South Africa’s "gold slaves"

After explosives reduce rock boulders to stone and dust, the real toil begins for the miners.
Each person is allocated a steel tin and iron rod to hammer down small stones until they become dust or ‘flour’. Next, swinging steel tins called pendukas are stuffed with rock dust, water, liquid mercury and salt, before being positioned on greased iron axles which are turned by workers for two hours until the rock dust starts to solidify into gold.
http://www.equaltimes.org/south-africa-s-gold-slaves#.VH72zcmOKP9