The SANIRE Gauteng Branch is hosting an evening lecture with a technical talk on
Topic : Risk Mitigation – Slope Stability Monitoring.
Huw Thomas – Principal Surveyor (Anglo American Technical Services)
Drinks and snacks will be provided.
Venue : AEL Mining Services, The Platform, Modderfontein
Time: 17H30 for 18H00 Date: 20th November 2014
RSVP to Philani Mpunzi before the 14th November 2014 by clicking on one of the boxes or by e-mail directly to email@example.com
Click HERE for more information
The American Rock Mechanics Association invites you to submit an abstract to the U.S. annual conference on rock mechanics and geomechanics, and visit the beautiful and vibrant city of San Francisco, California.
Abstracts are sought in mining engineering, petroleum engineering, civil engineering and interdisciplinary aspects of each.
For information on the symposium, abstract submission, accommodations, and sponsorship, visit:
Conference Dates: 28 June - 1 July 2015
Location: Westin St. Francis, Union Square, San Francisco, California, USA
Abstract Deadline: 1 November 2014
Author Notification: 15 January 2015
Paper Submittal: 1 March 2015
American Rock Mechanics Association
600 Woodland Terrace
Alexandria, VA 22302
INTERNATIONAL SYMPOSIUM ON SLOPE STABILITY IN OPEN PIT MINING AND CIVIL ENGINEERING
Open pit mines are being planned to increasingly great depths, often beyond the current experience and knowledge base, with the exception perhaps of some very steep and high natural rock slopes. Despite recent advances, there remains significant challenges in understanding the mechanisms of slope behaviour and failure, and methods of stability analysis for such slopes. In an attempt to bring together the state of the art capabilities in these fields, as well as new research and developments, the South African Institute of Mining and Metallurgy (SAIMM) in collaboration with the South African National Institute of Rock Engineering (SANIRE) are organising a specialist international symposium on the Stability of Rock
Slopes, to be held in Cape Town in October 2015. Cape Town is considered to be a very appropriate location for the symposium. There is a wide choice of hotels, within a few minutes walk of the symposium venue. In the area there are many steep natural rock slopes, and there are significant hard rock quarries within about an hourʼs drive. Technical site visits to various natural slopes and the quarries will be arranged.
Click HERE to read more
The SANIRE Coalfields Branch have the pleasure of hosting the annual SANIRE Symposium on the 11th September 2014 at Glenburn Lodge, Muldersdrift. This symposium has been ECSA approved for one (1) CPD credit.
Click HERE for programme
Dr. Roger Hart will be in South Africa on 18 and 19 September 2014. He has kindly agreed to give two free workshops on Distinct Element Modelling using Itasca's latest Particle Flow Code (PFC). Dr. Hart directed the development of Itasca's six software products, FLAC, FLAC3D, UDEC, 3DEC, PFC2D and PFC3D for more than 20 years and he has conducted over 100 training courses for Itasca software worldwide.
Protea Hotel – Fire and Ice! Melrose Arch
22 Whitely Street
Melrose Arch, Melrose
Click HERE to read more.
Click HERE for directions
Click HERE for directions street view
The Rock Mechanics Certificate - Paper 1 is a general theoretical Paper covering basic rock mechanics theory application in all types of mining enviroments, surface as well as under ground. To read more click Here.
The SANIRE Coalfields Branch have the pleasure of hosting the annual SANIRE Symposium on the 11th September 2014 at Glenburn Lodge, Muldersdrift. This symposium has been ECSA approved for one (1) CPD credit.
Click Here for programme
The Contribution of Rock Engineering to the Future of Mining
"Rock Engineering to the Rescue"
The SANIRE Coalfields Branch have the pleasure of hosting the annual SANIRE Symposium on the 11th September 2014 at Glenburn Lodge, Muldersdrift. We would like to encourage the contribution of technical papers and presentations from all mining commodities for the Symposium. Abstracts should not exceed 500 words and preferably be in MS Word.
Please forward all abstracts to the following e-mail firstname.lastname@example.org by the latest 31st July 2014. If you are interested in attending the SANIRE Symposium or intend to submit an abstract, please forward the following personal details to the enquiries e-mail: Name, Company, Designation, Contact Number and E-mail address
For submission of abstracts, please also include the following Information:
Title of paper and Author's full name.
Click here for registration
As a result of numerous problems with the administration of this exam it was decided that the Chamber of mines will administrate this exam as of the 1st of July 2014.
Please assist and inform your members of the new process:
THE CONTRIBUTION OF ROCK ENGINEERING TO THE FUTURE OF MINING
"ROCK ENGINEERING TO THE RESCUE"
11 th SEPTEMBER 2014
GLENBURN LODGE, MULDERSDRIFT
The SANIRE Coalfields Branch have the pleasure of hosting the annual SANIRE Symposium on the 11 th September 2014 at Glenburn Lodge.
The theme is "The Contribution of Rock Engineering to the Future of Mining: Rock Engineering to the Rescue".
We would like to encourage the contribution of technical papers and presentations for the Symposium.
Abstracts should not exceed 500 words and preferably be in MS Word.
Please forward all abstracts to the following e-mail email@example.com by the latest 7 July 2014.
If you are interested in attending the SANIRE Symposium or intend to submit an abstract, please forward your personal details to the enquiries e-mail.
From the 1st of July 2014 the Chamber of mines will be managing the registration for the Strata Control Practical exams. Examiners to inform Colin Anderson at the Chamber of the planned practical exam date. Registration forms will be available on the website www.comcert.co.za for the candidates to register.
ONLY candidates that register through the Chamber of mines will be allowed to participate in the exam. Examiners to ENSURE that only candidates which register through the Chamber of Mines are examined by obtaining a list of the candidates that registered prior to the exam.
Any queries can be directed to Yolande Jooste Yolande.firstname.lastname@example.org
"Creating value through innovative rock engineering"
12–14 May 2014 Misty Hills Country Hotel and Conference Centre, Cradle of Humankind
GROUP DISCOUNT - Register THREE delegates and the FOURTH delegate is free
Recent developments in the global mining industry have led to the conclusion that it is time for significant change. Mining needs to become yet safer and more efficient while addressing the challenges of rising costs, skills shortage, marginal ore, complex geology and greater mining depth. The easy pickings have been taken. Innovative rock engineering design is therefore essential for the future of the mining industry.
WHO SHOULD ATTEND
Sponsorship opportunities are available. Companies wishing to sponsor or exhibitshould contact the Conference Co-ordinator.
For further information contact:
Camielah Jardine, SAIMM,
P O Box 61127, Marshalltown 2107
Tel: +27 11 834-1273/7
Fax: +27 11 833-8156 or +27 11 838-5923
21 March 2014 marked a landmark in Zimbabwe’s mining history – the resuscitation of the Rock Mechanics Society in the form of the Zimbabwe National Institute of Rock Engineering (ZINIRE). ZINIRE President Omberai Mandingaisa reports:
Prior to its launch, the Zimbabwe National Institute of Rock Engineering (ZINIRE) held its first stakeholder engagement workshop at the Fairmile Motel in the Midlands provincial capital of Gweru on 21 March 2014. The workshop sought to provide a forum for stakeholders to provide input and share their expectations of ZINIRE. It therefore served as a springboard for the launch of ZINIRE, which is planned for June.
ZINIRE’s stakeholders include mining houses, the Chamber of Mines of Zimbabwe, the Ministry of Mines Inspectorate, suppliers, tertiary institutions offering mining qualifications, and rock engineering practitioners.
