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1
Li, Qi Nan, Guo Jun Ma, Xiang Zhang e Xun Cai. "Characteristics of Metallurgical Waste Slag and its Heating Behavior in a Microwave Field". Key Engineering Materials 680 (febbraio 2016): 574–79. http://dx.doi.org/10.4028/www.scientific.net/kem.680.574.
Testo completoAbstract (sommario):
Four kinds of typical metallurgical waste slags were characterized with their chemical composition, crystalline phases, microstructure and thermal behavior. The heating behavior of these slags in a microwave field were also examined. The results show that there is a high content of CaO in these waste slags. When the metallurgical waste slags were heated from room temperature to 1300°C, the weight loss of Blast Furnace (BF) slag and ladle furnace (LF) refining slag are only 2.25% and 0.9%, respectively, while the weight loss of Basic Oxygen Furnace (BOF) slag and electric arc furnace (EAF) slag are more than 5%. These metallurgical waste slags have a good absorption capacity for the microwave irradiation, the absorption capacity of microwave decreases in the order of converter slag > EAF carbon steel slag > baste furnace slag. In addition, the temperature-rising rates of the metallurgical waste slags increase with the microwave power and the quality or the particle sizes of slags. Furthermore, the crystalline phases of treated slag with microwave are similar with that of the untreated metallurgical slag. A number of internal cracks in particles of metallurgical slag can be found or extended after microwave treatment.
2
Gupta, Avishek Kumar, Matti Aula, Jouni Pihlasalo, Pasi Mäkelä, Marko Huttula e Timo Fabritius. "Preparation of Synthetic Titania Slag Relevant to the Industrial Smelting Process Using an Induction Furnace". Applied Sciences 11, n. 3 (27 gennaio 2021): 1153. http://dx.doi.org/10.3390/app11031153.
Testo completoAbstract (sommario):
A high titania slag that is used as a feedstock for TiO2 manufacturing is obtained by ilmenite smelting (FeO.TiO2). The composition of the slag obtained by smelting is dependent on the composition of the mineral used for slag preparation, i.e., ilmenite in our study. At the laboratory scale, ilmenite slags are mostly obtained by using ilmenite as the raw material. An easy and simple way would be to prepare the synthetic slag using the individual components and heating them to high temperature in a furnace. The titania slag has a high oxidizing nature and requires an inert atmosphere to prevent oxidation of the slag as well as the molybdenum crucible. This paper describes the preparation of synthetic ilmenite slag using an induction furnace and the study of the composition and the phases formed in the slag. X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and inductively coupled plasma-optical emission spectroscopy (ICP-OES) were used as analytical techniques for studying the slag. A comparison between obtained synthetic slag and industrial ilmenite slag was performed to test the possibility of preparing slags in the laboratory as per the required composition. The slags show similar phase formation as obtained in industrial ilmenite slags, which means that the synthetic slags are identical to the industrial slags.
3
Wiraseranee, C., T. Yoshikawa, T. H. Okabe e K. Morita. "Effect of Al2O3, MgO, and CuOx on the dissolution behavior of rhodium in the Na2O-SiO2 slags". Journal of Mining and Metallurgy, Section B: Metallurgy 49, n. 2 (2013): 131–38. http://dx.doi.org/10.2298/jmmb121221018w.
Testo completoAbstract (sommario):
Aiming to optimize rhodium recovery in the high temperature recycling process by minimizing rhodium loss into slags in an oxidizing atmosphere by controlling slag composition, the effects of representative slag components, such as Al2O3, MgO, and CuOx, on the dissolution behavior of rhodium into the Na2O-SiO2 slags was investigated. The solubility of rhodium was measured by equilibrating the sodium silicate based slags with pure solid rhodium at 1473 K in air. Considering that rhodium dissolved into slags as RhO1.5, the effect of the oxide addition on the activity coefficient of RhO1.5 in slags was determined. The dissolution of rhodium in slags was suppressed by the addition of Al2O3 and MgO, where Al2O3 behaved as an acidic oxide and MgO behaved as a diluent of slag basicity at a fixed Na2O/SiO2 ratio of 0.97. The content of copper in solid rhodium equilibrated with the CuOx bearing slags slightly increased with increasing content of CuOx, and CuOx was found to slightly enhance the dissolution of rhodium. Rhodate capacity of all slag systems increased with increasing optical basicity, suggesting that the correlation between rhodate capacity and the optical basicity enables the estimation of the content of rhodium in slags of which thermodynamic properties of rhodium are not clarified.
4
Long, Xiao, Wenbo Luo, Guohong Lu, Falou Chen, Xiaoning Zheng, Xingfan Zhao e Shaolei Long. "Iron Removal from Metallurgical Grade Silicon Melts Using Synthetic Slags and Oxygen Injection". Materials 15, n. 17 (1 settembre 2022): 6042. http://dx.doi.org/10.3390/ma15176042.
Testo completoAbstract (sommario):
Novel SiO2-CaO-CaF2-R2O-MgO based synthetic slags (R2O represents alkali metal oxides) with varied binary basicity values were used with oxygen injection to refine silicon melts and remove Fe from metallurgical-grade silicon. Silicon samples and slags at the silicon-slag interfaces were obtained during refinement. The compositions of the silicon samples were analyzed, and the quenched slag samples and mild cooling slags from the final crucible were inspected using scanning electron microscopy and energy dispersive X-ray spectroscopy. After 15 min of refinement, the Fe removal rate ranged from 52.3 to 60.1 wt%. During the refining process, the Fe-concentrated phase formed within the silicon droplets and was then transferred to the silicon-slag interfaces and wetted with slags. The Fe-concentrated phase at the silicon-slag interface can dissolve directly in the slags. It can also be transferred into the slag phase in the form of droplets, which can be affected by the binary basicity of the slags. Ti removal demonstrated a similar mechanism. Fe-bearing crystals were not detected in the quenched slag samples obtained during refinement, while complex Fe-bearing phases were detected in the final slag. This study demonstrates Fe removal from metallurgical-grade Si using slag refining methods and reveals the removal mechanism during the refinement.
5
Zhao, Qiang, Lang Pang e Dengquan Wang. "Adverse Effects of Using Metallurgical Slags as Supplementary Cementitious Materials and Aggregate: A Review". Materials 15, n. 11 (26 maggio 2022): 3803. http://dx.doi.org/10.3390/ma15113803.
Testo completoAbstract (sommario):
This paper discusses a sustainable way to prepare construction materials from metallurgical slags. Steel slag, copper slag, lead-zinc slag, and electric furnace ferronickel slag are the most common metallurgical slags that could be used as supplementary cementitious materials (SCMs) and aggregates. However, they have some adverse effects that could significantly limit their applications when used in cement-based materials. The setting time is significantly delayed when steel slag is utilized as an SCM. With the addition of 30% steel slag, the initial setting time and final setting time are delayed by approximately 60% and 40%, respectively. Because the specific gravity of metallurgical slags is 10–40% higher than that of natural aggregates, metallurgical slags tend to promote segregation when utilized as aggregates. Furthermore, some metallurgical slags deteriorate the microstructure of hardened pastes, resulting in higher porosity, lower mechanical properties, and decreased durability. In terms of safety, there are issues with the soundness of steel slag, the alkali-silica reaction involving cement and electric furnace ferronickel slag, and the environmental safety concerns, due to the leaching of heavy metals from copper slag and lead-zinc slag.
6
Haubner, Roland, e Susanne Strobl. "Slag from Modern Copper Production Found in Bergwerk, Burgenland, Austria". Solid State Phenomena 341 (15 marzo 2023): 11–16. http://dx.doi.org/10.4028/p-4zdd71.
Testo completoAbstract (sommario):
The investigated slags from Bergwerk (Burgenland, Austria) are from the 17th century and a byproduct of a copper smelting process. These slags are typical plate slags but metallographic studies have shown that these slags are atypical compared to alpine slags. There is an elongated texture running across the slag but the typical fayalite dendrites are absent. Noticeable are high sulfur and Fe levels. SEM-EDX element mappings show that FeO and FeS coexist locally, suggesting that a eutectic FeO-FeS mixture exists. The melting point could have been lowered to 930 °C by the FeO-FeS eutectic. CaSO4 was also detected in the slag. The glass phase, containing all the slag impurities, is located between the fayalite and the FeO-FeS mixture. The smelting process, in which these slags were formed, is currently unknown. It has been unproven as well, what advantages such a copper smelting process could have.
