The SAIMM is a professional institute with local and international links aimed at assisting members source information about technological developments in the mining, metallurgical and related sectors.
twitter1 facebook1 linkedin logo

pagesJournal Comment

A monthly publication devoted to scientific transactions and specialist technical topics is unlikely to be on the priority reading list of the majority of the mining and metallurgical community. But it is the ambition of the Publication's Committee to make the Journal of much wider interest to our general membership from technician trainees to mine managers to CEO's of our constituent companies. It is to entice general readership that some 1200 words of valuable space are devoted to the Journal Comment each month. This is intended to highlight some of the features and impact of the papers to excite and activate attention.

To entice this preliminary glance before confining the publication to the book shelf or even the wpb, the author has to call on a large measure of journalistic licence in style, titles and quotations. It is essential to be spicy, controversial and even provocative to separate it from the abbreviated authoritative but necessary scientific style of the bulk of the contents.
The Journal Comment aims to be an enticement to dig into some important feature of the papers in the issue. For this reason it has been decided to include it as a separate item on the Institutes Web Site. This might provoke those who enjoy twittering, blogging and googling to submit comment and criticism, all of which will be welcomed and responded to. At least it is proof that somebody has read it.
R.E. Robinson

Heavy Minerals Conference 2019

Heavy minerals is a small and often neglected field of mining and metallurgy. However, this industry produces some of the most important minerals and metals of the modern world. Where would we be without titanium for its multitude of uses, zirconium for its ultra-hard properties in zirconia, or the rare earth elements for their plethora of uses in modern technology?

The mining challenges of this industry are somewhat different to traditional hard-rock mining as the mines are almost exclusively surface operations. However, because of that, the environmental, social, and resource challenges of this type of mining have a character of their own. The economics of the industry can be rewarding, but because of the relatively low price of the intermediates the industry has to move large tonnages of material. The processing of mined minerals, although seemingly simple, has many nasty ‘hookers’ such as the effect of the surface properties of the minerals. The effect of atmospheric conditions on surface properties can have significant consequences regarding the recovery and grade of concentrates. In addition to the metallurgical challenges, the issue of radioactivity requires management. Although not at a level to cause any health issues, the levels are significant enough to attract attention from health and safety regulators. The challenges of the industry do not stop there as the end products of this sector often require high-cost and high-technology solutions. In no way can hightemperature chlorination in a gaseous atmosphere be considered straightforward. Similarly, the production of neodymium or samarium for high-powered magnets is not simple, a fact illustrated by the small number of facilities that operate this technology.

The International Heavy Minerals Conference series hosted by the SAIMM is an industry-driven initiative to allow sharing of ideas, technologies, and methods of handling the various challenges. The first conference was in 1997 and was held in Durban, South Africa. At this conference, which was organized by the Zululand and Western Cape branches of the SAIMM, there were 38 papers and over a 100 delegates. This was followed every second year by further conferences in the HMC series. The committees of the Institute encouraged sister organizations in other heavy-minerals-producing countries to participate, resulting conferences being held in Australia (2001), South Africa (2003), the USA (2005), South Africa (2007 and 2009), Australia ( 2011), India (2013), South Africa (2016), and finally this conference in South Africa in 2019.

At the most recent conference, held in Cape Town, there were 19 papers presented covering a wide range of topics including ore reserve evaluation, mining, minerals processing, pyrometallurgy, and mine closure. There were three keynote presentations given at the conference: Learning from Kwale to build Toliara by Colin Bwye, Executive Director at Base Resources; Tronox - to infinity and beyond by Willem van Niekerk, Senior Vice President at Tronox; and Do heuristics influence the mineral sands mining landscape? by Rob Hattingh, CEO at Sierra Rutile. The two-day conference was followed by a site visit to the Tronox Namakwa Sands Plant at Saldanha Bay.

The International Heavy Minerals series of conferences has become established as one of the main sources of collaboration for those in this industry. While not as large as some other mineral resource sectors, the diversity and complexity found in the heavy minerals industry stands on a par with any of the other resource sectors.


