperature. Further, high Al2O3 content improved the concentration of metallic iron and lowered the dripping temperature due to the decrease of slag liquidus temperature and viscosity. At a fixed basicity, it was indicated that there was a relationship between Al2O3 content and sinter softening-melting property. Based on the results, counter strategies to cope with the adverse effect of high Al2O3 content on the cohesive zone property were also proposed. It could provide guidance for the blast furnace operation of sinter with high Al2O3 content.

Jan 1, 2015

Microstructural investigation has shown that grain splitting or deformation banding ( DB ) develops progressively with increasing strains during cold rolling. Of particular significance to simulating texture development in cold rolled BCC polycrystals is the operation of higher order slip systems other than 110 and, the occurrence of DB in the rolling plane since the latter allows a new relaxation of the shears. Deformation banding ( DB ) model includes grain subdivision in the rolling plane and applies the Relaxed Constraints ( RC ) mechanism for the other shears. An energy criterion for deciding whether deformation banding occurs or not has been postulated, referred to as Deformation Banding Criterion ( DBC ). This paper reports the results of the investigations into the effects of different slip systems, i.e., those based on 110, 112 and 123 slip planes and their combinations using RC, DB and DBC models, in developing simulated BCC rolling textures.

Jan 1, 1999

By J. K. Brimacombe

Plant trials have been conducted at the Tacoma Smelter of ASARCO to assess the effect on tuyere blockage and refractory erosion at the tuyere line, of increasing the injection pressure of air into a Peirce-Smith con¬verter. Four tuyeres each having an ID of 19.1 mm (3/4 in) were installed toward one end of the tuyere line of the No. 4 Converter. Air and oxygen-enriched air were injected at 414 kPag (60 psig) through these tuyeres and at the usual 83 kPag (12 psig) through the remainder of the tuyeres in an otherwise normal converter campaign. The test campaign consisted of 88 charges and lasted for 89 days. During this period, punching of the high-pressure tuyeres was found to-be unnecessary; and when, as a precaution, the tuyeres were cleaned by hand at the end of a charge, they were always open. Also it was observed that the flow of high-pressure air remained constant. Accretion formation around the tip of the high-pressure tuyeres varied from charge to charge and was influenced by the matte grade and the level of oxygen enrichment.

Jan 1, 1983

By Andriy Burbelko, Daniel Gurgul, Wojciech Kapturkiewicz, Marcin Gómy

"The mathematical model of the globular eutectic solidification in 2D was designed. The proposed model is based on the Cellular Automaton Finite Differences (CA-FD) calculation method. The model has been used for studies of the primary austenite and of globular eutectic grains growth during the ductile iron solidification in the thin wall casting. The model mentioned above takes into account, among other things, non-uniform temperature distribution in the casting wall cross-section, kinetics of the austenite and graphite grains nucleation, solute diffusion and non-equilibrium nature of the interphase boundary migration.Some aspects of stochastic nature of the solidification processes are taken into account. The results of the CA solidification modeling have been shown, that differences between cooling curves obtained in the same conditions of the casting solidification may be a result of the stochastic nature of the grain nucleation.The results of modeling were compared with the experimental microstructure. The model is well worked for thin walled ductile iron casting, for fast solidification process.IntroductionNodular graphite cast iron, also known as ductile iron (DI), has major applications in critical engineering parts due to its mechanical properties and castability. The mechanical and physical properties of this material depend on the shape and number of the graphite grains andmicrostructure of the metallic matrix.Solidification of DI was a subject of many computer modeling programs described in literature [ 1-5], in which the stationary conditions of carbon diffusion in austenite is pre-assumed. Recently, a tendency for production of thin-walled castings has been observed [ 6-8]. In this technology, the process of the fast solidification may be very far from equilibrium and steadystate conditions [9].The purpose of the present work is a two-dimension model development for simulation of the DI structure formation during the solidification in the condition of non steady-state temperature and diffusion fields in the thin-wall casting.Model of process The CA-FD is one of the known methods of the simulation ofmicrostructure formation during the solidification [ 10, 11]. In the CA microstructure modeling the outer grain shape is the result of the simulation and does not superimposed beforehand. The model development for a onephase microstructure evolution is a subject of the numerous researches [12 -23]. Model of the eutectic solidification of DI in the uniform temperature field and superimposed cooling rate is known [24]."

