China's production of 10 major non-ferrous metals expanded 5.7 percent year-on-year in August, according to official data.

For the first eight months of the year, combined output of the 10 metals increased 3.8 percent from one year earlier to 35.71 million tonnes, according to data from the National Development and Reform Commission.

The 10 major non-ferrous metals are copper, aluminum, lead, zinc, nickel, tin, antimony, mercury, magnesium and titanium.

In breakdown, the country's copper production rose 11.4 percent to 5.84 million tonnes for January-August, accelerating from a rise of 6.2 percent during the same period of 2017. Output of electrolytic aluminum reached 22.21 million tonnes during the period, up 3.5 percent but with the pace of growth slowing 2.6 percentage points compared with the same period of last year.

Excess production capacity is a chronic problem for some non-ferrous metals.

In 2016, the State Council released a guideline for the sector, stating that the government would control new capacity for metals struggling with overcapacity, such as electrolytic aluminum.