The principal problem with Zinc (unlike Ni and Cu) is we have a lack of confirmed hard data on supply/demand. I was in the minerals business for many years and we steered clear of zinc because of the multitude of deposits and ease of bringing into production.
On the other hand we have funds that specialise in manipulating commodities and it is quite possible that the Zn price is being manipulated down to around the $1.50 mark and suddenly shortages will be declared from the rooftops with the price rising to over $2.
The facts are that LME stockpiles are down to very low levels but that we have no idea of what is happening in China re supply/demand and we have no idea of the manipulations of the hedge funds. So it is all a guess!
My guess is that Zn is needed for developing economies in a major way and the price will shortly zoom.