Atmospheric leaching of matte containing iron

Abstract From the Canadian patent

of Disclosure, A method is provided for leaching comminuted nickeliferous sulfide matte containing by weight about 20% to 75% nickel, about 5% to 50% copper, non-stoichiometric sulfur in the range of over 4% to about 20%, over 0.5% to about 15 or 20% iron, the sum of the nickel, copper and sulfur contents being at least about 80% of the matte composition with the balance, gangue or slag and incidental impurities. The matte because of the iron content, is first granulated by quenching molten matte from a temperature at least about 10°C above its solidus-liquidus temperature but below its boiling point, following which the matte is comminuted and subjected to atmospheric leaching to dissolve …