7
Xu, Zhong Hui, Dong Wei Li e Xi Peng. "Environmental Activity of Heavy Metals in Slags Treated by Electrokinetic Removal Technology". Applied Mechanics and Materials 84-85 (agosto 2011): 264–68. http://dx.doi.org/10.4028/www.scientific.net/amm.84-85.264.
Testo completoAbstract (sommario):
Ancient pyrometallurgical zinc generated large amounts of slag. Natural leaching from ancient pyrometallurgical zinc sites had contaminated the soil closed to the deposits. Enhanced electrokinetic removal technology was adopted to treat these slags. In this paper, atomic fluorescence spectrometer and scanning electronic microscope were used to investigate the total metal concentration and the surface topography of slags. The results showed that the heavy metals content in slags was high. The content of zinc in slags was up to 114550mg/kg. The surface topography of slags indicated that that the slags were corroded obviously by rainwater and lots of poisoning elements had released to the surroundings. The optimized BCR sequential extraction procedure was used to analyze the chemical speciation of heavy metals in slags. It could be determined that the evironmental activity of ancient pyrometallurgical slag decreased obviously after the treatment with electrokinetic removal technology and part of the residual fraction of heavy metals in slags transformed to the other fractions during the electrokinetic removal process.
8
Chowdhury, Saidur Rahman. "Recycled Smelter Slags for In Situ and Ex Situ Water and Wastewater Treatment—Current Knowledge and Opportunities". Processes 11, n. 3 (6 marzo 2023): 783. http://dx.doi.org/10.3390/pr11030783.
Testo completoAbstract (sommario):
Slags from the ferrous and nonferrous metallurgical industries have been used to treat toxic contaminants in water and wastewater. Using slag as a recycling or renewable resource rather than a waste product has environmental and economic benefits. Recycled smelter slags can be used in both in situ and ex situ treatment. However, their application has some limitations. One of the challenges is how to handle spent slag adsorbents, as they contain the accumulation of solid waste loaded with high concentrations of toxic contaminants. These challenges can be overcome by regeneration, recycling, reuse, and immobilization treatment of spent slag adsorbents. The present paper explored the scientific and technical information about the composition, reaction mechanisms, adsorption capacity, and opportunities of recycled slags while adsorbing toxic compounds from contaminated water. It comprehensively reviewed the current state of the art for using smelting slags as sustainable adsorbents for water and wastewater. The study revealed that ferrous slags are more effective in removing a wide range of toxic chemicals than nonferrous smelter slags. It investigated the necessary improved approach through the 5Rs (i.e., reduce, reuse, recycle, remove, and recover) using smelter slags as reactive materials in ex situ and in situ treatment.
9
Potysz, Anna, Bartosz Mikoda e Michał Napieraj. "(Bio)dissolution of Glassy and Diopside-Bearing Metallurgical Slags: Experimental and Economic Aspects". Minerals 11, n. 3 (3 marzo 2021): 262. http://dx.doi.org/10.3390/min11030262.
Testo completoAbstract (sommario):
Dissolution of diopside-bearing slag and its amorphous counterpart was investigated to decipher recovery potential of these slags. The contribution of direct slag phase dissolution was investigated using a biotic solution with Acidithiobacillus thiooxidans versus sterile growth medium, whereas citric acid was applied to demonstrate slags dissolution in organic medium. Potential metal donor slag phases and easily released elements were identified by comparing theoretical and experimental dissolution ratios. It was shown that K and Na were the most mobile elements leaching from glassy and diopside slag (up to 99%). Recovery targeted metals were released in the quantities of 56% (Cu)–96% (Zn) from glassy slag and 27% (Cu)–98% (Zn) from diopside slag. Results demonstrated that studied slags are good candidates for Zn recovery during short-term treatment, whereas extension of time would be required for efficient Cu extraction. Abiotic growth medium had little effect on metal leaching (up to 53% versus only 3% for the glassy and diopside slags, respectively). Glassy slag revealed greater susceptibility to dissolution as compared to diopside slag. Further studies improving recovery conditions are expected to improve environmental soundness of proposed treatments and to generate residues depleted in toxic elements. This study highlights the importance of evaluation of individual slags in terms of metal and major elements leachability.
10
Barnett, Vincent L. "Slags and Slag Heaps". Film International 20, n. 3 (1 settembre 2022): 36–43. http://dx.doi.org/10.1386/fint_00171_1.
Testo completo
11
Eric, R. H. "Chromous capacities of ferrochromium and matte smelting slags". Archives of Materials Science and Engineering 2, n. 93 (1 ottobre 2018): 49–58. http://dx.doi.org/10.5604/01.3001.0012.7354.
Testo completoAbstract (sommario):
Purpose: of this paper is to extend the slag capacity concept to sparingly soluble cationic species encountered for example in matte smelting and ferrochromium processing in terms of chromous capacities. Design/methodology/approach: In this context in order to develop the chromous capacity the experimental data on slag-metal equilibrium for ferrochromium smelting and on chromium distribution between slag and matte phases encountered in sulphide smelting of PGM (Platinum Group Metals) and chromium containing copper nickel concentrates were used. Findings: The calculated chromous capacities were in the 10-8 range for ferrochrome smelting slags and 10-4 range for matte smelting slags. These values indicate the very low and moderate chromous ion dissolving ability of ferrochromium smelting slags and matte smelting slags respectively. Research limitations/implications: Due to highly reducing conditions in ferrochromium smelting and the imposed low oxygen partial pressures in sulphide smelting of chromium and PGM containing concentrates chromium in the slag was assumed to be in its divalent state. The slag-metal/matte reaction for dissolution of chromium into the slag as a cation under reducing conditions -in contrast to reactions for dissolution of species such as sulphur and phosphorus into the slag as anions under oxidizing conditions – required the release of electrons. Thus to maintain charge neutrality the dissolution of chromium from the metal or the matte phases into the slag as Cr2+ ions was accompanied by consumption of these electrons by reduction of Fe2+ ions in the slag into metallic Fe which dissolved in the metal/ matte phase. This was supported by the experimental equilibrium data. Hence the slagmetal/ matte reaction defining the chromous capacity involved both O2- and Fe2+ ions of the slag phase. Moreover for matte smelting the thermodynamic activities of species in the matte phase were assumed to conform to ideal associated solution model due to lack of data. For future work it is advisable to determine such activities. Practical implications: The calculated chromous capacities were in the 10-8 range for ferrochrome smelting slags and 10-4 range for matte smelting slags. The results clearly indicate that in matte smelting lower basicity slags would be preferable to render chromium more soluble in the slag in contrast to ferrochromium smelting where higher basicity slags would be suitable to minimize chromium losses to the slag. Originality/value: This research and hence the paper is probably the first on dissolution of chromium as chromous ion in slags, thus it is novel and original.
12
Gmyzina, N. V., N. A. Sedinkina e O. E. Gorlova. "Study of BOF slags properties with the purpose of their utilization technology perfection". Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 75, n. 5 (20 giugno 2019): 623–31. http://dx.doi.org/10.32339/0135-5910-2019-5-623-631.
Testo completoAbstract (sommario):
Actuality of steel-making slags utilization is stipulated not only by the necessity to improve ecology situation at the sites of slag piles, but also by a possibility to obtain additional raw materials for metallurgical production. Increase of the domestic iron-containing raw materials at Magnitogorsky steel-works can be done by more effective processing of steel-making slags. To improve the technology of BOF slags processing, a work done to study their chemical and mineral composition. It was established, that primary and secondary BOF slags are attributed to basic and ultra-basic, since the SiO2 mass share is less than 25–40%. Petrographic study results and data of IR-spectroscopy showed, that larnite, alite, monticellite and oxide RO-phase (Fe2+, Mn2+, Mg2+)O are main mineral components of the BOF slags. In many cases, the structure of the secondary BOF slags has middle-size grains, and the structure of primary slags is fine-grained. The texture of the secondary and primary slag is more often massive. The BOF slags have globules of iron, the size of which varies from sub-millimeters up to 5 mm. Study of influence of various methods of BOF slag particles destruction on the degree of globules disclosure showed, that application of centrifugal-striking crushing facilities provides more selective globules disclosure comparing with other methods. It was proved, that dry magnetic separation in suspended state, due to its peculiarities, provides higher technological indices comparing with drum separator when separating fine slags even at increase material moisture up to 5%.
13
Pribulová, A., P. Futáš, A. Kmita, D. Márasová e M. Holtzer. "Impact of electro slag remelting on 14 109 steel properties". Archives of Metallurgy and Materials 62, n. 1 (1 marzo 2017): 181–85. http://dx.doi.org/10.1515/amm-2017-0025.
