AMMONIACAL AMMONIUM LEACHING OF NICKEL ALLOYS-WITH A TWIST

摘要

Naturally occurring nickel alloys such as awaruite (Ni_3Fe), commonly found in ultramafic rocks, are a potentially significant nickel resource, although a selective extraction process has so far proved elusive. We have developed a hydrometallurgical process using ammonia that operates at modest temperature and atmospheric pressure. Certain additives to the leach have overcome the passivation of the alloys in aerated alkaline solution. The process could also find application in the post-reduction leaching stage of the Caron process.