Jan 1, 2013

By XING Xiangdong, Zhang Jianliang, MA Jinfang, WANG Zhenyang

The non-equilibrium reflux reaction behavior of phosphorus was studied with synthetic slags formed by using the AR chemical reagents and changing the initial condition of basicity, FeO, MgO and Al2O3. Due to increase of viscosity, the dephosphorization slag with high basicity inhibits the full contact of slag with iron, which leads to the low reaction rate in the early stage. However, since the high basicity improves the activity coefficient of CaO, the dephosphorization rate and phosphorus capacity goes up in late reaction stage. FeO promotes the increase of reaction rate in early dephosphorization stage. But the polarization force of Fe2+ is stronger than Ca2+, which hinders the reaction between phosphate ion and CaO and reduces the stability of PO4 3-. Thus, high content of FeO will adversely impact on dephosphorization reaction. In addition, MgO has a promoting effect to the dephosphorization, whereas Al2O3 has a negative influence.

Jan 1, 2016

By J. H. Meza V

La Caridad operated at only 65% of design capacity during the first five years of operation. After the first major shutdown and repairs to the furnace in mid- 1992, the smelter quickly reached 95% of design capacity. Converter operation is now more efficient; blowing times have decreased from about 1.7 to 1.2 min/ton of matte. Anode copper production is now 15000 tons/month. The increased efficiency provided by better coordination and scheduling ensures La Caridad's ability to operate at present and expanded production capacity while simultaneously meeting environmental control standards.

Jan 1, 1993

By Yasuo Kudo, Wu, Hayato Sato, Hiroshi Nakazawa, Shouming

"In order to recover copper from a waste nickel condenser powder, bioleaching experiments were carried out using Thiobacillus ferrooxidans in a shaking flask. The content of nickel and copper in the waste nickel condenser powder in this study were 8.0% and 3.5%. X ray analysis showed the peak of barium titanate. In the preliminary study using metal nickel and copper powders , the dissolutions of nickel and especially copper were accelerated with the addition of ferric iron in the bioleaching of nickel and copper powders while not in the absence of ferric iron. Ferric iron oxidizes both metals, and Thiobacillusferrooxidans oxidizes ferrous iron resulting from the oxidation of metals, whereby the dissolutions of metals proceeds. The dissolution rates of nickel and copper increased with increase in the concentration of ferric iron in the bioleaching of the waste nickel condenser powder.1. IntroductionNickel condensers rejected from manufacturing plants are crushed and landfilled. Waste nickel condensers contain nickel and copper and could be considered as nickel and copper ores. Since the capacity of landfills is diminishing, it is required to recycle metals of waste nickel condensers in order to reduce the amount of wastes landfilled. Conventionally, metals in the waste were recovered by dry metallurgy after the incineration.Nickel has been refined by solvent extraction - electrowinning method (SX-EW method). Recently the amount of copper refined by SX-EW method has increased (Takahashi, et al. 1994). This method is cleaner and consumes less energy than conventional methods. Nickel dissolved well in acid solutions, but copper is not. If copper is leached efficiently from a waste nickel condenser powder, SX-EW method will be applied to recover copper from them"

