Optimization of conditions of metallothermic reduction of rare earth preconcenrtrates

Yılmaz, Serkan
Rare earth ferrosilicon alloy is an important additive for ferrous metallurgy. It is mainly used to control the detrimental effects of sulfur in steel and to modify graphite structures in cast iron. The aim of this study was to optimize the conditions for the production of rare earth ferrosilicon alloy by metallothermic reduction process using a preconcentrate prepared from a bastnasite type of ore present in the Beylikahır-Eskişehir region of Turkey. In this study, the rare earth preconcentrate was reduced by aluminum together with ferrosilicon and rare earth ferrosilicon alloys were produced. The optimum conditions of reduction, which are time, temperature, reducer amounts and the basicity of the slag phase, were investigated by smelting in an induction furnace. At the end of the study, a rare earth ferrosilicon alloy containing 39.3 % rare earths, 37.5 % silicon, 19.3 % iron and 3.9 % aluminum was produced under the optimum conditions determined with 57.7 % rare earth metal recovery.


Production of rare earth ferrosilicide alloy
Topkaya, Yavuz Ali; Geveci, Ahmet (2006-08-31)
Rare earth ferrosilicide is a versatile alloy mainly used to control the detrimental effects of sulfur in steel and to modify graphite structures in cast iron.
On the Preparation of Mg2Ni by Combining Electrodeoxidation and Electrolysis Techniques
ERDEN, Fuat; Karakaya, İshak; Erdogan, Metehan (2014-11-01)
Mg2Ni is a well-known hydrogen storage alloy. Most of the preparative methods for this alloy require high temperature processing of pure magnesium and nickel. The proposed method, studied in this work, involves the production of Mg2Ni alloy directly from NiO and MgCl2 in an electrochemical cell. This method can eliminate the difficulties that may arise, during handling due to the reactive nature of metallic components, especially Mg. XRD patterns of reduced samples indicated the partial formation of Mg2Ni. ...
Optimization of the mechanical properties of Ti-6Al-4V alloy fabricated by selective laser melting using thermohydrogen processes
BILGIN, Guney Mert; Esen, Ziya; Akin, Seniz Kushan; Dericioğlu, Arcan Fehmi (2017-07-17)
2-step Thermo Hydrogen Process (THP) including hydrogenation and dehydrogenation steps was applied to Ti-6Al-4V alloy fabricated by selective laser melting (SLM) process to refine the microstructure and to increase the ductility of the alloy. It was observed that as-fabricated alloy's surface was composed of oxides of titanium and aluminum, which may alter the hydrogenation kinetics. The hydrogen treatment for 1 hat 650 degrees C, the maximum hydrogen solubility temperature of the alloy, transformed startin...
Development of magnesium based negative electrode materials for nickel metal hydride batteries
Eyövge, Cavit; Öztürk, Tayfur; Department of Metallurgical and Materials Engineering (2017)
Negative electrode materials of the nickel metal hydride (NiMH) batteries generally based on AB5 or similar compounds that make use of rare earth elements. The high cost of these elements makes it necessary to look for other alternatives that are more readily available and of low cost. It is also desirable to aim for materials that would have discharge capacity higher than roughly 350 mAh/g, which is typical of AB5 compounds. Magnesium-based hydrogen storage alloys have attracted considerable attention as a...
Determination of degree of mixing in solid rocket propellants
Yeşilırmak, Yener; Yılmazer, Ülkü; Department of Chemical Engineering (2006)
Composite propellants are mainly composed of: crystalline oxidizer, metallic fuel, and polymeric binder. Additives, such as plasticizers, catalysts, bonding agents and curing agents may also be incorporated to propellant compositions in small amounts. These ingredients should be mixed rigorously in order to obtain a uniform microstructure throughout the cast propellant profile. The quality of the propellant mixture has to be determined quantitatively to improve the product quality and to reduce costs. In th...
Citation Formats
S. Yılmaz, “Optimization of conditions of metallothermic reduction of rare earth preconcenrtrates,” M.S. - Master of Science, Middle East Technical University, 2007.