Subjects -> METALLURGY (Total: 58 journals)
Showing 1 - 10 of 10 Journals sorted alphabetically
Acta Metallurgica Slovaca     Open Access   (Followers: 2)
Advanced Device Materials     Open Access   (Followers: 6)
American Journal of Fluid Dynamics     Open Access   (Followers: 44)
Archives of Metallurgy and Materials     Open Access   (Followers: 9)
Asian Journal of Materials Science     Open Access   (Followers: 4)
Canadian Metallurgical Quarterly     Hybrid Journal   (Followers: 21)
Complex Metals     Open Access   (Followers: 2)
Energy Materials : Materials Science and Engineering for Energy Systems     Hybrid Journal   (Followers: 24)
Graphene and 2D Materials     Open Access   (Followers: 6)
Handbook of Ferromagnetic Materials     Full-text available via subscription   (Followers: 1)
Handbook of Magnetic Materials     Full-text available via subscription   (Followers: 2)
High Temperature Materials and Processes     Open Access   (Followers: 6)
Indian Journal of Engineering and Materials Sciences (IJEMS)     Open Access   (Followers: 11)
International Journal of Metallurgy and Alloys     Full-text available via subscription   (Followers: 1)
International Journal of Metals     Open Access   (Followers: 7)
International Journal of Minerals, Metallurgy, and Materials     Hybrid Journal   (Followers: 11)
International Journal of Mining and Geo-Engineering     Open Access   (Followers: 4)
Ironmaking & Steelmaking     Hybrid Journal   (Followers: 5)
ISIJ International - Iron and Steel Institute of Japan     Full-text available via subscription   (Followers: 26)
Izvestiya Vuzov. Poroshkovaya Metallurgiya i Funktsional’nye Pokrytiya (Proceedings of Higher Schools. Powder Metallurgy аnd Functional Coatings)     Full-text available via subscription   (Followers: 2)
JOM Journal of the Minerals, Metals and Materials Society     Hybrid Journal   (Followers: 35)
Journal of Central South University     Hybrid Journal   (Followers: 1)
Journal of Cluster Science     Hybrid Journal  
Journal of Heavy Metal Toxicity and Diseases     Open Access  
Journal of Iron and Steel Research International     Hybrid Journal   (Followers: 11)
Journal of Materials & Metallurgical Engineering     Full-text available via subscription   (Followers: 2)
Journal of Materials Processing Technology     Hybrid Journal   (Followers: 21)
Journal of Metallurgical Engineering     Open Access   (Followers: 4)
Journal of Sustainable Metallurgy     Hybrid Journal   (Followers: 3)
Materials Science and Metallurgy Engineering     Open Access   (Followers: 6)
Metal Finishing     Full-text available via subscription   (Followers: 20)
Metallurgical and Materials Engineering     Open Access   (Followers: 7)
Metallurgical and Materials Transactions A     Hybrid Journal   (Followers: 41)
Metallurgical and Materials Transactions B     Hybrid Journal   (Followers: 32)
Metallurgical and Materials Transactions E     Full-text available via subscription   (Followers: 2)
Metallurgical Research and Technology     Full-text available via subscription   (Followers: 8)
Metallurgy and Foundry Engineering     Open Access   (Followers: 2)
Mining, Metallurgy & Exploration     Hybrid Journal  
Powder Diffraction     Full-text available via subscription   (Followers: 1)
Powder Metallurgy     Hybrid Journal   (Followers: 36)
Powder Metallurgy and Metal Ceramics     Hybrid Journal   (Followers: 8)
Powder Metallurgy Progress     Open Access   (Followers: 5)
Practical Metallography     Full-text available via subscription   (Followers: 6)
Rare Metals     Hybrid Journal   (Followers: 3)
Revista de Metalurgia     Open Access  
Revista del Instituto de Investigación de la Facultad de Ingeniería Geológica, Minera, Metalurgica y Geográfica     Open Access  
Revista Remetallica     Open Access   (Followers: 1)
Revue de Métallurgie     Full-text available via subscription  
Russian Metallurgy (Metally)     Full-text available via subscription   (Followers: 4)
Science and Technology of Welding and Joining     Hybrid Journal   (Followers: 7)
Steel Times lnternational     Partially Free   (Followers: 19)
Transactions of the IMF     Hybrid Journal   (Followers: 14)
Transactions of the Indian Institute of Metals     Hybrid Journal   (Followers: 5)
Tungsten     Hybrid Journal  
Universal Journal of Materials Science     Open Access   (Followers: 3)
Welding in the World     Hybrid Journal   (Followers: 7)
Welding International     Hybrid Journal   (Followers: 11)
Вісник Приазовського Державного Технічного Університету. Серія: Технічні науки     Open Access  
Similar Journals
Journal Cover
Journal of Sustainable Metallurgy
Number of Followers: 3  
 
