Gap851 Final Report Main Body

Prof. Nielen van der Merwe

Year of birth: 1947

Current position: Head, Department of Mining Engineering, University of Pretoria

Qualifications:

BSc Eng University of Pretoria

M Eng University of the Witwatersrand

Ph D University of the Witwatersrand

NvdM also holds a Mine Managers Certificate, is a registered professional engineer, and is a Fellow of the South African Academy of Engineering.

Experience:

NvdM has had 28 years experience as a rock engineering practitioner, researcher and academic. He has worked in various mining sectors: gold and platinum (10 years with Gencor and Gold Fields), coal (10 years with SASOL), consulting (2 years with Itasca), research (2 years with CSIR Miningtek), and academia (joined academic staff at the University of Pretoria in 2001).

NvdM has been very active in the rock engineering community. He has served several terms as President of the South African National Institute of Rock Engineering (previously the SA National Group on Rock Engineering, SANGORM). He is currently President of the International Society of Rock Mechanics (2003-2007).

Date of interview: 2 March 2005

STATUS REPORT

1. FAMILIARITY WITH ROCK-RELATED RESEARCH WORK

1.1 How many reports have you read? Which have had the greatest impact on your work?

NvdM has read all of the SIMRAC and Coaltech 2020 project reports relevant to coal rock engineering, and some of the hard rock reports that have relevance. All completed SIMRAC COL reports were briefly reviewed. NvdM made the following comments.

COL 001

Rock Engineering for Underground Coal Mining (a handbook on strata control practices in South African coal mines) JN van der Merwe (Itasca), BJ Madden (CSIR)

The handbook was sold out after 6 months. The authors (NvdM and B Madden) offered to publish a second edition in which certain sections will be revised and a few errors corrected. NvdM said that he and B Madden decided to do this at no cost to SIMRAC “for the privilege of not working through the SIMRAC committees”. NvdM accepts that checks and balances are necessary. However, mining company politics led to considerable interference in the section on of pillar extraction.

