Horizon Minerals Ltd (ASX:HRZ) has upgraded the mineral resource estimate for its Kalpini Gold Project in the Western Australian Goldfields, nearly a year after it acquired the project for $2.75 million.
The estimate now stands at 1.87 million tonnes grading 2.33 grams/tonne (g/t) gold for 139,000 ounces at a 0.8 g/t gold lower cut-off grade, with 78% of resources in the indicated category.
Horizon undertook infill, extension and validation drilling with a total of 49 reverse circulation (RC) holes and three diamond drill holes completed for 5,677 metres to infill areas for improved classification and for structural, geotechnical and metallurgical assessment.
Kalpini growth potential
Managing director Jon Price said the upgrade increased the company’s confidence in the project, which is 65 kilometres northeast of Kalgoorlie-Boulder.
“Kalpini was acquired late in 2020 for $2.75 million and it is very encouraging to see excellent drilling results enabling an improved JORC 2012 mineral resource estimate with significant open pit and underground growth potential,” he said.
“We now look forward to completing the mine optimisation and design studies for ore reserve generation as part of the consolidated feasibility study.”
Mineral resource update details
When Horizon originally acquired Kalpini, it had a historic JORC 2004-compliant mineral resource estimate of 4.6 million tonnes grading 1.6 g/t for 255,600 ounces before depletion.
The upgraded estimate has been compiled after depletion and significant work by Horizon over the past year, including bringing it up to JORC 2012 standard.
Most importantly, more than 78% of the resources are in the indicated category, which is the part of a mineral resource for which tonnage, grade and mineral content can be estimated with a reasonable level of confidence.
The new estimate followed drilling which included several significant results:
- 12 metres at 5.57 g/t gold from 203 metres including 2 metres at 12.92 g/t from 211 metres;
- 5 metres at 10.21 g/t from 70 metres including 1-metre at 28.83 g/t from 72 metres;
- 7 metres at 6.01 g/t from 91 metres, including 1-metre at 22.04 g/t from 93 metres;
- 1-metre at 41.53 g/t from 195 metres;
- 6 metres at 4.45 g/t from 90 metres, including 1-metre at 10.24 g/t from 92 metres;
- 1.5 metres at 20.74 g/t from 99.5 metres, including 0.5 metres at 54.25 g/t from 99.5 metres; and
- 5 metres at 3.97 g/t from 3 metres, including 1-metre at 11.04 g/t from 6 metres.
The results demonstrated open pit and underground potential with strong width and grade continuity, while mineralisation remains open along strike and at depth.
Next steps
Kalpini is one of six core open pit and underground satellite gold projects being advanced to complement the baseload Boorara Gold Project.
A consolidated feasibility study for Boorara is planned to deliver a minimum five-year initial mine and underpin the establishment of a standalone centralised processing facility at the Boorara mine site.
The latest results will be used to generate a maiden ore reserve for Kalpini, which is expected by March 2022.
- Daniel Paproth