Results to date show sorting of ore will significantly reduce the cost of hauling and processing Second Fortune ore.
Sorting will de-risk future underground mining at Second Fortune by rejecting waste dilution prior to haulage and processing, reducing one of the biggest risks in narrow vein mining.
John Davis, executive chairman, commented: “The commencement of processing operations is a major milestone in the development of the Second Fortune mining operation.
“We are very excited to be operating one of the first commercial sorting plants in the Australian gold mining business.”
Exterra’s projects are all located in the Archaean Yilgarn Craton of Western Australia, a world class gold province which includes the Kalgoorlie Golden Mile deposit, which has produced over 50 million ounces of gold.
During November 2016, Exterra commenced the construction phase of its recently approved Second Fortune gold mine.
The Second Fortune underground mine feasibility study highlighted the low cost entry to gold production.
Study details include:
- 131,000 ounces at 8.5 g/t gold JORC Resource at Second Fortune;
- 56,300 ounces at 9.7 g/t gold JORC Reserve at the Main Lode only;
- $97 million revenue to 300vm on Main Lode over 30 months;
- $34 million net cash flow (at A$1700 an ounce gold price); and
- +/-A$5 million pre-production capital.
Ore sorting technology is used in numerous mining operations to reject low grade material post mining and before haulage and processing expenses are incurred.
The plant is currently being operated on mullock material generated when the Second Fortune mine was operated in the 1980s.
Early indications of the circuit performance are very positive with sorted concentrate upgrades of 2 to 3 times the feed grade concentration.
The installed process plant, which is 100% owned by Exterra, has significantly greater capacity than that required for the planned underground mining operation.
Exterra continues to evaluate a number of opportunities that will utilise the spare capacity and provide production flexibility.
The ore sorting technology delivers a number of major advantages in line with Exterra’s strategy of generating near term gold production to fund exploration and expansion.
Exterra retains a number of mineralised dumps around the Second Fortune site and estimates over 40,000 tonnes of material is readily accessible.
Sampling campaigns on the dumps indicate that dump grades may be in the range of 1-2 g/t gold.
By running samples of this material through a screening and sorting process, Exterra can quantify the value of the dumps as a revenue source pre underground mining at Second Fortune.