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By Chang Wei, Fan Zhang, Zhigan Deng, Minting Li, Cunxiong Li, Gang Fan, Xingbin Li

Marmatite is an important resource of zinc, which exist in forms of high iron and high indium. In order to recycle the valuable metal from these ores, the testwork of simultaneous leaching on neutral residue mixed with zinc concentrate of high iron and high indium has been conducted. The primary objectives are to leach the zinc and indium remaining in the neutral leach residue as ferrite using acid, and to reduce the ferric iron in solution to the ferrous by zinc concentrate, thereby extracting the zinc and indium in the zinc concentrate. The results indicated that in the following conditions, mass ratio of neutral residue to zinc concentrate of 1:0.25, particle size of 74-58 μm, initial sulfuric acid concentration of 150 g/L, liquid to solid ratio of 8 L/kg, temperature of 90°C, reaction time of 4h, the leaching efficiency of zinc and indium were over 95%, nearly 90% Fe was Ferrous in the leaching solution. This process effectively extracted zinc and indium and converted Fe3+ into Fe2+ in solution, and simplified the traditional process of reduction after leaching.

Jan 1, 2016

By Djalma Souza, Rubén Sánchez, Regina Maria Pinheiro, Carlos Maurício Fontes Vieira, Sergio Neves Monteiro

"This work has for objectives to characterize a waste generated in the form of sludge during the treatment of the effluent of a paper making industry and to evaluate the effect of its incorporation up to 10 wt.% on the properties of a clayey body used for brick production. For the characterization of the waste the following techniques were used: X-ray diffraction, X-ray fluorescence, differential thermal analysis and termogravimetric analysis with mass spectrometry. Specimens were prepared by uniaxial pressing at 20 MPa before firing at 750 °C. The physical and mechanical properties evaluated were: linear shrinkage, water absorption and flexural rupture strength. The results showed that, in agreement with the characteristics of the waste, its recycling into red ceramic can contribute to decrease the consumption of fuel during the firing stage. However, the waste changes the physical and mechanical properties, generating a deleterious effect on the water absorption and flexural rupture strength of the ceramic.IntroductionAccording to the Brazilian Association of Pulp and Paper, in the last 10 years, the global production of paper grew 35%. Brazil produced 8,2 million tons of paper in 2004 and held the position of the seventh largest world manufacturer of pulp, with about 9,4 million tons per year [1]. The pulp and paper industry generates effluents that present problems related to their disposal, even after the treatment. Among the solid wastes generated by this industry, the main waste is the primary sludge from the effluent treatment plant (ETP).After the initial treatment the decanted solids go through a dewatering stage, generating the solid form denominated primary sludge. This sludge resembles a paper paste of dark gray color when humid, and clear gray color when dry. This primary waste is composed basically of kaolin, pulp, traces of chemical substances and water. This waste generated in the pulp and paper industry depends on the characteristics of the process and of the employed techniques. It can vary significantly from one industrial unit to another, even in the case that the final products are similar. Its composition is approximately 60% of kaolin and 40% of pulp, and these percentages can vary in some moments as a function of the process [2,3]."

Jan 1, 2008

By Rzyman Michal, Nakamura Takashi, Shibata Etsuro, Grabda Mariusz, Oleszek-Kudlak Sylwia

"Tetrabromobisphenol A (TBBPA) and many systems based on the synergistic effect of brominated organic compounds with Sb2O3 are extensively used as effective brominated flame retardants (BFRs) in many materials such as plastics and textiles. Thermal degradation of BFR containing plastics leads to the formation of hydrocarbons and gaseous compounds such as HBr and SbBr3. Our thermodynamic considerations indicate that these gases can act as bromination agents for metallic oxides such as ZnO, Cu2O, CuO, PbO and FeO. Moreover, these metallic oxides have the thermodynamic tendency to brominate easier than does Sb2O3. The aim of this study was to investigate experimentally the reactivity of ZnO with 1) HBr originating from the thermal decomposition of TBBPA and 2) SbBr3, which is formed during thermal degradation of brominated flame retardant plastics. The thermal treatments of the mixture of compounds of interest were investigated by thermogravimetry coupled with mass spectrometry.IntroductionTetrabromobisphenol A (TBBPA) and many systems based on the synergistic effect of brominated organic compounds with Sb2O3 are extensively used as effective brominated flame retardants (BFRs) in materials such as plastics and textiles. For instance, 4.5 million tons of flame retardant plastics containing BFRs are produced in Japan each year. Thus, in thermal treatments such as the incineration and melting of solid wastes, BFR containing plastics are intentionally or unintentionally included in the wastes. Thermal degradation of BFR-containing plastics leads to the formation of hydrocarbons and gaseous compounds such as HBr and SbBr3 [1-5]. Our thermodynamic considerations [6] indicate that heavy metal oxides such as ZnO, Cu2O, CuO, PbO and FeO should easily react with HBr prior to Sb2O3 and also with SbBr3, the main gaseous product in the thermal decomposition of TBBPA, forming low boiling point metallic bromides suitable for the volatile separation of heavy metals. The metal oxides are also expected to qualitatively and quantitatively affect debromination and decomposition of the flame retardant."

