Clearing the main shaft to rescue 22 gold miners who have been trapped underground since Jan 10 in Qixia, Shandong province, is expected to take at least another 15 days, the rescue headquarters said on Thursday.

The 22 miners, who were working more than 600 meters from the mine's entrance, have been trapped after an explosion took place about 240 meters from the entrance.

About 1,300 cubic meters of obstacles estimated to weigh 70 metric tons are still blocking the shaft, the rescue headquarters said.

Eleven of the miners were found Sunday through a channel drilled through the same day. Another survivor is believed to be in an adjoining chamber, while 10 others remain missing.

One of the 11 men found in the same chamber showed no signs of life on Wednesday night after being heavily injured in the blast and losing consciousness, despite efforts by his colleagues to save him.

Eight of the workers are in stable condition, with two who initially felt discomfort still weak.

The 10 miners have moved to a new place near a safer, newly drilled hole on the recommendation of the rescue headquarters.

"The previous chamber that housed them had water inflows," said Ma Jixiang, a member of the rescue headquarters' technical expert panel. "That influenced the living environment of the miners and had to be stopped to ensure safety."

Song Xicheng, deputy director of the medical rescue team, said that life-sustaining nutrient solutions and medical supplies, including ham, disinfectant and masks, were delivered down to the 10 miners at noon on Thursday.

"Special medical equipment to treat the dead miner's body was also delivered to them," he said. "We made 15 calls with the miners from Wednesday afternoon to noon Thursday."

By Thursday, 629 rescuers from 17 professional rescue teams and one fire team, together with 402 sets of rescue equipment, were working in shifts at the site, the rescue headquarters said.