China's zinc and zinc alloy output rose 3.5% in April from March to 412,000 tonnes, figures from research house Antaike showed on Friday, shrugging off a lack of overseas ore supply and falling treatment charges.

Supply of zinc concentrate, used to make refined metal, has dwindled due to mine closures, notably in key producer Peru, as countries around the world look to contain the spread of the novel coronavirus.

But the impact on Chinese zinc output was not great last month because smelters had adequate concentrate inventory, Antaike said in its survey of 49 smelters.

The April total fell 1.6% year on year.

Reflecting tight supply, treatment charges to process zinc concentrate in China slumped to $175 a tonne this week, down 42.6% from an 11-year high of $305 a tonne at the end of February and the lowest since January 2019.

"It is hard to find lead and zinc concentrate available in the China market recently," one zinc smelter source said.

Antaike estimates China's zinc output will dip slightly in May to 408,000 tonnes due to maintenance in Hunan and Qinghai.

(Reporting by Tom Daly; editing by Jason Neely)