Ann: RVR hits high-grade gold, copper and zinc in the gap at LT, page-25

They are more difficult to find because they vary from company to company and smelter to smelter but in the last RVR Quartery Report you can see they sold 10310 tonnes of Zinc concentrate for AUD$10.4M but you have to allow for presales and shipping etc so its a bit messy.

But this here explains a bit:

The Company has implemented a quotation period (QP) hedging program for sales of zinc and lead metal already produced. Typically between 80 and 90 % of the payable zinc and lead metal for each shipment of zinc and lead concentrates will be hedged for the period from the issue of the first provisional sales invoice to the final settlement of the sale
,which may occur between one and three months later. The QP hedges currently in place on the quarter’s zinc concentrate shipments range between USD $1.46 and USD $1.62 per pound of payable zinc metal and USD $1.07 per pound of payable lead metal.