COL 005a	The effect of structural discontinuities on coal pillar strength as a basis for improving safety in the design of coal pillar systems GS Esterhuizen (Pretoria U)	Excellent work, though largely ignored because the researcher did not have a profile as a coal rock mechanic. Only now are practitioners beginning to apply the findings.
COL 021	A reassessment of coal pillar design procedures BJ Madden, I Canbulat, BW Jack and GD Prohaska (CSIR)	Wasn’t a bad project, though there were some problems with the project team. Quite a lot of important information was gathered.
COL 026	Multi seam design procedures RW Hill (CSIR)	Really good work, though many practitioners still haven’t caught on the fact that rock engineering is a discipline that requires design skills, and prefer simple formulae and rules-of-thumb.
COL 307	Identification of causes of unsafe acts or neglect resulting in roof or sidewall accidents A Hamilton-Atwell, A du Toit, L Kirstein, M Louw, L Mtombeni, R Moses (NPI)	Excellent work, though NvdM believes that the final report was never distributed because it was “too honest” and the researchers refused to censor the report. For example, the report contained a quote from a mine manager along the lines of: “This emphasis on safety is a load a crap. Mining is dangerous, and I pay people to take risks”.
COL 326	Conceptual development of a method to determine the principal stress around coal mine workings to ensure safe mine design S Coetzer (CSIR)	Didn’t work, never used.
COL 327	Review the caving mechanisms around high extraction systems and determine the effect of the mechanism on the safety of the system G Sweby (CSIR)	Nothing new came of this.
COL 328	Review of current design methodologies to improve the safety of roof support systems, particularly in the face area, in collieries I Canbulat, BW Jack (CSIR)	Some paradigms were challenged and changed by the monitoring results. The design chart is not used, to NvdM’s knowledge.
COL 337	Coal pillar design procedures G York, I Canbulat, BW Jack (CSIR)	Nothing useful came from this.
COL 439	Determine the need to research the time-related stability decay of bord and pillar systems JW Oberholzer, GS Esterhuizen, PJ van Vuuren, BJ Madden, JN van der Merwe (CSIR)	The work identified the need to conduct research into time-dependant behaviour, but the SIMRAC committee rejected the recommendations without reading the report.
COL 451	Recommendations on setting illumination and visibility standards in South African coal mines	Very important report. The recommendations have been implemented and made a huge difference. Can’t believe that we worked in the dark for all those years!
COL 465	Determining the friction factors for underground colliery bord and pillar workings	Good work. Friction caused by CM picks scraping sandstone is an important cause of methane ignition. Rock engineering can also explain certain gas flow and concentration phenomena. It is totally wrong to do technical development in watertight compartments.
COL 502	Design, construction and testing of underground seals A Cook & JN van der Merwe (Itasca)	Don’t know if this was ever applied.
COL 503b	Literature survey on the advance detection of dykes in underground coal mine workings GA Fourie (Pretoria U)	Nothing new.
COL 504	Simple user's guide on roof support installation and evaluation JN van der Merwe (Itasca Africa (Pty) Ltd)	The key table is used quite extensively, but most users skipped over the section on design because there was some mathematics.
COL 609	Safe mining face advance and support installation practice in mechanical miner workings under different geotechnical conditions I Canbulat & JN van der Merwe (CSIR)	Good research and report.
COL 610	Assessing and Evaluating Acoustic Techniques to Test Roof Conditions in Coal Mines in Combination with SIMRAC No.9 P Altounyan, B Clifford & KM MacAndrew (Rock Mechanics Technology Ltd).	The report was very positive, but NvdM is not aware of the device being used.
COL 613	Investigation into the causes of falls of roof in South African collieries JN van der Merwe & JJ van Vuuren (Itasca Africa (Pty) Ltd), R Butcher (SRK Inc) & I Canbulat (CSIR)	Good work. Should be repeated. At first the mines were reluctant to provide information for fear of being punished. Once relationships had been established there was brilliant cooperation. The team promised to respond to call outs within two hours. The SIMRAC committee hindered progress as they would not allow a change of scope to investigate the smaller FOGs, which in fact injure far more people than the rare large FOGs.
COL 702	Current practice and guidelines for the safe design of water barrier pillars T Rangasamy, AR Leach, JJ van Vuuren, AP Cook & R Brummer (ITASCA)	Good work, but not sure whether it is used.
COL 703	Pre-feasibility investigation of system to provide an early warning of roof falls prior to support installation JA du Plessis (ISS Geophysics)	Nothing came of this.
COL704	Suitable long tendon (2.5m - 15m) technologies and practices P Altounyan & B Clifford (Rock Mechanics Technology Ltd).	Good quality work, even though it was largely a rewrite of British and European standards.
COL 709	Development of a method to estimate coal pillar loading DP Roberts, JN van der Merwe, I Canbulat, EJ Sellers & S Coetzer (CSIR)	This was an attack on tributary area theory! It was concluded that while TAT is a conservative estimate of load unless the overburden has failed, it is the best available. The study also provided useful input to other projects.
COL 802	Survey of horizontal stresses in coal mines from available measurements and mapping R Frith (Strata Engineering (Australia) Pty Ltd)	Felt that the researcher wanted to drum up work for his consultancy business. NvdM disagreed with the conclusions. NvdM believes that only 8% of roof falls are related to horizontal stress. The strength and quality of the roof material is a more important factor, and easier to measure.
COL 810	The impact of geotechnical factors on the secondary extraction of coal in the Witbank and Northern Highveld Coalfields, specifically related to safety LS Jeffrey (CSIR)	Had some use, though the report was essentially a duplication of work done for Coaltech 2020.
COL 812	Rating system for coal mine roofs I Canbulat & T Dlokweni (CSIR)	Good work that forms the basis of Canbulat’s PhD thesis. Excellent literature survey. Roof ratings are good for general classification into geotechnical areas, but cannot be used as input into design. NIOSH claims that CMRR used on 70% of mines, though this is by researchers, not by practitioners.
COL 814	Process guidelines for the integrated design and planning of underground coal mining processes to ensure safe, healthy and effective mining operations GA Fourie & DJ van Niekerk (Pretoria U)	Brilliant. Used as a handbook for teaching. Relevant to mines other than coal as well.

1.2 How many workshops and conferences have you attended?

Not discussed.

1.3 Have you supplied researchers with information and derived benefit?

Not discussed.

1.4 Have you hosted projects on your mine(s)?

Research work had been conducted on SASOL mines during NvdM’s tenure.

1.5 Have you worked as a consultant on a mine that has hosted research projects?

N/A

1.6 Have you been a mine/industry champion for a project?

N/A

1.7 Have you implemented research knowledge and technology?

NvdM described the implementation of new mine layouts and methods at SASOL collieries. This had led to an 80 per cent reduction in the number of CM burials. It had not been difficult to implement these changes: SASOL is an exceptional company, senior management realize that rock mechanics input is need and are very receptive to well-motivated proposals.

NvdM noted that it is important to find a client (say a mine captain) who was willing to try out his proposals in a section so that the new method / technology could be demonstrated. NvdM commented that it is generally far easier to change a coalmine layout than a gold mine layout. He also said that managers on coalmines tended to have a higher level of technical competence than gold mine managers. Some gold mine managers were intimidated by science and resisted new ideas.