J.H. Selby
Chairman: 2019 HMC Organizing Committee

The Ninth International Conference on Deep and High Stress Mining (Deep Mining 2019)

The Ninth International Conference on Deep and High Stress Mining (Deep Mining 2019) was held at the Misty Hills Conference Centre, Muldersdrift, Johannesburg from 24 to 26 June 2019. Conferences in this series have previously been hosted in Australia, South Africa, Canada, and Chile. This event, jointly organized by the South African National Institute of Rock Engineering (SANIRE), the Australian Centre for Geomechanics (ACG), and the Southern African Institute of Mining and Metallurgy (SAIMM), was attended by 196 delegates from 19 different countries. Most of the delegates were from Africa (146), but the other continents were well represented; Asia (6), Australasia (12), Europe (22), North America (5), and South America (5).

The Deep Mining series of conferences continues to contribute to our understanding of deep, high-stress mines. Around the world mines are getting deeper and the challenges of stress damage, squeezing ground, and rockbursts are ever-present and increasing.

Mining methods and support systems have evolved slowly to improve the management of excavation damage and safety of personnel, but damage still occurs and personnel are injured. Techniques for modelling and monitoring have been adapted and enhanced to help understand rock mass behaviour under high stress.

Many efficacious and dynamic support products have been developed, but our understanding of the demand and capacity of support systems remains uncertain. During the conference, 33 papers were presented addressing these topics, 11 of which have been selected for this Deep Mining edition of the SAIMM Journal.

Hagan et al. describe testing of rockbolts in full-scale laboratory conditions. This comprehensive approach includes both shear and pull testing, taking the mechanical properties of the rock mass into consideration. Crompton and Sheppard provide some practical insights into the design of resin-anchored tendons, optimizing resin mixing and the resin annulus. A new remote, mechanized bolting system for use in narrow reefs is described by O’Connor and Seritic, which could significantly improve the safety of underground workers. Limitations of South African narrow tabular deep mine layout design criteria are explained by Malan and Jooste and they discuss possible improvements by calibrating with stress measurements and rock mass monitoring. The evolution of mechanized mining and support methods for the wide reefs at South Deep gold mine is presented by Andrews, Butcher, and Ekkerd. Bouzeran et al. describe analyses of rock mass heterogeneity and buckling around excavations, which helps to understand stope drift stability in foliated ground under high stress conditions. Sharrock and Chapula provide a different perspective on similar challenges at CSA Mine, Cobar. Wesseloo presents some insights into seismic hazard and proposes a consistent terminology to avoid miscommunication. The influence of stopes on the seismic source is explored by Linzer et al. Jones et al. describe how underground stope surveys using autonomous drone systems can assist with the understanding of rock mass behaviour and failure mechanisms, which can in turn improve mine planning and design. An approach to big data analytics and artificial intelligence in rock mechanics is presented by McGaughey; this topic is becoming more important as greater quantities geotechnical and monitoring data are collected.

We are grateful to the presenters and delegates for taking time out of their busy schedules to come and share their knowledge and expertise at Deep Mining 2019. The sponsors are also thanked for their generous contributions, as are the organizing committee and technical reviewers. As always, we appreciate the dedication and organizational skills of the SAIMM secretariat.

W.C. Joughin

Rock engineering research and creation of value

This last issue of Volume 119 of the Journal of the Southern African Institute of Mining and Metallurgy is a truly international one, with papers from five continents and one from the Middle East. Authors of the papers are from Chile, China, Iran, Norway, South Africa and the United States. Although this issue is a General Papers Edition, the content shows a rock engineering focus and the topics of most of the papers are relevant to direct or indirect considerations in rock engineering design, which emphasise the importance of rock engineering research. The only paper in which the rock and rock mass have no relevance is the metallurgical paper dealing with high-carbon ferromanganese and silicomanganese.

