Over 7,000 members of South Africa's National Union of Mineworkers will down tools at Northam Platinum on Sunday night in a strike over wages, the union said on Friday.
NUM gave the company a 48-hour notice on Thursday of its intention to strike - a legal requirement - but said it was willing to continue talks.
It said in a statement on Friday morning that it was "now determined to strike at Northam".
NUM is demanding the company raise wages by between 22 percent and 43 percent, depending on the level of employees, and increase housing allowances by 69 percent.
Northam, a mid-tier producer, says it has improved its offer to include increases of 7 and 8 percent in the first year, above the current inflation rate of 6 percent.
The dispute involves the workforce at Northam's Zondereinde operation, which accounts for the vast majority of its annual production of 300,000 ounces a year.
Northam's looming stoppage comes as NUM's hardline rival, the Association of Mineworkers and Construction Union, prepares for a strike against top producers Anglo American Platinum, Impala Platinum and Lonmin which could hit at least half of global output.