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Formation of Tungsten Monocarbide from a Molten Tungstate-halide Phase by Gas Sparging.

Gomes JM; Raddatz AE; Baglin EG
U S Pat 4 489 044 1984 Dec; :
Sodium chloride and sodium silicate containing a tungsten ore (scheelite or wolframite) are melted, and the melt is sparged with methane or natural gas at 900 deg-1,100 deg c to form tungsten carbide, wc. Thus, wolframite containing wo3, fe2o3, and mno was mixed with nacl and na2sio3 and the mixture melted at 1,075 deg c. A very fluid halide phase containing 31.4 pct wo3 was formed and separated from the highly viscous silicate phase. The halide phase was treated with ch4 at 1,100 deg c by sparging. The recovery of w as wc was 81 pct, and the wc contained al 0.005, Cu 0.007, Fe 0.10, Mgo 0.005, Mn 0.05, Mo <0.001, Si 0.07, Sn 0.009, Ti 0.01, V 0.006, O 0.34, and c 6.19 pct. The specifications for commercial wc are: free c 0.10, Fe 0.15, Mo 0.10, Wt pct maximum, and the stoichiometric carbon content of wc is 6.13 pct.
Publication Date
Document Type
Fiscal Year
Identifying No.
PAT 4,489,044
NIOSH Division
Source Name
U.S. Pat. 4,489,044, Dec. 18, 1984; Chem. Abstr. 102:187,435K
Page last reviewed: October 1, 2021
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