  Hybrid Journal Hybrid journal (It can contain Open Access articles)
ISSN (Print) 2199-3823 - ISSN (Online) 2199-3831
Published by Springer-Verlag Homepage  [2626 journals]
  • Reduction Behavior and Direct Reduction Kinetics of Red Mud-Biomass
           Composite Pellets
    • Abstract: A large amount of red mud is discharged in the aluminum oxide production process, which contains a variety of valuable metals and is considered as a secondary resource. In order to reveal the mechanism of red mud carbon thermal reduction process, isothermal reduction experiments on carbon-bearing pellets of red mud were investigated with biomass carbon as a reducing agent. In this study, the reduction temperatures were conducted using a microwave stove in the temperature range from 850 to 1250 ℃, and the C/O molar ratio was 1.1. The results show that the reduction process of red mud is governed by a carbon gasification reaction, and the apparent activation energy is 88.44 kJ/mol. The optimum reduction process conditions were established to be 1150 ℃ for 13 min. Graphical
      PubDate: 2021-01-12
       
  • Correction to: Development of a Sustainable Alternative for the Ammoniacal
           Cyanidation of Copper–Gold Ores Through a Biological Approach
    • Abstract: There are inaccuracies in the graphical abstract presented in this article.
      PubDate: 2021-01-06
       
  • Prevention of Ladle Furnace Slag Disintegration Through Different Slag
           Additives
    • Abstract: Ladle refining is a popular secondary metallurgy process and plays a vital role in achieving the desired chemistry and temperature during steelmaking. The slag produced after ladle refining mostly contains dicalcium silicate (C2S). The presence of high C2S in slag leads to the disintegration of slag into fine powder during cooling due to phase transformation of C2S. The adverse impact is that the dust is easily aerated and carried by wind creating environmental pollution and makes the working area unsafe. In this paper, an attempt was made to study the effect of the addition of different additives on the disintegration of slag. Initial laboratory experiments were conducted with different additives such as Colemanite (boron-based mineral), silica-rich synthetic slag, and a siliceous natural occurring mineral perlite. Analysis of slag samples was carried out before and after treatment with additives. Based on the optimized conditions, industrial trials were conducted with different additives, and its success was measured in terms of lumpy slag formation. It was successfully studied that the addition of 10% of perlite during ladle furnace treatment process helped in preventing the slag disintegration by 90%. Graphical
      PubDate: 2021-01-05
       
  • Design of a Novel Fertilizer Made of Steelmaking Slag Using the Glassy
           Phase of the CaO–SiO 2 –FeO System. Part I: Optimization on the Slag
           Chemistry and Microstructure
    • Abstract: Fertilizers made of steelmaking slag are important inexpensive materials for recovering degraded paddy fields. The results of our previous works showed that essential Ca and Si elements were effectively supplied by the dicalcium silicate phase (C2S) while the glassy phase of the CaO–SiO2–FeO system served as an Fe source. In this study, we have developed a slag containing both the C2S and glassy phases that are capable of simultaneously supplying Ca, Si, and Fe elements to paddy fields. To determine the optimum conditions for supplying Fe from the glassy phase, the molten slag of the CaO–SiO2–FeO system was quenched from 1573 K, and the upper limits of its FeO content and basicity for glass formation were obtained. After that, slags consisting of the glassy phases with various compositions and the C2S crystal phase were synthesized and subjected to a leaching test. By analyzing the dissolution behaviors of different phases, a kinetic model was established to estimate the dissolved amount of each element and determine the optimum slag composition, which was obtained at a quenching temperature of 1573 K, basicity of 1.6, and FeO concentration of approximately 25 mass%. The dissolved amounts of Fe and Si produced by this slag exceeded those of commercial fertilizers prepared from steelmaking slag by factors of 6 and 2–3, respectively, while their respective amounts of supplied Ca were close to each other. Graphical
      PubDate: 2021-01-04
       
