Occupational safety and health

Mponeng mine, which employs some 5,700 people including contractors, is situated in the West Wits area of AngloGold Ashanti's South Africa region. (Mponeng means 'look at me' in Tswana.) The mine has had a great deal to be proud of in recent years, with lost time injury frequently rate (LTIFR) declining steadily from 22.7 in 1999 to 9.5 for 2004. Mponeng won the South Africa region safety shield in 2001 and 2003, and was the runner up in 2002. The mine has achieved 500,000 fatality free shifts on four occasions in the last two years, and achieved 116 'White Flag Days' (days on which no injury is recorded) in 2004, compared with 75 days in 2003.

Early in 2004, tragedy struck when four fatal accidents took place within four weeks. One of these events, which took place on 29 January and resulted in the loss of two lives, was attributable to a seismic fall of ground; one (on 23 January) was attributable to a failure to comply with equipment standards, and one (on 10 February) was a rigging hoist accident.

"No one went underground for three days after the third accident," says general manager Johan Viljoen. "Everyone on the mine - employees, unions and associations - went through an intensive process of renewing our commitment to safety."

Mponeng has implemented the SHARP (Safety, Health, Achieve, Respect, Productive) system. This was developed at Mponeng, based on the DuPont principles of peer observation. "The SHARP system represents a step in the process of taking the peer observation principle down to mineworker level," explains Viljoen. Before any task can be carried out, people have to ask four critical questions:

• Is there a procedure? Am I complying?
• What PPE (personal protective equipment) should be worn?
• Are tools and equipment in good order?
• Are people in the right position?

Only when the four questions are answered affirmatively may work begin.

All mineworkers have been comprehensively briefed on the implementation of the system, and training has been provided in a series of workshops and face-to-face communication sessions. Anyone not complying with the system is coached and counselled appropriately, and, ultimately, would be subject to the normal disciplinary procedure.

Stringent safety targets are set. "Targets vary according to discipline," explains Viljoen. "For example, development and services are measured on dressing cases, with a target of zero incidents. At this stage, the target for stoping is zero lost time injuries."

Teams of 'rock stars' have also been established. The 'rock stars' are members of the rock engineering department who are integrated into work teams across the mine. Their role is critically important in that they are able to make first-hand workplace assessments. Where support standards are not adhered to, they play a coaching and mentoring role with the work teams concerned.

Despite all these efforts, seismicity remains a fact of life at Mponeng, as at all deep level South African mines. To illustrate this, three of the five fatalities that occurred at Mponeng during 2003 were attributable to seismic falls of ground. The mine has a number of strategies in place to counter seismicity, ranging from macro elements such as mine design and layout to support and preconditioning at the micro level. (See case study: Control of mining-induced seismicity in the South Africa region.)

"We are one of the few mines in the industry to make extensive use of pre-conditioning," says Viljoen. Preconditioning refers to the drilling of holes ahead of the face to be blasted and detonating these with a light charge. This reduces the induced stresses on the advancing face." The mine is also increasing the use of backfill from the current 60% to a planned 95% of the stoping area by the end of 2006. (Backfill refers to the use of waste material or rock integrated with timber props to support the hanging wall after removal of ore from a stope. Backfill gives more effective support than conventional spaced support methods, such as packs or elongates, because it provides complete coverage of the area supported.)