Jan 1, 2000

By Ali S. Al-Watban

"In this paper, the room temperature friction and deformation properties of various polycrystalline diamonds; i.e. aggregates of diamond crystals with a ""binder"" phase of cobalt and a polycrystalline coating produced by a chemical vapour deposition processes (CVD) were studied when softer metallic and ceramic sliders were used. The experiments were conducted· at relatively low sliding speeds (10 mm/min), in a vacuum of 10-5 mbr after having cleaned the specimen surfaces by out-gassing them for about 30 min at 800 °C. As a result of increasing the number of traversals significant wear of the coated diamond by softer metallic sliders (aluminium and mild steel) was observed. With ceramic sliders, it is shown that the multiple traversals result in the formation of wear groove. With diamond silicon carbide, high friction and adhesion lead to significant metal transfer which then pre-empts cumulative deformation of the harder materials. With the diamond-cobalt composite, the friction is surprisingly low, there accumulation of wear debris on the tip of the slider but no permanent transfer of metal and the harder specimen is not damaged even after 5000 traversal.IntroductionPolycrystalline diamond is mainly produced as tool materials for the machining of hard metals and composites. Thus, the sliding friction and wear resistance are amongst the most important properties relevant to those applications.During cutting by PCD the wear mechanism is mostly influenced by the chemical affinity between the tool material and the workpiece. For example, diamond based materials are not recommended for machining ferrous materials because carbon is highly solubie in iron: This leads to the graphitisation of diamond particles and hence a high rate of diffusion wear is observed (Brookes and Lambert, 1982)."

Jan 1, 2000

By Toshiro Kuji, Masakazu Fujita, Tetsuji Saito

"The magnetic properties of the magnetic materials were deeply dependent on the microstructures. In this study, the novel technique to produce the desired microstructures in a controlled manner was proposed. The technique consisted of the production of the amorphous alloys and the control of the crystallization process. The technique was applied to improve the magnetic properties of Nd-Fe-B permanent magnets. The microstructural control of the magnets exhibited the excellently high energy-products of higher than 430 kJm-1. The relationship between the magnetic properties and the microstructures of the Nd-Fe-B permanent magnets was discussed.IntroductionThe intrinsic properties of the materials are basically determined by the properties of the constituent elements or the compounds. However, it is often noticed the difference between the observed properties and the theoretical values expected from the intrinsic properties of the materials. This indicates that the observed properties of the materials are determined not only by the properties of the constituent elements. In other words, the observed properties of the materials are also strongly dependent on the morphology of materials. This means that the microstructural control may creates a great improvement of the properties of materials.In Nd-Fe-B permanent magnets, the superiority arises from the uniaxial intermetallic Nd2Fe14B compound which has a large saturation magnetization and a high anisotropy field [1,2]. The magnetic properties of the Nd-Fe-B permanent magnets are dependent on the microstructure, that is, the size, shape and degree of the crystallographic alignment of the Nd2Fe14B phase. Currently, the Nd-Fe-B permanent magnets have been produced by either sintering or melt-spinning [3,4]. In the sintered magnets, alignment of the Nd2Fe14B phase is achieved by the prior green compaction of the crushed ingot powders in an applied magnetic field [3]. In the melt-spinning approach, alignment of the Nd2Fe14B phase is achieved by hot deformation [5]. Amorphous melt-spun ribbons are comminuted and then are consolidated into bulk form by hot pressing before hot deformation. As-hot-pressed magnets have randomly oriented Nd2Fe1~ grains [6]. Subsequent die upsetting of as-hot-pressed magnets gives rise to the crystallographic alignment of the Nd2Fe14B phase."

