Processing ores containing precious metals
AssigneeNewcrest Mining Limited
InventorJohn O'Callaghan
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Abstract
A method of recovering gold from gold-containing sulphide minerals in an ore that has a recovery-oxidation curve in a graph of % recovery of gold versus % oxidation of the minerals that has a slope of less than 1:1 in a higher % oxidation part of the curve, includes operating at least one oxidation unit to achieve a target % oxidation for sulphur in the ore that is in a higher oxidation part of the curve and producing an output having liberated gold as a consequence of sulphur oxidation in the oxidation unit and allowing variations of the % oxidation in the oxidation unit during the method.
Claims23
A method of recovering gold in a gold recovery plant from gold-containing sulphide minerals in an ore that has a recovery-oxidation curve in a graph of % recovery of gold versus % oxidation of the minerals that has a slope of less than 1:1 in a higher % oxidation part of the curve, including:
- (a) processing a mined ore in an ore preparation unit and producing an ore preparation unit output;
- (b) selecting a target range of % oxidation values for sulphur in the ore of the ore preparation unit output to be in a higher oxidation part of the curve and less than complete oxidation and selecting operating conditions for (a) that include a plurality of oxidation unit to achieve oxidation in the target range of % oxidation values for sulphur in the preparation unit output in the oxidation unit;
- (c) operating the oxidation unit in accordance with the operating conditions and oxidizing sulphur in the ore preparation unit output and producing an output of the oxidation unit having liberated gold as a consequence of sulphur oxidation in the oxidation unit;
- and
- (d) controlling operation of the plant by allowing variations of the % oxidation of sulphur in the oxidation unit within the target range of % oxidation values for sulphur during the method in response to changes in plant operating conditions.
A processing plant for recovering gold from gold-containing sulphide minerals in an ore that has a recovery-oxidation curve in a graph of % recovery of gold versus % oxidation of the minerals that has a slope of less than 1:1 in a higher % oxidation part of the curve:
- (a) an ore preparation unit that includes, for example, comminution and size separation units, such as crushing and milling units, for processing a mined ore and producing an ore preparation unit output from a mined ore, and
- (b) a plurality of separate oxidation units, such as autoclave units, in a parallel circuit, with each oxidation unit being operable for oxidizing sulphur in the ore preparation unit output at a target range of % oxidation value for sulphur in the ore to be in the higher oxidation part of the curve and less than complete oxidation,
- wherein operation of the plant is controlled by allowing variable oxidation of sulphur in the oxidation units within the target range of % oxidation values for sulphur in response to changes in plant operating conditions and producing an oxidation unit output having liberated gold as a consequence of sulphur oxidation.
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Dependencies are inferred from the claim text.