RVR Chart, page-161

Glencores' 2017 Australian Zinc production was down 11% on the 2016 number and lead production was down 16% as a result of the mine changes at Mount Isa.
Lady Loretta (Mount Isa zinc) is expected to restart production in the first half of this year, following its shutdown in 2015, but I feel that the environmental constraints imposed in China could be the strongest driver of prices in the near term and the slower than anticipated pace of mine restarts and new mines, will keep the Zinc price buoyant for a fair while yet.