Testo completoAbstract (sommario):
Abstract The Electro Slag Remelting (ESR) is one of the remelting processes in the field of metal refinery. In this process, the slag plays various roles, such as heat generation, protection of melt, and chemical refining. The main objective of the experiments described in this article was to identify the most appropriate slag composition for the electro slag remelting of the steel in order to achieve the chemical composition compliant with the standard applicable to the given steel, minimum sulphur content, minimum contents of oxide and sulphide inclusions, as well as mechanical properties corresponding to the standard applicable to the steel STN 14 109. Ten electrodes were remelted, whereas the remelting was carried out under 8 slags. The used slags containing 70% of CaF2 and 30% of Al2O3 with different addition of CaO, the slags consisted of the same components as previous slags, whereas the ratio of individual components was 1:1:1, and with SiO2 and MgO and slag without Al2O3. With regard to all the above mentioned facts, the slag types which may be regarded as the most appropriate for the STN 14 109 steel remelting are the basic slags containing 70% of CaF2 - 30% of Al2O3 with added 30 and 45 weight % of CaO.
14
Sinel'nikov, V. O., D. Kalish e R. D. Kuzemko. "The investigation of the converter slag's phase and mineralogical properties in splashing to improve the lining resistance". NOVYE OGNEUPORY (NEW REFRACTORIES), n. 8 (27 dicembre 2018): 36–42. http://dx.doi.org/10.17073/1683-4518-2018-8-36-42.
Testo completoAbstract (sommario):
The methods to improve the slag splashing operation were regarded in the article. The phase and mineralogical properties were studied for the converter slag's of one of the Europe Iron and Steel Works. The modeling results for the slags with different compositions are given on base of the earlier studies of the physical and chemical properties.Ill.8. Ref. 28. Tab.1.
15
Kenzhaliyev, B. K., S. A. Kvyatkovskiy, M. A. Dyussebekova, A. S. Semenova e D. Nurhadiyanto. "Analysis of Existing Technologies for Depletion of Dump Slags of Autogenous Melting". Kompleksnoe Ispolʹzovanie Mineralʹnogo syrʹâ/Complex Use of Mineral Resources/Mineraldik Shikisattardy Keshendi Paidalanu 323, n. 4 (23 maggio 2022): 23–29. http://dx.doi.org/10.31643/2022/6445.36.
Testo completoAbstract (sommario):
Pyro-metallurgy of copper production is characterized by the output of copper slag, which is regarded as a kind of solid waste. Moreover, this slag is identified as hazardous because it contains impurities, like Pb, As, and Cu. Obtaining dump slags in autogenous processes does not always meet the requirements of effective technologies, most often slags contain more than 1.0% of copper and need to be depleted. This work is presented a brief analysis of existing technologies used for copper slag depletion. The analysis of the existing technologies for the depletion of autogenous smelting dump slags showed that the most promising option seems to be the depletion of copper slags in one PV unit since by improving the process itself, by changing the unit design, it is possible to achieve technologically complete production of matte and dump slag with low copper content. There were proposed two technologies of improvement: electro-heating of slag siphon using the graphite electrodes and depletion process in two-zone PV furnace.
16
Zhang, Xiaomeng, Ziwen Yan, Zhiyin Deng e Miaoyong Zhu. "Effect of TiO2 Addition on the Melting Behaviors of CaO-SiO2-30%Al2O3-5%MgO System Refining Slags". Metals 13, n. 2 (20 febbraio 2023): 431. http://dx.doi.org/10.3390/met13020431.
Testo completoAbstract (sommario):
To improve the yield of titanium alloy, a certain amount of TiO2 can be added to the refining slag system of Ti-bearing steel grades. With the aim of understanding the effect of TiO2 addition on the melting behaviors of CaO-SiO2-30%Al2O3-5%MgO refining slags, the melting points of the slags and the phases in the slags are herein studied at different temperatures in the laboratory. It is found that with the increase in TiO2 content (0~10%) in slag, the melting point of the slags drops first, and then rises. The effect of slag basicity (R = w(CaO)/w(SiO2), 2~10) shows a similar tendency. The TiO2 content and slag basicity evidently affect the precipitated phases in the slags at a lower temperature (e.g., 1310 °C). With the increase in basicity, the liquid areal fraction increases first, and then decreases. Moreover, the CaO-TiOx-Al2O3 phase (CTA) and its TiOx content show a declining trend at 1310 °C. When R = 10, large amounts of solid calcium aluminates are precipitated. With TiO2 addition in the slags, the TiOx contents in both liquid and CTA phases increase. Excessive TiO2 addition (e.g., 10%) leads to the large precipitation of CTA, as well. To improve the melting properties of the slag and the yield of Ti alloys during the refinement of Ti-bearing steel grades, a small TiO2 addition (e.g., 5%) may be considered.
17
Shi, Guan-yong, Ting-an Zhang, Li-ping Niu e Zhi-he Dou. "Study on physical properties of Al2O3-based slags used for the self-propagating high-temperature synthesis (SHS) – metallurgy method". High Temperature Materials and Processes 41, n. 1 (1 gennaio 2022): 424–33. http://dx.doi.org/10.1515/htmp-2022-0046.
Testo completoAbstract (sommario):
Abstract The Al2O3-based slags are playing important roles in the preparation of Cu–Cr alloy through self-propagating high-temperature synthesis (SHS) – Metallurgy method. However, the current research on Al2O3-based slag is mainly concentrated on steel metallurgical slag and electroslag remelting slag, and the research on aluminum thermal reduction slag with high content of Al2O3 is still insufficient. Therefore, systematic studies of the physical properties of slag with high aluminum content were carried out in the present work, and the influence of CaF2, CaO, MgO, SiO2, and Na3AlF6 on viscosities, liquidus temperatures, densities, and surface tensions of high Al2O3 content slags was measured and analyzed. The results indicated that CaO and CaF2 have positive effects on the physical properties of Al2O3-based slags, MgO has positive effects when its content is not over 3%, and SiO2 and Na3AlF6 have negative impacts. CaO, CaF2, and MgO (not over 3%) could be used as additives to improve the metallurgical performance of Al2O3-based slags in aluminothermic reduction–slag refining method.
18
Ghosh, D., V. A. Krishnamurthy e S. R. Sankaranarayanan. "Application of optical basicity to viscosity of high alumina blast furnace slags". Journal of Mining and Metallurgy, Section B: Metallurgy 46, n. 1 (2010): 41–49. http://dx.doi.org/10.2298/jmmb1001041g.
Testo completoAbstract (sommario):
The composition and properties of blast furnace slags greatly affect the furnace productivity and the quality of hot metal produced. Viscosity is an important physical property of slags, strongly influenced by the chemical composition, structure and the temperature. Experimental measurement of slag viscosity requires high temperature equipment and is time consuming. Therefore, chemical parameters are used to identify trends in viscosity as function of chemical composition. Limited information is available for High Alumina Blast Furnace Slags, since much of the open literature deals with Low Alumina Slags, with alumina content less than 15 weight percentage. High Alumina slags (alumina content in the range of 15% to 30%) are predominantly encountered in Indian Blast Furnaces. It appears that these slags have higher viscosity and lower sulphide capacity than the low alumina slags. The effect of chemical composition / ionic structure on viscosity has been interpreted in this work, using the chemical parameter of optical basicity. Data reported in the literature have been used, along with the values of liquidus temperature, for high alumina slags. Three slag systems, i.e., CaO-Al2O3-SiO2, CaO-Al2O3-SiO2-MgO and CaO-Al2O3-SiO2-MgO-TiO2 have been considered in this work. The trends observed are discussed in the paper.
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Metelkin, A. A., O. Yu Sheshukov, M. V. Savel’ev, O. I. Shevchenko e D. K. Egiazar’yan. "Application of ionic theory to calculate sulfide capacity of slags". Izvestiya. Ferrous Metallurgy 64, n. 2 (2 aprile 2021): 104–11. http://dx.doi.org/10.17073/0368-0797-2021-2-104-111.
