Half the water from the flooded coal mine in Yunnan province's Qilin district has been pumped out, but no substantial progress was made in the search for the 22 miners trapped on April 7.
Twenty-six workers were working underground when the flooding occurred following which rescue teams were sent and four workers were rescued.
The workers are believed to be stranded at an depth of 1,876 metres - 10 metres below the level of the flood water that inundated a pit of Xiahaizi colliery in Qujing city, state-run Xinhua news agency reported.
"One more pump was installed on Saturday and a total of 12 are now at work, draining 830 cubic metres of water per hour," said Luo Shixiong, secretary-general of Qujing's city government and spokesman with the emergency rescue headquarters.
Xiahaizi colliery reports an annual output of 60,000 tonnes.