FRANK SMITH
Mine Resource
Between 1900 and 2002, the Frank Smith Mine produced a total of 72,338 carats of rough diamonds. In 2011 to 2015, 14,748 carats of rough diamonds have been recovered from 694,132 tonnes of tailings which generated a gross revenue of USD 3.9 million.
Currently, approximately 28% of the diamond resource (171,000 carats) is classified as indicated and contained in the surface tailings dump at an in situ grade of 3.5 cpht, giving a revenue of $9.66/ton. The remaining resource (449,000 carats) has an average grading of 7 cpht, revenue $31.6/ton, and lies above the 240m level. Historic underground mining indicated average recovery grades of around 4.8 cpht over a 30 year period.
The main pipe has been mined to the 160 metres below ground (mbg) level and the pipe contact is well established at this level. The Windsor Block is partially mined to the 125 mbg level, and the Weltevrede pipe is partially mined to the 85 mbg level.