If you look at zinc smelting market - the treatment charges have been increasing all through the 2H last year and during Jan:
https://www.spglobal.com/platts/en/market-insights/latest-news/metals/012319-zinc-tc-rc-benchmark-to-rise-in-2019-on-supply-resurgence-analysts
https://www.reuters.com/article/china-zinc-production/zinc-smelter-bottlenecks-propping-up-prices-for-now-idUSL4N1XR32H
Going forward the fact that 2 large zinc mines are unable to sell their product for a 1-2 months means less competition for RVR selling their product and zinc smelters will need to reduce their treatment charges when buying zinc concentrate.
It will be net positive to flat for RVR in the short term.