Most of the people who attended the event were practitioners from the Zimbabwean platinum industry, in which the main players are South African based mining houses, who have brought with them South Africa’s well developed rock engineering practices and legislative framework, enabling global leading practice to infiltrate the Zimbabwean mining industry.
The guest speaker, Walter Nemasasi is the general manager of Anglo American Platinum’s Unki mine. He gave some background on the evolution of mining, safety and rock engineering practices in Zimbabwe.
He said: “Rock Engineering in Zimbabwe saw a lot of research and the publication of high level applications of design principles at Shabanie and Mashava Mines in the 1970s. This saw the development of the widely used mining rock mass rating developed by Dennis Laubscher in 1977 in the massive mining environment, leading to predictions of support and the application of rock mass rating in support designs. Several great geotechnical engineers, such as Dennis Laubscher, Giovani Marano and Keith Viewing, put a very high level of technical design into the Shabanie and Mashaba mines.”
However, the late 1990s and early 21st century saw a drop to a near collapse of rock engineering practices in the Zimbabwean mining industry, which also shrunk as the economic meltdown took its toll.
The revitalization of the platinum industry has seen the return of the world’s best practices in terms of fall-of-ground management. This, however, still leaves other players in the industry without access to the available body of knowledge, a gap ZINIRE seeks to close in the near future.
Walter also went on to look at the strides made in the past in attempting to formalise and legislate the rock engineering practice in Zimbabwe. The work done by the likes of Richard Svotwa, who was with the Ministry of Mines in the 90s, was commendable. Svotwa and the previous association attempted to formalise a certificate of competence in rock mechanics through the School of Mines, but corporate support for this qualification became unavailable as the main mines that required designs and high level technical input downscaled.
In conclusion, Walter made a call for ZINIRE to play a key role in seeing to it that the plight of local practitioners is recognised and that sound rock engineering practices are legislated to ensure that all mines end up with guidelines to use in managing and reducing fall-of-ground accidents.
Presentations were also made by the head of the Mining Department at the Zimbabwe School of Mines (ZSM), Martin January, and Llen Barber, a representative from New Concept Mining. These presentations, in conjunction with the interactive brainstorming sessions led by the current president of ZINIRE, identified the following salient issues:
These issues form and shape the obligations, guidelines and the way forward for ZINIRE.
The CEO of Virimai Projects, Wenslous Kutekwatekwa, and the CEO of the ZSM, Dzingirai Tusai, took the podium and emphasised that the wait for ZINIRE to be born is over, but it will take the determination of all stakeholders for the institute become effective and deliver the required results. It is critical that members, especially those serving on the council, appreciate the need for a lot of sacrifice for the success of ZINIRE. The mineral economist and technical advisor of the Chamber of Mines, David Matyanga, sent in some considerations that guided the discussions around means of funding ZINIRE, as well as mechanisms to ensure mines are engaged at all times through institutional membership.
It was agreed that consultations with stakeholders that could not attend should be pursued during April and the launch should be planned for June. The date will be confirmed once feedback is obtained as to how to synchronise the ZINIRE, Ministry of Mines Inspectorate and Chamber of Mines of Zimbabwe calendar to ensure full participation at the main launch.
The ZINIRE council extends its sincere gratitude to the following for their participation in the workshop:
Hard work and excellent mentorship have brought SANIRE Vice-President Michael du Plessis thus far, as he pointed out in a chat with RockTalk. We hope you enjoy reading it.
1. How did your career in the mining industry begin and where are you now?
I am currently the group rock engineering manager for Lonmin. My career in mining started in 2002, when I was recruited by Anglo Platinum as a rock engineering graduate. During my final year of study, Anglo Platinum gave a brief presentation at RAU (now UJ) to recruit candidates for their rock engineering graduate pool.
Rock engineering appealed to me as it was in line with what I was studying and I had a fascination with rock formations and structure. I therefore completed the application form and was surprisingly invited to an interview. I was eventually appointed as one of the five successful graduates. We were from different universities across the country and had studied a combination of engineering, science and/or geology.
At the time, we did not really know what rock engineering entailed and none of us had any idea of what the underground environment looked like (with the exception of a trip down at Gold Reef city many years ago).
2. Tell us a bit more about your role as SANIRE vice-president.
I think the vice-president has the easy job. However, as you are groomed to take over the presidency, you have big shoes to fill. One of the key roles is to ensure the continuation of the strategies put in place by past presidents. Furthermore, we, as an organisation, need to reposition ourselves as times change and the requirements surrounding our fraternity change.
I am part of the team who looks after the interests of both our discipline and members. We, as a committee, have to envision what the future requirements of our discipline and industry will look like. Today we are seeing the results of decisions and strategies put in place by previous committees and presidents. An aligned strategy and vision is therefore transferred from president to president and committee to committee.
3. What is your vision for SANIRE?
We have always been seen as a very professional organisation. I want to make sure this continues.
I would, however, like to see us market SANIRE and our members at all levels of industry and not only in the rock engineering fraternity. We, as members, have to take the lead and show industry what we are busy with. We, as leaders in our organisations and as leaders in SANIRE, must encourage our staff and members to market themselves by sharing experiences, research and development, technologies, and so on by writing papers, presenting at multi-disciplinary symposia, and so on.
As SANIRE, we will be promoting this through our Practitioner of the Year, Salamon and Ortlepp awards. We must, however, encourage participation. This will take SANIRE to an entirely different level in industry.
4. In your opinion, what are some of the challenges that the organisation is currently facing?
We do not market ourselves enough. With the numerous section 54s issued, rock engineering has become a buzzword. However, very few mine managers or Inspectors know of SANIRE.
Furthermore, the needs of our members have changed. Most of the younger generation are aspiring to become rock engineers. Being an observer or strata control officer is only seen as part of a career path. Every person does, however, have different capabilities and attributes. Everybody will not be able to achieve the highest level. Getting our members to understand this and the fact that every level in a structure plays a very important part in providing a professional service is becoming more challenging.
5. In your opinion, what are some of challenges that members are currently facing?
Although rock engineering is still seen as a scarce skill, the crippling strikes are shaking up the industry.
Since the inception of the new study material, we have seen an increase in tickets. However, the strikes have brought along retrenchments and restructuring, resulting in fewer opportunities within and between companies. Career development is therefore limited and job security threatened.
Also, as the requirements on operations change, we do less engineering and more policing. Job satisfaction is therefore reduced and research and development is seen as an optional extra, especially in a cash-strapped environment.
6. You have done very well in your career to date. Please tell us a bit more about your career journey.
Since my recruitment as a rock engineering graduate, I have always been very fortunate to establish great relationships with good mentors. In Anglo, John Potgieter and Mike Treloar took me under their wings and guided me through my further studies and exposure to become an aspiring rock engineer.
After obtaining my rock engineering ticket, I joined Minova (2005). This was probably one of the best decisions at this point of my career as it matured me and gave me great exposure to different areas of industry across the country.
Two years later (2007) I was contacted by Mike Treloar regarding opportunities at Lonmin. I grabbed at the opportunity as I would be able to work with both Mike and Gregory More O’Ferrall, from whom I could learn and gain valuable experience. This was one of the best opportunities in my career. They gave me exposure and supported my inquisitive nature by providing me with the opportunity to work on research and projects, as well as exposing me to the leaders in our industry. This is also how I met Francois Malan, John Napier and John Ryder, who encouraged some of the work I was doing and motivated me to continue studying.
When Gregory More O’Ferrall resigned from Lonmin in 2009, I was appointed as the group rock engineering manager. Again I was supported by our mining executive vice-president and vice-president (Mark Munroe and Frank Russo Bello) who groomed and developed me through their ongoing and interactive mentoring.