  • Potentially Exploitable Reprocessing Routes for Recovering Copper and
           Cobalt Retained in Flotation Tailings
    • Abstract: This research aimed at recovering metals retained in the tailings from the flotation of copper (Cu) and cobalt (Co) ores conducted at the New Concentrator in Kipushi (NCK). Metals retention in the tailings (0.73% Cu and 0.37% Co) increased due to the removal of the gravity separation section from the processing circuit together with changes arising in the feed mineralogical characteristics namely the increase in sulfide minerals. The concentrator’s feed was traditionally composed of oxidized minerals of Cu and Co from the Luiswishi deposit (DR Congo). Experiments conducted at the laboratory scale enabled identifying two exploitable routes for recovering metals retained in the tailings: firstly, the sulfuric acid leaching of tailings under reducing conditions in view of preparing a leach liquor (2.43 g/L Cu and 1.10 g/L Co) that can be utilized for cementing Cu, using iron chips and precipitating Co; secondly, the flotation of valuable minerals using xanthates in view of obtaining a rougher concentrate grading 1.43% Cu and 0.75% Co recovered at 56% and 59%, respectively, and later on, the obtaining of a cleaner concentrate assaying 3.97% Cu and 2.4% Co at the recoveries of 35% and 43%, respectively. The final concentrate enables the hydrometallurgical extraction of Cu and Co. Graphical
      PubDate: 2021-01-04
       
  • Green Power Furnaces in Aluminum Cast House for Scrap Preheating Using CO
           2 -Flue Gas
    • Abstract: Implementing preheating furnaces in the aluminum industry, powered by waste heat, has been a subject of interest due to the economic and energy-saving benefits. Metal holding furnaces, keeping aluminum in a liquid state (approx. 760 °C) before casting, are powered by fuel burners. Hot flue gas escapes the cast house furnaces at very high temperatures close to the aluminum melting point and represents a significant energy loss. One can heat aluminum scrap by redirecting hot flue gases from the holding furnace to a metal scrap preheating furnace, which is to be melted, prior to loading them in the metal melting furnace. Introducing a preheating step, incredibly hot flue gas, will reduce the melting time required while saving energy. This present study examines the effectiveness of preheating aluminum sow and billet profiles with hot flue gases and find the optimal design considerations for a preheating furnace. Different approaches to achieve quantitative heat treatment in batch homogenizing furnaces were evaluated. Heat transfer modeling, analysis of flue gas furnace, and sows’ temperature coupled with thermodynamic analysis improve thermal equation prediction precision. Turbulent fluid flow and heat transfer physics are used in a computational fluid dynamics model to simulate aluminum heating by hot gas. Graphical
      PubDate: 2021-01-04
       
  • Efficient Electrochemical Recovery of Tellurium from Spent Electrolytes by
           Cyclone Electrowinning
    • Abstract: A novel process for recovery of tellurium (Te) from spent Te electrolytes by cyclone electrowinning was developed. The effects of current density, electrolysis time, flow rate of the electrolyte (FRE), electrolyte temperature and cathode substrates on current efficiency (CE), tellurium recovery, cell voltage, energy consumption (EC), and surface morphology were systematically investigated. 99.90% of purity Te deposits were obtained while 95.61% of CE was achieved under the optimum conditions: electrolysis time of 24 h, current density of 60 A·m−2, FRE of 300 L·h−1, temperature of 30 °C and cathode substrates of 316L SS. Meanwhile, Te recovery and EC were 82.89% and 1810.58 kWh·t−1, respectively. Furthermore, as the solution after the electrowinning is recyclable, the consumption of reagents and the liquid effluent are minimized. All the parameters indicate that the cyclone electrowinning technology might serve as a promising alternative for recovering Te from spent Te electrolyte. Graphical
      PubDate: 2021-01-04
       
