@sherrileemitch So if 3km is Crazy - why? and what length isn't? Is it 500m? Is it 1km? Is it 2km? Please share your knowledge.
We already know a decline of slightly over 1km was planned by Core as the access mechanism for Carlton (its unknown if that plan has changed). The cumulative length of the spiral decline to get to the bottom of BP33's recently increased JORC resource would be longer than 3km.
This comment came about as part of speculation as to how you could mine the lower reaches of BP33 and whether there may be ways to accelerate the speed at which ore was recovered. It has not been suggested by Core in any official document, it was blue-sky thinking in HC. It wasn't a suggestion it would work, it was a call for information as to why it wouldn't. If it wouldn't work that's fine. If it would work, then its perhaps a pathway to Core getting access to ore a cheaper way than constructing a series of $50m box cuts and surface works for each ore body.
If a long straight decline were technically and operationally possible at a non-crazy price point, there would be two major financial benefits for Core.
1. South of BP33 there are at least 3 deposits within 3km of BP33 where development would require box cuts / large open pits in an area with a river system. That's not impossible but probably a difficult permitting exercise. If a 2km decline extension from BP33 were technically possible then the Lei/Kelly pegmatite system would be accessible from the BP33 decline and mine system. The operator would then supplement that with vertical drilling for air services. If a 3km decline from BP33 were technically possible then Seadog and Ah Hoy could come within scope and be accessible from that decline. There's also speculation of other south of BP33 deposits. If Lei, Seadog & Ah Hoy are collectively the same size as BP33 a long decline doubles the length of time value is gained from the BP33 box cut and surface works.
2. Alternatively, it may be possible to concurrently mine the upper and lower reaches of BP33 as two separate mining operations in the same ore body if future prices were to justify more DMS capacity and a faster mining speed. The upper reaches would come out of the existing box cut. A long straight decline from Grants would intersect the lower reaches of BP33 and mean that when retrieving the ore from the decline it would exit at established crushing facilities located at Grants. Like you say, its probably a crazy idea, but how about sharing your knowledge as to why it wouldn't work?
In July 2022 Core noted that the development unit cost for BP33 was A$7,815/m. Carlton was noted as A$7,524/m. Even if the costs were higher at $10k/m then a 3,000m (3km) decline would be $30m. While expensive that isn't a financially impossible sum. That's cheaper than the box cut and surface works for BP33 meaning a decline of this length is potentially capital cost effective mechanism to get to these ore bodies south of BP33.
So this is blue-sky thinking from a non-mining individual. So please, where is the error? What is the technical, financial or operational error in this thinking. I'm happy if there is an error or issue, please just contribute constructively.
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