Social and labour violence have often hurt South Africa's mining industry and threatened its profitability in a country with high levels of unemployment and inequality.

Glencore said a security company at its Wonderkop Smelter, fired rubber bullets to disperse the protesters, who were demanding employment, with eight sustaining minor injuries.

"Employees were pushed around and the protesters threatened to burn trucks entering and exiting the Smelter," Glencore said, adding that operations at the chrome smelter, which is near Rustenburg, are continuing.

The firm, which has operations in more than 50 countries including the Democratic Republic of Congo, India and Australia, said 75 percent of the smelter's employees are from local communities.

The collapse of a chrome project near Impala Platinum's Marula mine which was set up with a tribal council, has triggered a wave of protests by local residents who had hoped to benefit from its revenue flows, the latest such deal to come unstuck and fan local anger.

(Reporting by Tanisha Heiberg and Ed Stoddard, editing by Louise Heavens and Alexander Smith)