  • Design of a Novel Fertilizer Made from Steelmaking Slag Using the Glassy
           Phase of the CaO–SiO 2 –FeO System. Part II: Evaluation of the Novel
           Fertilizer in a Paddy Soil Environment
    • Abstract: To recover degraded paddy fields, low-cost supplies of Ca, Si, and Fe are necessary. Steelmaking slag contains these three elements, which makes it a potential material for amending paddy soil. To simultaneously supply Ca, Si, and Fe to paddy field, the optimum slag chemistry as a fertilizer was found in our previous study to have a basicity of about 1.6 and FeO concentration of about 25 mass%, referring to the CaO–SiO2–FeO system. The optimum slag structure, which is the coexistence of the CaO–SiO2–FeO glassy phase and 2CaO·SiO2 soil solution, can be obtained by quenching the molten slag from 1573 K. In this study, to evaluate the effects of the above novel slag fertilizer on soil amendment, a column test using an actual paddy soil was conducted. During the 2 months of testing, the concentrations of Fe, Ca, and Si in the soil solution were increased by applying the novel fertilizer, compared to two commercial fertilizers made of steelmaking slag. From the soil analysis before and after the column test, the concentrations of easily reducible iron oxide, exchangeable Ca, and adsorbed silica of the paddy were also increased by the novel slag fertilizer. In addition, a model for predicting the time-dependent changes in soil conditions was established using PHREEQC software. This model effectively estimated the daily changes in pH, oxidation and reduction potential, and the concentrations of each element in the soil solution. Graphical
      PubDate: 2021-01-04
       
  • Removal of Cadmium, Zinc, and Manganese from Dilute Aqueous Solutions by
           Foam Separation
    • Abstract: As environmental regulations are becoming stricter, new techniques must be developed for the removal of trace concentrations of heavy metals from mineral processing effluents. Foam separation techniques are an interesting alternative to more conventional processes such as ion exchange because of their efficiency to treat dilute aqueous streams. In this paper, the simultaneous removal of Cd2+, Mn2+, and Zn2+ from dilute aqueous solutions was investigated by using sodium dodecyl sulfate as collector and triethylenetetramine as auxiliary ligand via a series of batch-mode flotation experiments. Experimental results showed that Cd2+, Mn2+, and Zn2+ can be completely removed in one step under the following conditions: pH 9.50, flotation time = 120 min, auxiliary concentration 0.1 mmol L−1, collector-to-metals molar ratio 2:1, ethanol concentration 0.5% (v/v), and a nitrogen gas flowrate set at 25 mL min−1. An excess in auxiliary ligand concentration yielded to low removal efficiency. The modeled speciation of the examined system suggested that the metals are separated from the bulk solution to the foam phase via a combination of ion flotation and precipitate flotation. Graphical
      PubDate: 2021-01-04
       
  • Slag Chemistry and Behavior of Nickel and Tin in Black Copper Smelting
           with Alumina and Magnesia-Containing Slags
    • Abstract: The global amount of waste electrical and electronic equipment (WEEE) is growing fast. Non-ferrous metals represent a large portion of this waste, and they can be potentially recovered via black copper smelting. Alumina and magnesia, originating from the e-waste or fluxes, can be present in the feed of a secondary copper smelter in varying concentrations. Our study focuses on the impact of MgO on the slag chemistry of high-alumina iron silicate slags. The distributions of tin and nickel as minor elements were also investigated and compared with literature data. The equilibrium study was performed at 1300 °C in reducing conditions. Three different slag mixtures with 0, 3, and 6 wt% MgO were used in the study. The MgO addition significantly reduced the solubility of alumina in the slag and changed the primary spinel phase composition. The combined effects of increasing MgO and decreasing Al2O3 concentration in the slag regarding the distribution of tin were noticeable, i.e., its deportment to metal phase increased, but for nickel the effect was negligible. Theoretical calculations were performed for estimating the isolated effect of MgO on the distributions and they confirmed the beneficial effect on the behavior of tin but showed no impact for nickel. Graphical
      PubDate: 2020-12-21
       
