Banter and general comments, page-38728

Oliver87, When they have got Audit signoff for their audacious plan to try and writedown the stripping asset to zero or when they give up on trying to play silly accounting games and in the process destroy the share price. The stripping asset work is the activity that enables there to be cheap ore remaining to be mined and why mining will restart at Grants. The strip ratio for this remaining ore in Grants is low enough that they are profitable to restart at current prices. The primary factors stopping the restart would appear to be getting a mining contractor onsite, restaffing the DMS and fear that Mt Holland, KV and Goulamina coming online may cause a further crash the lithium price in late 2024 / early 2025. There may be an opportunity to blitz the mining and get all the ore out of Grants so that the wet season is taken out of play and the Grants void becomes available for BP33 development work.

The spreadsheet below is my attempt to simplify the DFS Grants mining plan by using 10m slices and approximating the area of the pit to be two half circles and a rectangle in between these. What this shows is the way the top of the pit has much larger areas than the lower layers of the pit but doing it this way puts some perspective on the size of the scale difference. Those upper layers have been massively expensive to remove all the waste rock from, but those costs have now been incurred including pre-strip capex the average strip ratio to this point could be near 40:1. This version aligned to the DFS metrics indicates what's at the bottom of the mine is two-thirds of the ore that is to be recovered but <2M bcm of waste rock. The orange slice is 1.9M bcm of waste rock to recover 0.48M bcm of ore for a strip ratio of 3.9:1 (so better than PLS strip ratios).

The ex CEO answered a question a few months back noting 10.8M bcm of waste rock had been shifted of 12.2M bcm needing to be moved. That would mean some of the total waste rock movements have been taken out of the plan. I used the model below to test shallower slope walls for the top 30m with a small decrease in the planned depth while maintaining the same total length and width of the pit as estimated below. It was fairly easy to drop the waste ore from 13.1Mt down to 12.2Mt but there was ~100kt of ore not recovered if they couldn't get steeper than planned walls for the deeper extent of the mine. On this variant the yet to be mined strip ratio material is ~3:1.


Modelling notes:
>No ore is assumed to be recovered from the top 50m due to weathering
>The 62,500 bcm ore figure is 25m average width as per Core's statements but a 250m average length (Core notes 300m in length but diagrams show Grants cuts in to some unspecified lower length lower down)
>The volume of each slice is approximated by two half circles and a rectangle between them
>790,434 bcm of ore comes from the DFS and the pit depth is adjusted to match this volume
>13,103,309 bcm of waste rock comes from the DFS and the wall slopes are adjusted to match this volume. They are a 9.1m cut-in for every 10m drop.
>Green is the generally Complete work. Orange is yet to start. Both the 10.8M bcm of waste rock shifted and back-calculations of ore recovered fall in the slice in between these two (and they also fall in this in between slice on model changes involving 0.75M bcm of ore from 12.2M bcm of waste rock)
>No copy and pasting, it all my own work