Testo completoAbstract (sommario):
The article considers the issues of sulfur removal in the ladle-furnace unit. The sulfur distribution coefficient depends on sulfide capacity of the slag, sulfur activity coefficient, oxidizing potential of the medium and equilibrium constant. The sulfide capacity CS of slags is one of the most important characteristics of refining capacity of the slags used in extra-furnace steel processing. One of the factors affecting the sulfide capacity is temperature. The formula was proposed showing the dependence of sulfide capacity on the optical basicity and temperature, in the temperature range of 1650 – 1400 °C and when the optical basicity Λ is not more than 0.75; the error of the presented formula does not exceed 6 %. The formula for calculating the optical basicity is proposed, which takes into account the influence of basic, acidic oxides and amphoteric oxide Al2O3. It is shown that slags, completely consisting of a homogeneous phase, have an increased optical basicity of aluminum oxide. Heterogeneous slags have a reduced optical basicity of Al2O3 in comparison with homogeneous slags. Perhaps, this fact can be explained by the fact that in homogeneous slags there is a deficiency of the basic oxide CaO and in the conditions under consideration Al2O3 compound begins to exhibit more basic properties than acidic ones, thus, in homogeneous slags, the optical basicity of aluminum oxide is increased and approaches optical basicity of CaO oxide. Calculations carried out on the basis of real heats have shown that with an increase in the content of Al2O3 oxide in the slag, its optical basicity decreases. Known value of the optical basicity makes it possible to determine sulfide capacity of the slag, sulfur distribution coefficient between metal and slag, and, accordingly, final sulfur content in the metal. The research results have shown that it is advisable to apply the ionic theory of slags for the sulfide capacity determination.
20
Haubner, R., e S. Strobl. "Slags from Bronze Age copper production in Acqua Fredda". Practical Metallography 59, n. 12 (27 novembre 2022): 720–31. http://dx.doi.org/10.1515/pm-2022-1003.
Testo completoAbstract (sommario):
Abstract So-called “plate slags” from the archaeological Bronze Age copper smelting site Acqua Fredda were examined. What was common to all the examined slags was that their compositions, once converted and plotted on the FeO-SiO2-CaO phase diagram, were located at the phase boundary between olivine and wollastonite, resulting in melting temperatures of approx. 1100 °C for the slags. Slags with a composition which fall within the olivine region exhibit long, thin olivine crystals in a glassy matrix. Slags in the wollastonite region have a very fine-grained structure, making phase identification impossible. The copper-containing inclusions in the slag mainly consist of Fe-poor Cu2S, but FeO and SiO2 may also be present. General assertions about the local copper production in Acqua Fredda should not be made based on the slag analyses conducted in this study.
21
Babenko, A. A., M. V. Ushakov, A. V. Murzin e L. Yu Mikhailova. "Elaboration and mastering of technology of semiproduct smelting in EAF under magnesia slags". Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 75, n. 8 (6 settembre 2019): 936–43. http://dx.doi.org/10.32339/0135-5910-2019-8-936-943.
Testo completoAbstract (sommario):
Technology of magnesia slags forming provides increase of electric energy utilization efficiency and furnace lining resistance due to early formation of stable slag foam and decrease of aggressive slag impact on the lining. At the same time the practice of operation with magnesia slags shows, that excessive over-saturation them by magnesium oxide results in heterogenization, decrease of refining properties and deterioration of some technological, technical and economic process indices. Therefore, study and elaboration technology of rational composition magnesia slags forming by periods of a heating in EAF is an actual task. Results of numerical simulation of slag temperature and chemical composition effect on MgO saturation concentration during different melting periods in EAF presented. Besides, results of analysis of refining abilities of magnesia slags depending on MgO saturation degree also presented study of magnesia slags viscosity effect depending on MgO basicity and saturation concentration, as well as magnesia slag chemical and phase composition effect on foaming efficiency. Results of theoretical and experimental study were used as a base of elaboration rational slag composition by periods of melting in the EAF and technological techniques of their formation. A technology elaborated and implemented at PAO “Seversky pipe plant” EAF shop by leaving some amount of high-magnesia slags of the previous heat and addition in two stages high-magnesia flux of “Magma” grade during the oxidizing period. This resulted in a record resistance of the refractory EAF lining, exceeding 1900 heats within a campaign and a high level of technological, technical and economic process indices.
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Zhou, Sheng Bo, Ai Qin Shen e Geng Fei Li. "Interaction between Slag and Clinker during Cement Hydration Process". Advanced Materials Research 857 (dicembre 2013): 70–74. http://dx.doi.org/10.4028/www.scientific.net/amr.857.70.
Testo completoAbstract (sommario):
In order to investigate the activity of different original slags and the coupled relation between the slag and the clinker, the simplified slag cement system was designed in the experiment, in which clinker was replaced by lime.The reactional degree of slag in cement was determined through using chemical combined water content method, and the hydration processs were determined through using DSC-TGA. The results showed that for the different original slags, the destruction and rebuilding process of their microstructure were important to distinguish the activity of slags. And the process of slag hydration mainly experienced two stages, including microstructure destruction at early ages and microstucture rebuilding at later ages. And the variation of Calcium hydroxide content in cement indicated the interaction between the slag and clinker, and slag may improve the clinker hydration velocity.
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Zhantassov, K., Z. Bagova, G. Turebekova, B. Sapargaliyeva e G. Pusurmanova. "DEVELOPMENT OF TECHNOLOGY FOR THE EXTRACTION OF LEAD AND ZINC OXIDES FROM DUST AND SLAGS DURING THE UTILIZATION OF LEAD PLANT WASTE". SERIES CHEMISTRY AND TECHNOLOGY 2, n. 446 (12 aprile 2021): 81–85. http://dx.doi.org/10.32014/2021.2518-1491.30.
Testo completoAbstract (sommario):
The object of the study is lead-containing slag dumps from a lead plant. The slags of the lead plant contain a large number of toxic compounds: lead, zinc, osmium, cadmium, which are dangerous sources of environmental pollution. Due to the open storage of slags, it was found that the maximum permissible concentrations of lead were exceeded. Utilization of lead production slags allows to obtain non-ferrous metals and to reduce the technogenic load on the environment as a result of processing of slags. At the same time, slags are valuable raw materials containing compounds of non-ferrous and rare-earth metals. The article proposes methods for the extraction of lead and zinc from slag waste and selects the optimal method for the selective extraction of zinc and lead oxides from dust and slags of lead production. The proposed technology of continuous carbon-free selective extraction of zinc and lead from the dust of electric steelmaking production allows the use of lead production slag, which is fed into a rotating drum furnace in two oppositely directed streams. During the movement of lead slag in the furnace drum and the burning of the torch, lead and zinc are more completely extracted from the dust-like material, where the transporting object is compressed air, and the purified flue gas after the gas is further purified by means of a smoke pump is released into the atmosphere. When using the proposed selective method for extracting non-ferrous metals, the ecological state of the environment will be improved, and it will also reduce the negative impact on human health due to the disposal of toxic slags from lead production.
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Gudim, Yu A., I. Yu Zinurov e V. Z. Fel’dman. "Fuel-melting aggregate “MAGMA-1” for processing wastes of electric steelmaking". Ferrous Metallurgy. Bulletin of Scientific , Technical and Economic Information 77, n. 2 (25 febbraio 2021): 159–64. http://dx.doi.org/10.32339/0135-5910-2021-2-159-164.
Testo completoAbstract (sommario):
Toughening of ecological requirements to metallurgical production and economic factors, stipulated by competitiveness at the metal products market, increased actuality of utilization of slags, sludges and dust, obtained in steelmaking. It was shown, that from the economic point of view, processing of slags obtained at operation of modern ultra-powerful electric arc furnaces (EAF), is the item of highest interest. At present, their processing is restricted often by maximum possible recovery of metallic inclusions. At that the problem of utilization slag remains, dust and sludges remains unsolved. A pyrometallurgical method of electric steelmaking slags processing in EAF was considered. The process involves application of liquid phase reducing of metal oxides and correction of slag composition aimed at obtaining cast slag marketable products and clinker for cement industry. Data of test heats for slags utilization at the 5-ton EAF presented. The proposed technology enables to make industrial scale processing of slags with obtaining cast iron and melted clinker. Taking into consideration that EAF coefficient of efficiency, accounting fuel consumption for electrical energy obtaining is not high and is 23–24%, it was proposed to do slags processing in fuel-melting aggregates, in which the efficiency of primary energy utilization is higher (efficiency coefficient is 25–40%). The firm OJSC NTP “Akont” developed a technical project of a fuel-melting aggregate “MAGMA-1” for processing electric steelmaking slags. Its basic technical data and performance indices presented. It was shown that additional decrease of fuel consumption can be provided at utilization of liquid slag tapped out of EAF in a course of a heat, as well as at charge heating in a tubular rotating heater by waste gases.
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Miller, Duncan, e David Killick. "SLAG IDENTIFICATION AT SOUTHERN AFRICAN ARCHAEOLOGICAL SITES". Journal of African Archaeology 2, n. 1 (25 ottobre 2004): 23–47. http://dx.doi.org/10.3213/1612-1651-10017.