Jan 1, 1998

By Jilai Xue, Jun Zhu, Yongqiang Liu

"Up-grading silicon feedstock by removing B and metal impurities can improve process efficiency and lower production cost in metallurgical processing for solar cells production. Hydrometallurgical study has been carried out in laboratory through alternative treatments of the metallurgical grade (MG) silicon (-200 mesh) by using hydrogen peroxide, hydrofluoric acid (4 mol/L) and NH4Cl-NH4 F (30:5) solution. The experiments were usually performed under mechanical agitation at 70 ? for 5 h. ICP-AES analysis showed that B content in MG silicon after the hydrometallurgical treatment has reduced by 92.4 %, and Fe, Al, and Ca contents by 98.8 %, 98.0 % and 81 %, respectively. Kinetics of these processes was also studied for better understanding of the effects of silicon powder size, acid concentration, leaching and oxidizing time on the processing chemistry.IntroductionAs one of the most clean and promising new energy, solar energy is used more and more in many countries all over the world, especially in United States, Japan and European Union. Most of industrialized states have made their national photovoltaic plans, which have stimulated further increase in use of solar energy. Photovoltaic Industry is at a high growth rate about 30 % [1-2]. For silicon solar cells to remain the mainstay for the photovoltaic industry it is necessary to develop a low-cost solar grade silicon feedstock [3]. At the same time, the availability of the currently M-G silicon from the semiconductor industries becomes limited [4]. With the advantages of low cost and low energy consumption, metallurgical routes to product solar–grade silicon get more attention [5]. These routes mainly include pickling, slagging, vacuum processing and directional solidification, etc [6]. Among them the most important processing step is the directional solidification, but it still can not satisfy the industrial demand for removing B. Removing B from Si remains as one of the most difficult and important processes in making M-G silicon [7]."

Jan 1, 2012

By Xuewei Lv, Yuelin Qin, Guibao Qiu, Chenguang Bai

"Blast furnace slag (BF slag), is the main by-product in the ironmaking process, which contains large amounts of sensible heat. To recover the sensible heat, this paper described the hot experiments which were carried out in a rotary multi-nozzles cup atomizer, where the molten BFS was transformed into granules without water impingement; subsequently, a new method-pyrolysis the printed circuited board (PCB) with the hot BFS particle, was proposed for recovering the sensible heat in this study. The gaseous products were analyzed by gas analyzer. The residual of the PCB was analyzed by FT-IR and XRD respectively, and the obtained slag particles were analyzed by XRD.The results showed that it is a feasible process of pyrolyzing PCB powder with the hot BFS particle. The sensible heat of hot BF slag could be converted to chemical heat and a large amount of combustible gas could also be generated during the process.IntroductionDue to the rising of the product cost of blast furnace iron (BFI) and the increasing public awareness of environmental problems, the steel industries have to focus on the energy saving and emission reduction. Blast furnace slag (BF slag) is a byproduct from blast furnace exhaust temperature of 1450°C or so, is a high-quality waste heat resources. In China, the steel industry produces approximately 220Mt ofBFS per year, and the enthalpy of those slags is approximately equivalent to 13.3% of the whole energy consumption in the ironmaking process[!]. It can be seen, recycling waste heat is an important way of energy saving for iron and steel enterprises. The molten slag was treated by conventional water quenching method without any recovery of heat in spite of its huge potential. Also, the water quenching process consumes a plenty of water, pollutes the air and water[2]. Additionally, the extra energy is necessary for the drying process of slag to produce cement. As a kind of secondhand resource which can be reused, the BF slag contains a large amount of sensible heat. To recover the sensible heat of BF slag, three key problems should be considered, which refer to ( 1) the dry granulation of BFS without consuming water, (2) how to recover the heat of slag particles efficiently, (3) how to use the slag particles after heat recovery."

