Incitec blasts its way into future

Blasting an orebody is the latest front in mining’s ­pursuit of a high technology ­future

Incitec Pivot managing director Jeanne Johns.

The classic stick of dynamite has been one of the most recognisable images in popular culture since Wile E. Coyote first blew himself up chasing a roadrunner.

But blasting apart an orebody is the latest front in mining’s ­pursuit of a high technology ­future, according to Incitec Pivot and BHP.

Incitec owns the brand that spawned that image, Dyno Nobel, instantly recognisable to any child giggling in front of the television. And BHP runs some of the biggest mines in the world.

But when the two companies signed a new five-year deal for the supply of explosives to BHP’s Australian operations last week, it was technology, not just price, that lay at the heart of the deal.

The technology underlying blasting in bulk mining was relatively static for generations. You drilled long rows of holes into the orebody, pumped them full of an ­ammonium nitrate and fuel oil mixture, dropped in a couple of blasting caps and blew the lot to hell, before sending in the diggers and dump trucks to collect the rubble.

Now the sector is at the forefront of next-generation technology, as Rio Tinto and BHP auto­mate drilling rigs and Incitec moves towards automating ­mobile processing units (MPUs, the trucks that fill the holes with explosives).

Incitec Pivot managing director Jeanne Johns said Incitec had lost contracts for the supply of ammonium nitrate prill — a pellet form of the explosive used for the bulk of blasting — to rivals over the past few years and had set its sights on maintaining its position in the industry through delivering hi-tech solutions.

“Our play here was a pure technology play,” Ms Johns said. “We lost the prill contracts but that left the services, the emulsion, the detonation — all the high-end technology bits to play for. And the fact we secured that tender we think is a huge endorsement that ours is the technology they want in Australia — the most sophisticated mining environment in the world.”

Ms Johns said the real advances may come in techniques to tailor the design of the blast to account for specific characteristics of the rock it will fragment, using more advanced detonators, capable of triggering sequential explosions to the milli­second, as well as by varying the intensity of the blasts at different points.

The new techniques promise to make blasting cheaper and easier in a range of mines, from coal to gold, but it is in iron ore that it may yield big returns.

For years the holy grail at the intersection of explosives technology and iron ore mining has been designing a blast to guarantee a higher proportion of lump — or coarse grained ore — can be dug out of the ground.

Lump ore has always fetched a premium over so-called fines, which has a texture closer to dust. While the premium varies according to the market, it was worth about $US9 a tonne on the benchmark price of 62 per cent iron ore late last month.

Some iron ore mines yield better proportions of lump than ­others, and for decades miners have tried to lift that rate — mostly without noticeable success.

Former BHP iron ore boss Jimmy Wilson once ruefully estimated he’d authorised tens of millions or dollars in research into ways to increase lump yield through blasting but had eventually given up because even if you appeared to get a result once, you could never seem to be able to replicate it consistently.

But that may be about to change, courtesy of Incitec’s deal with BHP. The new five-year deal includes a promise from Incitec to spend $25 million over the life of the contract to optimise its technology at BHP’s mines.

The deal includes measures to research ways to reduce the emission of nitrous oxide and dioxide fumes resulting from blasting, ­according to BHP procurement boss Sundeep Singh, ways to source ethically produced palm oil — used as a emulsifier in ­ammonium nitrate, to turn it into a vaseline-like jelly, or even ­replace palm oil with canola, which could deliver side benefits to Australian farmers.

But the centrepiece is the rollout of Dyno’s differential energy technology, which the company says allows it to mix explosives on the spot at different densities, in a single MPU, to vary the intensity of the blast. Using a single truck speeds up the process of loading the blast, and time is money.

Varying the intensity of the blast at different points means hard rocks can be turned into fragments the same size as those in softer rock above and below, making it easier to haul away waste, and process ore.

Incitec chief technology officer Rob Rounsley said the technology, already in use in the US, could be the solution to the lump versus fines conundrum.

“It allows you to design blasts in a way that could never have been done before,” he said. “Why does that matter? Well, for example, we can start manipulating things like lump and fines. And for some big producers every 1 per cent of fines produced costs them $52m. So if you can manipulate that by a couple of per cent, there is an enormous benefit.”

Mr Singh said differential blasting could be a critical cost-saver for BHP’s Queensland coal operations, where the company hauls away 10 to 20 tonnes of waste rock for every tonne of high-grade metallurgical coal.

“The number one productivity opportunity for coal is pre-strip — removing all of that waste and getting to coal recovery as fast as possible. This is the start of that process, then you move to technologies like differential energies — you get better fragmentation because the energy is matched to the strata of the rock,” he said.

“And when you get better fragmentation, your dragline performance increases, your truck and shovel performance increases, because you’re moving dirt faster.”

Mr Singh said BHP had trialled Incitec’s differential energy blasting technology in its Pilbara iron ore mines, with some positive signs showing through.

“In the iron ore space we’re seeing those productivity benefits of it in terms of moving dirt faster, but that holy grail is more lump ore production.”

The reporter travelled to Incitec’s Morenbah ammonium nitrate facility as a guest of the company.