Three of the papers deal directly or indirectly with risk. The analysis of seismic event return periods in South African gold mining areas has relevance to the risk of occurrences of rockbursts; and there is an interesting comparison with earthquake event occurrences in Southern California.

The use of the Analytic Hierarchy Process (AHP) to determine confidence levels in the selection of longwall coal mining methods is effectively a risk evaluation process. AHP could also be used to assess the potential for value creation. The paper dealing with the improvement in the definition of geotechnical design sectors in open pit slope design is specifically risk-based. As a result of the research in this paper, significant value was unlocked at the mine, as stated in the company annual report: an annual increase in the NPV of R10 billion ($680 million), corresponding with an additional 50 million tonnes of ore.

Four of the papers deal with properties of rocks and rock masses: laboratory triaxial tests were carried out to determine the effect on rock strength of roughness and orientation of discontinuities. Coincidently, these topics are also dealt with in the risk-based paper. Static and dynamic testing of rock samples was carried out to determine the effect of water content and loading rate on rock strength and deformation properties. Such tests are important because ‘real’ conditions in mines, tunnels and other excavations usually involve moisture contents substantially different from those applicable in standard laboratory tests. The paper dealing with quantification of rock mass weathering using spectral imaging adds to the growing value of remote scanning methods in obtaining geotechnical data rapidly and safely, from often inaccessible locations. Such scanning techniques were used to great benefit in the risk-based paper. The fourth paper analyses zonal failure around deep excavations and the influence of layered jointing. Interestingly, three of the papers in the issue are associated with layering or anisotropy.

The paper describing the design and evaluation of drawbell excavation at the famous Chuquicamata Mine may also be regarded as having risk connotations. The stability of drawbells, and their life, are extremely important to efficient production in a block caving environment. Instability could be a risk to the mining process: disruption of the draw profile, repair requirements, disruption of scheduling, and consequently, loss of production with associated costs. The paper is therefore important in providing guidance on the optimisation of drawbell excavation, the minimisation of blast damage, and hence the creation of value.

Finally, there is a paper illustrating some beneficial technologies that can be learnt from nature, in this case spiders. No doubt there are many other aspects and concepts, already well-developed in nature, that could be directly transferable to our mining technologies, and we should be on the lookout for such information.

In summary, this issue of the Journal provides considerable value. The huge economic value resulting from the research described in the risk-based paper leads me to recommend that the use of a strategic, valuebased decision making criterion would be most appropriate for mining company executives - they should demand, from their managers and operational staff, quantified answers (not opinion-based answers), to the following question: ‘What are the quantified values that will be created in the short-, medium- and longterm due to the implementation of ……… (e.g. new development; new mining method; new mining layout; further exploration drilling; mechanisation; increased or improved rock support; more detailed site investigation, etc; in fact, any proposal or change that could significantly affect safety, production, cost, etc)?’ Such a criterion would result in value-based decisions rather than cost-based decisions. The latter may result in short term benefits, but often cause value destruction in the longer term.

T.R. Stacey

To Publish or not to Publish – and what to publish - that is the Question!

Knowledge is the key to life, employment, the economy, and the country. It is nowhere more important than in scientific and technical journals that aspire to deliver the ‘best of the best’ to the professional and intellectual members of society. Such knowledge is expected to encourage intellectual growth, to ensure innovation, to enhance understanding of key issues, and ultimately, to improve the prospects for the economy and the country.

However, knowledge comes in different ‘packages’. It may be manifested at different levels of originality, across different disciplines, and aimed at different technical communities. This multiplicity is compounded by the variety of sources from whence it comes, each with different purposes. In academia, ‘publish or perish’ is a requirement to ensure tenure and promotion for academic staff, while for postgraduate students publishing one or more papers in accredited journals is a requirement before success can be achieved and a degree assured. For academic institutions, successful publication in high-impact journals carries with it financial rewards for both staff and the institution as well as international recognition and status in global academic rankings. In fact, researchers who publish in journals with high Impact Factors are regarded as among the most important assets at any academic institution. For these reasons, university staff are strongly encouraged to publish in journals with the highest credit ratings. Credit rating is determined by what is known in scientific circles as the Impact Factor.

