Management of reactive ground at the Goedgevonden opencast coal mine in the Witbank coalfields of South Africa

Abstract

Reactive ground has been identified as the primary cause of a blasting incident at Goedgevonden Colliery in South Africa late in 2010. Current practices as well as potential new mitigating opportunities were investigated to ascertain what steps can be taken to reduce the risk of a repeat blasting incident due to reactive ground. To effectively manage the risk of reactive ground; current practices and potential new opportunities were investigated. A literature study of reactive ground highlights the major differences between spontaneous combustion and reactive ground, directing the study towards specific tools that will assist in the management of reactive ground. The research includes finding with regards to:  Reports and recommendations from mining personnel, a 3rd party laboratory and explosive suppliers,  Stemming methods,  The use of Liners in blast holes,  Incorporating Thermal imaging cameras in the process of identifying elevated temperatures,  Investigating the Pieter van Jaarsveld method for ‘on the block’ testing for reactive ground,  Investigating the allowable temperatures of explosives and the temperatures in the hole, highlighting the importance of blasting the holes immediately when explosive temperatures exceed 90°C,  Temperature monitoring equipment available in the immediate market. As a conclusion to the study recommendations are made that will assist the mining house to produce a procedure that will reduce the risk of working in reactive ground.