RE: Little update16 May 2020 09:10
Perhaps it has something to do with the 'ore sorting', it's been mentioned that they're establishing the best mechanism for that at the moment as well as the other works.
"When positioned correctly in a process flowsheet, a pre-concentration stage or sensor-based ore sorting mechanism can reduce material transport costs, meaning less waste is conveyed or hauled to the next part of the mining process.
All of this can, potentially, lead to reduced energy consumption, a smaller environmental footprint and increased profitability; goals the industry has been looking to achieve". (From Ausenco mining consultancy)