Jan 1, 2008

By Admire Chaendera

A gas jet was blown through submerged nozzles to stir the bath in the presence and absence of slag. Mixing and mass transfer rates were then studied. Water and kerosene (10% by volume) were used to simulate the metal and slag phases respectively in the cold model. The mixing time (Tmix), defined at 99.66% bath homogeneity level, increased with bath height and decreased with an increase in the gas injection rate. Its value in the model vessel was related to gas flow rate (Q), bath weight (W), and bath height (H) by, Tmix = 4.39Q-0.73W0.24H1.12. Inclusion of the slag phase increased Tmix by about 16% and the mass transfer parameter, [(Reloc,r)0.25(Ret)0.32], values by about 32%. Mass transfer rates were higher near the bath surface and in the gas-liquid plume region. They increased with gas flow rate but decreased with an increase in bath height. The relationship, K Q0.08, showing derived mass transfer coefficient (K) dependence on the gas injection rate (Q) was established. The proportionality constant in the equation varied with gas flow rate and sample location.

Jan 1, 2006

By Zhenyang Wang, Yiran LIU, Xiangdong Xing, Jianliang Zhang, Zhengjian Liu

Basic characteristics of marine placer were systematically studied by chemical analyze, scanning electron microscope and X-ray diffraction in this paper. It could be found that the marine placer mainly consists of titanomagnetite and titanohematite. A series of experiments were performed to investigate reduction-magnetic separation for Fe and Ti from the marine placer. Effects of reduction temperature, reduction time, carbon ratio, magnetic density, and grinding fineness on the reduction-magnetic separation process were investigated. And the optimal process parameters were obtained as follows: the reduction temperature 1300, the reduction time 30 min, the carbon ratio 1.1, the magnetic density 50mT, and the grinding fineness of 0.074μm 86.34%. Under such conditions, the metallization rate, iron grade of magnetic substance and iron recovery reached to 94.23%, 97.19% and 90.28% respectively, and the titanium grade in non-magnetic substance and recovery of was 57.94% and 87.22% respectively. The effective separation of iron and titanium could be achieved in reduction-magnetic separation process.

Jan 1, 2015

By Biswadeep Saha, Meenakshisundaram Ramanathan, Chai Ren, Sivaraman Guruswamy

"Fe-Ga alloys have a large low-field magnetostriction and these alloys are attractive candidates in energy conversion and harvesting applications. Small additions of W also increase the magnetostriction of Fe. In this paper changes in magnetostriction by W substitution for Ga in various Fe-x at.% Ga alloys are presented. Fe-Ga-W single crystals were grown using vertical Bridgman Growth technique. [001]-orientated single crystal samples were prepared with faces within 1 degree off <100> orientation. The samples were annealed at 1150 °C in the alpha-phase region and water quenched. The magnetostriction coefficient (3/2)A-100 measurements were made on these Fe-Ga-W single crystals. The result on the effects of W substitution and annealing on the magnetostrictive behavior of these alloys are discussed.*Support of this work by NSF-DMR under the award DMR-0854166 is gratefully acknowledged.IntroductionMagnetostrictive materials changes their dimension exhibit reversible strains and changes in elastic properties in the presence of an applied magnetic field or the reciprocal effect of changes in the magnetic properties with the application of stress [IJ and are very important in sensor, actuator device, linear motor, magnetomechanical devices, microelectro- mechanical devices, active vibration dampening devices application areas. The discovery of an order of magnitude enhancement in the magnetostriction of Fe with Ga addition coupled with low saturation magnetic fields, and excellent mechanical properties opened up the possibility of obtaining larger magnetostriction values in other low-cost ductile a-Fe phase based alloys with alloying additives that are less expensive than rareearths such as Tb and Dy [2·4l_ The magnetostriction values observed in Fe-Ga single crystals are sensitive to thermal history and composition. The formation of second short range ordering phases and local defects inside crystal structure can also cause a dramatic change to this alloy's magnetostriction behavior [5-9l_"

