| 摘要 |
<p>In a method of extracting metal values selected from cobalt, molybdenum, nickel, tungsten and vanadium from metal-containing particles, the particles are contacted for at least 15 minutes with an aqueous solution of ammonia, an ammonium salt and hydrogen peroxide. The aqueous solution has an initial pH of at least 9.5 and an initial hydrogen peroxide concentration of from 0.02 to 0.2 M, and the pH of the aqueous solution is maintained at 9.5. In the case of metal-containing particles such as spent hydroprocessing catalyst particles containing carbon residue, the particles are first roasted in an oxygen-containing atmosphere at a temperature of from 400 to 600 DEG C, prior to the leaching step.</p> |