7. What are some of the challenges of leading the Rock Engineering department of the third largest platinum producer in the world?
We are living in changing times. Since the multiple fatalities suffered by Impala as a result of a fall of ground in 2009, the presence of the Department of Mineral Resources (DMR) has increased and section 54s are issued daily to weekly. As a result, rock engineering workplace audits are becoming a routine activity. The 2013 milestones, DMR instructions and Mining Charter requirements are governing the rules of the game.
In a time where every organisation is striving to be the lowest cost and safest producer, striving for culture transformation and being bombarded with strike action, it remains difficult to have a vision that will influence future leading practices and milestones.
It is very important to have a strong team on whom you can rely and who will support you. At Lonmin, I am very fortunate in that I have a strong, diverse and mature rock engineering team. Furthermore, our senior management supports me in my vision with regard to decision making, leading practices, research and development and training. As we are regarded as the safest mine, our management team is very supportive in developing new mining and support strategies to ensure that we remain the industry leaders.
8. What is the key principle/philosophy that has contributed to the success of your team?
I have very mature and experienced rock engineering managers. They play a key mentoring role to ensure that our team remains competent, even when they retire. Each person in my team has strengths (training, research and development, and so on). As a unit, we supplement each other.
Five years ago, we put a training programme in place for a pool of learners to ensure the continuity of local skill and experience for all levels of people in our department. We breed local knowledge through every year’s learner pool intake. These learners will become our future strata control officers, rock engineers and managers.
We also have very close working relationships with the mining team and form a critical part of the decision making unit on every mine.
9. One of the benchmarks in judging the success of rock engineering is the elimination of rock related incidences in South Africa mines. In your opinion, what needs to be done in order to lower these incidences to Australian or Canadian standards?
We need to influence people’s behaviour and train competence. We are too forgiving when it comes to non-compliance and focus only on production (blasting discipline, support installation, and so on). We allow the DMR to stop a mine, yet we as managers walk past sub-standard practices and behaviour. We are currently trying to engineer out behaviour. We do, however, see that even the smartest system can be bypassed or sacrificed as a result of people’s behaviour.
10. What are some areas that you believe will become of increasing importance in the near future of the rock engineering discipline?
The DMR issued an instruction towards the end of last year requesting risk related workplace assessments conducted by the rock engineering department. The DMR questions the integrity and training of our mining team and therefore has put an increased emphasis on the policing function of trained rock engineering personnel, who can identify rock related hazards.
The function and duties of the rock engineering department will therefore have to be aligned to ensure effective up and down communication to and from the mining face, ensuring that workplaces are effectively risk rated and that the recommendations issued are appropriate, communicated and implemented. The rock engineering appointment will carry more weight and will come with more accountability. We have already seen the temporary suspension of rock engineering tickets.
Furthermore, all attempts will have to be made to develop systems to prevent falls of ground. Similar to bolting and netting, the next generation support must be developed to prevent all falls of ground. This will become the next leading practice within the next five to ten years.
11. Having completed a Masters degree in Rock Engineering you have started on your PhD. What motivated you to start on the PhD?
Francois Malan and Gregory More O’Ferrall persuaded me to pursue a PhD. It was never a goal of mine and personally I do not think it is something I would have put within my reach. Having a mentor such as Francois coaching and guiding me makes a world of difference.
12. What are some of the aspects you are covering in your PhD?
My PhD is focused on understanding the behaviour of crush pillars. I am investigating the effect pillar width has on crush pillar behaviour. On many mines using crush pillars, we have seismicity associated with the pillar behaviour. I hope to understand the mechanism driving pillar crushing so that I can devise a design strategy to prevent pillar seismicity and ensure safe and effective pillar crushing.
13. Who or what drives you?
When you are younger you seem to chase everything. This varies from qualifications, to positions, to money, etc. There is actually no winner or timeline. Setting achievable goals is important.
Having job satisfaction, good relationships and a healthy lifestyle is what drives me. I always work hard to achieve my goals. I do not have a role model, but I have several people who inspire me. This ranges from people who have a calm and steady approach to situations, to ones with super intelligence, ones with wisdom or people who truly enjoy life.
14. What role has mentorship played in your personal and professional growth?
Mentorship has played a major role in my life. As mentioned, I have always been fortunate in having good relationships and good mentors. Even when growing up, I always had good mentors supporting me. This has helped me to achieve milestones which would normally be above my own expectations.
Through my professional career and studies, having people who motivate and guide me has made an enormous contribution to what I have achieved.
I, however, believe that people see potential in all of us. It all depends how hard you are willing to work to achieve a goal. Mentors are purely people who see some talent and dedication, believe in you and guide you in your journey.
15. What advice would you offer people aspiring to be in your position?
Hard work always pays off. Being one of the crowd is not good enough. You need to make sure you always work hard enough so that you are a step ahead of the rest.
If you sit and wait for opportunity to find you, you will be waiting for a long time. Your future is in your own hands and it is your responsibility to make the most of it.
16. What is the best advice you have ever been given?
The grass isn’t always greener on the other side.
When he’s not hard at work studying or leading the Lonmin Group rock engineering team, Michael du Plessis enjoys cycling, travelling and good red wine.
RockTalk had a chat to Obed Masinge, who started his career in mining and rock engineering in June 2006 and is the chairman of SANIRE’s recently launched Nothern Cape branch. Read on to find out what he had to say.
1. What is your educational background?
I studied geology and obtained a National Diploma and BTech, for which I majored in engineering geology and hydrogeology.
2. How did your career in the mining industry begin and where are you now?
I was recruited as a trainee in the Rock Engineering Cadet Programme at Anglo Platinum mines (Rustenburg), and rotated around Angloplats’s underground mines for both the UG2 and Merensky reef mining environment. Before joining the company, I was involved in hydrogeological and geophysical exploration programmes at the Department of Water Affairs.
3. What got you into Rock Engineering?
The opportunity to expand in rock mechanics. Rock engineering integrates geophysics methods (seismic monitoring and ground penetrating radar), hydrogeological studies and engineering geology in investigating and addressing the rock-related challenges that are often encountered in both underground and surface mines. I saw my background in geology as giving me an opportunity to advance my engineering geology career, specialising in rock mechanics.
4. You initially worked as a strata control officer at a shallow depth scattered platinum mining operation in the North West. What are some of the triumphs and challenges that you experienced in this environment?
Challenges in this mining environment were both in ground control and in human resources.
Mining there is in close proximity to potholes, which are, in most cases, associated with curved domal and shallow dipping structures. These areas result in problematic hanging wall conditions. The successful introduction of trigger-action response, which was referred to as the ABS system, proved successful in timeously addressing the conditions encountered. Compliance to layout was often a challenge with regard to pillar cutting.
5. You then left for the Northern Cape to take up a similar role in a relatively new operation, with shafting sinking and horizontal development only currently taking place. Why the move and how do you compare the two environments?
With the development of a new mine, data collection, designs, and the compilation of management documentations are essential. This move was an opportunity for me to be involved in risk assessments, compilation of codes of practice and standard operating procedures. In terms of geological differences, manganese ore is located in the sedimentary basin, with the mode of occurrence of the layers being inter-bedded, while the UG2 and Merensky reef are mined within the igneous rocks of the Rustenburg layered suite. The thicker manganese ore makes higher mining width possible, up to 5 m, with the bord and pillar mining method being applied.