1.8 Have you personally performed research work?

NvdM has performed research work for his PhD degree (on the topic of surface subsidence), and under contract for SIMRAC and other clients while employed by Itasca, CSIR Miningtek and Pretoria U. He is listed as an author of 10 SIMRAC reports.

1.9 Have you proposed research projects to SIMRAC?

Not discussed.

1.10 Have you evaluated research proposals?

Not discussed.

1.11 Have you evaluated research progress and outputs?

Not discussed.

1.12 How could the SIMRAC research program be improved?

NvdM said that there were “always problems” when dealing with SIMRAC. He had not dealt with SIMRAC since 2000 and had experienced severe frustrations. NvdM said that he did not believe that there was a problem with the SIMRAC system; in fact he thinks that it is good. It is the people serving on SIMRAC committees that cause the problems. He identified the following shortcomings:

• 
  Some members fail to attend meetings; with the result sometimes decisions cannot be taken as there is not a quorum.
  
• 
  Some members lack objectivity and promote company agendas.
  

NvdM endorsed the idea of SIMRAC sponsoring research that is aimed at solving mine specific problems, with the mine providing matching funding. This could be used to turn generic findings into mine specific guidelines. It could also be an excellent opportunity for the researchers to gain practical on-mine experience.

NvdM proposed that researchers be invited to propose research needs. They would probably be better informed regarding the type of fundamental work that is required to progress in applied research. Without fundamental research, the ability to do applied research will eventually diminish.

2. IMPACT OF ROCK-RELATED RESEARCH WORK

2.1 Has research work enabled you to do your work better?

NvdM described how research work had improved practice on SASOL mines (see 1.7 above).

2.2 / 2.3 Has research work produced knowledge and technology that have improved safety in the SA mining industry? / on your mines?

NvdM noted several developments:

• 
  Salamon’s pillar strength formula had prevented another Coalbrook disaster.
  
• 
  Improved lighting had made a big difference.
  
• 
  Better equipment (e.g. roofbolters, continous miners), mostly developed in the USA.
  

NvdM said that SIMRAC research had only a very limited impact on safety in SA mines, but this did not surprise him as research always leads implementation by 5-10 years.

NvdM referred to a “wonderful paper” presented by Chris Mark of NIOSH, who showed that mines had often to be forced by regulation to implement technology (in this case roofbolts).

2.4 How would you describe the research work carried out by SIMRAC?

NvdM rated the quality of South African coal rock-related research as being on a par with efforts elsewhere in the world, though there is nowhere where it is particularly good. With respect to pillar design research, NvdM rated South African efforts as being slightly ahead of Australia, and far ahead of the USA as South Africans have addressed issues such as pillar scaling and time-dependance. The linear formula (developed by NvdM) is being applied in iron mines in France.

In terms of rock mechanics in general, NvdM said that the bulk of the research was being done in China and Japan, focusing on discontinuities.

2.5 Are research products effectively transferred to practitioners?

and

2.6 Are practitioners able to effectively implement the research?

NvdM said that while there had not been another Coalbrook disaster, we must not become complacent. There have been other serious collapses in coalmines since then, some in the recent past, which could have killed many people. Fortunately they happened over weekends, or people were able to escape. It is critical to have a detailed knowledge of changes in roof and pillar strength.

NvdM said that knowledge / technology transfer and implementation were huge issues. He attributed this to several factors:

Many certified rock engineering practitioners have a relatively low level of academic training. In many countries (Australia, Europe, USA, Zambia) the minimum academic qualification is a bachelor degree. In SA, only a rock mechanics certificate is required, which has been evaluated and found to be equivalent to only 6 per cent of a B-degree. However, South African rock mechanics practitioners are required to deal with some of the most complex problems in the world, while they lack an understanding of engineering fundamentals and fields such as statistics.

Practitioners generally do not keep up to date by reading papers, reports or attending symposia. However, new regulations will make some professional registration compulsory, with a requirement for continuing professional development.

Centralized rock engineering and training departments have been closed or downsized. In the past, practitioners would be assigned tasks such as reading research reports and customizing the findings to local conditions. Presently most practitioners are deployed on shafts and are kept busy with their day-to-day duties.

Mine managers sometimes do not seem to be concerned about the actual competence of their staff, and merely check that the practitioner has the minimum qualifications required by regulations.

NvdM said that he had previously thought that practitioners should be given the freedom to carry out engineering designs from first principles, but had reconsidered this view in the light of the generally poor level of skill and ability.

2.7 Have SIMRAC funds been well spent?

Not discussed.