Jan 1, 2012

By Herman Wotruba

Mercury emissions and other environmental impacts in small-scale gold mining are a world-wide problem. "Clean" or better: "Cleaner" technologies have -apart from being environmentally sound -to guarantee a higher income and better working conditions for the miners in order to have a chance for long-term acceptance. In small scale primary gold mining in several South American countries, a number of techniques have been adapted and improved so that they not only were accepted due to their efficiency and easy handling, but they could also significantly lower mercury emissions.

Jan 1, 2003

By Zhigang Zak Fang, Michael L. Free, Jaehun Cho, Syamantak Roy, Amarchand Sathyapalan

Leaching characteristics of impurity removal from the Upgraded Titania Slag (UGS) using hydrochloric and boric acids has been investigated. Specifically, this study has focused on removal of iron oxides from the UGS that has been reduced by hydrogen gas and magnesium at 750oC for 5 hours. Reduced UGS is mainly composed of titanium hydride and impurities like iron oxides, silicon oxide, aluminum oxide, and magnesium oxide. The concentration of hydrochloric and boric acids and the leaching temperature have been chosen as the prime variables to identify the optimum conditions and leaching characteristics for removal of iron oxides. It was observed that under the constraint that 1 wt % of titanium hydride loss is the maximum amount tolerable, 0.1M HCl with 1M boric acid and 90oC are the most effective parameters for iron removal from the reduced UGS. Also, the overall rate of reaction seems to follow interfacial reaction controlled kinetics. The calculated activation energy of the reaction is 73.90kJ/mol.

Jan 1, 2016

By Pedro Morales C.

From its beginning in the 1970s, the Teniente Converter has consistently achieved continuous improvement, and has contributed to the competitiveness and sustainability of Codelco&apos;s copper operations. The later introduction of the Slag Cleaning Furnace technology has helped to create a full technology package, referred to as the Teniente Technology. This paper outlines the features of a new research and innovation program designed to bring the Teniente Technology as a modem, competitive technology into the 21st century. The overall objectives and features of the program are described and discussed. It is fully anticipated that these activities will help position the Teniente Technology as a world-class modem technology, well-integrated and operating in a fully continuous mode in conjunction with the other units at the plant, a competitive technology which operates in harmony with respect to environmental regulations.

Jan 1, 1999

By Stuart D. Miller, Clayton L. Rumble

"A field net acid generation (NAG) test procedure has been utilized on-site to identify, classify and map potentially acid forming overburden at the PT Kaltim Prima Coal (K.PC) mining operation situated in the tropical equatorial region of East Kalimantan, Indonesia. The field procedure involves routine use of a calibrated, site specific NAG test (rapid oxidation test using hydrogen peroxide) which has a tum-around time of less than 24 hours and requires minimal sample preparation. It is used on geological drill-hole samples, for forward planning and overburden management; blast-hole samples, for day-to-day operational control and overburden scheduling; and final dump surface samples, for verification testing. This operational monitoring program has been in use at KPC for the past four years.Calibration and implementation of the field procedure has involved validating the NAG test using conventional acid-base accounting techniques, producing an overburden geochemical classification scheme, optimizing laboratory and sample preparation procedures, and ongoing quality management. This paper presents background theory and practical application in a case study format."

Jan 1, 1999

By M. M. Coleman

An investigation of the behaviour of sphalerite, chalcopyrite, galena and pyrite during flotation was conducted on selected circuits in the Brunswick Mining and Smelting Corporation Ltd. concentrator in Bathurst, NB. Samples were collected from 59 locations and analyzed for Zn, Pb, Cu, Ag, Fe, As, Sb, Sn, Bi and S. Metal balances were computed using the CAMP Material Balance Program (MATBAL 5) and the metal recoveries for each cell and circuit were calculated. An automated image analyzer interfaced with an electron microprobe was programmed to measure the size of sphalerite, chalcopyrite, galena and pyrite grains in each sample. The percentage of each mineral occurring as free grains and the relative amount of each mineral present in binary and ternary particles was calculated. The recoveries and losses of Pb, Zn and Cu are compared with the amount of liberated and unliberated galena, sphalerite and chalcopyrite present in the concentrates and tailings.