6. What are some of the interesting aspects of such a new operation? Are the knowledge and experiences gained from an old operation adequate?
The abrupt changes in lithological units and conditions bring challenges and I guess out of such challenges come learning and a different approach towards mining and support. With such conditions, geotechnical core drilling and logging would be a requirement, to ensure that the planned mining faces will mine through competent rock masses. The knowledge and experience I gained in the platinum and chrome environment was adequate, although the structural geology and nature of rock masses are different. The conditions of mining compare to those for UG2 sections and MG chromitite bands, where hanging wall beam failure is often the mode of failure. Ongoing structural mapping and core-logging is essential in defining the rock mass behaviour and weak parting planes in the hanging wall of the planned mining faces.
7. Please tell us a bit more about the new Northern Cape branch.
The members or potential members of the branch are rock engineering specialists and rock support suppliers. The rock engineering specialists offering technical services to manganese, diamond, iron ore, zinc, lead, copper and silver mines in the Northern Cape region are likely to be members.
The branch is essential, as there is evidence that some of the SANIRE members who had affiliated in the gold and/or platinum branches found it difficult to participate in activities because of distance and work constraints. Although the distance between operations still appears to be an issue, proper planning and timeous communication will improve matters.
8. How has the Branch been received by the local practitioners and other stakeholders?
The branch has been well received by the rock engineering specialists in the region. Nineteen members attended the first meeting. The specialists who could not be part of the first meeting responded by email, indicating their excitement about the initiative.
9. What is your vision for the branch? What do you want to see happening or changing in the Northern Cape during your time?
The branch is fairly new and has few members who are located far apart.
In terms of participating in the SANIRE activities, my intention is to offer the necessary support to the branch to ensure that the organisational goals and objectives are realised.
Competency assessment and evaluations with regard to strata control and rock mechanics should be formalised in the region. Rock engineering specialists in similar types of mining from other countries should be consulted and be invited to give presentations on geotechnical aspects.
Training and development in consultation with the service providers will be offered to the rock engineering specialists in the region at venues in the region. Building competency and confidence will result in younger Rock Engineering specialists being given a platform to give presentations.
10. You are young and energetic with a young branch to take care of. Where do you see yourself in the medium term?
My current goal is to pass the rock mechanics practical exams, qualify as a rock mechanics practitioner and manage a rock engineering department. I will be blending my geology and rock mechanics studies with post-graduate business management studies to enable me to add value in mineral resource management as well as SANIRE.
11. In your opinion, what are some of the challenges identified in the rock engineering discipline in your region?
Ground conditions are challenging, especially when mining exposes the contact planes between hematite (Iron rich) and brunite lutite (manganese rich) strata. The sharp contact between different lithological units continues to provide hanging wall failure points. As the underground operations are close to surface, ground water resources or aquifers are mostly saturated, and draining into mine openings in close proximity. The occurrence of a dolomitic layer above the mining horizon, which is susceptible to cavities, also plays a role in ground water storage and release in the lower excavations. Development of shafts also proves challenging, especially in the initial stages, because of thick Kalahari sands.
12. In your opinion, what are some of challenges facing young rock engineering practitioners in the region?
The Kalahari basin is not well researched and documented compared with the platinum and gold mining areas. There are few permanently employed experienced practitioners in the region from whom younger practitioners can learn.
13. Who is your role model?
My parents are my role models. From them I have learned that a true captain of life is patient and sticks to the planned objectives, while learning from the undesired outcomes.
14. What is the best advice you have ever been given?
When I started out in rock engineering, I was in my first three months of a Masters degree in mineral resource management. I was advised that starting a career in rock mechanics would require 100% dedication and split attention would result in undesired outcomes in both fields of learning. It was important that I had to concentrate on the practical and theory side of rock mechanics before I deviated into other fields of learning.
15. What advice would you offer people aspiring to be in your position?
The most important thing to remember about learning is that you should never say you have arrived when you obtain a certificate. Rock mechanics requires intense studying and patience. Competence is an ongoing process, not a one-off event. With different mining settings come different challenges and learning.
16. How do you unwind?
I spend time with my lovely family; in most cases listening to music and rarely watching movies. I look forward to watching Kaizer Chiefs matches whenever time allows.
In recognition of his concerted effort in service of and contribution to the discipline of rock engineering, Ben Kotze recently received the SANIRE Honorary Life Fellow award from SANIRE. This a fitting way to celebrate the impact made by a man who has dedicated his life to the discipline. Les Gardner’s citation stated clearly what brought him to the point of achieving this accolade. Read more about Ben and his achievements here.
Theunis Johannes Kotze, known to most of us as Ben, was born on 7 May 1940. He spent his early life in Klerksdorp and was educated at Klerksdorp Hoërskool. After matric, he joined Stilfontein Gold Mine as a learner official, and a year later he was awarded a General Mining bursary to study mining engineering at the University of the Witwatersrand.
It was during Ben’s final year at Wits that he had his first exposure to formal training in rock mechanics. The course material was presented by Professor Black, who was responsible for introducing the first formal rock mechanics training in a South African institute. As an aside, Roger More O'Ferrall, who was involved with reviewing or marking some of Ben's work during that period, reckons that Ben's handwriting is one of the most difficult he has ever had to decipher!
Following his graduation, Ben did a stint as a shift boss at Stilfontein and then joined the Union Corporation, where he spent considerable time in the group's Study department at Evander, dealing with the rock mechanics problems on the group’s mines in Evander and on the East Rand. One of the most unique of these was the shale footwall heave on the East Rand mines, which, under severe conditions, could lead to stope closures.
(When asked by RockTalk, Ben explained that the Rock Engineering Department at Evander was located at Bracken mine, one of the four there, all of which are now closed down, except for two shafts, known locally as No 7 shaft and No 8 shaft.)
Ben’s career had its roots in an era where engineers still used log tables and manual calculators to do their work. Electronic calculators still lay in the future and the application of elastic theory to the rock mass was still to be proved. Rock mechanics practitioners still referred to themselves as such and the term "engineer" was still a distant dream, possibly not achievable in one’s lifetime.
The practitioner’s opinion still only carried the same if not lesser weight than that of a junior manager with scant knowledge of the subject. He had to work very hard to prove his case.
When asked to clarify this, Ben added: “I think the difference is that, in those early days, we were still trying to establish the rock engineering science, which is generally accepted today. Today, the practitioner only has to prove himself.”
As the work load increased, Ben started signing on staff, which led to the formation of the Group Rock Engineering department located at the now-closed Bracken mine. At this time, Anglogold, General Mining JCI, Rand Mines and Goldfields had Rock Engineering departments.
Eventually, the work load in the Free State also increased to the extent that staff members were placed at the St Helena, Unisel and, later, Beatrix mines. A feature of his leadership and management style is that he wanted only the best people for the department, and did not suffer fools gladly. On a personal note, I think I was one of the people who managed to surprise Ben when, against all expectations, I passed my RMC at the first attempt.
During this time, Union Corporation opened the first of their four Platinum mines in the Rustenburg area, known as Impala Platinum. Together with the late Dr Neville Cook, Ben was very involved with developing a support system for the "stiff" and sparsely jointed strata of the region, which, if not properly supported had a tendency to collapse massively. With increasing rock engineering activities at Impala, staff members were also placed there, with the first practitioner being the late Nick van Lavieren.