FORESIGHT REPORT

3. What changes do you predict will affect the SA mining industry during the next decade?

1. 
   The government holds the view that mining is an important vehicle for poverty alleviation for South Africa and the continent. NvdM believes that there is massive scope for small-scale mining e.g. gem- and semiprecious stones; coalfields such as the Molteno could be opened and small power stations built.
   
2. 
   Gold production will decline and large gold companies will move the locus of their operations outside SA. The Rand will continue to be strong, thus the Rand income from gold sales will decline. No significant increase in demand for gold is expected, as it has no significant industrial use. NvdM believes that part of the reason for cutting back on gold production is to preserve the value of the gold already on the surface.
   
3. 
   Platinum could be vulnerable if a substitute catalyst is found.
   
4. 
   China will dominate the world economy in 15 years time.
   
5. 
   Coal has a good future, for the next 50 years at least, as it is the prime source of cheap energy. New coalfields (e.g.Waterberg, Free State, Molteno) will be developed. Technologies such as in situ gasification could be implemented.
   
6. 
   It is possible that significant oil reserves will be discovered in Mozambique.
   
7. 
   The environmental impact of mining would receive increasing attention.
   

4. What advances could significantly address the above-mentioned changes?

1. 
   Must provide technology, training and support for small-scale and emerging miners. Technology could be as simple as better wheelbarrows and shovels. The support must not just be technical, but should include issues such as finance, access to mineral rights, and marketing.
   
2. 
   Research will be required to support the development of the new coalfields e.g. thick seams, “dirty coal” (i.e. intercalated shale and sandstones)
   

5. What advances could significantly reduce rock-related safety risks?

and

6. What factors could improve rock-related safety?

1. 
   NvdM said that he believed that all major rock-related research needs in the coal sector had been addressed. The main risks remained pillar collapse and fall of roof. It was now time to revisit these issues and conduct more detailed and intense research on topics such as:
   

• 
  factors affecting pillar strength (regional and local variations, deterioration with time, etc),
  
• 
  mining methods (e.g. long thin pillars cut by continuous miners)
  

2. 
   NvdM said that there is very little that is unique to the South African coalfields from a rock engineering point of view. There are great similarities with Australia and the USA. The conditions in SA are easier, if anything: seams are thicker, and the physical environment is more stable. While SA coalfields are intruded by dolerites, strong sandstone layers cause greater problems in Australian mines.
   
3. 
   NvdM said that there is a real possibility of another Coalbrook disaster, unless local variations in pillar strength and roof stability are monitored and taken into account in mine design. COL 005a, which deals with the deterioration in pillar strength caused by discontinuities, is of great relevance. The presence of methane presents an even bigger threat.
   
4. 
   NvdM strongly emphasized the need for fundamental research, as it forms the basis for future applied research.
   

NvdM expressed the view that the SIMRAC committees tended to be reactive and to take a very simplistic view of research. “Let us, for once, do the research before it is absolutely required.”

7. NEED FOR ROCK-RELATED RESEARCH

7.1 Should research work continue in SA

“Yes.”

7.2 Should research effort be increased significantly?

“Yes, the research effort is currently far too small. The research effort should be related to the size of the problems to be solved, not tied to production.”

7.3 / 4 Do we have the research competency / capacity?

“We are lacking in both. The fact that many senior researchers are approaching retirement is a cause for serious concern. It is also very important to have top quality researchers. Twenty brilliant researchers can do more than 200 mediocre researchers.”

NvdM said that the CSIR’s coal rock engineering competence had been reduced to virtually zero, but was very concerned that CSIR continue to be involved in Coaltech 2020.

The interviewer raised the issue of the role of the university in the research endeavour. NvdM said that he believed that a university rests on three legs: teaching, research and community services (participation in scientific and professional societies, etc). If you remove one leg, the structure collapses. NvdM said that the Mining Department at Pretoria University does not have a single full-time research student on campus. All the postgraduate students are based on mines, contact with the university is limited and largely administrative, and much of the supervision is in practice “sub-contracted” to CSIR Miningtek. Attempts to recruit an emeritus researcher had been thwarted by budget cuts.

7.5 Do we have the research facilities?

The rock testing labs are probably OK. CSIR has always taken good care it its equipment.

Pretoria University has very limited rock-testing equipment (in the Metallurgy and Civil Engineering Departments). The Mining Department generally uses the CSIR laboratories.

7.6 Should the focus be on implementation rather than on more research?

“Both, its not a choice between one or the other.”

7.7 Should research work be abandoned?

“Strongly disagree.”

7.8 Would stricter enforcement have a greater impact than more research work?

“A qualified yes, because this would only be true in the short-term. Stricter regulation and enforcement is needed to improve the safety statistics. This had been shown to be the case in the USA.”