Jan 1, 1989

By F. Patisson

One of the major issues with multiparticle reactors is to handle their multiscale aspect. For modeling, it usually comes to coupling a reactor model (describing the phenomena at the macroscopic scale) with a so-called grain model (simulating the behavior of a single grain or a particle). An interesting approach proposed by H.Y. Sohn (1978) is to use the law of additive reaction times in order to calculate, approximately but analytically, the reaction rate of a particle in the reactor model. Its great advantage, compared to a numerical grain model, is to drastically reduce the computation time, particularly in the case of complex reactor models. This is the approach we retained for modeling the moving bed furnace, a counter-current gas-solid reactor used in the nuclear fuel-making route for producing uranium tetrafluoride from uranium trioxide. The numerical model we developed is 2-dimensional, steady-state and based on the finite volume method. It describes solid and gas flow, convective, conductive and radiative heat transfers, and six chemical reactions involved in the process. The law of additive reaction times is used to calculate analytically the rate of the three principal gas-solid reactions at every discrete point in the reactor. We have demonstrated the validity of this approach by comparing its results with those calculated from a numerical grain model. Also detailed in the paper are the main results of the moving bed furnace model itself and the possibilities of optimizing the process revealed by the calculations.

Jan 1, 2006

By Akira Nishikawa

During the twentieth century, the copper smelting industry achieved dramatic expansion corresponding to the vast growth of global economy. This was largely due to innovations in pyro-metallurgical processes, such as autogenous smelting and continuous smelting and converting technologies. However, as copper production capacity increased, its impact on the environment also could not be ignored, and thus with increasing global environmental awareness, many smelting operations either had to renew or rebuild their facilities. In addition to these changes, in places like Japan and Europe, with scarce primary resources, the treatment and recovery of metals from a variety of items such as car shredder dust, used electrical appliances and electronic devices, on top of scraps traditionally treated, is having a profound effect on the reduction of waste and the preservation of primary resources. Thus compared to the days when copper smelting focused on the environmental control in order to break with "Smoke Stack Industry", copper smelting today is making an important contribution to the sustainable development of human society.

Jan 1, 2003

By Akira Nishikawa

During the twentieth century the copper smelting industry achieved dramatic expansion corresponding to the vast growth of global economy. This was largely due to innovations in pyro-metallurgical processes, such as autogenous smelting and continuous smelting and converting technologies. However, as copper production capacity increased, its impact on the environment also could not be ignored, and thus with increasing global environmental awareness, many smelting operations either had to renew or rebuild their facilities. In addition to these changes, in places like Japan and Europe, with scarce primary resources, the treatment and recovery of metals from a variety of items such as car shredder dust, used electrical appliances and electronic devices, on top of scraps traditionally treated, is having a profound effect on the reduction of waste and the preservation of primary resources. Thus compared to the days when copper smelting focused on the environmental control in order to break with "Smoke Stack Industry", copper smelting today is making an important contribution to the sustainable development of human society.

Jan 1, 2003

By Petre Stelian Nita

In small steelmaking shops, in foundries and forging plants, there are not too many option to recycle the basic slags, which are not suitable for many purposes of recycling, because of their low chemical and structural stability. A solution of an adequate recycling is a direct recycling in EAF. Several quality requirements, physico-chemical properties and proportions of slags must be analysed. The progress in this fields permites to establish an adequate proportion of recycled slag, based on enough exact computation of the related property. For oxydizing slag, obtained during melting and in the first part of decarburization operation, the problem of phosphoms contents can be analysed using the phosphate capacity (C PO34-). For reducing periods, during deoxidization operation, desulphurization also occurs and the problem of the sulphur contents can be analysed using the sulphur and sulphide capacities ( Cs / Cs) Between this two complex thermodynamic indicators of the slags. a direct relation is established, using thermodynamic aspects, resulting from the equilibrium constants for dephosphorization and desulphurization process and also, using the optical basicity of slags, computable from the chemical analysis of the slags. On this basis starting from the steel quality requirements. adequate strategies can be established in order to obtain high rates of recycling (between 50-80%) of steelmaking slags. Important cost savings are obtained through this procedure, based on the correct amounts of the fresh lime, iron ore and fluidizers. Keywords: Slag, Properties, Recycling

Jan 1, 2003

By Carlos Eduardo Gomes de Souza, Luis G. S. Sobral, Paulo A. Medeiros da Silva, Selma G. F. Leite, Renata de B. Lima

