Scielo RSS http://www.scielo.org.za/rss.php?pid=2225-625320200009&lang=en vol. 120 num. 9 lang. en http://www.scielo.org.za/img/en/fbpelogp.gif http://www.scielo.org.za http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532020000900001&lng=en&nrm=iso&tlng=en http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532020000900002&lng=en&nrm=iso&tlng=en South Africans have experienced material change since the 1980s. The country saw the end of apartheid and the beginning of a new era under the leadership of a man who raised expectations of a Rainbow Nation and an equal society. Unfortunately, this has not since transpired. There has been a dearth of effective leadership, with daily reports of unethical behaviour in the media. Productivity is low, the economy has deteriorated, unemployment is higher than ever, and South Africans are finding themselves becoming more polarized as a society. At the same time the South African mining industry, which has the potential to be the catalyst for national economic growth, has shrunk significantly. This is partially due to both an evolving and increasingly turbulent global environment, and a result of international divestment as the legislative and socio-economic environment becomes increasingly difficult. This industry traditionally supported the activities of the Southern African Institute of Mining and Metallurgy (SAIMM), but this has also changed. The SAIMM is now finding it difficult to retain members and as a consequence is in the process of repositioning itself around six pillars of value to arrest this decline. One of these pillars is about enhancing ethical awareness, and by extension, establishing a climate where ethical leadership can thrive, because this is now urgently needed in South Africa. This address briefly describes the challenges facing South Africa, the mining industry and the SAIMM, and how the organization is responding to remain relevant in today's rapidly changing world. Morals, ethics, and leadership are explained in support of a call for higher levels of ethical awareness, and more ethical leadership, in all areas of South African society. As professionals, SAIMM members are already committed to ethical behaviour, and accordingly, are well placed to assist in making this happen. http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532020000900003&lng=en&nrm=iso&tlng=en South Africans have experienced material change since the 1980s. The country saw the end of apartheid and the beginning of a new era under the leadership of a man who raised expectations of a Rainbow Nation and an equal society. Unfortunately, this has not since transpired. There has been a dearth of effective leadership, with daily reports of unethical behaviour in the media. Productivity is low, the economy has deteriorated, unemployment is higher than ever, and South Africans are finding themselves becoming more polarized as a society. At the same time the South African mining industry, which has the potential to be the catalyst for national economic growth, has shrunk significantly. This is partially due to both an evolving and increasingly turbulent global environment, and a result of international divestment as the legislative and socio-economic environment becomes increasingly difficult. This industry traditionally supported the activities of the Southern African Institute of Mining and Metallurgy (SAIMM), but this has also changed. The SAIMM is now finding it difficult to retain members and as a consequence is in the process of repositioning itself around six pillars of value to arrest this decline. One of these pillars is about enhancing ethical awareness, and by extension, establishing a climate where ethical leadership can thrive, because this is now urgently needed in South Africa. This address briefly describes the challenges facing South Africa, the mining industry and the SAIMM, and how the organization is responding to remain relevant in today's rapidly changing world. Morals, ethics, and leadership are explained in support of a call for higher levels of ethical awareness, and more ethical leadership, in all areas of South African society. As professionals, SAIMM members are already committed to ethical behaviour, and accordingly, are well placed to assist in making this happen. http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532020000900004&lng=en&nrm=iso&tlng=en South Africans have experienced material change since the 1980s. The country saw the end of apartheid and the beginning of a new era under the leadership of a man who raised expectations of a Rainbow Nation and an equal society. Unfortunately, this has not since transpired. There has been a dearth of effective leadership, with daily reports of unethical behaviour in the media. Productivity is low, the economy has deteriorated, unemployment is higher than ever, and South Africans are finding themselves becoming more polarized as a society. At