Jan 1, 2012

By Jafar Safarian, Merete Tangstad, Leiv Kolbeinsen

"Silicon and its binary alloys have several applications in metallurgical, chemical, photovoltaic and semiconductor industries. Silicon goes to its liquid state within its production, refining and when it is alloyed with other elements. Therefore, the characterization of silicon melts thermodynamics is important and useful. The liquidus and activities in several silicon binary systems have been recently calculated by the application of two liquidus constants, which were established using the experimentally determined liquidus data. In the present study, the thermodynamic properties of six silicon binary melts, which are simple eutectics, are calculated by analytical approaches. In this case, the changes in the partial and integral Gibbs free energies and enthalpies of mixing are calculated and compared with the experimental data in literature. The enthalpies are calculated by two methods and the calculation results are compared to the data from the literature. It is shown that thermodynamic properties of silicon binary melts can be accurately predicted without the use of complicated thermodynamic software.IntroductionSilicon and its alloys have several industrial applications. Silicon is used for making aluminium-silicon alloys to produce cast parts, mainly for automotive industry. Silicon in the form of ferro-silicon is used to deoxidize and alloy steel and cast iron. The photovoltaic (PV) industry has had a rapid growth in the recent years and silicon is the dominant material used for the fabrication of solar cells. Silicon is primarily produced through carbothermic reduction of quartz in electric arc furnaces and the produced metallurgical grade silicon (MG-Si) contains around 1 wt% impurities. It is further refined to produce solar grade silicon (SoG-Si) with above 99.9999 wt% Si to fulfil the chemical requirement for PV application. Since molten silicon is processed all along the metallurgical route, obtaining fundamental thermodynamics knowledge about silicon melts is valuable for the related industries."

Jan 1, 2012

By Marco Antônio Siqueira Rodrigues

The possibilities for treating rinse waters fiom chromating bath by electrodialysis are discussed together with the possibilities of optimizing the treatment process for waste reduction and reuse of water and chemical products. An industrial effluent with 4600 ppm of Cr(VI), besides other metallic contamination, was used as work solution. This solution has been recirculated on an electrodialysis cell of three compartments, using exchange membranes Selemiom AMT and CMT. A migration of dichromate ions into the anodic compartment was obtained, so that an extraction of circa 99.9 % of Cr(VI) present on the solution was observed, resulting in water with a Cr(V[) concentration of 4 rnd. These results show that electrodialysis can be used to treat these effluents, and this water could be reused as rinse water. The solution of the anodic compartment, consisting at the beginning of the experiment of H2S04, 0.1 N, reached 7200 mg/l of Cr(VI). This concentrate could be reused on the chromating bath itself.

Jan 1, 1999

By Xu-ling Chen, Qian Li, Yong-bin Yang, Zhao Jing, Tao Jiang, Guang-hui Li

"It is generally known that alkali metals are harmful to blast furnace production resulting in aggravating RDI of sinters, abnormal expansion of pellets, deteriorating blast furnace lining, etc. Sinters regarded as dominating burden of blast furnace are determined as the main source of alkali metals. In this study, the removal behavior of potassium and sodium oxides by pre-reduction sintering during the sintering process was studied. The removal ratio ofK20 and Na20 was greatly influenced by coke powder content, carbon species, coke powder adding ways, additive and so on. Under the conditions of carbon rate 12% and 5% dosage of CO supplied in the sintering process, the corresponding removal ratio ofK20, Na20 was 69.00% and 32.79%, and metallization ratio could reach 4.65%. This technology provided a novel process for reducing the content of alkali metals in sinters and dramatically improving the quality of blast furnace burden.IntroductionSinter is the main iron-bearing charge of blast furnace for iron-making in China, making up about 80% of the total burden; therefore, its quality has a significant influence on the quality of pig iron and blast furnace operation. Research and practice of numerous years prove that potassium and sodium coming from ores are brought into blast furnace and upgraded, which is one of the essential reasons that lead to blast furnace nodulation and influences its strength. Currently, effective flow sheet to remove potassium and sodium is weak magnetic separation-intensive magnetic separation-flotation [l], while iron ore concentrate is still ofhigh levels of potassium and sodium. As sintering process is also not effective to remove potassium and sodium, blast furnace in China is of high alkali burden, e.g. it reaches 5.6-6.2kg/tFe in Baotou iron making plant, which is greater than international tolerated level of2.55kgltFe [l]."

