scholarly journals PlatMine pillar strength formula for the UG2 Reef

Author(s):  
B.P. Watson ◽  
R.A. Lamos ◽  
D.P. Roberts

The Upper Group 2 (UG2) chromitite reef is a shallow-dipping stratiform tabular orebody in the South African Bushveld Complex, which strikes for hundreds of kilometres. Mining is extensive, with depths ranging from close-to-surface to 2 500 m. Pillars are widely used to support the open stopes and bords. Little work has been done in the past to determine the strength of pillars on the UG2 Reef and design was done using formulae developed for other hard-rock mines. This has led to oversized pillars with consequent sterilization of ore. In this paper we describe a back-analysis of stable and failed UG2 pillars on the Bushveld platinum mines, and provides a strength formula for UG2 pillars. The formula may be used cautiously on all Bushveld platinum mines with similar geotechnical, geometrical, and geomechanical conditions to the pillars in the database.

Author(s):  
B.P. Watson ◽  
W. Theron ◽  
N. Fernandes ◽  
W.O. Kekana ◽  
M.P. Mahlangu ◽  
...  

The research described in this paper was done to confirm the Upper Group 2 (UG2) PlatMine peak pillar strength formula (Watson et al., 2007), which was determined from a back-analysis of failed and unfailed pillars. Underground measurements were made on a stable pillar that was loaded by firstly reducing it's length and then by mining the surrounding pillars until pillar failure took place. The pillar was instrumented with suitably positioned strain cells and closure meters, which allowed both the average pillar stress and strain to be determined. The paper describes the methodology applied to identify a suitable position for the instrumentation, as well as the results. A stress/strain curve is presented for a UG2 pillar with a w/h ratio of 2.0, at Booysendal Platinum Mine. The measured pillar strength was similar to the predicted strength using the PlatMine pillar strength formula for UG2 pillars. The PlatMine formula has been successfully implemented on Booysendal Platinum Mine, and about 3 670 pillars have been cut without a single failure. An additional revenue of US$1.3 billion was calculated for the 25-year life of the mine as a direct result of the improved pillar design, given the January 2020 platinum group metals basket price. An extended life of mine and better mining efficiencies will also be realized.


Author(s):  
Mogomme Alpheus Masoga

Every humanity has some form of indigeneity – whether conscious or unconscious. It behooves all humanity to redefine and reflect on its indigenous roots. Indigenous Knowledge (IK) has been termed in different ways. These include traditional, cultural, local, community knowledge, etc. All these are interlinked and imply that IK is a body of “knowledge” owned by local people in their specific communities and passed on from generation to generation. Therefore, IK is that knowledge which is known to a group of people or is embedded in a community. It could be rural or urban. The chapter aims to present and reflect on selected local narratives to construct a context. This chapter argues for the ‘contextual' dimension when looking at IK. For the past eighteen years the researcher has worked with a number of practitioners and knowledge holders whose experience has shaped his understanding of the South African IK dialogues, debates, research and studies. The approach adopted for this study is a reflexive one.


2015 ◽  
Vol 14 (4) ◽  
pp. 413-430 ◽  
Author(s):  
Nicholas Addai Boamah

Purpose – The purpose of this study is to explore the applicability of the Fama–French and Carhart models on the South African stock market (SASM). It examines the ability of the models to capture size, book-to-market (BM) and momentum effects on the SASM. The paper, additionally, explores the ability of the Fama–French–Carhart factors to predict the future growth of the South African economy. Design/methodology/approach – The paper relies on data of 848 firms from January 1996 to April 2012 to examine the size, BM and momentum effects on the SASM. The paper constructs the test assets from a 3 × 3 sort on size and BM and a 3 × 3 sort on size and momentum. The paper estimates momentum as the past six-months’ cumulative return. The momentum portfolios are monthly rebalanced. Additionally, the size and BM portfolios are formed annually at the end of each June. Findings – Evidence is provided that size, BM and momentum effects exist on the SASM; also, the small- and high-BM firm portfolios, respectively, appear riskier than the big- and low-BM firm portfolios. The paper provides evidence of past winners outperforming past losers aside from the small-firm group. Additionally, the models only partially capture the size and value effects on the SASM. The Carhart model partly captures the momentum effects, but the Fama–French model is unable to describe the returns to the momentum-sorted portfolios. The evidence shows that the models’ factors predict future gross domestic product growth. Originality/value – The models do not fully describe returns on the SASM; any application of the models on the SASM should be done with caution. The Carhart model better describes returns than the Fama–French model on the SASM. The Fama–French–Carhart factors may relate to the underlying economic risk of the South African economy.


2009 ◽  
Vol 618-619 ◽  
pp. 147-154 ◽  
Author(s):  
Oliver Damm ◽  
Willie du Preez

Through focused investment by the CSIR, the South African Innovation Fund, the Automotive Industry Development Centre and the Department of Science and Technology over the past eight years, the national Light Metals Development Network has been established and grown into a well aligned collaborative research and development programme. The research and development focus has been primarily on aluminium and titanium technologies as applied in the automotive and aerospace industry sectors, with the latter growing in prominence over the past three years. Since 2009 the titanium-related research and development activities have been consolidated in a Titanium Centre of Competence. This paper provides an overview of the current status of the programme, the R&D focus areas, the collaborating entities and the industry involvement. It also highlights some of the significant achievements of the network and notable outputs produced. The Titanium Centre of Competence as a vehicle for strengthening industrial research and innovation capabilities in specific fields of technology is discussed and some initial experiences are shared.


Author(s):  
Tamlyn Monson ◽  
Jean-Pierre Misago

The South African government declared last year's xenophobic attacks over on 28 May 2008. As early as July 2008, it began to assure displaced foreigners that conditions were favourable for their return to affected communities, and that it would be safe to do so. Yet in the past year there have been repeated attacks in a number of the same communities that fell victim to immigration-control-by-mob in 2008. Why? In this article we argue that the state's reluctance to protect and assist foreigners in the past perpetuates violence, social instability and injustice – for nationals and non-nationals alike. We examine the source of this reluctance, and show how it creates the conditions for weak protection and judicial responses.


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