Metallurgy electrolysis

G. Pastztov, The Possibility of Producing Aluminum with Higher Purity on the Basis of the Electrochemical Model of Electrolysis, Mineral Processing and Extractive Metallurgy Review, Vol. 8, p. 119, 1992. 

Lithium chloride is used in the production of lithium metal by electrolysis. It also is used in metallurgy as a eutectic melting composition with potassium chloride (LiCl 41 mol% KCl 59 mol%). Other applications are in low temperature dry-cell batteries as a dehumidifier in air conditioning in welding and soldering flux as a desiccant in fireworks and in mineral waters and soft drinks. 

The addition of a chemical reducing agent to precipitate metals from their salt solutions has been considered for many years as an alternative to displacement reactions and electrolysis. The developments in the field of powder metallurgy in recent years have increased interest in this reduction method since the final product obtained is high-purity metal powder. The ease with which these high-purity powders can be converted into readily handled forms such as briquettes has improved their marketability to other metallurgical users. 

Derivation (1) Reduction of thorium dioxide with calcium (2) fused salt electrolysis of the double fluoride ThF4 KF. The product of both processes is thorium powder, fabricated into the metal by powder metallurgy techniques. Hot surface decomposition of the iodide produces crystal bar thorium. 

The use of large amounts of electrical energy in electrolysis makes production of aluminum from ores an expensive metallurgy. Methods for recycling used A1 use less than 10% of the energy required to make new metal from bauxite by the Hall-Heroult process. 

Among the pentavalent elements, the most important are niobium and tantalum. Niobium is an excellent material for surface treatment of steel materials for chemical industry due to its high hardness and corrosion-resistance in wet acidic conditions. Nowadays, niobium is also used for the preparation of superconductor tapes and it is used in other branches of industry, for instance in nuclear technology and metallurgy. Tantalum is also of similar importance. For these applications, it is necessary to prepare high purity metal. Molten salt electrolysis, as an alternative process to classical thermal reduction, provides niobium and tantalum with required quality. In order to optimize these processes, it is necessary to know details of both complex formation and redox chemistry of the species present in the melts. 

Metallurgy. — Metallic, rubidium may be prepared in a variety of ways (1) electrolysis of the fused chloride, (2) heating RbOH with aluminium or mugnesinin, fH) heating Rb,t 0 with carhon or magnesium, (4) heating It Iff 1 wilh calcium, (5) heating the tartrate to white heat. 

Metallurgy. — The metals of most of the cerium group elements have been prepared, three general methods having been used t (1) fusion of the anhydrous halides with sodium, potassium, calcium, or aluminium (2) electrolysis of the fused chlorides or of a solution of the oxide in the molten fluoride (3) heating the oxides with magnesium, calcium, or silicon. Reduction with aluminium has also been tried, but it is not satisfactory except possibly for cerium itself. Electrolysis has been the most successful, the other methods usually giving at best an alloy. 

Metallurgy. — Thallium is very easily prepared from its compounds in several ways (1) fusion of the thallous chloride or iodide with Na2C03 and KCN (2) electrolysis of the carbonate or sulfate (3) addition of zinc to a thallous solution (4) heating thallous oxalate in a covered crucible. 

Fig. 7.3. Zirconium Electrolysis cell (Shelton, S. M., Zirconium Production Methods, Metallurgy of Zirconium, McGraw-Hill. U.S.A.E.C. Copyright).

Buddery, j. H. and Hedger, H. J. Production of uranium metal by electrolysis. Progress in Nuclear Energy, Ser. V, Metallurgy and Fuels, vol. 1. Pergamon Press (1956). 

Gerard, G. (ed.) (1963) Extractive Metallurgy of Aluminium. VoL 1. Alumina. Interscience, New York. Grojotheim, K. Krohn, C. MALINOVSKY, M. Matiasovsky, K. ThonstaDT, J. (1982) Aluminium Electrolysis. 

Electrometallurgy is that part of metallurgy that involves the use of electric current to reduce compounds of metals to free metals. It includes uses of electrolysis such as metal plating, metal refining, and electroforming. Electrolysis in this context does not include the cosmetic use of electrolysis in hair removal. 

Metallurgy For the production of corrosive metals, glass-like carbon crucibles are used as containers for molten salt electrolysis. 

Wong, M M and Haver, F P, 1977. Fused salt electrolysis for the production of lead and zinc metals, in Proceedings international Symposium on Molten Salt EJectrolysis in Metal Production, pp 21-29 (Institution of Mining and Metallurgy (IMM) London). 

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