Jan 1, 2013

By José Carlos Abreu

This work presents a kinetics study covering the effects of temperature over the reduction rates of a carbon composite briquette, aiming its use as burden in some of the new alternate ironmaking technologies, such as the Tecnored process. It is reported that increases in the temperature increases the reaction rate. Additionally, the morphology of the iron phase generated during the reduction of these briquettes is presented. It was possible to verify that three types of iron morphology occurred during the process: an external, dense and continuous iron layer, the presence of iron globules at the center of the briquettes and whiskers at the briquette's core. The measurement of the carbon content on the globules and the external iron layer is also presented.

Jan 1, 2003

By Stefan Mutl

By the term sorting one understands the separation of a material mixture into two or several products according to different material characteristics in the preparation technology. The oldest sorting procedure, the handpicking, is less and less used to separate different material mixtures because of the considerable personnel expenditure and the strict hygienic regulations at the workplaces in Europe. In general, the manual assortment is able to solve separation tasks, which could not be solved by machines so far. The picking is one of the most selective processing methods. However, the progress in the computer and sensor engineering today makes the creation of automatic picking devices possible, whose efficiency goes far beyond the possibilities of handpicking. Therefore in the future automatic picking will not only be applied to already common applications like the waste glass assortment by colour, but also to the assortment of complex composed material mixtures e.g. old shreddered cars. Thus, the automatic picking, supported by high performance computer systems and new sensor technology, gains more and more significance within many applications of waste processing. However, in order to apply automatic sorting procedures for different material streams within recycling processes, a substantial research and development need still is existing. The desire of the users is to sort more extensively in order to achieve products with bigger material varieties, In addition, the requirement of the accuracy of recognizing and sorting out of single grains rises, This lecture illustrates the procedure of the hand picking before it was employed in waste processing. Thus, a renaissance of a long forgotten method is happening in terms of today's state of the art procedure "automatic picking". Possible technologies, fields of application and future potentials of this technology are pointed out.

Jan 1, 2003

By M. J. Walker

The lead .smelter at Cominco's operations at Trail, B.C. has been undergoing. a modernization program since 1986. In that year a contract agreement was reached with German-based Lurgi GmbH which allows Cominco to construct and operate a lead smelter using Lurgi's QSL process. Cominco Engineering Services Ltd. (CESL), a subsidiary of Cominco Ltd., was contracted to provide project management, engineering, procurement and construction management? services for the project. The new smelter replaces the existing sinter-blast furnace plant ?and will have a capacity of up to 1601000 tonnes per year of refined lead. This new smelting proc.ess results in significant operating cost reductions and major environmental .improvements. Start-up of the new plant is scheduled for the fall of 1989. The metallurgy and the operating parameters, important to the design of the new smelter, are described together with projected deportments of lead, zinc, silver and minor metals. A plant description, will be given for the following major areas that make up the modernization project: the pressure filter operation for the preparation of ,zinc leach residues feed material, the QSL reactor and boiler itself, together with its feed system and process gas treatment, and the drossing plant with a new continuous drossing furnace and oxygen softening and thallium removal. Slag from the QSL reactor will be treated in existing slag furnaces until a subsequent second phase of the modernization is completed in the 1990s.