Ben’s first involvement with the Bushveld occurred when he was invited to visit a very shallow chrome mine (about 50 m below surface) where the pillar system failed and surface subsidence occurred. Based on a back analysis of the pillar failure and using the coal pillar strength formula, Ben discovered that the value of the constant “k” in the formula was +- 1/3 x UCS which is identical to the ratio of the of the k- value for coal pillars (7.2MPa) and the UCS of coal (21 MPa). This was an important discovery and he says he has been using this ratio ever since with great success. For more detail regarding chrome pillar design, Ben recommends a paper entitled ‘A review of the pillar support strategy being followed on chrome mines belonging to the SAMANCOR group’ which was published in a 1993 SANGORM symposium entitled Rock Engineering Problems Related to Hard Rock Mining at Shallow/Intermediate Depth.
Ben recalls, “When Impala was started towards the end of 1968, there was no rock engineering input in the mine design and stoping was started with matpacks as the only support. When the first two stopes reached spans of roughly 90 m, both stopes collapsed. Based on observations, I reached the conclusion that the lower hangingwall beam up to the Bastard Merensky reef collapsed, which the pack support could only support after about 30% compression. This failure is now known as a backbreak and the best strategy to cope with this hazard is to leave in-stope pillars, which was the strategy followed following the initial collapses.
As it turned out, our pillar design was incorrect but due to the presence of considerable solid in the form of potholes, we could mine from surface down to a depth of 150 m for the first four years without any problem. After this period, Impala experienced two massive collapses, the largest one occurring at 4 Shaft Bafokeng South. A large area measuring 600 m x 900 m was involved, with the average depth being 160 m. The hangingwall failure reached up to surface leading to the development of cracks in the mine hospital walls. The fall was bounded on the up dip and down dip side by a fault and a dyke respectively. Stope convergence and the displacement on surface was identical, equalling 30 cms.
Since there was no evidence of pillar scaling or stick failure prior to the collapse, it was concluded that, up to the time of the collapse, the hangingwall loading system remained stiff and the pillars were not overloaded. Once the shear strength of the fault and dyke was exceeded to allow slippage along these structures, creating a soft loading system, the pillars were subjected to the full overburden load, leading to their collapse since they were underdesigned.
Since rigid in-stope pillars imply ever-increasing pillar dimensions, which would become impractical at depths approaching 1 000 m, it was decided to opt for regional pillars to support the overburden to surface and to leave in-stope yielding pillars with constant dimensions to combat the backbreak problems.
A 20 m width for the regional pillars was opted for to conform with a guideline that existed in those days that long pillars with w/h > 10 will not fail and to ensure that no pillar punching of the hanging or footwall will take place.
The issue of regional pillar spacing was investigated in depth and it was concluded that the spacing should preferably be equal to Depth/2, but spacings approaching the depth below surface were still considered to be stable, with a 400 m spacing being the maximum.
After a number of variations the dimensions of the yielding pillars were standardized at 6 m x 3 m. This system of pillar support was successfully practised until recently on all Impala mines.
A paper summarising some of these issues was submitted to the fifth International Congress on Rock Mechanics held in Australia in 1983. It was entitled ‘Strata Control Problems Resulting from Mining at Shallow Depth in the Hard Rock Measures of the South African Bushveld complex’.
The understanding and appreciation for Rock Mechanics changed with the advent of the electric resistance analogue computer, which allowed layouts to be modelled and quantified. Early on in the 70s Ben, together with the late Rex Tucker, built an analogue computer and began doing his own modelling. He has never looked back.
Building the Analogue computer involved, among all the obvious parts such as the front plate, framework and the electrics, the soldiering together of more 20 000 resistors, involving some 500 000 connecting points.
There were no further developments of the analogue computer since, in the 80s, all efforts were focused on the development of digital models such as MINSIM and, more recently, MAP3D.
In the mid-70s, the mining groups formed a working committee that met under the chairmanship of the Chamber of Mines. As the representative of Union Corporation Limited, Ben became a member of this elite group of individuals, who formed the nucleus of practicing rock mechanics specialists for the principal mining groups. They included David Ortlepp (Rand Mines), Frank Jansen (AAC WDL) and later John Wilson (AAC, OFS), Roger More O'Ferrall (General Mining), Chris de Jong (Gold Fields), Flippie Venter (Anglo Vaal) and Harold Cahnbley (JCI).
The members of that original group of group rock mechanics practitioners, together with scientists of the various research organisations and universities, had to work for years to build the science into what it is today.
He was a founder of the technical certificates as they exist today and was, for many years, one of the examiners. He recalls: “Two of my staff members, the late Sergei Steyn and Nick van Lavieren, approached me with a problem. The problem was that should I get unhappy with them or they get unhappy with the group, they possessed no qualification to prove to another mining group that are qualified to do the job. At one of the regular meetings of the Chamber of Mines sub-committee on rock engineering, I raised the issue and it was subsequently decided to establish the certificate. The certificate numbers of the two practitioners in question are among the first five certificates issued. The original examiners were not required to get the ticket.”
In 1984, General Mining acquired the mining assets of Union Corporation to become General Mining Union Corporation Ltd, more commonly known as Gencor, the remaining assets of which now belong to the Billiton Group. When this process was completed, Ben found himself as the Assistant Group Rock Mechanics Engineer in charge of operations.
At this stage, the group department had expanded to four regional offices, providing a service to some 43 mines and covering the full spectrum of minerals mined by the Gencor subsidiaries - Gengold, Ingwe, Samancor, Gefco and Impala Platinum. Following Roger More O'Ferrall’s retirement in 1990, Ben took over the role of Group Rock Engineer for Gencor.
In 1996, however, it was decided to unbundle the Gencor Group into four constituent parts that were destined to go their separate corporate ways. Ben, like many of his engineering colleagues, moved over to Hatch Africa, where he spent some time before becoming a private rock engineering consultant in 1997.
During this time, Ben became a part of the Government's Rockburst Commission, and even spent a short period of his supposed “early retirement” lecturing at Pretoria University. It is a measure of Ben’s dedication to his profession that, as recently as a few months ago, I was informed by a junior colleague that he’d come across Ben while busy with a feasibility study for a new mining project. Ben still practises as an independent consultant.
Ben has always been a very private person, and was reluctant to include any details, but he always had a very friendly relationship with staff members. Typical examples Include Martin Pretorius and Sergei Steyn, both sadly now deceased, Dave Spencer, Ben Streuders, Dirk Venter, John Keen, Kobus Geyser and Kevin Brentley.
Ben Streuders had the following to add: “Ben could take a really complex problem, simplify it to an understandable concept, analyse it and come up with a practical solution. He has an enquiring mind and was always eager to ‘research’ deeper into the factors that he knows are weaknesses in the rock engineering knowledge base. As a young rock engineer, he shaped my thinking and my approach towards problem solving. I also learned from him that there is something called ‘company politics’ and company ‘philosophy’ and how to manage it.”
He has always been a keen traveller and could tell many stories about his amazement with the building skills of those that lived a 1 000 years and even 2 000 years before us, using arches and dome structures that are still standing after all these years. He was also keen on local travelling and showed his “green” side when he bought his Nissan Sani and became one of the early day 4x4 explorers.
Trevor Rangasamy, one of the founders of Middindi Consulting, spoke to RockTalk about himself and his career thus far. Get to know him a little by reading on.
1.When and how did your career within the mining industry begin? What got you into rock engineering?
After graduating in Applied Geology, I did odd jobs to keep the pennies flowing. At that time, around 1991, there was a surplus of mining related professionals. My first love as a young delinquent was Geology. At that time, I had never heard of a field called rock mechanics, or rock engineering, as it is known today.
