The workers likely to go are contractors from Thiess. Glencore Xstrata announced in February that it would be taking over the day-to-day operation of the mine later in the year.
The mine has been losing money and Glencore Xstrata is understood to be suspending operations there at the end of the week.
The company has made no secret of the fact that it wants more flexible work practices at its coal operations.
It is part of the productivity push that is likely to sweep through the Australian coal sector as mine owners try to rein in cost explosions.
Glencore will likely seek to re-engineer the operations with technology to make the operation more productive.
According to an ABC report, Glencore is insisting it will only reopen the mine if there are more flexible working conditions and that it is seeking to have a greenfields agreement put in place at the operation.
Workers have been told that Glencore Xstrata will not be transferring the Thiess agreement.
The Construction, Forestry, Mining and Energy Union says the company is trying to sign up employees to individual contracts.
It argues that there are no grounds for a change to the industrial relations arrangements.
The union says Collinsville is not a new operation, only that the ownership has changed from Xstrata to Glencore Xstrata due to Glencore’s takeover of the mine’s owner earlier this year.
It also argues that there is no call for a greenfield arrangement because the mine has been operating for more than 100 years.