摘要 |
<p>Sulphides of copper and other metals which form insoluble sulphides more readily than nickel in acid and neutral solutions containing nickel and/or cobalt salts, e.g. sulphates, are separated by reacting the solution at a pH from 1 to 7 with sulphur dioxide and with an amount of finely divided particles of elemental sulphur in excess of the amount required to form the sulphides, agitating at above 50 DEG C. in an inert atmosphere and then separating the precipitated sulphides. Other metals which may be precipitated are silver, germanium, tungsten, bismuth, platinum, cadmium, rhodium, molybdenum, tin, vanadium, mercury, palladium, arsenic, lead, titanium and antimony. The sulphur dioxide may be formed in the solution by the addition of ammonium sulphite or sodium sulphite. The elemental sulphur may be mixed with a wetting agent before dispersion in the solution. Examples are given.</p> |