Testo completoAbstract (sommario):
nents of southern African Iron Age sites. Their correct identification is crucial to understanding technological processes performed at these sites. This paper presents criteria for distinguishing between iron smelting slags, iron forging slags, copper smelting slags, crucible slags resulting from melting activities, vitrified clay and various biomass materials. Slag identification should entail a combination of morphology, microscopic study, chemical analysis, and assessment of the archaeological context. It is a necessarily specialist activity and superficial classification without materials analysis can be misleading. Archaeologists need to be mindful of both the archaeological opportunities and the potential technical difficulties in the interpretation of slags.
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Davydov, S. Ya, R. A. Apakashev, N. G. Valiev e V. A. Perepelitsyn. "Industrial utilization of complex, multicomponent technogenic formations and their safe movement". NOVYE OGNEUPORY (NEW REFRACTORIES), n. 3 (31 maggio 2023): 3–8. http://dx.doi.org/10.17073/1683-4518-2023-3-3-8.
Testo completoAbstract (sommario):
The description of slags produced by LLC «Klyuchevskaya concentrating factory» is given. Samples of metallic chromium, ferrochrome and ferrotitane slag are presented. The chemical composition of high-alumina refractory cements used for the production and the physico-mechanical properties of cements obtained by remelting metallic chromium slags are given. The chemical composition of the alumina intermediate obtained during the remelting of metallic chromium slags for the smelting of synthetic slags. Charge compositions during remelting of metallic chromium slags. The scheme of covering the bottom of the dump truck body is given. Ill. 5. Ref. 10. Tab. 3.
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Babenko, А. А., L. А. Smirnov, Е. V. Protopopov, A. G. Upolovnikova e А. N. Smetannikov. "Fundamental studies of physicochemical properties of environmentally friendly fluorine-free slags and their use in ladle steel industry". Izvestiya. Ferrous Metallurgy 65, n. 6 (22 giugno 2022): 406–12. http://dx.doi.org/10.17073/0368-0797-2022-6-406-412.
Testo completoAbstract (sommario):
The article describes theoretical and experimental studies of dependence of viscosity, coefficients of sulfur and boron distribution between slag and metal, and wear degree of periclase-carbon refractories on basicity and boron oxide content in slag. It is shown that formed slags have basicity of 2.0 – 5.0 and rather high liquid mobility. These slags are characterized by an equilibrium interfacial distribution coefficient of sulfur increased to 5 – 20, which provides equilibrium sulfur content in the metal reduced to 0.001 – 0.005 %. The results of fundamental studies of the physicochemical properties of refining slags of СаО – SiO2 – В2O3 – Al2O3 – MgO system formed the basis for development of the composition of environmentally friendly fluorine-free ladle slags and technological methods for their formation in ladle-furnace unit. The recommended composition of such slags of low viscosity, which allows deep metal desulfurization, direct steel microalloying with boron and low aggressive effect on periclase-carbon refractories, provides formation of slags with a basicity of 3.0 – 4.0, containing 1 – 4 % B2O3 , 15 % Al2O3 and 8 % MgO. The formation of environmentally friendly ladle slags of the recommended composition was carried out in a ladle-furnace by loading lime, boron-containing material – colemanite (Turkey) containing 39 – 41 % B2O3 , 26 – 28 % CaO, not more than 5 % SiO2 and 3 % MgO, and pyramidal aluminum into the steel-teeming ladle for slag deoxidation and boron recovery. Introduction of the developed technology for the formation of ladle slags of recommended composition ensured the production of economically alloyed low-carbon structural boron-containing steels with a low sulfur content, incl. for large diameter pipes with high strength properties.
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Malzev, K. Y., O. B. Kolmachikhina e Sergey E. Polygalov. "Research for the Processing of Stale Slag from the Ural Region by the Pyro-Metallurgical Method". Materials Science Forum 989 (maggio 2020): 406–10. http://dx.doi.org/10.4028/www.scientific.net/msf.989.406.
Testo completoAbstract (sommario):
Pyro-metallurgical copper production is characterized by the formation of a large amount of slags. The copper content in the smelt slag is 0.5-2 %, in the vessel slag - about 5%, which often exceeds the copper content in the mined ores (about 1%). This makes depletion of slag a necessary operation in the pyro-metallurgical production of copper. In addition, about 110 million tons of copper slags have been accumulated in the dumps of copper factories in the Urals. The processing of these slags which contain up to 2.5% Cu is a very important task, the solution of which will allow extracting copper and reducing the areas occupied by the dumps.
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Luz, A. P., S. Ribeiro, V. G. Domiciano, M. A. M. Brito e V. C. Pandolfelli. "Slag melting temperature and contact angle on high carbon containing refractory substrates". Cerâmica 57, n. 342 (giugno 2011): 140–49. http://dx.doi.org/10.1590/s0366-69132011000200003.
Testo completoAbstract (sommario):
In this work the sessile drop technique was used in order to evaluate the melting temperature of synthetic and industrial slags, and their contact angle as a function of time and temperature on substrates of an Al2O3-SiO2-SiC-C castable containing 10 wt.% of carbon or its matrix. The best experimental conditions for the evaluation of the wetting behavior of refractory castables were attained when 25 x 25 x 10 mm³ matrix substrates and cylindrical slag pellets of 3 mm diameter and 5 mm high were used. This substrate - slag set resulted in contact angle values with good reliability. Small differences between the contact angle behavior on ground and polished matrix surfaces for synthetic slags were also detected. Additionally, industrial slags containing various oxide components, showed high values of contact angles and lower liquid spreading when compared with synthetic slags. This difference can be associated to the interaction liquid-solid at the material interface. Besides that, the wetting experiments were presented as a good alternative for measuring the melting temperatures of slags, as their values are difficult to determine due to the high oxide variety in the industrial slag compositions and the interaction between the slag and the substrate.
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Lu, Xian Jun, Shu Gang Hu e Zi Qiao Jin. "Chemical Activation of Cementing Properties of Granulated Blast Furnace Slags". Advanced Materials Research 454 (gennaio 2012): 11–16. http://dx.doi.org/10.4028/www.scientific.net/amr.454.11.
Testo completoAbstract (sommario):
Using CaO, NaOH and Na2CO3 as activators, the effects of dosage and combination of the activators on the cementing property of granulated blast furnace slags were investigated, and the hydration products of the activated slags were detected by X-ray powder diffraction (XRD) analysis. Results indicate that CaO can be used as an effective activator for the slag samples and its optimum dosage is about 10%, but the CaO activated slags shows much lower early strength than the Portland cement. However, the early strength of the CaO activated slag can be remarkably improved by the addition of NaOH or Na2CO3. Under the addition of about 6% NaOH or Na2CO3, the overall compressive strength of the alkali activated slag is higher than a 42.5MPa Portland cement. XRD analysis revealed that the hydration products of the alkali activated slags are mainly amorphous materials, which is quite different from that of the Portland cement.
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Michalek, K., L. Čamek, Z. Piegza, V. Pilka e J. Morávka. "Use of Industrially Produced Synthetic Slag at Třinecké Železárny, A.S." Archives of Metallurgy and Materials 55, n. 4 (1 dicembre 2010): 1159–65. http://dx.doi.org/10.2478/v10172-010-0019-z.
Testo completoAbstract (sommario):
Use of Industrially Produced Synthetic Slag at Třinecké Železárny, A.S. The paper summarises experience with using synthetic slags on the CaO - Al2O3 oxide basis in the technological flow of the oxygen converter steelworks in TŘINECKÉ ŽELEZÁRNY, a.s. These slags are used as an alternative to slags containing fluorspar which unfavourably affects both the service life of ladle linings and the steelwork's working environment. The content gives the first knowledge of using the Refraflux type synthetic slag to desulphurize steel, and it also provides a basic statistical evaluation of the heat produced.
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Kasina, Monika, Piotr R. Kowalski e Marek Michalik. "Mineral carbonation of metallurgical slags". Mineralogia 45, n. 1-2 (1 giugno 2015): 27–45. http://dx.doi.org/10.1515/mipo-2015-0002.
Testo completoAbstract (sommario):
Abstract Due to increasing emissions of greenhouse gases into the atmosphere number of methods are being proposed to mitigate the risk of climate change. One of them is mineral carbonation. Blast furnace and steel making slags are co-products of metallurgical processes composed of minerals which represent appropriate source of cations required for mineral carbonation. Experimental studies were performed to determine the potential use of slags in this process. Obtained results indicate that steel making slag can be a useful material in CO2 capture procedures. Slag components dissolved in water are bonded as stable carbonates in the reaction with CO2 from ambient air. In case of blast furnace slag, the reaction is very slow and minerals are resistant to chemical changes. More time is needed for minerals dissolution and release of cations essential for carbonate crystallisation and thus makes blast furnace slags less favourable in comparison with steel making slag.
