Chinese metals producers Jiangxi Copper and Hunan Nonferrous Metals have started to restore operations after severe snowstorms before the Lunar New Year forced them to scale back production.

More than 80 percent of output capacity of Jiangxi Copper's mines had resumed, said Pan Qifang, company secretary of China's largest integrated copper producer.

The company's smelters were running at 70 percent of normal levels, Pan said, adding that railway disruptions were still hampering transport of sulphuric acid, making it hard to predict when operations would be fully restored.

Hunan Nonferrous Metals Corp's Zhuzhou smelter, the nation's largest zinc smelter, has already restarted, and is operating at over half its capacity, said an official with Zhuye Torch Metals.

"When we can return to full production depends on the power situation. We are taking as much electricity as the grid can supply," he said.

Hunan Nonferrous plants in Hengyang and Chenzhou, also in Hunan Province, were expected to restart as soon as power supplies were restored, the South China Morning Post said on Wednesday, quoting Chen Zhixin, chief financial officer of China's largest zinc and tungsten producer.

Snow and ice storms across southern and central China last month brought the coldest weather in 50 years to Hunan. The weather disrupted coal transport and downed power lines.

Last week, Jiangxi Copper said snowstorms in the southern part of China had a significant impact on production, as at least half of production activities of its copper mines in Jiangxi province had ceased.