Jan 1, 1990

By Shekhar Bhansali, Shyam Aravamudhan

"This paper reports on the design and simulation results of a silicon bulk-micromachined diaphragm-type piezoresistive pressure sensor capable of operating linearly over a wide dynamic range (0-1000 meters of water). The piezoresistor elements of the sensor are arranged in a wheat stone bridge configuration to achieve a higher output response. Simulation results (output voltage and sensitivity analysis) obtained using coupled MemPZR-MemMech module of the CoventorWare2003 Finite Element tool are presented. The effect of diaphragm size, diaphragm thickness and thickness of the piezos on output sensitivity were analyzed and optimized to get a linear response over the wide dynamic range.IntroductionThe physical and biological processes in the ocean are critically influenced by ocean parameters (pressure, salinity and temperature). Thus there is a need to develop inexpensive and reliable sensors to continuously measure large volumes of sea-space over long time spans. A key component in any such system will be a pressure/depth sensor. This sensor is routinely employed in marine applications such as wave and tide gauges, tsunami detection, platform leveling etc. More significantly, pressure measurement is needed for depth determination. Depth sensors are vital for remote operated vehicles (ROVs), profiling instruments and towed arrays.Several techniques have been routinely used in the past to measure pressure in the marine environment [1-3]. In general, the pressure sensor design is based on a flexible membrane as the spring element for the sensing pressure [4]. The deflection of the membrane, induced by the applied pressure, is converted into an electrical output through a component that is sensitive to diaphragm deflection (capacitive coupling) or associated stresses (piezoresistors, strain gauges). The temperature compensated pressure measurement can be readily converted to depth using"

Jan 1, 2004

By Xuling Chen, Yi Wang, Xiaohui Fan

"The current control method of grate-kiln iron ore oxide pellet production is lack of accuracy and normalization due to the limited detection conditions. Therefore, mathematical models of grate-kiln temperature field are presented. With calculation of gas-particle heat transfer as well as enthalpy changes of moisture evaporation and magnetite oxidation, the thermal history of pellets throughout grate-kiln process can be acquired and used for production status estimation. Taking the calculated results as well as detected data in production as inputs, process parameters such as running speed, fan opening and coal injection rate as adjusting objects, expert system for grate-kiln pellet production is outlined. And the preheating section dominated control strategy is explained. Results of production application show that the stability rate of gas temperature in gas hood of preheating section is increased from 91.0% to 94.2%, compressive strength and first grade rate of pellet are increased by 3.62% and 2.36%, respectively, while FeO content is 18.18% lower. Control guidance of this expert system can solve production anomalies effectively, stabilize grate-kiln iron ore oxide pellet production and improve pellet quality.IntroductionSteel industry in China has developed rapidly in recent years. China’s crude steel production in 2010 is nearly 627 million, which is 44.2% of the world total production. Burden with higher quality is demanded by enlargement and modernization of blast furnaces. And oxide pellet production has become a growing concern. In 2010, the total production of pellet in China is 110 million, and about 60% is produced by grate-kiln process."

Jan 1, 2012

By R. Lanza, M. Hytros, N. Saka, I. Jureidini, J. H. Chun, D. Kim

"A novel method for delineating the solidification front in metal casting has been developed using the attenuation phenomenon of electromagnetic radiation (y-rays or x-rays) and computed tomography (CT). The densities of the liquid and solid phases that exist during metal casting may differ anywhere from 4 to 12 % depending on the metal. As in the medical imaging field, CT provides an excellent means of mapping this density variation in a solidifying casting into two-or three-dimensional images.In an effort to develop an industrial-scale sensor, laboratory-scale experiments have been conducted using a cobalt-60 (Co60) radioisotope and a sodium-iodide (Nal) scintillation detector. The CT image reconstruction was performed on a crucible containing pure tin in a two-phase state. Although the spatial resolution and data acquisition speed were not optimum, the CT images clearly differentiate the liquid and solid phases of the tin in the crucible. To maximize resolution and minimize data acquisition time, a linear accelerator (linac)-based CT sensor is being developed and tested for application in the continuous casting of steel and aluminum alloys.IntroductionIn all casting processes, the quality of a finished product and its production rate depend upon the shape and movement of the solidification front. From a quality perspective, it is well documented that solidification kinetics (heat and mass transfer, fluid flow, microstructure evolution) greatly influence the final properties of castings [l,2,3]. Product shortcomings, such as surface defects, cracks, macro-and microsegregation, and inclusions are directly controlled by the solidification process. By understanding the role the solidification front plays in the casting process, product quality may be dramatically increased through the reduction of defects."

Jan 1, 1997