"The use of mixed cultures of acidophilus microorganisms that act in different temperature ranges, aims at speeding up the digestion of chalcopyrite, highly refractory sulphide mineral, the major mineral in the flotation concentrate of Caraíba Mining Co., with an attractive processing cost. The concentrate under consideration contains mainly chalcopyrite (CuFeS2) and bornite (Cu5FeS4) with contents of, approximately, 70 and 30%, respectively. It was observed in this study, the performance of consortium of mesophiles, moderate and extreme thermophile microorganisms, in the oxidation of the aforementioned sulphides minerals, evaluating operational parameters such as pH of the leaching solution, the reaction temperature and redox potential, with consequent extraction of 80% of the concentrate copper content within 60 days of bioleaching. Such high copper extraction was achieved in column bioleaching tests.INTRODUCTIONThe solubilization of metals by the application of microorganisms from the mineral ores and the subsequent recovery of metals from solution are referred to as bioleaching (Rohwerder, T et al, 2003). This is an economical method for the recovery of metals from minerals; especially lowgrade ores, overburden, and waste from current mining operations which requires moderate capital investment with operating cost (Watling, 2006).Furthermore, bioleaching is generally more environmentally friendly than conventional metal recovery processes such as concentration and smelting. Those physicochemical metal extraction processes generate sulphur dioxide, a toxic emission that is increasingly the target of regulatory legislation (Stott et al., 2000; Olson et al., 2003). Bioleaching of chalcopyrite is the key industry target. The main problem hindering commercial application of chalcopyrite bioleaching is the slow dissolution rate (Fu et al, 2008).Dissolution of acid-soluble sulphide minerals such as sphalerite, and to a lesser extent chalcopyrite, occurs by a combination of ferric iron and proton attack via the polysulphide pathway (Rohwerder et al., 2003)."

Jan 1, 2008

By Donghai Li, Cheng Pan, Xuyang Liu, Xuewei Lv, Chenguang Bai

"Fine chromite ore is the common raw material to produce ferrochrome alloy through the submerged electric furnace process. The electric resistivity of fine chromite ore plays an important role in the operation efficiency because it determines the current distribution. The effect of particle size and the contact area of the particles on electric resistivity for several of chromite were investigated at room temperature, and the relationship between the electric resistivity of mixed particles and the volume fraction of lump ore to fine ore was also studied. The results shown that the electric resistivity increases with the increase of particle size, and the electric resistivity of mixture decreases with the increase of volume ratio of fine ore.IntroductionChromium is one of the most important alloying elements in manufacturing of stainless steel that used at high temperature and corrosive environment applications [I, 2]. As the raw materials to be charged into the steel, ferrochromium alloys and charge chromium are produced directly by smelting of chromite ore with the reducing agent in submerged electric arc furnace (SAF). During the process, the oxides of chromium and iron were reduced by carbon and meanwhile the electrical energy were consumed [3,4]. The ideal industrial process is to achieve high recovery level of Cr and Fe with minimal power consumption. In SAF process, the electric resistivity of charge stock has significant effect on the current distribution, which determines the heat distribution, molten bath structure and chemical reactions in the furnace. High resistance of the charge is desired to reduce the current distribution through the charge stock, thus the electrodes may insert into the charge stock with proper depth to form a high temperature arc heat source, and proper smelting can be realized[5]."

Jan 1, 2012

By Samir N. Shoukry, Mourad Y. Riad, Gergis W. William

"Setting of concrete material is defined as the transitional period between states of true fluidity and true rigidity. Initial and final setting times are measured in the laboratory on the mortar sieved from the mix in a controlled environment where temperature and moisture values are constant. On the other hand, field applications are held in outdoor environments where environmental variations have direct impact on setting time values. In this study, initial setting time of class K concrete, usually used for bridge decks and concrete pavements, are investigated highlighting discrepancies between laboratory and field measurements. 72 mixes have been cast in variable environments and collected data from concrete mixes and the ambient conditions are reported. In light of the collected data, the effects of variable setting times on early age cracking of concrete material are studied and means to minimize such cracks are presented.BackgroundSetting of concrete material is defined as the transitional period between states of true fluidity and true rigidity [1]. Continuous hydration of the cement within the matrix transfers the mix from a state of setting to hardening. Initial and final Setting times are measured in a laboratory setting following ASTM C 403 specifications. Initial setting approximates the time at which the cement paste can no longer be plastic under compaction (or can be handled in a proper fashion), while the final setting approximates the time at which hardening occurs. The standard test described in ASTM C 403 is conducted on the mortar sieved from the mix (paste passing from 4.75 mm sieve opening). Initial and final settings are described as the elapsed time after the initial contact of water and cement till the mortar reaches a penetration resistances of 3.5 MPa (500 psi), and 27.6 MPa (4000 psi) respectively."

