Todd Russell and Brant Webb were given a standing ovation when they turned up for the meeting in the small Tasmanian town of Beaconsfield.
"It was a surprise but it was great to see our two members Brant Webb and Todd Russell at the meeting," union leader Bill Shorten said.
The pair, who are expected to be offered lucrative deals for the media rights to their story, did not speak to reporters.
About 40 mine workers had voted unanimously during the meeting that the mine, one of Australia's richest, should be reopened if safety could be assured, Mr Shorten said.
"The view of the workforce is that they do want the mine to proceed and be open but obviously not at any price.
"Our members are ready to work but not at the expense of false guarantees of safety, which can be broken by another catastrophe."
The mine is the economic mainstay of the small town of Beaconsfield and miners and local businesses have been concerned about their futures if it is closed permanently.
An earth tremor widely attributed to mining activity caused the rockfall that killed one miner and trapped Mr Russell and Mr Webb on April 25.
A similar rockfall had occurred last October, without causing injuries.
The miners reported further seismic activity around the mine during the two weeks that the rescuers spent digging a new tunnel to reach the trapped men, Mr Shorten said.
The operators of the mine, Allstate Explorations, said the mine could be reopened if it proved to be safe and viable.
"Over the next few weeks, Allstate will also be examining the safety of the mine, along with regulatory, financial and other considerations," administrator Michael Ryan said in a statement.
"We will try and determine whether it is safe and viable to recommence underground operations.”
The Tasmanian state government has agreed to union demands for an independent investigation into the disaster.