As per July 2021 reports, Grants open pit started with 13.1...

As per July 2021 reports, Grants open pit started with 13.1 million cubic metres of waste to move. This allowed 0.79 million cubic metres of ore (2.14Mt of material for the ROM). The mining plan was front-end loaded with a lot of the waste rock removal at the start of the plan and very little at the end.

An unknown but significant amount of this waste rock removal has occurred. The mining of ore lags the waste removal. The processing of that ore lags behind the waste rock removal. A significant mining crew was required to move the 13Mt of waste rock, but what's important now (and Core hasn't advised) is how much waste rock still needs to be shifted. From this point on, is Core at a 12:1 strip ratio, a 10:1 strip ratio, an 8:1 strip ratio or something higher/lower than this range?

The lower this forward looking strip ratio is, the lower the break-even price and the more restarting become whether Core is making enough from planned sales to implement its plan and provide a reward for shareholders From the markets share price reaction you would think that waste rock percentage complete is similar to the ore removal percentage complete meaning the very high cost structure observed will exist into the future.

How far complete is the waste rock removal?
Core hasn't provided guidance on this. The picture below is what Core looked like in the satellite picture of 4 January 2024. The second picture is the original design schematic as per the water management plan of 28 October 2018. The third is the picture of Grants mine after stage 2 as per the April 2019 DFS. The water management plan of October 2018 will have been feeding into the 2019 DFS. That DFS was for an ore resource of 2.89Mt which has little change to later reported values so while these are older documents, they are still relevant. The reason for using these earlier references is they give a clearer view of what the pit was expected to look like.

Core would appear to have taken about 0.75Mt of ore out of Grants (35% of the total ore). Costs have been very high. What percentage of the waste rock would appear to have been removed? The top layers where most of the waste rock exist look to be getting close their final shape. These top layers are where most of the waste rock exists (simplistically grants pit is an upside down stretched cone). It would appear a lot, but that raises the odd question, if there is an announcement Core could make around being well progressed in waste rock removal, why haven't they?


Core provided graphic below in the 2019 DFS. The purple measured was 1.09Mt. This was also the top area of the Grants so it will be the area that is mined first. If 0.75Mt of material has been taken almost exclusively from the then Measured resource, perhaps 65-70% of the measured resource below has been removed. I'd love to see confirmation of it by Core, but does appear a large proportion of the waste rock from the mining plan has been removed.