Anglo forced to defend sustainable investment in Zimbabwe »

Posted on June 25th, 2008 by John Chadwick

Following media pressure in the UK and elsewhere, Anglo American has defended its investment in Zimbabwe. Anglo is to be commended on its position. Investment of this nature can be to the benefit of a great number of the country’s people, especially if that investment is controlled by a company like Anglo, a driver in the ICMM and a company with excellent sustainable development credentials. It would be wrong to cease such long-lead investments in the country. Zimbabwe will need projects like this to rebuild its economy once it rids itself of the Mugabe madman and returns to democracy.

It would be wrong for Anglo to pull out. This would hand an advanced mining project to Mugabe’s criminal regime. That would be double jeopardy, potentially increasing the regime’s access to foreign currency and depriving local communities of the potential benefits.

The following statement is Anglo American’s response to media reports relating to its business activity in Zimbabwe. “Anglo American has been an investor in Zimbabwe for 60 years.  The Unki platinum project in Zimbabwe, which has been in development since 2003, is a long-term investment for a mine which is yet to start production and will not generate revenues for some years. Anglo American is deeply concerned about the current political situation in Zimbabwe and condemns the violence and human rights abuses that are taking place.  Anglo American is monitoring the situation in Zimbabwe very closely and is reviewing all options surrounding the development of the project. It has been made clear to Anglo American that if it ceases to develop this project, the Government of Zimbabwe will assume control.

“Anglo American has a clear responsibility to protect the wellbeing of its more than 650 employees and contractors, as well as their families and all those who depend indirectly on the activity around the project, all of whose livelihoods would be jeopardised should the company withdraw from Zimbabwe. The responsible development of the Unki mine will create a long-term viable business which will be important to the economic future of Zimbabwe for years to come.  Anglo American continues to support the communities around the project with a number of important social development activities, including the provision of basic food and supplies, the building of a dam to help support agriculture through the reliable supply of water and the provision of financial and other assistance to the primary and secondary schools and community health facilities.  

“Anglo American is in full compliance with all relevant national and international laws relating to its activities in Zimbabwe.”

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PERC 2008 – another resource code »

Posted on June 18th, 2008 by John Chadwick
The Pan-European Reserves and resources Reporting Committee (PERC) was formed in 2006 to resume the work of the previous IMM Reserves Committee which had developed the original 1991 IMM Code, and to take responsibility for managing and updating the Reporting Code 2001 which had been developed under the aegis of the Committee for Mineral Reserves International Reporting Standards (CRIRSCO), with sponsorship from the Institute of Mining and Metallurgy (IMM), the European Federation of Geologists (EFG), the Geological Society, and the The Institute of Geologists of Ireland (IGI), for use in the UK and western Europe. PERC members represent its parent organisations as well as key sectors of the mining and financial communities in the UK and Europe more generally. The PERC Code 2008 has been developed as an update to incorporate improvements in the international CRIRSCO ‘template’ as well as details specific to the European extractive industries (such as for industrial minerals, dimension stone, and aggregates). It is a CRIRSCO-compliant Code and shares identical reserve and resource definitions with other Codes in the CRIRSCO family such as JORC, SAMREC, and CIM.

The “exposure draft” for consultation was launched on June 17, with a six-month consultation process leading to launch of the final version of the Code in mid-December 2008. There was lively discussion at the launch event in the Council Room at IOM3 (Institute of Materials Minerals and Mining), in London. Among the questions raised was the need for reporting standards for scoping, prefeasibility and feasibility studies. This is a question that has been well aired in these pages, first in the December 2007 issue and followed up in various issues thereafter. Readers are further encouraged to send us their opinions and ideas on study reporting standards.

To take part in the PERC discussions and give your opinions on that code go to

www.PERCreserves.com

 

 

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Strata control debate - comments welcomed »

Posted on June 18th, 2008 by John Chadwick

Professor Ernesto Villaescusa, Industry Chair in Mining Rock Mechanics, Western Australian School of Mines, Curtin University of Technology notes that he “read with interest the article entitled Strata control” in International Mining’s May issue. He comments: “Leading photo. It raises a lot of questions… For example if this would be a typical installation practice, the position of the operator leaves a lot to be desired. In unsupported ground, on a typical development face, it means that the operator is indeed exposed to instability from above.

“The statement ‘hard rocks mines are moving from mechanical to resin anchor bolts to improve ground support efficiency’ needs qualification. In Australia, most mines rely on frictional bolts and there is documented evidence of problems with the efficient installation of resin bolts.”

In the paper by Villaescusa E, et al, . Quantifying the performance of resin anchored rock bolts in the Australian underground hard rock mining industry. Int J Rock Mech Mining Sci (2007), doi:10.1016/j.ijrmms.2007.03.004, the authors conclude: “The overcoring data show that for the majority of the current bolt–hole size combinations, reinforcement systems and installation practices used in the Australian hard rock mining industry, the best resin mixing and bolt encapsulation occurs within the middle region of the bolt. In all cases of low load transfer, poor resin mixing was identified as the main cause. In addition, the majority of the overcored bolts had no resin at the collar region, indicating that effective plating of the bolts is very important for long-term effectiveness. The worst conditions in terms of encapsulation and load transfer are found towards the toe region of the bolts.”

Villaescusa continues: “However, the biggest issue I have is with the shotcrete section of this article.

