JOHANNESBURG (miningweekly.com) ­– A search and rescue operation is under way at Impala Rustenburg after a mud rush at 6 Shaft on Monday, when all operations at Impala Rustenburg's 6 Shaft and 16 Shaft complexes were suspended until a full and comprehensive report was available.

The underground mud rush incident, which occurred on Sunday, November 28, followed a separate incident at the 16 Shaft mining complex on Saturday, when a contract employee was fatally injured during underground drilling operations.

When the mud rush occurred, seven employees were working at the bottom of 6 Shaft. Two managed to escape with minor injuries but at the time of going to press, five remained missing, and two search and rescue teams have been working underground to locate the missing employees.

“The impact of these events will probably permeate the entire lease area and potentially to other shafts. We will have to assess and prevent similar risks from occurring at any of the operations,” Implats CEO Nico Muller told a media conference attended by Mining Weekly.

The Department of Mineral Resources and Energy (DMRE) and the relevant union leadership have been informed of this incident.

Contact has been made with the families of the missing employees to provide updates on the search and rescue mission, as well as counselling and support.

Muller said it was difficult to predict the duration of the closure of the shafts, particularly at the mud-deluged 6 Shaft.

“In the interest of safety, it’s important to stop the operations and to assess all the risks,” said Muller during a media conference.

“The concern for us at 6 Shaft is we had a mud rush at the bottom of the 265 m shaft. It is typically a dry shaft so the source of the ingress has to be determined because we may be at risk at other shafts.

“It is critically important to understand the source of the risk and to make sure that the risk is mitigated across all operations not only at Implala Rustenburg, but all our operations within the group.

For how long 6 Shaft might be out of commission would depend on the assessment of Implats and the DMRE.

“We will be collaborating and providing updates as we progress,” said Muller.

As it is one of the smaller shafts, 6 Shaft contributes less than 7% to overall production, with 16 Shaft a much bigger shaft.

But in trying to assess the overall impact, it would be naïve to base that on the impact of 6 Shaft alone, said Muller.

The focus over the next few weeks would be to ensure that no employee was put at risk.

“I do expect that this is going to have a material bearing on particularly the lease areas’ production for this quarter. As things stand, we’re still engaged in a search and rescue operation and that is our only focus at this time,” Implats said.

“The safety of our employees is our utmost priority, and our mine proto teams are doing everything possible to locate the missing employees. It is with deep regret that we record this incident, which comes at a time when we have made significant improvements in the group's safety performance, with several historic safety records achieved in the past year. Our thoughts and prayers remain with all involved,” Muller emphasised in a media release to Mining Weekly.