Fortunately, Anglo-American advertised a plethora of positions in mining in the Sunday Times and I applied, thinking that geology was required for one of them. When I got to the interview, I answered questions to the best of my young uninfluenced geological knowledge, not knowing that it was actually a rock engineering position. I got the job and the passion has never waned since that interview. By the way, I was interviewed by Gary Dukes and Dion Booyens.
2. What is your educational background?
I have an MSc (Engineering) (Rock Eng) through research, a BSc (Applied Geology), a GDE (Rock Engineering), the advanced RE Certificate and the chamber tickets. I am of Indian descent, so the business skills came naturally.
3. What are some of the qualities needed to do what you do?
Once you have the knowledge and understanding, believing in your professional worth is paramount. If you don’t, others reflect that aura. The professional and natural world is full of different energies that make up different personalities. They will cross your path, no doubt. Handle situations with even-handedness and honesty. It always triumphs.
There is no substitute for being exposed to the environment we ply our trade in. It builds confidence and enriches our knowledge with a wealth of understanding.
4. You co-founded a Rock Engineering firm, Middindi Consulting. Where did Middindi Consulting come from?
Johan Hanekom and I met at the Mining Qualifications Authority (MQA) 12 years ago). Both of us were contracted to write unit standards and learning material for rock engineering. We did know each other by sight when we worked for AngloGold, but that’s about it. Johan had a company called MIDD Consulting and mine was called IndiRoc Consulting. It’s easy to deduce the name Middindi if you know our original company names.
We decided to throw in our lot with each other, using fundamental principles that have held us together ever since: Trust, honesty and communication. Sounds like a marriage; believe me, it probably is.
5. What is the key principle/philosophy that has contributed to the success of your organisation?
Above all, deliver a quality product that is packaged to suit the needs of the client. Never compromise on founding principles that could allow the outcome of the job to produce something reckless. Have a balanced approach that provides an optimised, defendable result rather than be overly conservative or too aggressive. There is worth in every person, find it and use it to develop and grow your business.
6. What are some of the highlights of your career?
Certainly, being the first local black certificated rock engineer in South Africa was a highlight. So was working with some really hard-assed production personnel and learning to cope and grow from the differences and the similarities we shared. I have really valued being involved, from a forensic perspective, in most, if not all, rock related multiple fatalities in RSA for the past decade and discovering the huge strides that we have made in mitigating rock related deaths. I have enjoyed publishing about 30 papers and co-authoring three guidebooks. A rather unusual highlight was being retrenched from the now-defunct JCI, which showed me that there is hope in adversity by spawning the seed of my business.
7. Who/What has motivated you over your career span?
Three people have played a role in my career. In chronological order: Johan Laas for showing me the grit and patience needed to grow and to construct thought in concept before leaping into solutions. Dr John James, one of the smartest guys I know, for giving me the leeway to think and for to have a very balanced approach to life in general. This balance provided clearer thought when the mind was cluttered. Phil Piper for his astute business principles and organised approach to anything, really.
8. Would you say the rock engineering discipline has changed over the years? If it has, what are some of the distinct changes that you have noted?
Yoh, it has man! There are a lot more people in rock engineering than ever before. Once we received the regulatory status (in about 2000), our work became more recognised and we have become an integral part of mine design, not just an afterthought. Sadly, the focus on research and development has met an untimely death.
Probably a good 30-40% of our fraternity operate outside the mining houses in consultancies and this is certainly a shift. In the past, maybe 90% of rock engineers worked in mines. I think this trend will grow in the next 10 years to probably an even split between mine-based rock engineers and those who work from consultancies.
From a demographic perspective we have a large base of junior rock engineers and a dwindling senior level. We don’t seem to be rejuvenating the top echelons at the rate of attrition.
9. What are some of the rock engineering issues do you think remain unsolved in the South African mining industry? How can these issues be addressed?
Hard rock pillar strength derivation is still unchanged from that proposed by Hedley in 1972. The concept is inherently compressional; the behaviour of pillars is not. For operating depths below 400 m, we need to populate a database of failed/unfailed pillar states categorised by reef type and then use this data to validate and/or revise the Hedley formula. I am certain that the exponents will become reef/seam specific.
Multiple-seam mining and related rock mass effects in the platinum industry are a reality that requires founding guidelines similar to those formulated for coal mines by Salomon et al. This is of particular importance when mining the UG2 as a secondary operation in transitional and/or pothole reef facies. The difference between the platinum and coal rock mass is the behaviour of the interburden due to its lithostratigraphy, rock quality signature and strengths. Extraneous loading of the platinum reefs is a huge complication. This subject sparks my enthusiasm, so I had best leave it alone.
The choice of panel and bord spans is still somewhat subjective, although use of empirical charts is an effort to make the choice more engineered. I believe that our focus is more on the stuff in between the panels (pillars) rather than the span design. They are both equally important and equal effort must be provided in their design, not just adopting a simple approach of scraper efficiencies and drill boom effective widths.
Quite obviously, the seismicity emanating from the platinum mines needs research and understanding since this layered intrusion is not the Witwatersrand Goldfield; we have done that, we are yet to do this.
10. One of the benchmarks of judging the success of rock engineering is the elimination of rock related incidences in South Africa mines. In your opinion, what needs to be done to lower these incidences to Australian or Canadian standards?
I believe that the relationship between state, employers and unions needs to be less adversarial, since ultimately we all have the same objectives. We need to collaborate our efforts and find solutions that are technically sound, yet practical and ethically correct. I can remember when fatalities topped 500 per annum. It is now less than 150. There has no doubt been huge improvement.
We, as rock engineers, need to place more emphasis on the anomalous conditions since, in my experience, it is the out-of-the-norm conditions that have resulted in some of our major incidences. These conditions are not vast and ever present, but probably constitute a mere 5% of the exposed workplace. They often and likely go unnoticed.
The wealth of understanding that can be gained from data gathering is better than simply applying knowledge without thought or reason. We must develop the habit of validating continuously, since the rock mass is dynamic. A condition today may never be seen tomorrow. We must gather data comprehensively and find quick, effective ways of letting the data tell us about our environment. Our decisions will then be informed. Safe declaration is static, safe declaration with timely data is dynamic and effective.
11. Within the rock engineering discipline, what are some of the areas that you believe will become of increasing importance in the near future?
Our role and accountability for rock related safety is becoming increasingly recognised. We are now part of the safe declaration procedure in some mines, whereas we never performed this role in the past. We have to still find a balance between being designers and implementers. The focus may become skewed towards implementation and the basic tenants of design may become lost. I am still unsure whether multi-skilling actually works. We may be unknowingly creating another division of rock engineering. This may have some conflict with the original roles and responsibilities we first saw for ourselves.
12. You have previously been involved as a Rock Mechanics Certificate (RMC) examiner. In your experience, is the ticket a good system or do we need to system like the Engineering Council of South Africa (ECSA) professional registration system?
I think we need both. The ticket tests knowledge and understanding and the registration tests its relevance. Having been an examiner for a number of years and having worked with a number of people who don’t yet have the ticket, I strongly believe that the ticket is not a true measure of competency but one of the tools.
Having said that, written examinations have been around for centuries so there cannot be anything wrong with using it to measure certain facets of competence. I remember structural geology examinations from my time at university. The contribution for the final mark was from a written exam (50%), field work (25%) and basic research investigative studies (25%). This meant that a single element did not constitute one’s entire test of competence. In fact, it is the same for certain courses in the Graduate Diploma in Engineering (GDE) programme. Maybe we should be testing some of the papers this way and not haive a final overarching practical examination. The logistics may be onerous, though.
