Processes for treating materials containing nickel and iron

Claim 1

IN A PROCESS OF TREATING MAYARI TYPE ORE, THE STEPS OF MIXING A 10% TO 70% BY WEIGHT AQUEOUS SOLUTION OF NITRIC ACID WITH THE ORE, THE QUANTITY OF CONTAINED NITRIC ACID BEING AT LEAST SUFFICIENT TO MEET THE STOICHIOMETRIC REQUIREMENTS OF THE NICKEL, COBALT, MANGANESE AND ALUMINUM OF THE ORE BEING TREATED BUT INSUFFICIENT TO MEET SUCH REQUIREMENTS AND ALSO NITRATE A MAJOR PORTION OF THE IRON OF THE ORE, HEATING THE MIXTURE OF SOLUTION AND ORE TO A TEMPERATURE OF BETWEEN 310* F. AND 650* F. IN AN AUTOCLAVE TO PRODUCE A VAPOR PRESSURE WITHIN THE AUTOCLAVE SUFFICIENT TO RETAIN WATER AND NITRIC ACID IN THE LIQUID PHASE, MAINTAINING THE MIXTURE AT SUCH TEMPERATURE FOR A SUFFICIENT TIME TO DISSOLVE MOST OF THE NICKEL AND COBALT OF THE ORE BUT RETAIN MOST OF THE IRON IN THE SOLID PHASE LOW IN NICKEL CONTENT, AND SEPARATING THE SOLUTION CONTAINING NICKEL AND COBALT FROM THE TREATED ORE.