  • Improving Zinc Recovery from Steelmaking Dust by Switching from
           Conventional Heating to Microwave Heating
    • Abstract: Recently, microwave energy has attracted increasing interest for accelerating thermal reactions. This study investigated the impact of microwave heating on the zinc recovery rate from electric arc furnace (EAF) and chromium converter (CRC) dusts. The results indicated that microwave heating required a lower temperature to recover zinc from EAF and CRC dusts compared with that in conventional thermal heating. For CRC dust, zinc recovery rates of 37.84% and 97.43% were obtained with conventional and microwave heating, respectively, at 850 °C. For EAF dust, zinc recovery rates of 79.88% and 98.20% were obtained with conventional and microwave heating, respectively, at 850 °C. The improved zinc recovery in this study was concluded to results from the rapidity of microwave heating and the interactions between the electromagnetic microwave field and the molecules of heated materials. Graphical
      PubDate: 2020-12-21
       
  • Development of a Sustainable Alternative for the Ammoniacal Cyanidation of
           Copper–Gold Ores Through a Biological Approach
    • Abstract: Due to the problems arising from the presence of copper in the gold cyanidation process, including high cyanide consumption and occupation of the activated carbon surface, biological ammoniacal cyanidation was implemented as a resolution. Bacillus megaterium was implemented to produce cyanide and ammonia in nutrient broth and vinasse media. Maximum cyanide concentrations of 29.8 and 47.5 mg/L were produced using 3 g/L glycine in the mentioned media, respectively. Afterward, the Box-Behnken experiment design method was implemented to optimize ammonia biogenesis in vinasse culture, where 1974 mg/L ammonia was synthesized at 13.56 g/L calcium chloride, 7.2 g/L urea, and pH = 7.9. Three different strategies, namely: (1) bio-cyanidation, (2) bio-ammoniacal cyanidation, and (3) bio-ammonia pretreatment/bio-cyanidation, were employed to recover gold and copper from a 1% solid pulp. Afterward, using the nutrient broth medium, 49% gold was recovered by the first approach; the second approach extracted 9.2% gold and 33.5% copper, and 77% copper removal and 76% gold recovery were achieved through the third technique. Nutrient broth substitution with vinasse increased the gold recovery to 97% in the third approach. Hence, ammoniacal pretreatment, in combination with bio-cyanidation, is suggested to recover gold from copper–gold ores. In conclusion, the originality of the present work lies first in developing a bacterial culture procedure in which nutrient broth was replaced with vinasse as an industrial byproduct to make the process more eco-friendly. And secondly, in using the biogenic ammonia to leach out copper from the copper–gold ore and prepare it for gold biocyanidation. Graphical
      PubDate: 2020-12-09
       
  • Design for Recycling Principles Applicable to Selected Clean Energy
           Technologies: Crystalline-Silicon Photovoltaic Modules, Electric Vehicle
           Batteries, and Wind Turbine Blades
    • Abstract: The global growth of clean energy technology deployment will be followed by parallel growth in end-of-life (EOL) products, bringing both challenges and opportunities. Cumulatively, by 2050, estimates project 78 million tonnes of raw materials embodied in the mass of EOL photovoltaic (PV) modules, 12 billion tonnes of wind turbine blades, and by 2030, 11 million tonnes of lithium-ion batteries. Owing partly to concern that the projected growth of these technologies could become constrained by raw material availability, processes for recycling them at EOL continue to be developed. However, none of these technologies are typically designed with recycling in mind, and all of them present challenges to efficient recycling. This article synthesizes and extends design for recycling (DfR) principles based on a review of published industrial and academic best practices as well as consultation with experts in the field. Specific principles developed herein apply to crystalline-silicon PV modules, batteries like those used in electric vehicles, and wind turbine blades, while a set of broader principles applies to all three of these technologies and potentially others. These principles are meant to be useful for stakeholders—such as research and development managers, analysts, and policymakers—in informing and promoting decisions that facilitate DfR and, ultimately, increase recycling rates as a way to enhance the circularity of the clean energy economy. The article also discusses some commercial implications of DfR. Graphical
      PubDate: 2020-12-03
       
