Huludao Zinc, the second-biggest zinc smelter by capacity in China, said on Friday it is doubling copper smelting capacity by late next year, a move which could raise its demand for copper concentrate imports.

"We are doing the upgrading project," a company official said.

The project is to upgrade Huludao's sole copper smelter with capacity around 80,000 tonnes a year to 150,000 tonnes.

For now, Huludao has no plan to expand its 100,000-tonne-a-year copper refining facility.

"Logically, smelting and refining facilities should match," the official said.

Huludao has 390,000 tonnes of zinc production capacity, the second-biggest after Zhuzhou Smelter which has 500,000 tonnes of zinc capacity, and 30,000 tonnes of lead capacity in Liaoning province.

The firm produced 155,000 tonnes of zinc in the first half of the year, down 12 percent from a year earlier. Production of lead inched up 1 percent to 8,350 tonnes in the same period, according to the company's statement.

Huludao is majority owned by MCC Group, which raised $2.34 billion in Hong Kong's biggest IPO so far this year, after raising slightly more in Shanghai last week for total proceeds of $5.12 billion. The dual-listed stock is the second-largest IPO in the world this year.