The rehabilitation of abandoned asbestos mines is set to continue with the three-year renewal of minerals and metallurgical specialist Mintek’s rehabilitation contract with the Department of Mineral Resources (DMR).

This contract includes the rehabilitation of a granite and a clay quarry and two asbestos mines, Mintek mineral economics and strategies unit senior researcher Herman Cornelissen tells Mining Weekly.

Late last year, Mintek completed the rehabilitation of five asbestos mines, in the Northern Cape, under the DMR’s derelict and ownerless mines programme.

“Former asbestos operations were among the first to be targeted for rehabili- tation by the programme, owing to the direct impact of asbestos pollution on health. “While most of the larger sites have already been rehabilitated, asbestos rehabilitation remains a high priority for the DMR,” he says.

The mines that are prioritised are those that pose a significant threat to the environment and to the safety or health of the people living in the area, says Cornelissen

The first aim of a rehabilitation project is to, in as short a time and as cost-effec- tively as possible, decrease the environ- mental risks and hazards. However, a secondary aim of the project is, where possible, to source contractors and workers locally.

But Mintek points out that rehabilitation will remain a challenge, given the department’s budget constraints.

“The average cost of rehabilitating one medium-sized asbestos mine is between R5-million and R7-million. This also depends on any specific requirements of the mine, as well as its location,” says Cornelissen.

Further, it is believed that, owing to the volume of material that must be moved to rehabilitate a site, it is cheaper for mining operations to under- take the rehabilitation during the mining phase, as the infra- structure needed is already in place. However, as many of these mines are derelict and abandoned, the establishment of a temporary operating facility on site is required.

“This would involve the transport and housing of employees, ensuring that there is clean water, sanitation, ablution faci- lities and equipment to work with,” he says.

Implementing Plans
The DMR has established a ten-year medium-term plan to rehabilitate all the derelict and ownerless mines. However, it is expected that it will take up to 2038 to rehabilitate the derelict and ownerless mines at a cost of R1,4-billion.

A progress report by the DMR, in October 2010, stated that the measures taken to deal with derelict and ownerless mines’ environmental impacts include the development of a database of derelict and ownerless mines, prioritisation and ranking of the different cases according to urgency, the assessment of financial requirements and, in some cases, the start of rehabilitation.

The ten-year plan comprises three phases. During phase one, from 2010 to 2013, the DMR will examine methodological development, such as the devel- opment of a generic rehabili- tation manual. Large-scale sites will also be prioritised as well as sites with greater risks and impacts on society and the environment.

From 2013 to 2016, phase two will comprise the priorti- sation of large-scale sites with medium risks and impacts, as well as the examination of monitoring and evaluation of treatment designs.

Phase three will involve full-scale rehabilitation of all sites from 2016 until completion, which is expected in 2038.

The report points out that, in 15 to 20 years, owing to the possible emergence of new environmental impacts of some of the seemingly stabilised rehabilitated sites, monitoring and evaluation will be an ongoing activity and latent impacts would be evaluated.

During the past number of years, the DME has focused its rehabilitation efforts on abandoned asbestos mines primarily because of the health risks.

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