A journal’s Impact Factor, however, is of little relevance to the industrial mining and metallurgical community. In the latter case, papers dealing with innovative topics and practical applications are of greater relevance. Proof of this is the extremely high number of ‘hits’ (i.e. the number of SAIMM Journal papers opened on-line per month) are been reported compared to all other journals in South Africa. This reflects high interest in the SAIMM Journal content. However, the Journal’s Impact Factor, namely, the referencing of SAIMM papers in other journal papers, was reported to be among the lowest relative to other accredited journals. This is of concern to the discerning academic community.

In a country such as South Africa, with highly active mining and metallurgical communities in both the academic domain and in industry, a good balance between papers supplying both applied technology information for those in industry and highly accredited fundamental research for those in academia is of the utmost importance.

The question going forward is how to achieve the balance in the SAIMM Journal in order to serve the interests of both sectors. This matter will be addressed when new ‘Rules of Engagement’ for the SAIMM’s Journal are considered by the Publication Committee and members from ASSAf and SciELO at a meeting to be scheduled in early 2020. All concerned will be welcome to attend. The prime purpose will be to address the needs for both sectors in 2020.

Impact Factor. As described on the website: A Journal Impact Factor is a measure reflecting the average number of citations to articles published in science and social Journals. In simple terms, a citation occurs when an article is cited (quoted as a formal reference) in other published articles, all in accredited journal[s].

NB: ASSAf: ASSAf is the official national Academy of Science of South Africa and represents the country in the international community of science academies. It was formed in response to the need for an academy of science congruent with the dawn of democracy in South Africa - activist in its mission of using science for the benefit of society. The mandate of the Academy encompasses all fields of scientific enquiry and it includes the full diversity of South Africa’s distinguished scientists. The Parliament of South Africa passed the Academy of Science of South Africa Act (Act 67 of 2001), as amended, which came into operation in May 2002.

NB: SciELO: SciELO South Africa is an open-access (free to access and free to publish) searchable database of selected, high quality South African scholarly journals. The project is inspired by a global movement towards the implementation of online journals, pioneered by the Scientific Electronic Library Online (SciELO) project, based in Brazil.

R.M.S. Falcon

Journal Comment - v119n10

In this edition of papers for general interest, you can find twelve contributions from different part of the world – Botswana, Canada, China, France, Iran, Spain, and South Africa. This is a good indication that the SAIMM Journal continues to attract papers from the international community, which is one of the requirements for inclusion on the Department of Higher Education and Training’s (DoHET) list of accredited journals. The DoHET list includes ISI, IBSS, South African journals (DHET), Scopus, SciELO SA, and Norwegian journals; and articles in these journals are eligible for subsidy. Academic institutions in South Africa rely on that subsidy to support their research initiatives. This highlights the importance of publishing articles in the SAIMM Journal in a timeous manner.

In the past, the SAIMM Journal accumulated a considerable backlog of papers of general interest awaiting publication, and such papers used to take up to a year to appear in print. The SAIMM Publications Committee understands the importance of publishing research results as soon as possible, and efforts are being made to address this issue in the most efficient manner.

The twelve papers that have been selected for this edition of the Journal cover topics ranging from a coupling simulation model between a coal mine ventilation network and gob flow field; the use of forensic laser scanning technology in mining incident investigations; prospects for value addition in copper in the emerging Kalahari Copper Belt of Botswana; modelling of generic excavation sequences for bore-and-fill mining; and evaluation of shaft locations in underground mines by means of fuzzy multi-objective optimization. Papers about the dissolution kinetics of tellurium during alkaline sulphide leaching of gold concentrate, CO2 reactivity of briquettes derived from discard inertinite-rich Highveld coal incorporating lignosulphonate and resin as binders, and microcrack formation in vanadium-titanium magnetite using different crushing processes also make for interesting reads.

