Bonies that is just pure crap. I have been warning about the Zinc TCs for more than a year!!!! You and your other mates were in the same denial mood this time last year.
I highlighted the risks early Feb last year (https://hotcopper.com.au/posts/37336797/single): Potential upside + NCZ could undertake asset sales to avoid/reduce the size of the CR + Significant improvement in recoveries combined with producing within specifications
Potential downside - Recoveries not increasing enough, producing in specification leading to difficulties in selling the concentrates - TC for zinc concentrates rising further (lack of smelting capacity) - Capital raising to continue producing and/or repayment of the working capital facility - Sales exposure to Nyrstar if bondholders don’t agree to restructure