Recovery of metal values from ores

Claim 2

The process for the leaching of metal values from minerals comprising copper, iron and sulfur comprising contacting said minerals with an aqueous leach solution containing at least 10 grams per liter of iron ions and sufficient chloride ion to form soluble metal chlorides of the nonferrous metal values leached from said minerals at a pH in the range of about 2.4-6 at a temperature of at least 80*C. in the presence of a molecular oxygen-containing gas intimately dispersed therein while precipitating ferric hydroxide from the said leach solution.

Claim 3

The process of claim 1 wherein the temperature is maintained in the range 95*-105*C.

Claim 4

The process of claim 2 wherein the partial pressure of oxygen is maintained at at least 90 psig.

Claim 5

The process of claim 3 wherein the precipitation is continued until the leach solution is substantially free of iron.

Claim 6

The process of claim 1 wherein cupric ion is initially present in the leach solution.

Claim 7

The process of claim 4 wherein cupric ion is initially present in the leach solution.

Claim 8

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

Claim 9

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

Claim 10

The process of claim 7 wherein the oxygen partial pressure is at least 90 psia.

Claim 11

The process of claim 8 wherein the cupric ion is reduced to cuprous ion in the initial stage by contacting said leach solution with excess minerals.

Claim 12

The process of claim 7 wherein the final stage is conducted at a temperature in the range 95*-105*C.

Claim 13

The process of claim 9 wherein the final stage is conducted at a temperature in the range 95*-105*C.

Claim 14

The process of claim 11 wherein at least 0.5 parts of oxygen per part of solids from step (b) are introduced in the final stage of leaching.

Claim 15

The process of claim 11 wherein the copper mineral is substantially chalcopyrite.

Claim 16

The process of claim 13 wherein the liquid from the initial stage contains 30 to 90 grams of cuprous ion per liter.

Claim 17

The process of claim 13 wherein at least 50% excess chalcopyrite is maintained in the initial leaching.

Claim 18

The process of claim 7 wherein at least 3.5 gram equivalents of chloride per kilogram of solution is maintained in each leach.

Claim 19

The process of claim 10 wherein at least 3.5 gram equivalents of chloride per kilogram of solution is maintained in each leach.

Claim 20

The process of claim 3 wherein iron ions are present when said minerals are in contact with said oxygen-containing gas.

Claim 21

The process of claim 10 wherein iron ions are present when said minerals are in contact with said oxygen-containing gas.

Claim 22

The process of claim 10 wherein inert gas is introduced in said initial stage.