No-one mines concentrate - they mine ore and it is quite rare for zinc bearing ore to be mined at levels that allow smelting without the ore first being processed into concentrate.
ABARE uses and quotes figures from ILZSG for their report - they have a pretty good reputation and where else would they get them?
When you say there is a "massive concentrate deficit", do you mean a shortage in concentrate in relation to global smelting capacity? What mechanism somehow prevents that manifesting as a matching deficit in the metal?
I agree zinc price still looks good, but still have doubts about it running much over $1.80 - bit perplexed by the stock levels though. A metals trader posting on another site says China has plenty of it and happy to supply it at a high enough price.
Still, the estimates of going into surplus still have to eventuate and China activity is gigantic, although their ability to control renegade mines may prove easier said than done.
Been a very interesting story so far, bound to have a few more twists.