Patent ID: 8038767

Claim:
A method of recovering metal values from ores containing iron, nickel, cobalt, magnesium, and aluminum, comprising: a) leaching the ore with HNO 3 for a sufficient time to form a slurry; b) precipitating the iron from the slurry as Fe 2 O 3 ; c) precipitating aluminum as Al 2 O 3 , and leaving a solution containing nickel and cobalt values; d) mixing Mg(OH) 2 with the nickel-cobalt solution, then performing thermal hydrolysis, or pH balance (shift) or solvent extraction to form Ni(OH) 2 and Co(OH) 2 or Ni/Co salts in solid form, and removing the nickel-cobalt values as a precipitate; e) recovering HNO 3 and NO x from the process; and f) reforming the removed NO x containing gases into nitric acid for further use.