  • Carboaluminothermic Production of Ferrotitanium from Ilmenite Through
           Thermal Plasma
    • Abstract: Ilmenite is the prime mineral used for the production of titania-rich slag and ferrotitanium alloy throughout the globe. In the current research, a 30 kW DC extended arc plasma reactor is employed for the aluminothermic reduction of ilmenite into ferrotitanium. For low-temperature operation, flux is added targeting low melting slag where CaO/Al2O3 ratio is varied from 0.8 to 1.6. Further, to lower down the Al consumption, carboaluminothermic reduction tests are carried out in stages without interruption. The effect of stage-wise reductant addition and CaO/Al2O3 ratio on ferrotitanium yield and titanium recovery is studied, corroborated to the slag chemistry. FeTi26 alloy is obtained through the carboaluminothermic smelting route with 25% excess stoichiometric Al in charge composition. The formation of calcium titanate and calcium aluminates governs slag chemistry and reduction kinetics. Graphical
      PubDate: 2020-12-01
       
  • Hydrometallurgical Processes for the Recovery of Metals from Steel
           Industry By-Products: A Critical Review
    • Abstract: The state of the art for the recovery of metals from steel industry by-products using hydrometallurgical processes is reviewed. The steel by-products are different slags, dusts, and sludges from a blast furnace (BF), basic oxygen furnace (BOF), electric arc furnace (EAF), and sinter plant, as well as oily mill scale and pickling sludge. The review highlights that dusts and sludges are harder to valorize than slags, while the internal recycling of dusts and sludges in steelmaking is inhibited by their high zinc content. Although the objectives of treating BF sludges, BOF sludges, and EAF dust are similar, i.e., the removal of zinc and the generation of an Fe-rich residue to be returned to the steel plant, these three classes of by-products have specific mineralogical compositions and zinc contents. Because wide variations in the mineralogical composition and zinc content occur, it is impossible to develop a one-size-fits-all flow sheet with a fixed set of process conditions. The reason for the interest in EAF dust is its high zinc content, by far the highest of all steel by-products. However, EAF dust is usually studied from the perspective of the zinc industry. There are not only different concentrations of zinc, but also variations in the all-important ZnO/ZnFe2O4 (zincite-to-franklinite) ratio. In many chemical processes, only the ZnO dissolves, while the ZnFe2O4 is too refractory and reports to the residue. It only dissolves in concentrated acids, or if the dust is pre-treated, e.g., with a reductive roasting step. The dissolution of ZnFe2O4 in acidic solutions also brings significant amounts of iron in solution. Finally, due to its high potassium chloride content, sinter-plant dust could be a source of potassium for the fertilizer industry. Graphical
      PubDate: 2020-11-13
       
  • A Kinetic Study on Selective Leaching of Phosphorus from Dephosphorization
           Slag
    • Abstract: Phosphorus recovery from dephosphorization slag generated during steelmaking has enormous potential to secure a stable supply of phosphate. Because P and Fe in slag are concentrated in different mineral phases, P can be recovered by separation of the P-bearing phase, and the residue can be reutilized in steel plant at the same time. In the present study, we adopted selective leaching of P and investigated the effects of leaching parameters on the dissolution behavior of slag. It was determined that with the decrease in particle size and increase in stirring speed, the P dissolution ratio increased significantly. When particle size was less than 53 μm and stirring speed exceeded 200 rpm, most of the P-bearing C2S−C3P solid solution was dissolved and separated. Increasing temperature and decreasing the mass ratio of slag to liquid had a slight influence on promoting P dissolution, while the Si dissolution was significantly suppressed in the case of high temperature and mass ratio due to the formation of silica gel. The P dissolution ratio reached 84.9%, and the Fe dissolution was negligible. Through selective leaching, the residue primarily consisting of magnesioferrite could be used as a flux in steelmaking process. The shrinking core model was successfully used to describe the dissolution kinetics of P. As temperature increased, apparent rate constant increased slightly. The calculated activation energy was 9.23 kJ/mol, demonstrating that the P dissolution was controlled by diffusion in the residue layer. Graphical Most of the P-bearing solid solution in dephosphorization slag was dissolved and the dissolution of Fe-bearing phase was negligible, achieving selective leaching of P. The P dissolution from slag was controlled by diffusion in the residue layer.
      PubDate: 2020-11-11
       
