191 research outputs found
Atazanavir and Cardiovascular Risk Among Human Immunodeficiency Virus-Infected Patients: A Systematic Review
Robert J. Baczuk v. Salt Lake Regional Medical Center and Dr. Brian Moench : Reply Brief
APPEAL FROM A FINAL JUDGMENT OF THE THIRD DISTRICT COURT THE HONORABLE HOMER F. WILKINSO
Stabilization of Basic Oxygen Furnace Slag by Hot-stage Carbonation Treatment.
Treatment and disposal of Basic Oxygen Furnace (BOF) slag, a residue of the steel production process characterized by high basicity and propensity for heavy metal leaching, is a costly burden on metallurgical plants; a sustainable valorization route is desired. The stabilization of BOF slag utilizing hot-stage carbonation treatment was investigated; this approach envisions carbonation during the hot-to-cold pathway followed by the material after the molten slag is poured and solidified. Three experimental methodologies were employed: (i) in-situ thermogravimetric analyzer (TGA) carbonation was used to assess carbonation reaction kinetics and thermodynamic equilibrium at high temperatures; (ii) pressurized basket reaction carbonation was used to assess the effects of pressurization, steam addition and slag particle size; and (iii) atmospheric furnace carbonation was used to assess the effect of carbonation on the mineralogy, basicity and heavy metal leaching properties of the slag. Free lime was found to be the primary mineral participating in direct carbonation of BOF slag. Initial carbonation kinetics were comparable at temperatures ranging from 500 to 800 oC, but higher temperatures aided in solid state diffusion of CO2 into the unreacted particle core, thus increasing overall CO2 uptake. The optimum carbonation temperature of both BOF slag and pure lime lies just below the transition temperature between carbonation stability and carbonate decomposition: 830-850 oC and 750-770 oC at 1 atm and 0.2 atm CO2 partial pressures, respectively. Pressurization and steam addition contribute marginally to CO2 uptake. CO2 uptake progressively decreases with increasing particle size, but basicity reduction is similar independent of particle size. The solubility of some heavy metals reduced after carbonation (barium, cobalt and nickel), but vanadium and chromium leaching increased
Comparative oxidation behavior of Nd-Fe-B magnets for potential recycling methods::Effect of hydrogenation pre-treatment and magnet composition
Influence of Al2O3 Level in CaO-SiO2-MgO-Al2O3 Refining Slags on Slag/Magnesia-Doloma Refractory Interactions
status: publishe
Influence of Al2O3 Level in CaO-SiO2-MgO-Al2O3 Refining Slags on Slag/Magnesia-Doloma Refractory Interactions
status: publishe
Viscosity of partially crystallized BOF slag
In order to stabilize free lime in the basic oxygen furnace (BOF) slag to achieve high value products, quartz sand and other additives are injected into slag. However, the current hot stage slag stabilization does not work in case of slag (before treatment) with a liquid fraction lower than 90%, where the slag containing solid particles is too viscous. Therefore, it is essential to understand how solid phases affect the viscosity of the slag system. In this study, the industrial BOF slags were investigated with respect to the correlation between volume fraction of solid phases and its viscosity. Slag viscosity was measured with a rotating type viscometer at temperatures below the liquidus. The volume fraction of solid phases was quantitatively calculated with FactSage. The Einstein-Roscoe equation was employed to predict the viscosity of BOF slag.status: publishe
Sustainable high temperature metallurgical processes and engineering materials recycling techniques
status: publishe
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