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Electrolytic Preparation of Tungsten Metal and Tungsten Carbide from Wolframite.
Gomes-JM; Uchida-J; Wong-MM
NTIS: PB 190 035 :8 pages
Two methods for electrowinning tungsten from wolframite [(fe,mn) wo4] were investigated. The first method, direct electrowinning from wolframite concentrate dissolved in molten salt mixtures composed essentially of various combinations of sodium phosphates, sodium borates, and sodium halides, yeilded impure products. The second method was electrowinning from a halide-tungstate melt that was obtained from a high-temperature, two-phase extraction of tungstic oxide (wo3) from wolframite. Electrolysis in electrolytes prepared from addition of sodium metaphosphate (napo3) and boric oxide (b2o3) to the halide-tungstate melt produced tungsten metal of 99.9 percent purity. Tungsten carbide (wc) was electrodeposited from the halide-tungstate melt when the melt was adjusted to contain 82 mole-percent nacl and 6.0 Mole-percent each of wo3, sodium metaborate (na2b2o4), and caustic soda (naoh).
IH; Report of Investigation;
NTIS Accession No.
NTIS: PB 190 035
Page last reviewed: April 12, 2019
Content source: National Institute for Occupational Safety and Health Education and Information Division