Ngwenyama, Philani Larrance; De Graaf, Wolter Willem; Preis, Eugene Pieter
(Southern African Institute of Mining and Metallurgy, 2017-03)
The depletion of coal reserves in the Witbank coalfield in Mpumalanga
Province has resulted in mining companies exploring the possibilities of
extracting coal pillars. These are pillars that were left behind for
hangingwall ...