“First of all, shotcrete does not provide active support ‘within minutes’, and the fibres are not designed to secure a ‘good bond’ with the rock. Most importantly, the suggestion that ‘most mining fatalities are caused by small stones weighting less than 1 kg’ is plainly wrong. This is a dangerous statement that is clearly designed to discredit the role of wire/chain link mesh in rock support (in favour of shotcrete). Our experience and research outcomes clearly show that mesh is a critical component of a ground support strategy, specially when deformations exceeding 50 mm are likely to be experienced when the shotcrete is no longer effective.

“Furthermore, the statement that TSL can be used as ‘a replacement for wire mesh’ is also not correct or scientifically justified. Our research shows that the current TSL products have serious force-displacement deficiences.”

John Chadwick responds: “Both Mike Rispin and I were able to discuss these points with Professor Villaescusa at the recent MassMin conference in Sweden and the other contributor to the shotcrete discussion has been made aware of Villaescusa’s points.

Michael Rispin, Head of Mining, UGC International, BASF Construction Chemicals Europe: “In response to Dr. Villaescusa’s concerns regarding the article, I will first and foremost address his concern with respect to the part on TSL as contributed by BASF. He and I had the opportunity to speak about this face-to-face at MassMin and I believe that we came amicably to an equilibrium regarding the issue and attributed it primarily to interpretation and semantics.

“The passage in the article reads: ‘Largely designed to be a rapidly applied, temporary ground support or as a replacement for wire mesh in conjunction with rock reinforcement, TSLs offer …’. We stand fully behind this statement.

“The interpretation of the effectiveness of TSL or that of wire mesh is not represented by the statement and is, of course and as with other means of ground support, dependent upon local conditions, application specifics, thickness of TSL, gauge of wire mesh, etc. Notwithstanding that, the statement as published is maintained to be accurate.”

Further comment and contributions are welcomed.

 

 

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GPS for underground operations - great potential for controlling block caves, saving trapped miners and machine automation »

Posted on June 10th, 2008 by John Chadwick

Today (June 10) at the MassMin conference in Lulea, Sweden, Greg Baiden of Laurentian University, Canada (also Chief Technology Officer of Penguin Automated Systems) presented on a newly developed Underground Positioning System (UPS). The UPS has a range of some 2 km through rock and accuracy better than 3%. Mine trials are to be undertaken later this year and in 2009. Going forward, this has tremendous potential for finding trapped miners, for equipment mechanisation and mine wide asset management. The system employs VLF and would rely on a network of ’satellites’ placed to surround an orebody or underground workings.

The system has been developed in block cave mining research. In such mines, determining the rock breakage characteristics is of paramount importance to placing drawbells and accurately controlling the pull of the ore. Gathering rock flow information is difficult as the cave, once started, is completely independent inside the rock mass. Only gross controls such as drawbell pulling can be used to attempt to change the pull characteristics, but typically results are significantly after the fact and correlation with changes are difficult to measure.

Several attempts have been made to study flow using markers injected in the cave from above and retrieving them as they exit the cave. This approach provides the entry and exit positions with the assumption that the markers travel in a straight line between the points. This method has several deficiencies with the most notable being losing the markers in the cave. Several other groups have approached the problem using computer modelling. These models are difficult to validate and therefore the results are based on empirical evidence. Both approaches suffer from the lack of real field data.

The ongoing research is between Penguin Automated Systems and Rio Tinto with funding partners including the Ontario Centres of Excellence (OCE), Centre of Excellence in Mining Innovation (CEMI) and Laurentian University.

The concept behind the work is based on creating synthetic rocks (Smart RocksTM) with embedded computational, networking and positioning systems that can be injected into the cave. Positioning of each synthetic rock in real time is the result of using large scale VLF transmission systems embedded in the mine acting like satellites. Each rock keeps track of time-of-flight from each satellite at a known position. The position and time-of-flight information is then used to triangulate the synthetic rock position. As the cave moves all of the synthetic rocks move and are plotted using an animated display that accurately emulates the movement of the cave front determined by the synthetic rock movements.

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Many mine start ups since April »

Posted on May 22nd, 2008 by John Chadwick

The latest issue of International Mining Project News is now available (May 23). In addition to almost 35 feasibility and prefeasibility studies, it reports on some 40 projects in development and notes a higher than normal number of new mines going into production over the past two weeks. Big news is Couer d’Alene Mines noting that San Bartolome, “the world’s largest pure silver mine” is now in the final stages of startup. Peñasquito is another big one and Goldcorp has poured its first gold at that project in Zacatecas, Mexico. Nearly 2 Mt of ore has been stacked on the heap leach pads, “with percolation rates, heap chemistry and gold recovery rates meeting or exceeding expectations,” the company reports. Peñasquito will be an Operations Focus feature in the September issue of International Mining. Another one starting up is River Diamonds’ 100% owned Vatukoula gold mine in Fiji. At European Minerals Corp’s Varvarinskoye gold/copper project in Kazakhstan further positive progress has been made in bringing the plant to commercial production. In the same country, Hambledon Mining reports its first export of gold from Sekisovskoye and the positive results of the study into the underground resource. The commissioning program of Avoca Resources’ new 1 Mt/y CIL treatment plant at Higginsville in Western Australia has commenced. Read more…

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