摘要 |
<p>The invention provides, in part, a process for extracting nickel from a source material including iron and nickel, by contacting the source material (e.g, an ultramafic ore) with an aqueous ammonia solution containing an iron-complexing agent (e.g., citrate) under suitable conditions, thereby extracting the nickel. The aqueous ammonia solution may optionally contain a sulfur-containing reductant, such as thiosulfate.</p> |