The Publications Committee hopes you enjoy reading the general papers in this month’s Journal.

B. Genc

The Public Funding of Research

The Journal this month is referred to as the ‘Student Edition’, as the papers are the published output of students registered for university degrees in various minerals-related subjects across Southern Africa.

As one might expect, the topics of the research cover a broad spectrum ranging from mine planning, optimization of mining operations, productivity, safety, mineral processing, environmental treatment of wastewaters, to even the recycling of electronic scrap.

Furnace Tapping 2018

The 2nd Furnace Tapping Conference (Furnace Tapping 2018) was held in Skukuza, the main camp of the world-renowned Kruger National Park, from 14 to 17 October 2018. As with the 1st Furnace Tapping Conference (Furnace Tapping 2014), Furnace Tapping 2018 was well supported and attended by 144 delegates from 17 different countries spanning five continents.

A problem-based event, the Furnace Tapping conference series was established to serve the pyro- metallurgical industry at large, focusing on a very specific challenge: tapping of furnaces. Drawing from various perspectives on the topic, participants represented industry, consultants, service providers, and research institutions. The latter were a welcome addition to the conversation with contributions from Mintek, the Norwegian University of Science and Technology, SINTEF, and Carnegie-Mellon University gratefully acknowledged. These institutions all delivered on the call, issued in the Journal Comment for Furnace Tapping 2014, for ‘strong contributions from research institutions (focusing on the application of CFD modelling with associated assumptions, including properties of materials and validation of these models; studies on taphole clay; and studies on refractory interaction with slag/metal/matte specifically under the tap-hole conditions)’.

SAIMM Geometallurgy Conference

With the increasingly challenging techno-economic climate we now operate in, coupled with the rise in the need to mine more heterogeneous and complex orebodies, geome tallurgy represents a collective, multidisciplinary mine-planning approach to both maximizing value and managing the risk emanating from ore variability. The first SAIMM Geometallurgy Conference, held from 7 to 8 August 2018 at the Lagoon Beach Hotel in Cape Town, was attended by close to 90 delegates from 13 different countries spanning several continents and representing industry, consultants, service providers, and academia. This edition of the Journal contains some of the excellent papers that were presented at the Geometallurgy Conference. Each of the papers published here has been through a formal peer review process in line with the requirements of the Journal.

Recognizing the immense contribution of Professor Dick Minnitt

This volume of the Journal recognizes the immense contribution of Professor Dick Minnitt, of the School of Mining Engineering at the University of the Witwatersrand (Wits), where he is one of their four NRF-rated academics and one of only three Professor Emeritus appointments in the School. He spent most of his career at Wits, supervising not only postgraduate (MSc/PhD) candidates and publishing his own research, but also presenting courses in geostatistics and mineral economics for mining investment in his specialized fields of mineral economics and mineral resource evaluation. Over the years he not only materially contributed to, but also supported and maintained a close association with, the Southern African Institute of Mining and Metallurgy (SAIMM). Though ‘retired’, he continues to provide valuable insights and inputs for ongoing mineral resource research to both industry and academia.

Diamonds: Source-to-Use, 2018

1journalfeb19This edition of the Journal is dedicated to the Diamonds: Source-to-Use conference held during June 2018 at the Birchwood Conference Centre in Johannesburg. It was attended by 107 delegates, some of whom came from as far away as Botswana, Namibia, Canada, the UK, and Belgium. It was the seventh conference in the series, which targets the full spectrum of the diamond pipeline from exploration through to sales and marketing. 2018 saw a renewed enthusiasm in the diamond mining sector in Southern Africa, even if it was tempered by tough economic conditions and political uncertainties. The theme of the 2018 conference, Thriving in Changing Times, bears testimony to how large and small companies are adapting to these circumstances, addressing risk and applying advanced technologies to well-tested exploration, mining, and processing methods.