  • Low-Energy Feasibility for Leaching an Indigenous Scheelite Ore for
           Industrial Applications
    • Abstract: In recent times, the increasing demand for pure tungsten and its compounds in defense, medicine, high technology, and emerging innovations due to its excellent properties such as its tensile strength, corrosion resistance, and high modulus of elasticity cannot be overemphasized. In this study, an acid leaching route was adopted for the extraction of pure tungsten from a Nigerian scheelite ore consisting primarily of scheelite (Ca4.00W4.00O16.00: 96-900-9627) and quartz (Si6.00O6.00: 96-900-5019). At optimal leaching conditions (2.5 mol/L HCl, 70 °C, < 75 µm), 88.5% of the initial 10 g/L ore reacted within 120 min. The low apparent activation energy (Ea) estimated as 22.94 kJ/mol with the reaction order of 0.96 affirmed the dissolution reaction to occur through the diffusion control mechanism of the first-order relation. The low Ea obtained further supports the feasibility and eco-friendly dissolution process as ⁓11.5% of the undissolved materials analyzed to contain silica (SiO2: 96-900-5302) could be used as raw materials for some defined industrial applications. Graphical
      PubDate: 2020-11-03
       
  • Processing of Discarded Printed Circuit Board Fines via Flotation
    • Abstract: The recovery of metals from discarded printed circuit boards using environmentally-friendly physical routes is gaining importance. Physical separation of metal values from non-metallic constituents exploits various characteristics of crushed powder such as density, liberation, shape, size, and wettability. However, the generation of fines during grinding/crushing of the printed circuit boards is an unavoidable but essential by-product. The fine fractions are discarded due to the higher amounts of non-metallic fraction and poor separation of metallic values. In this study, the flotation process was studied to separate metallic and non-metallic values without the addition of external additives from the fine fraction of printed circuit boards (< 212 µm). The natural hydrophobic response of plastic and organic matter in fines stabilized the froth without additional reagents. The difference in tapped density for tailing (~ 0.5 g/cm3) and concentrate (~ 2.7 g/cm3) fraction ensures good separation. The metallic fraction increases from 14.3% in the feed to 91.7% in the concentrate. Recovery for metallic values was observed as ~ 72.3% with a purity of ~ 92% and comprised 77.9% Cu, 8.3% Sn, and 5.5% Pb. Graphical
      PubDate: 2020-10-29
       
  • Influence of Process Parameters on Countercurrent Reactor Reduction of
           
    • Abstract: Mill scale is treated as a waste product by the steel industry, so it is essential to recycle and reuse this waste for recovery of metallic iron and its single oxide derivative. Most of the study in the field of mill scale reduction focuses on the static mill scale reduction. Optimizing the process in dynamic conditions becomes more difficult because of the complexity involved inside the process. In the present method, mill scale having particle size ranges from 106 to 53 µm was converted to single-phase oxide Fe2O3 by blowing pure oxygen at 1100 °C and then it was subjected to a reducing atmosphere of 50% H2 and 50% N2 (1:1) at 875 ± 5 °C at a varying reactor angle from 2° to 5° and different mass flow rates varying from 0.037 to 0.148 kg/min. A generalized experimental model (GEM) has been formulated for the degree of reduction of oxide, which encompasses twelve parameters consisting of reactor design and process parameters. A Buckingham theorem was used to obtain dimensionless parameter for the degree of reduction, and a logical correlation using the proposed model has been established. Graphical
      PubDate: 2020-10-28
       
  • Review on Reduction Kinetics of Iron Ore–Coal Composite Pellet in
           Alternative and Sustainable Ironmaking
    • Abstract: The use of iron ore–coal composite pellet as a raw material for iron making is an ongoing area of research. Investigations on composite pellet reduction have reported some interesting phenomena, and experimental and modeling results, in which consistent and inconsistent conclusions have been presented in the literature. The aim of this review is to summarize the fundamentals of reduction kinetics of iron ore–coal composite pellet and the effect of various process parameters such as compositions, particle size, pellet geometry, ambient atmosphere and its partial pressure, heating conditions, and compaction pressure, etc., on it. The industrial application of composite pellet is also discussed. This article will be useful for the researchers carrying out experimental as well as modeling work related to the iron oxide–carbon composite pellet reduction. Graphical
      PubDate: 2020-10-26
       
 
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