The proposal is to mine and process ore from the supergene/basement deposits at the Boddington Goldmine. The supergene orebody is that zone of mineralisation which lies at the interface of the weathered oxide zone and the fresh basement rock. Standard open cut methods, as currently employed for the oxide ore mining operation, will be utilised to mine the deeper supergene and basement ores.

The supergene and some basement ores contain copper mineralisation which can interfere with the existing Carbon In Leach (CIL) processing method. This factor together with the hardness of the basement ores will necessitate the construction of a new treatment plant. The new plant will utilise floatation processing of the supergene and those basement ores which have copper mineralisation. The remainder of the basement ores will be treated using the existing CIL process.

In addition,owing to the hardness of some of the basement ores, further crushing and grinding equipment will be required. The new treatment plant will incorporate, a run-of-mine stockpile, separate crushing stations for supergene and basement ores, an intermediate crushed ore stockpile, milling and classification facilities, and a floatation facility housing gravity concentration, froth floatation, and product and residue thickening facilities. An additional throughput of approximately 2,000 tonnes per day would be generated by processing of the supergene/basement ores.

Note: Also see Boddington Gold Mine Project - Modification to processing and disposal of supergene and copper-rich basement ores (s46) [238B]