Miners were protesting over the sale of the mine to Australian-listed Riversdale Mining, raising concerns over benefits such as severance pay, the Financial Review reported.
Miners had staged a protest underground since last week. Reports indicated anywhere between 500-1200 miners took part in the strike.
During February this year, BHP sold the mine to Riversdale for 91 million rand ($US14.7 million). Riversdale Mining will hold 74% of ZAC with the remaining 26% to be held by a black economic empowerment consortium.
The mine produced 561,000 tonnes of saleable anthracite in the twelve months to June 2004 and has a workforce of some 700 employees and 300 contractors.