Underground mining and tunnelling services and solutions provider Normet will introduce a new energy-absorbing rock bolt onto the South African market this year to provide additional support in high-stress rock masses prevalent in underground mining.

This follows Normet’s acquisition earlier this year of Norway-based rock bolt manufacturer Dynamic Rock Systems (DRS) – a spin-off company initially owned partly by the Norwegian University of Science and Technology (NTNU) – which has developed and patented the D-Bolt rock bolt system, designed for efficient and reliable rock reinforcement in burst-prone strata with high stresses and deformations.

“The D-Bolt replaces what is typically used as a plain reinforcement bar (rebar) in construction and mining,” says Normet rock reinforcement director Trond Skogseth, who adds that traditional rebars cannot handle the dynamic conditions of underground mines.

“Existing rock bolt systems are either too stiff for dynamic rock masses or they allow too much deformation with low loads, whereas the D-Bolt can not only bear a static, high-deadweight load but also absorb energy when there is displacement in the rock,” he says.

The D-Bolt technology is based on a smooth steel bar with several anchors along its length. It is anchored in a borehole, with either cement grout or resin, and is only fixed with the grout in the anchors’ positions, while the smooth sections between the anchors can freely deform when subjected to rock dilation.

Skogseth emphasises the importance of safety in any mining operation and, while recognising that no system can provide 100% assurance that it will prevent unfortunate incidents, he believes the D-Bolt system is effective in terms of reducing the risks and the consequences of unforeseen incidents.

He adds that, in addition to saving lives, preventing rockfalls will eliminate the consequential cost of downtime.

This patented technology was devel- oped at NTNU by rock mechanic Professor Charlie C Li, who identified problems attributed to failing ground-support systems when he was working in Sweden’s mining industry.

On investigating the root of the problem – rock bolt failure – Li developed the D-Bolt, bringing it to market under DRS, which is now part of Normet’s rock reinforcement business division.

Skogseth tells Mining Weekly that, globally, market acceptance of the D-Bolt has been good since 2009, when DRS started delivering the system to mines on a test-phase basis.

“Before long, there were major commercial breakthroughs, as mining companies saw the benefits of the technology and started placing paid orders,” he says, adding that the division currently has major customers in Australia, Sweden, Canada, the US and Chile, with South Africa soon to follow suit.

Normet Africa GM Gary Clench tells Mining Weekly that the first shipment is likely to arrive in September. Meanwhile, the team of Normet Africa is meeting with consultants and various mining houses to determine the lengths of the D-Bolt likely to be required.

Clench adds that one of the challenges currently facing Normet Africa is to prove that the benefits of the D-Bolt outweigh the costs, as the bolt is more expensive than a standard rebar.

Skogseth, however, has confidence in the product and believes that Normet will achieve buy-in from the South African market.

“If South Africa becomes a major market for us, which we think it will, we will also consider establishing in-country manufacturing capability. From a marketing point of view, it is cost effective and beneficial to have the D-Bolt manufactured locally,” he says.

Meanwhile, Clench hopes to reach the R50-million mark in turnover this year, which he acknowledges is optimistic, considering that the company only recently completed its first year in the South African market.

While Normet products are already known to local companies through distributors, Clench admits that it has been a challenge to reintroduce the product as part of its own operation.

“We’re currently focused on getting the right people in, conducting the right training and regaining market acceptance from operators,” he says.

The company has, however, already made significant inroads as a construction chemicals manufacturer, following its 60% acquisition of construction chemi- cals manufacturer TAM International last year.

It has also supplied concrete-spraying equipment to mining companies throughout Southern Africa, including Palabora, Impala Platinum, Petra Diamonds and De Beers.

“We pride ourselves on our concrete-spraying equipment and services, which seem to be our strong point in South Africa,” says Clench.

He adds, however, that business is growing in the rest of Africa, including in the Democratic Republic of Congo, Zambia, Ghana and Mali.

Normet Africa also supplies the full range of branded spare products from its warehouse in Johannesburg.