Anglo American Platinum has fired 12,000 striking South African miners after a protracted strike over wages.
Amplats said three weeks of illegal strikes by 28,000 workers in Rustenburg have cost it 39,000 ounces in output, worth 700 million rand ($US82.3 million) in revenue.
The BBC reports South African mining has been hit by a wave of wildcat strikes, in which miners and officials have been killed.
Thirty four miners at the Marikana platinum mine were shot dead by police on 16 August. Two police officers there were killed by strikers the previous week.
A separate strike is continuing at GoldFields, another mining company.
On Tuesday, GoldFields evicted 5000 striking employees from company dormitories, saying they were intimidating fellow workers.
Analysts say about 75,000 miners are currently on strike in the gold and platinum sectors, most of them illegally.
Amplats said on Friday that the miners had failed to attend disciplinary hearings and had therefore been dismissed.
Attendance levels of less than 20% meant four of the company's mining operations in Rustenburg could not operate properly.
Employees would learn the outcome of disciplinary hearings later on Friday and would have three days to appeal over their outcome.
"Approximately 12,000 striking employees chose not to make representations, nor attend the hearings, and have therefore been dismissed in their absence," said the company.
Anglo American Platinum is the world's biggest platinum producer.