The declining level of blasting skills and understaffing of planning departments involved in planning and coordinating blasts at opencast mines are costing the mining industry millions of rands each year in lost productivity, says mining explosives supplier Bulk Mining Explosives (BME) director Tony Rorke.

He adds that intensive investment in training and the use of new blasting technologies are needed if opencast mining operators are to take full advantage of the booming commodities market over the next few years.
Effective blasting, probably the most crucial aspect of opencast mining, is largely being neglected as operators, accustomed to the results they are getting, do not examine the opportunities available to them to increase their outputs.
“Effective blasting is crucial to successful opencast mining. An error in a blast means that digging rates are slowed down, and wall damage often occurs, which reduces profits. As mines expand their operations to meet the demand for commodities, so these errors multiply and costs increase as more suboptimal blasts take place,” says Rorke.

Exacerbating the problem is the use of standard timing layouts for different blasts that are constantly repeated by blasters who do not have the skills to design individual blasts to match particular circumstances.

The one-size-fits-all approach to blasting and expecting the explosives to provide satisfactory results when preparation and drilling on site have been poor are unrealistic and expensive, reiterates Rorke, adding that the advantages of alternative technologies, such as electronic detonators, are often not considered.

“Proper blast planning and the use of electronic detonators that can be programmed to fire sequentially at one millisecond intervals provide blast timing design flexibility and, hence, better results,” he says.

The key to resolving the problem lies in training, he argues.

“At BME, this is regarded as one of the company’s most valuable ‘add ons’ for customers. The company is bridging the knowledge gap through its dedicated training facility in Witbank, where both BME staff and customers are given the opportunity to develop their knowledge and skills by using the latest technology available. “This programme is being backed by a BME-driven initiative in Namibia to have appropriate blasting skills taught through a major technology institute there,” says Rorke.
Further, BME is also the sponsor of an annual conference on blasting. Held in Pre-toria in 2010, this conference attracted a record 300 delegates from the mining industry.

“The sector is serious about the acquisition of skills and is showing its concern by supporting all our programmes,” says Rorke.
The company, which is well known for its blast planning BlastMap software technology, also helps customers with blast planning, drilling plans and explosives placement.
“We are often requested to use in-house capacity at BME to undertake blast and timing designs for customers. “This is always done by highly skilled mining engineers. This data is then passed on to the customer who implements the recommendations on site. “Combined with electronic technology, this data gives good-quality blast results,” says Rorke.

“The belief that explosives will compensate for poor planning and drilling at a blast site is more common than most people would think,” says Rorke, who is often requested to use technology and explosives to solve what miners already know to be poorly prepared blast sites.

The company is regularly asked to help customers with timing designs that will “ensure good fragmentation and low vibration”, when drilling has already been completed and a number of drilled holes have been lost owing to collapses prior to blasting.

“If South African opencast mines are to keep their competitive edge and ensure that they have the production levels needed to take advantage of the present commodities boom, they must reassess their training for blasting crews and examine all the technologies available to increase productivity in the future,” concludes Rorke.