Zinc output in China increasing faster than consumption, concentrate market in China no longer tight as a result, will likely weigh on LME zinc futures in short-term, says Singapore-based trader. Adds, LME-grade zinc cash premium at $20-$30, while non-LME grade now at discount. "Demand is good but Chinese production is growing faster than demand." LME 3-month zinc at at $3,670/ton, +$50 on London PM Wednesday kerb.