NIOBIUM RECYCLING FROM THE INDUSTRIAL WASTES
Recycling technologies of the wastes containing niobium with using various methods are considered. Advantages of the hydrometallurgical method of industrial wastes treatment are shown. Thermodynamic characteristics of the leaching process are calculated. The process parameters of niobium compound dissolution are determined. Some methods of production of metallic niobium powder of various dispersions are proposed. Niobium refining processes using oxygen-free ionic melts, which allow extraction of niobium powder or compact electrochemical niobium coatings, are investigated. The influence of current density, temperature and electrolyte components concentration on a current efficiency and characteristics of coatings are established. Increasing of current density and coating thickness, respectively, leads to the deposition of macrocrystalline coatings. Niobium deposition on copper leads to deposition of coatings with a slight interdiffusion. The proposed niobium refining methods allow receiving high purity metal in a compact or powder form. Bibl. 5, Fig. 2, Tab. 1.
Korovin S.S., Drobot D.V., Fedorov P.I. [Rare and dispelled elements. Himija i tehnologija], Moscow : Moskovskij institut stali i splavov, 1999, 461 p. (Rus).
Bajrachnij B.І., Ljashok L.V. [Rare and dispelled elements. The Technology of Production and Use], Kharkov : Nacional’nyj tehnicheskij universitet «Har’kovskij politehnicheskij institut», 2007, 288 p. (Ukr).
Savickij E.M., Burhalov G.S. [Refractory metals and their alloys], Moscow : Metallurgija, 1986, 331 p. (Rus). 4. Lidin R.A., Molochko V.A., Andreeva L.L. [Chemical properties of mineral substances], Moscow: Himija, 2000, 480 p (Rus).
Zelikman A.N. [Metallurgy of refractory rare metals], Moscow : Metallurgija, 1986, 440 p. (Rus).