灰重石からタングステンの抽出

抄録

We studied extractive methods which were not based on the usual acid process-the decomposition by the roasting with a mixture of sodium carbonate and carbon and the autoclavesoda process. Tested are is flotation concentrate from Otani mine that has 26-28% WO³ and the particle size is minus 150mesh.
Following results were obtained.
1) roasting process The maximum value of extraction, 97.46%, was obtained when she mixture of 2g ore, 2g sodium carbonate and 0.5g charcoal powder was roasted at 750°C. At the same condition without carbon, the value of extraction was 91.48%. The amount of sodium carbonate required was 7.7 times the theoretical one.
2) autoclave-soda process Effects of concentration of sodium carbonate solution, temperature, pressure, keeping time, pulp density and r.p.m. of the stirrer on the extraction and the dissolution of impurities were studied. The best result was obtained at the under condition and the extraction was 96.5%. pulp density-400g/l; concentration of solution-20% sodium carbonate; temperature-190°C; pressure-13atm.; keeping time-4hrs.; 45r.p.m.
The amount of soda required was about 4 times the theoretical one.