The miners were arrested in October 2012 during a strike, it said in a statement.
“They were accused of unlawfully assembling to disturb public peace and security by protesting during a wage dispute with their employer, Samancor.”
After their arrest, the mineworkers refused to accept a plea agreement, claiming they had protested peacefully in the weeks leading up to and including the day they were arrested.
They said they had not given any indication that the strike would turn violent.
Lawyers for Human Rights said it welcomed the decision, but raised concern that had taken the National Prosecuting Authority nearly two years come to the decision.
“This type of overzealous action against striking mineworkers has, unfortunately, become a trend in South Africa.”