Occupational safety and health

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Because of the nature of mining which puts considerable stress on rock masses, some of which already lie on fault lines, many injuries and the majority of the fatalities are attributed to falls of ground. These are either seismic-related or gravity-based: seismic-related falls of ground occur when energy is released into the environment resulting in ground movement and possible rock falls; whereas gravity-based falls of ground are  nduced by an external stressor, for example, exertion of a pinchbar on rock.

Typically speaking, seismic events create large falls of ground and, therefore far greater damage, while gravity-based falls of ground are usually less severe, often involving rock fragments smaller than 30 centimetres in diameter. All of AngloGold Ashanti’s South African mines house sensitive monitoring equipment which detect all types of rock movement and rock fracturing, whether on a small or large scale. (See box on Integrated Seismic Systems International (ISSI).

Of the 17 fatalities recorded at AngloGold Ashanti for 2005, 15 (88%) were fall of ground-related. Statistics show that AngloGold Ashanti attained a 0.17 fatal injury frequency rate (FIFR), for 2005 (41% improvement on 2004’s FIFR of 0.29) which, while comparing favourably with other deep level South African gold mining companies’ statistics for the same period, is well above the group’s target of zero fatalities.”

In complying with mine health and safety legislation to effect specific outcomes, AngloGold Ashanti is proactive in a number of safety and health strategies.

In 2002, the company initiated a holistic five-point fall of ground management strategy to address the incidence of fall of ground-related accidents and fatalities. This is a five-pronged strategy focusing on mine design, mine support standards, mindset, monitoring and research.

When the strategy was implemented four years ago, it was decided to allocate a specific focus to each year. The focus in 2002 was on the prevention of adverse rock conditions by looking at mine design and mine layout. Numerical modelling systems are introduced at this stage looking at, for example, the size of the support pillar, stope dimension and extraction sequence. Since mining involves either fracturing rock structures or working with already fractured rock, this is the stage where proactive measures can be taken to minimise damage to the rock during mining. Back analysis of previous rock-related accidents is also useful in preventing accidents due to ‘bad ground behaviour’.

In 2003, focus was placed on the stage at which one controls the conditions that have been created in the mine design and layout phase. This stage of the programme addresses the design of support, including types, systems, standards and procedures. All types of mine support standards were reviewed and paper-based systems were replaced by electronic-based systems which could be incorporated into computer aided design (CAD) plans and made accessible by all mines.

2004’s focus was on the monitoring stage – evaluating how well the mine’s design (stage 1) and support strategy (stage 2) has been implemented. Stringent auditing systems were introduced during 2004, including the concept of ‘Rock Stars’ – whose job is to complete regular audits so that information is immediately fed into a database, prior to analysis and implementation of remediation strategies. Driven by AngloGold Ashanti's Integrated Risk Management System, this information is released monthly in the form of a safety, health and environmental statistical report which is accessible by all mines. Improvements have been apparent particularly in the reduced number of underground panels with sub-standard support. Lessons are also learnt from mine accidents and incidents, which are followed up by in-depth reviews to  determine remediation strategies.

The third stage, which is about changing and managing ‘mindset‘, was the key focus in 2005 and emphasises performance standards, education, training, knowledge, attitude and level of compliance. It often requires reversing bad habits and discarding the ‘it won’t happen to me’ maxim. World-renowned safety training organisation DuPont was tasked with implementing a peer-on-peer safety management and auditing technique (SMAT), which is being implemented top-down at all mines. Production managers have been given the responsibility of ensuring that the system cascades to every employee at every level of each operation. Instead of delivering a set of safety commands, SMAT training adopts an ‘observe and discuss’ approach. Training and education takes place both on surface and in the workplace, and workers are equipped with mini-fall of ground management manuals in various forms for quick and easy reference at any time. Although success is difficult to quantify, tangible improvements have been witnessed during several mine visits by management.

Research, development and technology, which make up the fifth stage, are ongoing elements of the whole strategy and are an essential precursor to mine design and layout, the starting point for actual operations. AngloGold Ashanti interacts with a number of industry bodies which deal with developing systems, methodologies and technologies – for example, the Council for Scientific and Industrial Research (CSIR), Safety in Mines Research Advisory Council (SIMRAC) and ISSI. Through its own Technology and Innovation Fund, AngloGold Ashanti is funding the secondment of a rock engineer to ISSI to take part in a three-year project called Integrated Damage Rheology Model (IDRM). IDRM is focusing on numerical modelling of mining and seismic data, and integrating the two in an attempt to distinguish between theoretical and actual outcomes. AngloGold Ashanti is also one of the drivers of the Rock Engineering Advisory Committee, a SIMRAC initiative focusing on rockfall and rockburst research.

Having reinforced the four operational fall of ground management pillars, AngloGold Ashanti’s focus for 2006 is revitalisation and integration of those components. It comes at a time when the whole industry is under scrutiny by the Department of Minerals and Energy, following the March 2005 seismic event at Stilfontein which closed down DRDGOLD’s North West operations. A panel of experts has been appointed to examine a range of issues from the efficacy of support systems to whether the event was natural or mining-induced. AngloGold Ashanti has been invited to give submissions to the panel of experts who are expected to release their findings in late 2006.

The fall of ground management strategy, currently only in place at AngloGold Ashanti deep-level South African mines, is to be extended to Obuasi mine in Ghana, the company’s only other deep-level mine on the continent.