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Livi, K. J. T., D. J. Farthing, L. A. Veblen e B. A. Wing. "Tackling the Complexities of Analyzing Phases in Metallurgical SLAGS". Microscopy and Microanalysis 6, S2 (agosto 2000): 930–31. http://dx.doi.org/10.1017/s1431927600037144.
Testo completoAbstract (sommario):
In many areas of the world slags pose potential environmental threats to their surroundings. Heavy metals, toxic and radioactive elements contained in some slags may leach into drinking water and contaminate agricultural areas. Leaching experiments can estimate short-term alteration rates, but such tests cannot reproduce long-term weathering processes. Such studies are particularly important in the case of U- and Th-bearing slags which may remain hazardous for 103 104 years. These radioactive slags are of concern to decisions regarding the termination of a nuclear materials license and the subsequent allowances for unrestricted public use of the smelting sites and slag piles. To thoroughly evaluate leaching from slags, one must understand the distribution of elements among the slag phases and the stability of each phase. Questions regarding the distribution of elements among multiple phases are best answered by detailed electron microprobe (EMP) studies.Slags are often mineralogically and compositionally complex, and may have complicated exposure histories.
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Loncnar, M., A. Mladenovic, M. Zupancic e P. Bukovec. "Comparison of the mineralogy and microstructure of EAF stainless steel slags with reference to the cooling treatment". Journal of Mining and Metallurgy, Section B: Metallurgy 53, n. 1 (2017): 19–29. http://dx.doi.org/10.2298/jmmb150910018l.
Testo completoAbstract (sommario):
TIn the present study the differences in the mineralogical composition and microstructure of various types of EAF stainless steel (EAF S) slag with regard to the cooling path, the operation practice in an EAF (electric arc furnace) and environmental ageing reactions were evaluated. It was shown that the mineralogy of the investigated EAF S slags varied from one slag to another, depending on the quality of the produced stainless steel. The production process of the treated steel also has a strong influence on the mineralogy of the slags. The conditions during water cooling were not sufficient to prevent the crystallization of primary mineral phases, which occurs predominantly in air-cooled EAF S slags, probably due to the high basicity of the investigated slags. However, the water cooling of hot slag leads to the absence of ?-CaSiO4 and the formation of secondary mineral phases predominantly calcite, portlandite, ettringite, calcium aluminate hydrate and calcium silicate hydrate. It has been shown that during the environmental ageing test (down-flow column test) secondary mineral phases were formed, which were the same as those formed during the water cooling of slags.
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Yang, Xue-min, Jin-yan Li, Meng Zhang, Fang-jia Yan, Dong-ping Duan e Jian Zhang. "A Further Evaluation of the Coupling Relationship between Dephosphorization and Desulfurization Abilities or Potentials for CaO-based Slags: Influence of Slag Chemical Composition". Metals 8, n. 12 (19 dicembre 2018): 1083. http://dx.doi.org/10.3390/met8121083.
Testo completoAbstract (sommario):
The coupling relationships between dephosphorization and desulfurization abilities or potentials for CaO–FeO–Fe2O3–Al2O3–P2O5 slags over a large variation range of slag oxidization ability during the secondary refining process of molten steel have been proposed by the present authors as logLp + 5logLs or logCpo3-4 + logCs2- in the reducing zone and as logLp + logLs - 5logNFetO or logCPO3-4 + logCs2- in the oxidizing zone based on the ion and molecule coexistence theory (IMCT). In order to further verify the validation and feasibility of the proposed coupling relationships, the effects of chemical composition of the CaO-based slags are provided. The chemical composition of slags was described by three group parameters including reaction abilities of components represented by the mass action concentrations Ni , two kinds of slag basicity as simplified complex basicity and optical basicity , and the comprehensive effect of iron oxides FetO and basic oxide CaO. Comparing with the strong effects of chemical composition of the CaO-based slags on dephosphorization and desulfurization abilities or potentials, the proposed coupling relationships have been confirmed to not only be independent of slag oxidization ability as expected but also irrelevant to the aforementioned three groups of parameters for representing the chemical composition of the CaO-based slags. Increasing temperature from 1811 to 1927 K (1538 to 1654 °C) can result in a decreasing tendency of the proposed coupling relationships. In terms of the proposed coupling relationships, chemical composition of slags or fluxes with assigned dephosphorization ability or potential can be theoretically designed or optimized from its desulfurization ability or potential, and vice versa. Considering the large difference of magnitude between phosphate capacity CPO3-4 and sulfide capacity CS2- , the proposed coupling relationships between dephosphorization and desulfurization abilities for CaO-based slags are recommended to design or optimize chemical composition of slags.
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Kolodezhnaya, E. V., M. S. Garkave e I. V. Shadrunova. "Areas of use of waste from incineration". IOP Conference Series: Earth and Environmental Science 1061, n. 1 (1 luglio 2022): 012039. http://dx.doi.org/10.1088/1755-1315/1061/1/012039.
Testo completoAbstract (sommario):
Abstract Most of the solid household waste generated in the world is disposed of by incineration. Wastes generated during the incineration of debris pose a danger to the environment and must be disposed of. Determining the application areas of incinerator slags is an urgent research task. The article provides information on the conditions and volumes of slag formation. It is possible to extract copper-containing material from slags during gravitational enrichment. The use of complex processing technology contributes to the production of iron and aluminum-containing products. The potential of using slags for carbon dioxide sequestration was estimated. Suitability of silicate tailings of slag processing as geopolymer binders is determined. The use of waste incineration slags in production will not only reduce their number at landfills, but also prevent their further storage.
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Shyrokykh, Tetiana, Lukas Neubert, Olena Volkova e Seetharaman Sridhar. "Two Potential Ways of Vanadium Extraction from Thin Film Steelmaking Slags". Processes 11, n. 6 (28 maggio 2023): 1646. http://dx.doi.org/10.3390/pr11061646.
Testo completoAbstract (sommario):
During the steelmaking process, a great amount of slag is generated as a by-product. Vanadium-bearing steelmaking slags are classified as hazardous and require special handling and storage due to the toxicity of vanadium pentoxides. At the same time, such slags are valuable sources for the recovery of vanadium. The present work reviews the investigations on vanadium recovery from CaO-SiO2-FeO-V2O5 thin film slags under the neutral and oxidizing conditions in the temperature range 1653 K to 1693 K (1380 °C to 1420 °C) using Single Hot Thermocouple Technique (SHTT). The slag samples were analyzed by SEM/EDX. The results indicated that vanadium pentoxide evaporation can be up to 17.73% under an oxidizing atmosphere, while spinel formation under an argon atmosphere was detected in the conditions of thin film slags.
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Sariev, O. R., M. S. Dossekenov, B. S. Kelamanov e A. M. Abdirashit. "High-carbon ferromanganese smelting on high-base slags". Kompleksnoe Ispolʹzovanie Mineralʹnogo syrʹâ/Complex Use of Mineral Resources/Mineraldik Shikisattardy Keshendi Paidalanu 4, n. 315 (10 dicembre 2020): 63–73. http://dx.doi.org/10.31643/2020/6445.38.
Testo completoAbstract (sommario):
The article presents the results of laboratory trials for the smelting of high-carbon ferromanganese on highly-basic slags. Laboratory trials have confirmed that an increase in the basicity of ferromanganese production slags has a positive effect on the reduction of manganese to the metal and a decrease in the concentration of silicon in it. However, the high basicity makes the slag high-melting and tough, leading to large losses of manganese with the slag. The use of on borate fluxes solves this problem by affecting the physical and chemical properties of the final slags, which allows the process to be carried out at high basicities with the achievement of optimal technological indicators. The obtained positive results of laboratory experiments served as the basis for approbation the developed technology on a semi-industrial scale with the smelting of high-carbon ferromanganese by the flux method from the manganese ore of the «Bogach» Deposit. As a result of studying the smelting of carbonaceous ferromanganese in large-scale laboratory conditions, the possibility of converting manganese ores on highly-basic slags with appropriate regulation of the transport properties of slag to a standard metal with high technical and economic indicators was established. The best results are achieved when the CaO/SiO2 ratio in the slag is 1.8 and the boron oxide content in the slag is 0.8%. It is established that under these conditions, the obtained boron-containing highly-basic slags of carbonaceous ferromanganese are not subject to slaking.