the same time the South African mining industry, which has the potential to be the catalyst for national economic growth, has shrunk significantly. This is partially due to both an evolving and increasingly turbulent global environment, and a result of international divestment as the legislative and socio-economic environment becomes increasingly difficult. This industry traditionally supported the activities of the Southern African Institute of Mining and Metallurgy (SAIMM), but this has also changed. The SAIMM is now finding it difficult to retain members and as a consequence is in the process of repositioning itself around six pillars of value to arrest this decline. One of these pillars is about enhancing ethical awareness, and by extension, establishing a climate where ethical leadership can thrive, because this is now urgently needed in South Africa. This address briefly describes the challenges facing South Africa, the mining industry and the SAIMM, and how the organization is responding to remain relevant in today's rapidly changing world. Morals, ethics, and leadership are explained in support of a call for higher levels of ethical awareness, and more ethical leadership, in all areas of South African society. As professionals, SAIMM members are already committed to ethical behaviour, and accordingly, are well placed to assist in making this happen. http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532020000900005&lng=en&nrm=iso&tlng=en Reasonable Prospects for Eventual Economic Extraction (RPEEE) is the critical basis for effective implementation of the SAMREC Code as it applies to Mineral Resources, and implicitly to Mineral Reserves that are derived from Mineral Resources. This implementation follows the founding principles of materiality, transparency, and competence. The SAMREC definition of a Mineral Resource specifically includes RPEEE. SAMREC provides guidance for all minerals on what RPEEE means, with some specific additional guidance for diamonds. SAMREC instructs the Competent Person that RPEEE must be demonstrated through reasoned assessment of multiple technical and non-technical parameters, and with disclosure in reporting. A recommended chapter in a CPR includes a sub-section for RPEEE. SAMREC definitions and guidance are presented with discussion of the factors that must be assessed to demonstrate RPEEE. Comparison with guidance in other reporting countries and examples of actual practice are presented. http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532020000900006&lng=en&nrm=iso&tlng=en The mining of old tailings storage facilities (TSFs) or dams/dumps has become a common operation in South Africa. This practice has several interesting aspects that are different to normal surface mining operations. When considering the estimation of Mineral Reserves, the Competent Person must take into account the conditions of mining historical TSFs that are often situated in close proximity to communities. This paper discusses the Modifying Factors required to convert a Mineral Resource to a Mineral Reserve, such as mining sequence, dilution, mining losses, and environmental, social/community, and government factors. The paper also investigates the role that Inferred Mineral Resources may play in the life-of-mine plans for tailings dam projects. http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532020000900007&lng=en&nrm=iso&tlng=en Most equations used to predict the ground motion produced by explosions were developed using confined blasts that were detonated for breaking rock in mining or tunnelling. Ground motion is usually recorded by geophones or seismometers. The air blast produced by open-pit blasts and explosions on the surface can pose a significant risk, thus microphones and pressure gauges are often also used to monitor the effects of the explosion. The aim of this study is to determine whether the predictive equations developed for confined explosions can be used to predict the effects from explosions on the surface, with appropriate adjustments to the various coefficients. Three predictive equations developed for buried explosions were tested. The study shows that the US Bureau of Mines peak particle velocity (PPV) predictive equation is the most reliable. In addition, a predictive equation that uses the secondary atmospheric shock wave phenomenon also produced good results, and uses the scaled delay time parameter, which is easier to measure. These equations may be utilized for demolition sites, where old and potentially unstable explosives and obsolete equipment are destroyed on the surface, and for assisting in forensic seismology to determine the details of an unexpected and unknown explosion. http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532020000900008&lng=en&nrm=iso&tlng=en The neutralization of acid mine drainage (AMD) with coal discards in percolating columns was investigated as a potential