ASSMANG, which is jointly owned by African Rainbow Minerals and Assore, is adopting all the measures it can think of to ensure its Khumani mine takes advantage of each opportunity to rail more iron ore to the coast.

Assmang, which operates two iron ore mines in the Northern Cape as well as manganese mines, is adding expansion project after expansion project at its iron ore mines to make sure it benefits from the strong iron ore market.

The flagship Khumani iron ore mine has grown from 8,4-million tons a year to 10-million tons and has now added capacity for 16-million tons, but it is only operating at about 14-million tons because of constraints on the railway line. The R7bn expansion due to be completed next month came in R1bn below budget and ahead of deadline.

Assmang has installed the very latest technology to ensure that the 342 railway wagons it loads with ore are weighed, loaded precisely and then weighed again to ensure Transnet has no excuse to delay shipments to Saldanha.

It is also building a 3-million-ton stock yard with more stackers and reclaimers than it needs to give it spare capacity in the event that one of the machines breaks.

"Any capacity you lose here in the loading side you can't get back, and that hurts because of the prices and export volumes you lose," says Khumani GM Pierre Becker, who has been with the mine from the start.

"It must be right the first time," he says.

The mine was commissioned in May 2008 and has already produced 34-million tons of ore.

It has put in two railway loops capable of accommodating the 4km-long trains, each line equipped with a 25m-tall hi-tech loading facility that can load a painstakingly measured 100 tons of ore in less than a minute.

Assmang has bought two diesel locomotives and it has put in extra sidings to park what is known as a "swing set", which is one set of 114 wagons that it loads and has ready for departure. This means that instead of waiting to load three sets of 114 wagons, it has to just load two.

In six hours all 342 wagons are ready to be hauled the 861km to the coast. "We want to take any and every opportunity that comes our way," Mr Becker says. "We also don't want Transnet to claim they're waiting for the mines. They're certainly not going to wait for Khumani."

The operational relationship between Khumani and Transnet has improved over the past two years, with a keener understanding of the challenges each faces and a combined effort to resolve them, he says.

This efficiency is important, he says, because Khumani has an extra 2-million tons of capacity that it wants to exploit.

Among the projects to beneficiate the ore coming from the Bruce and King mines that make up Khumani is the R1,3bn wet high intensity magnetic separation (WHIMS) plant that will treat tailings to extract about 500 000 tons of fine iron a year, which will be blended with fines product - one of three product lines coming from Khumani.

One of the potential future projects is to pelletise the iron coming from the WHIMS plant, but, at half-a-million tons a year, the volumes are too low to justify the expense and the volumes would need to at least double, Mr Becker says.

Next month, Assmang will start a feasibility study into adding a jig plant to treat the ore going through the plant treating its high-grade material. The Khumani operation uses water-based jig plants to upgrade lower qualities of ore. By adding the extra jig plant, the operation can deal with lower-yielding ore and extend the life of the mine, Mr Becker says.

The study will take about a year to complete, and could take the mine to 18-million tons of export capacity.

"This could position us for the expansion of the rail capacity to 83-million tons a year or more," he says.

The work is being done carefully and with close consultation with Transnet to ensure the mine does not have redundant capacity as it does now, he says.

Khumani is using extensive drilling, including material extracted from holes drilled to blast the ore, and the latest computer programmes to plan its mining and reconcile expected grades and actual yields as well as to track the history of mined ore, Mr Becker says.

This also allows the mine to feed its plant an optimal blend of ore for treatment.