Production of Tungsten by Pulse Current Reduction of CaWO4

2016-02-14
Özdemir, Furkan
Erdoğan, Metehan
Elmadağlı, Mustafa
Karakaya, İshak
Tungsten is mainly produced by H-2 reduction of WO3 which makes its production difficult and costly. A promising method was recently reported for direct electrochemical production of tungsten from CaWO4 (scheelite) which is estimated as the seventy percent of the all tungsten reserves of the world. This paper investigates the application of pulse current in the electrochemical reduction of CaWO4 pellets attached to a current collector. The electrolyte was composed of calcium chloride and sodium chloride salts at eutectic composition (48 pct mol NaCl at 873 K). The reduced samples were cleaned with dilute hydrochloric acid solutions and characterized by X-ray diffraction and scanning electron microscopy. Examination of the results revealed that metallic tungsten was obtained by pulse current reduction.

Suggestions

Recovery of tungsten from tungsten bearing compounds
Erdoğan, Metehan; Karakaya, İshak; Department of Metallurgical and Materials Engineering (2013)
Extensive research in recent years has failed to develop any essentially new method of large scale tungsten production. A new tungsten powder production technique from calcium tungstate (CaWO4) has recently been reported. In this thesis, this technique was further explored from the aspects of electrochemical reduction mechanism and kinetics, applicability to scheelite concentrates and industrial production. Cyclic voltammetry, constant potential and constant current electrochemical reduction tests were perf...
Investigation of the larger scale tungsten production by the electrochemical reduction technique
Özdemir, Furkan; Erdoğan, Metehan; Elmadağlı, Mustafa; Karakaya, İshak (null; 2016-11-01)
Hydrogen reduction of WO3 is the major industrial process in tungsten production. A promising cost and energy efficient method was recently reported [1-3] for direct electrochemical production of tungsten from CaWO4 (scheelite) which is estimated as the two third of the all tungsten reserves of the world. Following the above mentioned patent, several studies verified the production of metallic tungsten by electrochemical reduction of calcium tungstate in the laboratory. This study investigates the applicati...
Use of Different Alkylammonium Salts in Clay Surface Modification for Epoxy-Based Nanocomposites
Nakas, G. Ipek; Kaynak, Cevdet (Wiley, 2009-03-01)
Layered silicates become widely used reinforcement material in the polymer nanocomposite production in recent years due to their high aspect ratio, ease of processing, and low cost. In this present study, the aim was to evaluate the usability of a raw clay source (Resadiye, Turkey) in the production of epoxy/clay nanocomposites and to investigate the effects of different surface modifiers. For this purpose, raw Namontmorillonite clay was first purified and then surface modified by using different types of a...
Production and characterization of aluminum matrix composites for small-scale unmanned aircraft engine pistons
Demiralp, Muammer; Kalkanlı, Ali; Department of Metallurgical and Materials Engineering (2020)
The composite materials are used in every stage in life, from the aerospace industry to agriculture. In most composites, the primary purpose of adding reinforcement to the matrix material is to increase the strength and stiffness of the matrix. Nowadays, most engineering materials are replaced with the composite materials due to higher specific strength. In this study, particle reinforced metal matrix composite is used to produce pistons for a small-scale unmanned aircraft engine. Conventional pistons are p...
Manufacturing of Functionally Graded Porous Products by Selective Laser Sintering
Erdal Erdoğmuş, Merve; Dağ, Serkan (2008-09-25)
Selective laser sintering (SLS) is a rapid prototyping technique which is used to manufacture plastic and metal models. The porosity of the final product obtained by SLS can be controlled by changing the energy density level used during the manufacturing process. The energy density level is itself dependent upon manufacturing parameters such as laser power, hatching distance and scanning speed. Through mechanical characterization techniques, it is possible to quantitatively relate the energy density levels ...
Citation Formats
F. Özdemir, M. Erdoğan, M. Elmadağlı, and İ. Karakaya, “Production of Tungsten by Pulse Current Reduction of CaWO4,” 2016, p. 151, Accessed: 00, 2021. [Online]. Available: https://hdl.handle.net/11511/82299.