Ann: December 2021 Quarterly Activities and Cashflow Reports, page-68

Now there is finally more clarity about the costs. Unfortunately, there was an "explosion" in mining costs ( Q2 : 19.030 million, compared to Q1 : 7.048 million). The increase took place in November and December, but not yet in October.

What was the reason for this ? Does anyone have an explanation?

The Quarterly Report implies that in Q1 the pre-strip costs for Missouri were included under "CAPEX (sustaining)" and as of Q2 the stripping costs are now included in "Mining costs". But that only explains a small part of the increase in mining costs. And an expansion in mining activity doesn't seem to be the reason, with nearly the same amount of material (waste and ore) being moved compared to last quarter. My guess is that the cost might be related to the termination of the underground mining.

In any case, the costs will now drop significantly, for the following reasons:
1.) The costly UG mining is terminated. Notice: "Stoping cut-off" is 2.7 g/t for underground
2.) The stripping ratio for Missouri is improving. This allows the mining fleet to be reduced (until the start of "Sand King" in 1.5 years).