Jan 1, 2012

By Jing Zhan, Chuanfu Zhang, Yonglin Yao

"The Ni/Co arbitrary ratios of fibrous precursor were investigated during coordinated coprecipitation by changing the precipitating medium. The results show that the original molar ratio ofNi2+ to Co2+ in reaction solution can be maintained in the coprecipitate at pH'.'05.0 and the coprecipitate is single phase solid solution using water and water-X precipitating medium. But the original Ni/Co ratios are no longer kept and composition of the coprecipitate is not uniform at pH>5.0 in water precipitation medium. In order to obtain the precursors with the required morphology and accuracy Ni/Co ratios, the optimum conditions of fibrous precursors were chosen as follows: ammonia used as complex agent and pH adjustor, water-X solvent as precipiting medium, oxalate as coprecipitated agent, 8.0-8.4 for pH value, 50-70°C of reaction temperature, 0.5-0.8 mol/L of initial nickel and cobalt salt concentrations and excesses of oxalic acid of 10% - 20%.IntroductionNi-Co alloy as an important transition metal alloy with high mechanical strength, good anti-deformation, corrosion resistance, thermal conductivity, thermal stability, electrical conductivity, electrical contact, and special magnetic properties indicates that it can be used as high-temperature catalyst, special magnetic material, high-temperature electrochemical devices, and so on [1-6]. An ideal composite powder should have an appropriate stoichiometric ratio, good uniformity of chemical composition, appropriate phase, low impurity content and small particle size [7]. Similarly, the composition of nickel-cobalt alloy powder has an important impact on its crystal structure, properties and applications. Guo[8] found that magnetisms of CoxNi1-x such as magnetic anisotropy, curie temperature, and the shifts of the spin steering are very sensitive to the composition of alloy powder."

Jan 1, 2013

By Christian Bernhard, Mario Hartl, Susanne K. Michelic

"One aspect of an efficient process and product optimization of the liquid steelmaking process is the understanding of reactions and interactions between the components steel, slag and nonmetallic inclusions. The present paper focuses on a fundamental study of this topic by combining the powerful methods of thermodynamic modeling with systematic experiments on a laboratory scale and subsequent SEM/EDS analyses. The modeling aspect is addressed by the commercial software FactSage 6.1; laboratory experiments are performed for a low-alloyed, Ca-treated carbon steel combined with varying slag compositions. The consequent SEM/EDS analyses provide a detailed insight into the inclusion landscape which offers a strong tool for characterizing the modification of inclusions. In the present study the combination of these methods is mainly applied to oxides, due to their crucial influence on the final product quality, thus giving important indications for further optimizing the secondary metallurgy processes.IntroductionIn recent years, the range of application for steels has been enlarged continuously; also resulting in extreme surrounding conditions combined with considerable stresses for the material. This trend is directly linked with higher demands on the properties of steels. In order to optimize the final product quality, the cleanness of steels is an important criterion. For this reason, the broad topic ""Steel Cleanness"" has become one of the main research points at the Chair of Metallurgy. Next to the continuous optimization of methods for the characterization of cleanness, the primary aim is to combine thermodynamic modeling and laboratory experiments in order to describe the changes in inclusion landscape under different conditions.The steel cleanness can particularly be influenced in the processes of secondary metallurgy. In different processes the reactions and interactions between the components steel, slag and nonmetallic inclusions (NMI) are essential for the final inclusion landscape. Consequently, the understanding of the occurring reactions is a fundamental aspect for further development and process optimization. In secondary metallurgy especially oxide-slag systems consisting of the components Ca0-Ah03-Mg0-Si02, which significantly influence the modification of NMI, are of importance. Several works dealing with the interactions of oxide non-metallic inclusions with different slag systems have been published in the last years [1-4]. In order to observe the dissolution of oxides in different slag compositions a Laser Scanning Electron Microscope is frequently used. A very detailed study on the ternary system Ah03-Ca0-Mg0 and its subsystems was also done by De Aza et al. [5, 6]."

Jan 1, 2011