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Karimov, Kamolkhon, Nodir Turakhodjaev, Azamat Akhmedov e Sherzod Tashbulatov. "A mathematical model of the technology of extraction of copper from industrial slags". E3S Web of Conferences 264 (2021): 04077. http://dx.doi.org/10.1051/e3sconf/202126404077.
Testo completoAbstract (sommario):
The article substantiates the relevance and necessity of developing mathematical models in foundry production, as well as the problems and prospects of their use. Based on an analytical review of the world literature on foundry production, it was emphasized that in many studies of the authors and literary sources, not enough attention is paid to the development of mathematical models of the technological process of extracting non-ferrous metals from slag and industrial waste. A brief description of the developed technologies for the high-temperature treatment of industrial slags and waste, separation treatment in electric furnaces, and metals extracted from liquid slag is given. During the development and analytical implementation of the mathematical model, the developed technology for extracting copper from slags is presented as an research object. Based on the study of the dynamics of changes in the thermophysical properties of the components as a function of temperature, a mathematical model of high-temperature treatment of slags is compiled. This will allow you to predict the process of processing slags and the results obtained. Also, a mathematical model of the extraction of copper from the slag is compiled, taking into account the chemical properties of metal inclusions in the slag. This serves as the basis for automating the process of extracting copper from slags and waste products.
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Zhang, Mingjun, Li Fu e Huaiwei Zhang. "Continuous cleaning process of molten copper slags in a channel reactor under the external electric field". E3S Web of Conferences 78 (2019): 03006. http://dx.doi.org/10.1051/e3sconf/20197803006.
Testo completoAbstract (sommario):
Continuous cleaning process of the molten copper slags in a channel reactor under a vertical electric field is proposed. The copper-matte settling velocity under the vertical electric field is much faster than that only under the gravity in the molten slags, and the electric field can also accelerate the magnetite reduction. Cu content in the slag can fall below 0.35 wt. % during the continuous cleaning process, which exceeds much more existing slag treatment process. In addition, the behaviours of some other heavy metal elements in the molten slags during the continuous process are also discussed.
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Cao, Jianqi, Yao Li, Wanming Lin, Julong Che, Feng Zhou, Yunfang Tan, Dongliang Li, Jie Dang e Chao Chen. "Assessment of Inclusion Removal Ability in Refining Slags Containing Ce2O3". Crystals 13, n. 2 (23 gennaio 2023): 202. http://dx.doi.org/10.3390/cryst13020202.
Testo completoAbstract (sommario):
The elimination of inclusions in steelmaking processes has been widely studied. The removal of inclusions by slags containing the rare earth oxide Ce2O3 are studied using an integrated numerical model. The integrated model involves the inclusion motion model, interfacial tension calculation model, surface tension calculation model of slag, and the mass action concentration model, based on ion and molecule coexistence theory. The motion behaviors of both solid Al2O3 inclusions and 50%wtAl2O3–50%wtCaO liquid inclusions of varied sizes at CaO-Ce2O3-SiO2-Al2O3(-MgO) slag systems are evaluated. The results show that it is more difficult to remove the inclusions with smaller sizes and in slag with a higher viscosity. Liquid inclusions are more difficult to remove than solid inclusions. It is found that the CaO-Ce2O3-SiO2-Al2O3-MgO refining slag shows a better ability to remove Al2O3 inclusions than that of the CaO-SiO2-Al2O3-MgO slag. The reason for this is that the addition of the rare earth oxide Ce2O3 can decrease the viscosity of slags, as well as improving the wetting effects of slags on Al2O3 inclusions. For two slags systems, the CaO-Ce2O3-SiO2-Al2O3-MgO slag system shows a better ability to remove Al2O3 inclusions than the CaO-Ce2O3-SiO2-Al2O3 slag system. The addition of 5% to 8% Ce2O3 in a CaO-SiO2-Al2O3-MgO slag is an optimized case for industrial applications.
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Lebedev, A. B., e V. S. Shuiskaya. "Influence of composition and cooling rate of alumocalcium slag on its crumblability". Izvestiya. Ferrous Metallurgy 65, n. 11 (22 novembre 2022): 806–13. http://dx.doi.org/10.17073/0368-0797-2022-11-806-813.
Testo completoAbstract (sommario):
The main components of metallurgical slags are iron compounds, which are extracted by reduction smelting. There are several types of this process with obtaining various products based on iron and slags of various compositions (aluminum-calcium self-disintegrating), etc. The mode of smelting and cooling of alumocalcium slag, formed during melting in the furnace, should ensure the most complete spontaneous crumbling of it, as well as high rates of extraction of REM from it. Synthetic slags similar in phase composition to industrial samples after smelting of iron-containing ores were selected for the experiments. The simulated samples correspond to the region of primary crystallization of bicalcium silicate on the triple state diagram of CaO – SiO2 – Al2O3 system. The slag after crumbling was subjected to a sieve analysis using a mechanical sieve. In the experiments, slags with a silicon module k = 2.0 were used, which actively crumbled during their cooling. With an increase in the silicon module, the crumbling deteriorates. It was established that it is impossible to precisely limit the areas of compositions of crumbling slags at certain cooling rates. The conducted studies showed that the crumblability of slags improves as it approaches the center of the bicalcium silicate region. The composition of slags close to composition of the intersection points of the lines 2CaO·SiO2 – 2CaO·Al2O3 and 2CaO·SiO2 – 12CaO·7Al2O3 with the lines of the permanent silicon module granulometric composition almost does not depend on the cooling rate. The temperature mode from smelting to cooling affects the slags crumblability. The most promising are slags with a silicon module in the range of 2.85 – 3.00, close to the phase triangle 12CaO·7Al2O3 – 2CaO·SiO2 – 2CaO·Al2O3 .
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De Colle, Mattia, Ross Kielman, Andreas Karlsson, Andrey Karasev e Pär G. Jönsson. "Study of the Dissolution of Stainless-Steel Slag Minerals in Different Acid Environments to Promote Their Use for the Treatment of Acidic Wastewaters". Applied Sciences 11, n. 24 (19 dicembre 2021): 12106. http://dx.doi.org/10.3390/app112412106.
Testo completoAbstract (sommario):
Several stainless-steel slags have been successfully employed in previous studies as substitutes for lime in the treatment of industrial acidic wastewaters. This study deepens the knowledge of such application, by analyzing the neutralizing capacity of different slags related to their mineral compositions. To do so, firstly the chemical and mineral compositions of all the slag samples are assessed. Then, 0.5 g, 1 g, 2 g of each slag and 0.25 g and 0.5 g of lime are used to neutralize 100 g of 0.1 M HCl or HNO3 solutions. After the has neutralization occurred, the solid residues are extracted and analyzed using XRD spectroscopy. Then, the solubility of the minerals is assessed and ranked, by comparing the XRD spectra of the residues with the obtained pH values. The results show that minerals such as dicalcium silicate and bredigite are highly soluble in the selected experimental conditions, while minerals such as merwinite and åkermanite, only partially. Moreover, Al-rich slags seem to perform poorly due to the formation of hydroxides, which generate extra protons. However, when the weight of slag is adequately adjusted, Al-rich slags can increase the pH values to higher levels compared to the other studied slags.
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Diotti, Alessandra, Luca Cominoli, Adela Perèz Galvin, Sabrina Sorlini e Giovanni Plizzari. "Sustainable Recycling of Electric Arc Furnace Steel Slag as Aggregate in Concrete: Effects on the Environmental and Technical Performance". Sustainability 13, n. 2 (7 gennaio 2021): 521. http://dx.doi.org/10.3390/su13020521.
Testo completoAbstract (sommario):
The aim of this research work was the evaluation of the feasibility to utilize industrial by-products, such as electric arc furnace steel slags, for sustainable concrete production. The paper evaluated the environmental and mechanical properties of steel slags and concrete, respectively. Specifically, the release of contaminants from steel slags was investigated by leaching test and the properties of fresh and hardened concrete were evaluated for a concrete mixture designed with a partial substitution (30%) of natural coarse aggregates with electric arc furnace steel slags. The results show that the concentrations of pollutants were lower than the legal limits imposed by the Ministerial Decree 186/2006 and the addition of steel slag can enhance the mechanical performance of concrete. The compressive strength of cubic specimens was also measured after different cycles of alternate wetting–drying. The steel slag incorporation results in a stiffness comparable to that of a traditional concrete. Overall, the mechanical and leaching characterization has shown that the reuse of electric arc furnace steel slags for sustainable concrete production is feasible and reliable.
