| 摘要 |
<p>A process for the soda ash digestion of refractory tungsten concentrates is provided, the process comprising forming a slurry of the concentrate in an aqueous solution to which sodium carbonate is added in stages while digesting the slurry in an autoclave at a selected elevated temperature of at least about 180oC to control the concentration of the sodium carbonate during digestion to provide high extraction yields of the contained WO¿3?. The total amount of the Na2CO3 added stage-wise to complete the digestion is substantially inversely correlated to the digestion temperature and substantially directly correlated to the Na2CO3/WO3 weight ratio such as to effect dissolution of at least about 97%, and generally at least about 98%, of the WO3 in the concentrate and provide a pregnant liquor containing WO3, the stage-wise addition of the sodium carbonate being such as to inhibit the dissolution of gangue minerals, such as silica, contained in the concentrate.</p> |
