Conveyor or Hoist - Pros and Cons

[RationalAssessor]

Lots of discussion around the bazaars regarding how NCM might increase the amount of ore that might be extracted.

Choices appear to be either a conveyor or a hoist to augment the extraction which might be possible via the explortion decline.
I am far from an expert in these subjects but wanted those who are better placed to comment on the pros and cons of each method.

My initial thinking is that a hoist would be cheaper and quicker to build. However, a conveyor would have more capacity and would also deposit the ore much closer to Telfer and therefore reduce transport costs/increase capacity.

Grateful for anyone's thoughts. Especially those in the know......Bamps?? Richard??

ATB RA.

[Bamps21]

Hi RA
The conveyor decline would need to come from the base of the mine, so you looking at a kind instalment time.
I’ve put pics up on the Havieron pages

[speedymeadie]

Hi Bamps. If Hav prooved up 30mill ozs how on earth will we get it out f the ground.? i have just done some sums and life of mine will need to be 100+ years at 10 mill tons a year. We will need a bigger conveyor belt more trucks or stop finding so much gold. ATB Speedy
elt

[Bamps21]

Hi Speedie
A conveyor belt continuous to Telfer will take 30m tons per annum so that’s 33 years but the trucks would have taken out 100-200m tons by then.
10% maybe of waste rock / weak ore will be reused underground when each stope is complete a 300mm layer of waste rock will be laid on the floor and the paste fill laid on top.
When the sill section is eventually removed below this waste rock , the waste will go to the waste rock mound not far from the box cut.
I can’t remember how much that mound holds.
I’m estimating at present there is to be 1bn-1.1bn ton of ore to come out, but expecting it to rise to 1.5bn ish so trucking may have to continue alongside a conveyor.
A conveyor though I can’t see how will be any use on the SLOS operation until it gets near the crusher unit near the base.
The bulk caving is where it will come into its own

[Bamps21]

A hoist/ shaft could go down halfway until the conveyor is ready lower down

[Bamps21]

This is my quick sketch with the SLOS and Eastern breccia bulk cave running simultaneously but a few years after the mine commencement.
Underground crusher used for both operations probably at about 1300m depth of ore

[Bamps21]

An underground crusher needs a big cavern to be sited below the base of the ore body.
The conveyor will come from here

[speedymeadie]

Hi Bamps. I cannot thank you enough for your indepth response. This mine is going to be a real beast and economy of scale is probably with us. Can Telfer handle that much ore without serious capex? ATB Speedy

[Hydrogen]

I've been discussing this with Bamps and our gold mining friends for a year or so...

Our understanding is that a haul shaft would be cheaper and much, much quicker to install than a conveyor ... Further construction could in-principal commence today.

If your goal is long term cost efficiency a conveyor could probably still be justified in addition to a haul shaft.

THe principal reason being, that as bamps says, a hefty crusher needs to be located at the deepest point of the mine development, which inprinciple is at least 4 years away (depending on how fast they progress the block cave).

However, a haul shaft system could be installed in a matter several months.

This could be used to increased production from the SLOS for the next 3-5 years until block cave conveyor construction... And if it's dedicated to underground SLOS operation it could potentially up operate for life of mine, increasing production by 1-2mt per shaft (ie from 3mt to 5mt or more) depending in the diameter size of the shaft installed.

It would also be electric and thus renewably powered. And there are plenty of examples - Olympic Dam mine uses 3 dedicated Haul Shafts and 2 declines to lift 9mt

For me, bamps, - and Shaun Day now - it seems its a no-brainer. When you're pulling out 3-5g/t material you will massively increased profitability and production quickly ramping it up (if that's your goal).

NCM may think differently...

[Rotherby]

Hydrogen,

NCM will do the figures and if a conveyor works out best that is what will happen.

I have always thought a conveyor or conveyors to Telfer was the solution due to the abundance of Sun and Wind in the Paterson, the world does not want road trains, much more disturbance to the environment.

Bamps,

Could they not install crushers as two levels, or move the installation once the mine gets deeper?

[Hydrogen]

Hi Bamps,
Sorry I think we both agree a conveyor to telfer... for the bulk.
I think it depends how fast they want to up the IRR though...
If they want a faster return on investment, then a Shaft answers that desire.

[Bamps21]

Hi Hydro
The underground crusher is a massive operation I don’t think there will be one half way down, it will be at the bottom of the SLOS and probably of no use to the SLOS.
I’m thinking shaft/ hoist halfway down to increase early production but only my early thoughts.