precursor to lime neutralization. The neutralizing capacity of three coal samples, A (70% ash), B (25.3% ash), and C (28.9% ash, estimated), sourced from three South African coal mines, was determined at different crush sizes (-40 mm, -12.5 mm and -6.3 mm). AMD solution obtained from another local coal mine was percolated over the coal samples packed in 1 m and 6 m columns, until the pH of the accumulated drainage solution measured approximately pH 7. Samples B and C, with an alkalinity content equivalent to 2.3% CaCO3, achieved neutralizing capacities of 2112 L AMD and 929 L AMD per ton coal respectively, at a -6.3 mm crush size. Sample A, with an alkalinity content equivalent to 0.48% CaCO3, neutralized only 282 L AMD per ton coal at the same crush size. An economic analysis was performed to compare neutralization with waste coal against lime neutralization in tanks. The analysis was based on a rate of AMD generation of 1750 m³/d, a neutralizing capacity of 1.4 m³ AMD per ton coal, with capital costs estimated at R18 million for lime neutralization and R27.6 million for coal neutralization. Operating costs were estimated at R24 million for lime neutralization and R9 million for coal neutralization. AMD neutralization with suitable waste coal may therefore be less expensive than neutralization with lime. http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532020000900009&lng=en&nrm=iso&tlng=en Because of their high degree of geological complexity, kimberlite-hosted diamond deposits are exceedingly difficult to evaluate for economic viability. Accordingly, standard mineral asset evaluation protocols (e.g., the Cost-, Market-, and Income Approaches defined in the SAMREC Code) may not hold sufficient predictive abilities for these deposit types, especially at the early stages of exploration. Here we present a novel tool, a cost filter approach towards preliminary evaluation of economic viability of southern African kimberlite-hosted diamond deposits, using the AK6 and BK11 diamond deposits from the Orapa diamond field as case studies. The development of this cost filter is underpinned by elements of both the Market Approach (i.e., comparisons to similar deposits) and the Income Approach (i.e., use of net present value (NPV) calculations) for mineral asset evaluation. Importantly, the cost filter is constrained through modification of only two primary variables (the average diamond value and the diamond grade) and thus differs significantly from other cost filters that rely on estimation and assumptions for every parameter input into an NPV calculation. The cost filter correctly predicts the sub-economic status of the BK11 diamond pipe, and is thus presented as a useful geo-economic tool for early stage kimberlite evaluation within the local southern African context. The approach and its theoretical underpinning foreseeably hold vast potential for use in the economic evaluation of other ore commodities, particularly where socio-economic and political risk factors can be negated by employing a geographic constraint. http://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S2225-62532020000900010&lng=en&nrm=iso&tlng=en Whole-body vibration (WBV) exposure measurements taken from 105 truck drivers employed in 19 mines and other workplaces were evaluated with the criteria prescribed in EU 2002/44/EC directive, BS 6841 (1987), ISO 2631-1 (1997). and ISO 2631-5 (2004) standards. The highest vibration acceleration was measured on the vertical Z-axis. The highest WBV exposure occurred in the RETURN, HAUL, and SPOT phases while the lowest exposure took place in the LOAD and WAIT phases. Crest factors on all axes were generally greater than nine, yet strong correlation coefficients were achieved in VDV-eVDV analyses. Driver seats generally dampened the vibration along the Z-axis but exacerbated it along X and Y axes. The dominant frequency for the X and Y-axes rose up to 40 Hz while it ranged between 1 Hz and 2.5 Hz along the Z-axis. While the probability of an adverse health effect was higher with BS 6841 (1987) and ISO 2631-1 (1997) standards, it was low according to EU 2002/44/EC and ISO 2631-5 (2004). The 91 t, 100 t, and 170 t capacity trucks produced lower vibration magnitudes. Drivers were exposed to approximately equivalent levels of WBV acceleration and dose in contractor-type trucks and mining trucks. Rear-dump trucks exposed their drivers to a slightly higher level of vibration than bottom-dump trucks. Underground trucks exposed their drivers to a significantly higher level of vibration than mining trucks. Both driver age and driver experience were inversely proportional to vibration acceleration and dose. Conversely, there was a positive relationship between the truck service years and the WBV acceleration and dose to which drivers were exposed to. Loads of blocky material exposed drivers to higher vibration acceleration and dose levels than non-blocky material.