PILLAR
For the purpose of this SOP a Pillar is defined as-
- Any portion of In-situ reef or waste rock/ unmineralized portion that had been designed with specific load bearing capabilities for the purpose of providing either regional and/or local stability.
–Regional Support Pillar
–Shaft Pillar
–Protection Pillar
–Local Support Pillar
–Geological Pillars
For the purpose of this SOP the following are not defined as Pillars –
- “Inter-Level Lock-Up“- (IL):
A strategically left in situ-portion of mineralised structure to allow the mineralised feature above and below the “IL” to be simultaneously extracted if required.
Inter-level Lock-up’s occur currently during Cut and Fill Mining as the stope reaches final7.Om
prior to holing into the up-dip stope along the continuation of the mineralised zone along dip extent.
It should be noted that the Strike Span will remain constant depending on the persistence of the mineralised feature along strike.
Dip-Spans will be managed by waste fill following behind the advancing face. Waste fill will effectively ameliorate the risk of large dip spans being generated.
IL’s that are not deemed to be safely extractable will be classified as a “Protection Pillar”.
This would typically be if the upper panel along dip extent does not have a specifically constructed floor as described in Appendix D of the SOP 1 or if the panel above had previously not been Cement Backfilled.
- “Final portion of reef prior to holing“:
These portions of ground occur when Open Stoping Mining panels and or Raises are approaching holing.
These areas mentioned in points a) and b) above are declared and treated as Special Areas as required by the current COP 1 and the mining method and support requirements are detailed on the Special Area Instruction Form which is singed off as per the current COP 1.
REGIONAL SUPPORT STRATERGY
- The very nature and types of mineralized structures that host the gold, together with the presence of occasional major faulting dictates that scattered mining layouts have to be used. These typical scattered mining layouts make the orebody available for exploitation by means of pre-developed drives, cross cuts, traveling ways/ ramps, ore passes and on reef raises.
- For all intents and purposes, the mining environment on Barberton Mines Limited is considered to being “intermediate” in depth, where natural fault losses and large barren stretches of host-rock between the mineralized structures serve as “Regional Support Pillars”
- Depending of the dip of individual mineralized structures, either open stoping, shrinkage mining or a hybrid semi mechanized up-dip/breast cut and fill mining method can be used. These various methods are adequately described in SOP 1.
- No mining is to be carried out within any designed pillar such as has been mentioned in point 5.1 above. These designed pillars have a particular purpose and should be demarcated on the mine plans as such. Demarcation of such pillars is the responsibility of the 2.17 appointee (i.e the surveyor)
LOCAL/ GEOLOGICAL/PROTECTION PILLAR SUPPORT STRATERGY
- The local support strategy in the Open Stoping areas on the mine requires that support I protection pillars are utilised above the reef drives and also every 20m whether mining in a dip or breast mining direction. The size and spacing of these local Support Pillars are governed by the stoping width and described in detailed in the current SOP 1.
- Geological Pillars are also left in-situ due to grade and geological features that occur in the normal stoping operation.
- In the Cut and Fill Mining Operations Protection Pillars are left in areas where it is deemed unsafe to hole through to the mined out area above (5.1.2 c) or on the side of the current mining operation,these Protection Pillars are demarcated on all the survey plans.
- Due to the Regional Support Strategy these local/Protection Pillars can be investigated and identified for later extraction following the DMR Directives pertaining to Pillar removal and Extraction (MS-3-2018). The actual extraction sequence and mining method is only done after a full investigation has been carried out as detailed in this SOP.
COMPETENT PERSON
Means a person who –
- Is qualified by virtue of his knowledge, training, skills, and experience to organize the work and its performance; and
- Is familiar with the legal requirements which apply to the work to be performed; and
- Has been trained to recognize any potential or actual danger to health and safety in the performance of the work; or
- Is in possession of an appropriate certificate of competency where such certificate is legally required.