I believe the current attitude shared by many is that we examine to fail and candidates hope for luck. Examinations for candidates should be based on study and understanding and the written papers should be a breeze. Examinations for examiners should be based on testing founding principles that can be applied in many contexts. This subject can be debated ad infinitum and, like political rhetoric, it is opinionated.
13. What are some of challenges facing younger rock engineers today?
Rock engineering is greater than the borders of South Africa and the exposure we get in this country to different mining methods and orebodies is very limited and, in some cases, only applicable to South African conditions. We need to start learning about other deposits and methods used to extract them so that we are globally marketable. We tend to be too stereotyped in our approach to geomechanical problems in this country, there’s a lot to learn from others if we take the time to open our eyes and look.
14. What is the best advice you have ever been given?
The mine manager some years ago at JCI always used the term “back to basics”. At that time, it was the first I heard of it. That stuck with me. We tend to find comfort in complexity and are embarrassed by simplicity – I don’t get it.
15. What advice would you give the varous generations of engineers?
Never lose sight of governing first principles, no matter how complex the geomechanical problem is. Our environment consists of rock, so there is no substitute for knowing the rock, first geologically and then mechanically.
16. How do you unwind?
I think a lot about nothing (the pulse of energy that formed us) and everything (the universe). Thought is my relaxation.
"Cultivating the Future of Geotechnics"
is intended to establish a network forum and opportunity for young geotechnical engineers to better acquaint themselves with the industry and products available. This takes place in a young environment where all presenters and most of the delegates are under the age of 35. The conference is held every three years and aims to provide delegates with the opportunity to develop their writing skills and publish a technical paper which will be published in the conference proceedings. In addition presenters can exercise presenting skills in front of a more forgiving audience and delegates attending can all learn from like-minded peers.
Who should attend?
Geotechnical practitioners under the age of 35 in the mining and civil construction industry. More experienced geotechnical practitioners are encouraged to motivate the YGE 's working under them to attend the conference and explain the advantages of presenting their work at the conference.
For a list of sponsorship and exhibition options please contact the conference secretariat.
Yolandé van den Berg
RCA Conference Organisers
082 323 3910
Gregory More O’Ferrall’s news from Western Canada takes a detour through South America in this issue. Enjoy finding out a bit more about the Cerro Lindo Mine, which both William Joughin and Gerrie van Aswegen have apparently also visited.
Cerro Lindo Mine is situated in the Inca region of Peru, as shown in Figure 1. The mine currently exploits zinc and copper, making use of an openstoping mining method. Of interest to me, besides the rock engineering issues that the mine is currently facing, is that the mine uses desalinated water that is pumped from the desalination plant at the coast across the mountains to the mine (a distance of 67 km) in a single 200 mm diameter column. This water services the mining operations, including the processing plant and the mining village. Figure 2 indicates some of the harsh environment across which the water is pumped.
This was also the first time that I had been on the South American continent, in a mountainous coastal desert region and seen the size of remote control equipment that is used in the underground mining industry – new “toys for boys”.
I had a mini-adventure just to get to site. I flew out of Vancouver for my first stopover in Toronto, which is a five-hour flight (amazing how large Canada is). I opted for this flight, as the alternative was to fly via the USA, which would have caused endless issues as I need to get a permit to travel into the USA. If I travelled on my South African passport, then I’d have to apply for a visa, which would be even more of an issue.
While on the flight across Canada, Toronto experienced unusual weather in the form of heavy thunderstorms. When we landed at Toronto, I thought it very unusual to have so many “spare aircraft” parked in queues alongside the runway (it actually looked like a mall parking lot). However, instead of taxiing to the arrivals gate, we parked behind the aircraft in one of the queues. Only then did I realize that there were queues of aircraft waiting to get to arrivals gates. We waited in the queue for over three hours until we were eventually allowed to disembark.
My onward flight to Lima was scheduled to depart two hours before we disembarked, and no Air Canada staff members were to be found to enquire about the onward flight – it was 01:30 in the morning. I eventually found somebody who was being harassed by hundreds of stranded passengers (the Air Canada priority telephone line was also not being answered) at 04:30, and he informed me to wait at a specific counter until 07:30, when the check-in staff would be able to assist me. At 07:45, I was then informed to go to another gate, where all stranded persons were being allocated new flights. After standing in this queue for the next 7 hours, I eventually got to the check-in counter and was informed that the next flight was in two days.
I went searching for my luggage only to be informed that it was impossible to retrieve it, and I was given a complementary toiletry kit to make me feel more human (maybe my then unshaven appearance and grumpy attitude had something to do with it). Then it was off to find a hotel for the next two nights. I managed to find one close to the airport, had a most-welcome shower and breakfast/lunch/afternoon snack (I did not know what it was, as I had not eaten for well over 15 hours by then) and went to buy a change of clothes and a cellphone charger.
I eventually managed to get on a flight to Lima at 06:30 two days later, and was assured at check-in that my luggage would be loaded on the same flight. After a rather pleasant seven-hour flight, I landed in Lima and waited for my luggage at the carousel until the arrivals section was vacated, except for five passengers on my flight. So, off we went to the missing baggage counter, which was manned by three Peruvians – one constantly talking on a cellphone, the other trying to chat up a female colleague and the third extremely slow (I got to appreciate that African Time is far quicker than Peruvian Time – actually the Chileans joke about Peruvian Time, where everything appears to come to a standstill).
Two hours of standing in the queue brought me to the counter to claim for lost baggage. Did I mention that I cannot speak Spanish? Between my school French and my army Portuguese (sometimes almost including a Fanakalo word or two), I did not do a bad job of getting my message across. Surprise! My luggage had arrived two days before – on the flight that I had missed. I did not query how this happened, as I was only too pleased finally to be reunited with clean clothes and toiletries. Lesson learned – travel with spare clothing and toiletries in your hand luggage.
The following day, I was off to site. I had never met the rest of the AMEC project team before, as they originated from the Lima and Santiago offices. Two of the project team travelled with me to site, and neither could speak English and my main Spanish phrase was “poquito Español” (little Spanish). The five-hour trip was spent mainly sleeping, as it was dark and rainy, and I could not communicate. However, when we turned off the coastal road and headed inland into the mountains, the sun was breaking through and I was treated to some picturesque desert sights.
The 67 km road from the coast to the mine takes approximately three hours to travel. As a safety precaution, the drivers of vehicles are required to have a 10 minute break after two hours, so a tiny oasis has been constructed where a comfort and safety break is enforced (Figure 3).
An hour further along the road, which is actually a single lane dirt road that hugs the sides of the mountains, with occasional passing lay-byes, brought us to the mining village/camp.
I was pleasantly surprised to see what I thought was green grass in the camp, which was a small soccer field. This grass is Astroturf, and the soccer field appeared to be permanently occupied, except during meal times (Figure 4).
Thankfully when I arrived at camp, I was one of two Gringos on site (word quickly spread that another Gringo had arrived). The other Gringo was another AMEC employee, who is Canadian and had lived in Chile for three years. He quickly became my translator, as nobody else on site could speak English (poquito Español, Señor).
Our accommodation was pleasant, with each room having a shower and toilet en-suite. Unfortunately, my room was next to the mining offices (Figure 5) and, due to this being a 24-hour operation, seven days a week, and a safety requirement for all vehicles on site to sound their horn every time they moved (blow their hooter in South African terminology) and to be fitted with a back-up signal (reversing alarm), I did not get much sleep and resorted to working 20-hour days for the 10 days that I was on site. It’s amazing how much you can achieve in the early hours of the morning.