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Diotti, Alessandra, Luca Cominoli, Adela Perèz Galvin, Sabrina Sorlini e Giovanni Plizzari. "Sustainable Recycling of Electric Arc Furnace Steel Slag as Aggregate in Concrete: Effects on the Environmental and Technical Performance". Sustainability 13, n. 2 (7 gennaio 2021): 521. http://dx.doi.org/10.3390/su13020521.
Testo completoAbstract (sommario):
The aim of this research work was the evaluation of the feasibility to utilize industrial by-products, such as electric arc furnace steel slags, for sustainable concrete production. The paper evaluated the environmental and mechanical properties of steel slags and concrete, respectively. Specifically, the release of contaminants from steel slags was investigated by leaching test and the properties of fresh and hardened concrete were evaluated for a concrete mixture designed with a partial substitution (30%) of natural coarse aggregates with electric arc furnace steel slags. The results show that the concentrations of pollutants were lower than the legal limits imposed by the Ministerial Decree 186/2006 and the addition of steel slag can enhance the mechanical performance of concrete. The compressive strength of cubic specimens was also measured after different cycles of alternate wetting–drying. The steel slag incorporation results in a stiffness comparable to that of a traditional concrete. Overall, the mechanical and leaching characterization has shown that the reuse of electric arc furnace steel slags for sustainable concrete production is feasible and reliable.
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Ju, Jiantao, Wenguo Liu, Xiangdong Xing, Jing Wang e Jialiang An. "Sulphide capacity of CaO-SiO2-8%MgO-Al2O3-BaO slags ranging from 0% to 5% in BaO". Metallurgical Research & Technology 116, n. 1 (18 dicembre 2018): 106. http://dx.doi.org/10.1051/metal/2018077.
Testo completoAbstract (sommario):
The sulphide capacities of CaO-SiO2-MgO-Al2O3-BaO slags were measured at 1773 K and 1823 K using the gas-slag equilibration method to estimate the desulphurization ability of the blast furnace slags that contained barium. The effects of basicity, the Al2O3 and BaO content of slags on the sulphide capacity of slags were studied. The relationship between the sulphide capacity and the optical basicity of the slags was also investigated. The experimentally determined results were compared with the sulphide capacities estimated by some previously reported models. The results showed that the sulphide capacity increased significantly when the basicity (CaO/SiO2) increased from 1.0 to 1.2, but decreased when the Al2O3 content increased in the slag. The increasing BaO content increased the sulphide capacity. The desulphurizing ability decreased when the BaO content was more than 3.5%. There was a linearly increasing relationship between the optical basicity and the sulphide capacity. The experimentally determined sulphide capacities were closest to the predicted values obtained by the Sosinsky and Sommerville’s model.
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Belov, B., A. Trotsan e O. Vlasova. "ANALYSIS OF THE STRUCTURAL-CHEMICAL MILL DUPLEX-SYSTEMS OF SILICATE-SILICIDE OF LUNG-EARTH METALS. Message 3. The mechanism of desulfurization in the smelting of blast-furnace pig iron". Casting processes 152, n. 2 (1 giugno 2023): 33–40. http://dx.doi.org/10.15407/plit2023.02.033.
Testo completoAbstract (sommario):
The mechanism of cast iron desulfurization through structural and chemical reactions in smelting slags corresponding to the composition of the main mineral phases is presented: monticellite (MT, SiO2MgOCaO) → mervinite (MP, 2SiO2MgO3CaO) → ockermannite (OK, 2SiO2MgO2CaO) →diopside (DP, 2SiO2MgOCaO) → rankinite (pH, 2SiO23CaO) and eutectic slags (E, 3SiO2MgO4CaO). A sequential series of adsorption capacity of slag phases with respect to sulfur (АС, mas. %) and the depth of metal desulfurization – Δ(S), ppm was determined: Е (3.54/36) → MR (4.8/49) → OK (5, 7/59) → DP (7.14/74) → MT (9.8/103) → RN (20/222). In factory conditions, the efficiency of smelting slags of eutectic composition and diopside for ladle processing of cast iron was tested. The expediency of using such blast furnace slags for ladle processing of cast iron has been established, which at a consumption of 5-10 kg/t provide a desulfurization depth of 200-400 ppm. The consumption of slag is significantly reduced with the additional deoxidation of smelting slags with carbon during the release of melt in the ditch of the foundry and in the pig iron ladle.
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Haubner, Roland, e Susanne Strobl. "Slag Investigation from Iron Smelting and Iron Processing Sites in Austria – From Hallstatt and Medieval Period and the 19th Century". Materials Science Forum 782 (aprile 2014): 635–40. http://dx.doi.org/10.4028/www.scientific.net/msf.782.635.
Testo completoAbstract (sommario):
Slags from three iron smelting and processing sites were investigated. The composition of the slags is connected to the metallurgical processes and the investigation should provide an indication of the process conditions.A slag from a small bloomery furnace at the archaeological site Waschenberg (Hallstatt period) was investigated. Slags from the medieval period were found near Eisenerz and at this time iron was produced in developed bloomery furnaces (Stuckofen). These slags are termed fayalitic slags and they consist of wustite (FeO), fayalite (Fe2SiO4) and glass-phase (amorphous silicates) in various concentrations. Three solidification-types were described and correlated with the microstructures and the FeO-SiO2-CaO2 phase diagram.During the 19th century steel was produced in puddling furnaces by remelting iron products from Eisenerz. Such slags, from this process, found in the surroundings of Palfau, were investigated and contain FeO and Ca rich glass-phase, but no fayalite.Due to the different compositions of the slags the solidification and the microstructures are different.
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Ogirigbo, O. R., e I. Inerhunwa. "Strength and Durability Performance of Slag Blended Cements in High Temperature Environments". July 2017 1, n. 2 (luglio 2017): 265–72. http://dx.doi.org/10.36263/nijest.2017.02.0042.
Testo completoAbstract (sommario):
In this study, two slags of different chemical compositions were blended with a CEM I 52.5R-type Portland cement at 30% wt. replacement ratio. Various tests such as strength, water and chloride ion permeability test were carried out at a high temperature of 38°C. The performances of the slag blends were measured against that of a CEM I 42.5R-type Portland cement. The results obtained showed that the performances of the slag blends were better than that of the CEM I 42.5R cement. In comparing the performances of the slags, the blend prepared from slag 1 had higher strengths and better transport properties than that prepared from slag 2, and this was attributed to the higher basicity and alumina content of slag 1. The findings of the study suggest that in tropical/ high temperature environments, the chemical composition of the slags play an important role in determining their performance.
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Anatoliy, Shevchenko, Volodymyr Kislyakov, Borys Dvoskin, Ivan Manachyn e Kostyantin Chubin. "STUDY OF CHANGES OF THE SULFUR CONTENT IN CAST IRON AND THE COMPOSITION OF SLAG IN TECHNOLOGICAL PROCESSING DURING THE PREPARATION OF CAST IRON FOR THE CONVERTER MELTER". Modern Problems of Metalurgy, n. 25 (8 aprile 2022): 201–19. http://dx.doi.org/10.34185/1991-7848.2022.01.17.
Testo completoAbstract (sommario):
The article analyzes the change in the sulfur content of cast iron and the composition of slag in the technological chain of preparing cast iron for converter smelting. On the basis of the results of the conducted research, technical solutions and technological techniques aimed at eliminating cast iron resulfurization were developed and recommended. Spot probe scanning of bucket slag samples showed that in the slag phase, along with CaO∙SiO2∙Al2O3 type systems with different ratios of components containing 0.2–3.5% sulfur, CaxSiyAlz type systems containing up to 1% sulfur were found; in "beads" the sulfur content varies no more than 0.1 - 0.85% and in the form of sulfides of the (Fe, Mn)S type, mainly MnS, and in the non-metallic inclusions of "beads" the sulfur content is no more than 15 - 30%. Studies of the compositions of dry, friable and liquid glassy ladle slags after desulfurization showed that they do not change the phase composition, but unlike the original ladle slags, in the slag phase of such slags there are mainly CaO·SiO2·Al2O3·MgO type systems, enriched with magnesium oxides with variable ratio of components. At the same time, sulfur in the slag phase of dry slags is mainly in the form of (Ca, Mn, Mg, Al, Si)S complexes, and in the slag phase of liquid slags it is mainly in the form of MnS and less often in the form of (Ca, Mn)S complexes. According to the results of industrial experiments carried out at a number of enterprises in Ukraine and China, it was established that in order to limit the introduction of sulfur into converter steel with slag at the level of ≤0.002%, the remaining ladle slag after desulfurization should not exceed 0.5-0.7 kg/t of cast iron.