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AssigneeInternational Ore Technology, Inc.
InventorJohn G. Posel
Estimating the term…
The ore is subjected to nitric acid leaching and the leach solution is heated to a temperature at which one of the additional sulfur and iron values is selectively insolubilized with respect to the solution, while the other is maintained in solution for subsequent separation from the liquor after the insolubles have been removed and the liquor has been neutralized. In addition, in one embodiment of the invention the heating and acid neutralization steps are controlled within certain prescribed limits to make it possible to remove the metals from the liquor by solvent extraction without the problem of lasting precipitates forming in the liquor and fouling the extraction process. Where there is a sizable amount of dissolved iron in the liquor, the liquor may be subjected to autoclaving at a temperature above about 149.degree.C (300.degree.F) to precipitate the iron as the oxide thereof. This effect is possible even where the liquor is high in sulfate concentration.
A method of recovering one or more metal values of the group consisting of copper, silver, nickel, cobalt and zinc from a sulfur containing ore of the metal or metals, comprising intermixing the ore and at least a stoichiometric amount of nitric acid of about 30-50% by volume concentration to form an aqueous acid leach solution of the same, heating the solution to a temperature at or above the melting point of sulfur while the solution is contained under pressure in a relatively inert atmosphere, controlling the temperature of the solution to precipitate the sulfur from the solution, relatively separating the sulfur precipitate from the acid soluble phase of the solution, and recovering the metal value or values from the acid soluble phase.
A method of recovering one or more metal values of the group consisting of copper, silver, nickel, cobalt and zinc from an iron and sulfur containing ore of the metal or metals, comprising intermixing the ore and at least a stoichiometric amount of nitric acid of about 30-50% by volume concentration to form an aqueous acid leach solution of the same, heating the solution to a temperature at or above the melting point of sulfur while the solution is contained under pressure in relatively inert atmosphere, controlling the temperature of the solution to precipitate the sulfur from the solution, controlling the pH of the solution to precipitate the iron values from the acid soluble phase of the solution, relatively separating the precipitates from the acid soluble phase of the solution, and the acid soluble phase of the solution from the acid insoluble phase thereof, and recovering the metal value or values from the acid soluble phase.
A method of recovering one or more metal values of the group consisting of copper, silver, nickel, cobalt and zinc from a polysulfide ore of the metal or metals, comprising intermixing the ore and at least a stoichiometric amount of nitric acid of about 30-50% by volume concentration to form an aqueous acid leach solution of the same, heating the solution to a temperature of about 115.degree.-125.degree.C, while containing the solution under pressure in a relatively inert atmosphere, to melt the sulfur, crystallizing the sulfur, and relatively separating the sulfur and the acid insoluble phase of the leach solution from the acid soluble phase thereof and recovering the metal value or values from the acid soluble phase.
A method of recovering one or more metal values of the group consisting of copper, silver, nickel, cobalt and zinc from a polysulfide ore of the metal or metals, comprising intermixing the ore and at least a stoichiometric amount of nitric acid of about 30-50 percent by volume concentration, to form an aqueous acid leach solution of the same in a container pressurized at about at least 50 psi above atmospheric pressure with a relatively inert gas, heating the solution to a temperature of about 115.degree.-125.degree.C so that the sulfur in the suspension melts but does not substantially react with the acid, crystallizing the sulfur and relatively separating the sulfur and the acid insoluble phase of the leach solution, from the acid soluble phase thereof, and recovering the metal value or values from the acid soluble phase.
In a process of recovering one or more metal values of the group consisting of copper, silver, nickel, cobalt and zinc from a polysulfide ore of the metal or metals, the steps of leaching an aqueous suspension of the ore with at least a stoichiometric amount of nitric acid of about 30-50 percent by volume concentration, while agitating the leach solution in a container pressurized at about at least 50 psi above atmospheric pressure with a relatively inert gas, heating the solution to a temperature of about 115.degree.-125.degree.C, for at least about 30 minutes, crystallizing the sulfur, crystallizing the metal value or values, and recovering the crystals from the solution.
In a process of leaching an aqueous suspension of a polysulfide ore of copper, silver, cobalt, zinc, and or nickel, with nitric acid of about 30-50 percent by volume concentration, to recover the metal values, the steps of heating the leach solution to about 115.degree.-125.degree.C, in an atmosphere of a relatively inert gas pressurized at about at least 50 psig, for at least about 30 minutes, cooling and pressure relieving the leach solution to a temperature of less than about 100.degree.C to precipitate the sulfur, and relatively separating the precipitate from the solution.
Dependencies are inferred from the claim text.