The mine is in a desert region (thankfully it was the middle of winter and the temperature was around 27 °C to 32 °C), which has its own wildlife (Figure 6). This brought great concern to the Chilean project members, as they had not expected to find wildlife (must be city slickers) in this arid region. They quickly learned to lift their boots off the floor at night, not to walk barefoot and to ensure that their boots were unoccupied before putting them on.
An item that I will not miss after this site visit is the cuisine. For all three meals a day, and for 10 days in a row, the only food available at the canteen was Pollo y Arroz (Chicken and Rice). The difference on most occasions was the spice in the water in which the chicken was boiled. I had never eaten chicken and rice for breakfast before, yet alone for all three meals in one day. On the way out of the desert, I saw numerous chicken farms that had sprung up since the mine was started, and I personally wanted to call in drone attacks to destroy these farms and hence save the mine employees from having to endure this culinary torture any longer.
Before you think that this visit was a tourism expedition, I suppose that I’d better show/tell you something about the mine (Figure 7). Entrance to the massive orebodies (of which eight have been identified thus far and mining is taking place in four of these) is via portals/adits (Figure 8).
The operation is fully mechanised, and openstope dimensions are typically 20 m wide, 30 m high and vary in length between 40 m and 70 m. As I mentioned earlier, these boy’s toys are far bigger than the remote-controlled cars I used to dream of having (I suppose things truly are bigger in America) (Figure 9.).
This mining method is very challenging, particularly in the geotechnical environment in which it is taking place. The strength of the ore is extremely variable; with the uniaxial compressive strength varying from 20 MPa to 110 MPa. (Very few laboratory tests have been conducted.) In some areas it is possible to crush the “rock” in your hand, whereas in other places it is difficult to break it with a geology pick. (Figures 10 and 11.)
Needless to say, with this variation in ore strength, the sizing of the excavations in the orebody is very difficult to optimise without the frequency of strength variation being known. (It varies considerably over 5 m intervals.)
The plan is for mined-out stopes to be filled with a pastefill, but teething problems associated with pastefill plants has resulted in some of the open voids being unfilled, resulting in the collapse of the stopes. In one instance, the collapse propagated to a height of 250 m, resembling more of a cave mining operation.
The 10 days were spent visiting all the underground working places, the core sheds, pastefill plants and participating in meetings and workshops. The personnel on site were extremely pleasant and helpful. However, before I finish the write-up about the mine, I thought I’d post a familiar-face-to-some. Ruben Maza (Figure 12) visited Impala Platinum a few years back and fondly remembers his visit to South Africa, including his visit to Jackpot (New Concept Mining’s manufacturing facility at Nasrec) and to the Carnivore Restaurant, where he got to sample lion meat. (The Peruvians at site frequently asked me if it was true that we South Africans eat lions. I informed them that it was only tourists that did so.)
I managed to spend half a day in Lima to do some form of sightseeing/gift shopping. I managed to avoid the delicacy of grilled guinea pig on the dinner menu and was threatened that the next time I am in Lima, I will eat it. (Apparently it is flayed out like the roast pigs that you see in some pictures with an apple in the mouth. They probably put a grape in the guinea pig’s mouth.)
My impression of Lima is that there is a more evident wealth differential than you see in South African cities. Thank goodness I had a driver, as the traffic is more chaotic than I experienced in Ghana. The person with the biggest vehicle and loudest horn has right of way, and any pedestrian attempting to cross at a stop street or pedestrian crossing may have a death wish.
Figure 13 features some photographs of the buildings that I walked past. What really intrigued me was that the petrol stations are located on the island in the busy parts of the suburb where I was staying, and yet these did not interfere with the traffic flow. I would definitely not promote this location for filling stations in South Africa.
Figure 1: Location of Cerro Lindo mine.
|Coastal desert with fertile valley.
||Desalinated water pipeline over mountain tops.|
|Figure 2: Terrain over which the desalinated water is piped.|
Figure 3: Tourist photograph at safety oasis along mountain pass.
Figure 4: Artificial turf soccer field (must be lunchtime).
Figure 5: Visitor and Senior Official sleeping quarters and Underground Mine Office.
Figure 6: An ex-wildlife member of the Peruvian coastal desert region and cacti behind accommodation.
Figure 7: Gregory More O’Ferrall at the entrance to the mine site.
Figure 8: Main access to underground operations.
Figure 9: Remote-controlled LHD (note the operator wearing the remote-control harness)
Figure 10: Variation in strength of ore (freshly drilled core in the core tray)
Figure 11: Medium- and coarse-grained chalcopyrite
Figure 12: Ruben Maza, Cerro Lindo’s geotechnical engineer.
View from hotel room – construction
|Typical architecture in wealthy suburb.|
|Electric fence – consequence of
|Old church and parliamentary building.|
|Fuel station on island between traffic lanes.||Catholic cathedral.|
|Figure 13: Some sights in Lima.|
SANIRE offers you access to global rock engineering excellence through the International Society for Rock Mechanics (ISRM). Find out more about it here.
There are several benefits to being a member of SANIRE. All such benefits are in line with SANIRE’s mission statement, which reads:
In the spotlight in this issue of RockTalk is point (e), SANIRE’s provision of access to global rock engineering excellence through its affliation with the International Society for Rock Mechanics (ISRM).
To promote the advancement of rock mechanics and rock engineering, the ISRM has established various means of providing leading practice knowledge in the form of; the ISRM Suggested Methods, online video lectures and the ISRM digital library.
Registered members of SANIRE, are automatically ISRM members and thus have full access to the above mentioned sources of knowledge.
The ISRM Suggested Methods provide a systematic approach of documenting procedures relating to field testing, laboratory testing, site investigations and various other aspects of the discipline. These documents are accessible for download on the ISRM website ( http://www.isrm.net/gca/?id=177).
You can also access them in the ISRM Blue Book (publications from 1974 to 2006, Edited by R. Ulusay and J.A. Hudson), various issues of the International Journal for Rock Mechanics and Mining Sciences and, of late, Rock Mechanics and Rock Engineering.
This system was developed in the early 1970s and has records of suggested methods from these early years. The records extend up to 2014. This goes to show how much the ISRM is committed to keeping its members abreast with best practice and the latest standardised developments in the discipline.
Here are just some of the topics on which Suggested Methods have been published in the past three years:
Online video lectures
The ISRM website hosts video lectures that you, as a member, can view for free. Four lectures have been presented to date, all of them in 2013:
To view these lectures, go to http://www.isrm.net/gca/?id=1104 .
The SANIRE Council is pleased to announce that, beginning this year, SANIRE will also be producing video lectures on various topics for the benefit of its members. Two lectures are scheduled for the year and the number may increase in future.
ISRM digital library
The ISRM digital library is hosted on www.onepetro.org, which is run by the Society of Petroleum Engineers. It contains publications from ISRM meetings and congresses as well as publications from various other journals.
As SANIRE members registered on the ISRM website, you are allowed to download, at no cost, up to 100 papers per year. ISRM corporate members can download 250 papers.
The login details to onepetro.com where recently changed. New or old registered members who have not yet upgraded their login details as per the new login requirements can update their details by following the instructions on the ISRM website ( http://www.isrm.net/gca/?id=992 ).
Find out more
For further information or any queries about the ISRM, please contact Jacques Lucas. He is the current Vice-President for Africa on the ISRM board. Back home, Jacques is a former President of SANIRE and now holds the ISRM Liaison portfolio on the SANIRE Council. For Jacques’s contact details as well as some highlights of his career, please visit http://www.isrm.net/gca/index.php?id=1034 .