BHP had warned unions
- All 490 permanent staff would be offered new positions within the company.
- No other mines in the Bowen Basin "family" were at risk of closure.
- CFMEU strike action has hit BMA's seven Central Queensland projects.
BHP says it warned unions the Norwich Park mine near Dysart could shut down and cost 1400 jobs if sites were hit by strike action.
It emerged on Thursday that workers were told at 2pm on Wednesday about the closure, the same time it was released to the media.
However, all 490 permanent staff would be offered new positions within the company while the fate of the 910 contractors was unclear.
A spokesman for the company said it explained "this particular mine would be vulnerable if they proceeded".
"They knew it would be put under very special pressure."
He stressed no other mines in the Bowen Basin "family" were at risk of closure.
But while the industrial action may have had an effect, the spokesman said it was a "purely economic decision" by BHP.
The operation was delivering a lower quality coal he said, but BMA - which BHP partially owns - was paying more to mine it because of challenges with the site..
Combined with the cost of bad weather and the strong Australian dollar, it was difficult for BMA to keep Norwich Park operating.
The spokesman said the project "had a history of struggling", forced to cut workers and pay cheques in the hangover of the GFC in 2009.
District president Stephen Smyth met with the company for two hours in Dysart on Thursday.
He denied BHP had ever told the union Norwich Park could be under threat, except to say the operation would be "hampered" by action.
But Mr Smyth said the company could never show exactly how industrial action would make the operation less profitable.
He also pointed to the apparent resignation of the site's general manager earlier this year as a sign the mining giant had simply "mismanaged" the site.
Beyond the Central Queensland battleground, in Canberra, federal Opposition spokesman for energy and resources Ian Macfarlane blamed the loss of work on "union militancy" and warned the coming carbon and mining taxes would deliver more damage to the industry.
Minister for Resources Martin Ferguson said it was disappointing for Dysart, but the Coalition could not blame the closure on the government, nor industrial action because it was not a "significant consideration" for the mining giant.
"It is deliberately misleading of the Opposition to suggest a mine such as Norwich Park would be affected by the Mineral's Resource Rent Tax because it is clearly not super profitable," Mr Ferguson said.
"Similarly the carbon price would have little impact on such a mine, which has a relatively small emissions profile."
CFMEU strike action has hit BMA's seven Central Queensland projects, including Norwich Park.