"These thousand people have been dismissed and over the weekend," spokesman Christopher Tsatsawane told AFP.
"They have until , , to appeal their dismissal."
Workers downed tools last Tuesday on the Helena, Magareng and Thorncliffe sites in the northern province of Limpopo.
A member of the upstart Association of Mineworkers and Construction Union (AMCU) accused a shift supervisor of assault, which provoked the strike.
AMCU and the powerful National Union of Mineworkers (NUM) are locked in a struggle for members and power over South Africa's mines.
NUM, which is allied with the ruling African National Congress, has been bleeding members who accuse it of being too close to mine companies.
The rivalry has often descended into violent clashes and strikes as AMCU members demand union recognition from mining companies.
Last November, Xstrata, based in the canton of Zug, fired 400 illegal strikers who stopped work over an internal disciplinary system.
Thousands of mines workers have been fired and then re-hired during the rash of strikes across South Africa's mining sector in the past year.
Strikes often turned deadly, with 34 people shot dead by police on one day at the Lonmin platinum mine in the North West province last August.
Last week, President Jacob Zuma called on strikers and firms to find swift solutions to disagreements amid renewed wildcat stoppages.
Mining and related sectors account for around 20 percent of Africa's largest economy.