scholarly journals Multiphase Mass Transfer in Iron and Steel Refining Processes

Author(s):  
Lucas Texeira Costa ◽  
Roberto Parreiras Tavares
Author(s):  
Владимир Чередниченко ◽  
Vladimir Cherednichenko

The book deals with theory and practice of development and operation of distilling electric furnaces wherein electrotrchnological processes of separating and refining mixed metals are ac-companied by heat exchange and mass transfer between molten metal and condensation surfaces, connected by flows of vapor-gas mixtures. There are considered principles of operation and theory of distilling electric resistance furnaces, distilling induction, arc and plasma furnaces which provide for production of pure and ultrapure metals, processing powders used in bag fil-ters and in electrostatic filters, scrubbers, as well as mixed metal separation in ferrous and non-ferrous metallurgy. The book presents the results of realizing distilling process in commercial equipment. The present book is appropriated for the specialist of engineering plants and scientific organ-izations, of design and research institutions, design departments, occupied with development, manufacture and operation of the equipment applied for realizing distilling and refining processes, as well as for students, undergraduates, post-graduates and teachers of various special-ties.


2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Irem Zeynep Yildirim ◽  
Monica Prezzi

Steel slag is a byproduct of the steelmaking and steel refining processes. This paper provides an overview of the different types of steel slag that are generated from basic-oxygen-furnace (BOF) steelmaking, electric-arc-furnace (EAF) steelmaking, and ladle-furnace steel refining processes. The mineralogical and morphological properties of BOF and electric-arc-furnace-ladle [EAF(L)] slag samples generated from two steel plants in Indiana were determined through X-Ray Diffraction (XRD) analyses and Scanning Electron Microscopy (SEM) studies. The XRD patterns of both BOF and EAF(L) slag samples were very complex, with several overlapping peaks resulting from the many minerals present in these samples. The XRD analyses indicated the presence of free MgO and CaO in both the BOF and EAF(L) slag samples. SEM micrographs showed that the majority of the sand-size steel slag particles had subangular to angular shapes. Very rough surface textures with distinct crystal structures were observed on the sand-size particles of BOF and EAF(L) slag samples under SEM. The characteristics of the steel slag samples considered in this study are discussed in the context of a detailed review of steel slag properties.


2020 ◽  
Author(s):  
Alexander Ponomarenko

The composition and properties of fluorine–anhydrite and steel–refining slag which are wastes of production of hydrogen fluoride and steel were determined. It is established that fluorine–anhydrite of the current output does not meet the requirements to materials for the production of Portland cement. Therefore to improve the technical and consumer properties of fluorine-anhydrite (for increasing the amount of CaSO4 ⋅2H2O and neutralization of H2SO4) the studies of its’ conditioning processes with steel– refining slag were carried out. It was found that the mass transfer coefficient of sulfuric acid through the capillary and the degree of its neutralization by slag depend on the dispersion of fluorine–anhydrite, its porosity and initial acidity. The most effective binding of sulfuric acid occurs with the introduction of slag in stoichiometric amounts, the size of fluorine–anhydrite granules up to 20 mm and a processing time of 60 minutes. After storage in air-humid conditions for 12 hours of fluorine–anhydrite treated with slag the strength of its granules, the amount of dihydrate gypsum and toxicological properties meet the requirements. Keywords: techno–gypsum, refining slag, neutralization, conditioning, gypsum stone, Portland cement


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1477
Author(s):  
Hidenori Tsukidate ◽  
Seika Otake ◽  
Yugo Kato ◽  
Ko Yoshimura ◽  
Masafumi Kitatsuji ◽  
...  

Iron and steel slag (ISS) is a byproduct of iron refining processes. The lack of iron in seawater can cause barren grounds where algae cannot grow. To improve the barren grounds of the sea, a supply of iron to the seawater is necessary. This study focused on bacteria interacting with ISS and promoting iron elution in seawater. Sulfitobacter sp. (TO1A) and Pseudomonas sp. (TO1B) were isolated from Tokyo Bay and Sagami Bay. The co-culture of both bacteria promoted more iron elution than individual cultures. After the incubation of both bacteria with ISS, quartz and vaterite appeared on the surface of the ISS. To maintain continuous iron elution from the ISS in the seawater, we also isolated Pseudoalteromonas sp. (TO7) that formed a yellow biofilm on the ISS. Iron was eluted by TO1A and TO1B, and biofilm was synthesized by TO7 continuously in the seawater. The present research is expected to contribute to the improvement of ISS usage as a material for the construction of seaweed forests.


Author(s):  
J A McGeough ◽  
J R Thomson

Iron foil of approximate thickness 0.05 mm has been electroformed from an electrolyte solution, composed mainly of ferrous chloride and flowing at Reynolds numbers ranging from 1620 to 19 400. Current densities between 15 and 45 A/dm2 have been used. At low Reynolds numbers, the current efficiency for metal deposition is limited by inadequate mass transfer. As the Reynolds number is increased, the current efficiency rises to a maximum, after which the efficiency is again reduced due to excessive occurrence of a reaction involving the reduction of ferrous hydroxide to iron. The Young modulus of the material along the direction of electrolyte flow is less than the recognized value for polycrystalline iron and steel. This is because of the crystal orientation and internal stresses of the electrodeposited metal. Electrolyte flow induces hydrogen embrittlement of the foil. This condition is found to exert a greater influence than grain size on tensile strength, ductility and proof stress. Its effects can be alleviated by stress relief. The hardness is unaffected by hydrogen embrittlement, but is increased at higher Reynolds numbers, due to the formation of smaller grains. Direct heating of the cathode reduces material hardness without affecting tensile properties. The introduction of electrolyte flow raises the rate of electroforming of iron only by about 50 per cent when compared with that obtained from an unstirred electrolyte. This surprisingly small effect of flow is attributed to the slowness of the chemical reactions which have more control over the rate of deposition of iron than the rate of mass transfer.


2012 ◽  
Vol 476-478 ◽  
pp. 340-345 ◽  
Author(s):  
Qi Xuan Rui ◽  
Guo Guang Cheng

With an increasing demand for high grade electric magnetic steels, SSRF(Single Snorkel Refining Furance) has got much attention due to its high efficiency of both decarburization and desulphurization. However the desulphurization mechanism of this kind SSRF is remarkably different from that of other steel refining processes such as LF,RH etc. , so it is necessary to understand the behaviour of desulphurization clearly. A mathmatical model has been established in this paper to investigate the degree of desulpurization with time on the basis of the influencing factors such as sulphur capacity of flux ,stirring energy of molten steel. It is shown that the desulpurization rate constant is about 1.0E-8 in accordance with the data from the practical test of a steel plant with SSRF.


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