The unions had agreed on a wage deal with the company earlier this month after almost three months of strike action, but did not sign an agreement as some finer aspects of the deal were still being negotiated.
Sibanye, which also mines platinum group metals in South Africa and the United States, had said on Friday that certain terms in the draft agreement had not been agreed by the parties and as a result they were not allowed to return to work.
Sibanye had locked out its employees from its gold operations since the time the strike began in early March.
Sibanye did not immediately respond to an email seeking comment.
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