Stats produced by CRU Group's Allan Trench at a nickel conference in Perth late last year backed this up: 54% from laterite ore via hydrometallurgical and pyrometallurgical processes, versus 46% sulphide ore via pyrometallurgical processes.

Pointing to a culprit, Brock said sulphide discoveries were getting scarcer, with Sirius Resources' Nova-Bollinger find in Western Australia's Fraser Range the first in the state for over 10 years, and "we're not seeing too many discoveries in North America or elsewhere".

"The world needs laterites, it doesn't really have a process that's readily commercially acceptable, and we've arrived at about the right time in history," Brock added.

But Matsa Resources - one of several Aussie juniors hunting the Fraser Range for more sulphides - begs to differ on the scarcity of nickel sulphides.

Matsa managing director Paul Poli summed up his reasoning for pursuing sulphides.

"We would not be spending millions of dollars if we didn't really believe that we've got very strong prospects of having a nickel sulphide deposit within our tenement.

"I am convinced the Fraser Range cannot contain only one nickel deposit, and we hope to prove it in the near future. It can't just be one mine. It's too big, too impressive, too much of a strong geological feature to be a once-off."

He noted with particular interest the encouraging results from Sheffield Resources, just to the south of Matsa's tenements. Sheffield is starting to get similar geology at surface to the Nova-Bollinger mineralised zone.

Sheffield's recent results show that the geology seems conducive to nickel sulphide deposits.

"We are really sandwiched by Sheffield and Nova, and we think the assay results due in the next week from our recently completed air core drilling program will give us similar results, if not better, to Sheffield," Poli told MiningNews.net.

"This supports my model that the locality hosts geology and fertile rocks which can host substantial new nickel sulphide deposits."

The progress of Matsa and Sheffield has changed the game for these prospective sulphide hunters.

"We are not interested in playing the nearology game. We're beyond that. We've got gravity and magnetic anomalies and soil chemistry, which suggest to us that we've got potential," Poli said.

"We need to define the bedrock categories of our geology, but preliminary observations tell us that it's very conducive to nickel sulphides."

Then there is the cost issue. Brock said Direct Nickel's opposition in laterite processing - high-pressure acid leaching (HPAL) and ferronickel plants - were looking at capital costs of about $US35/annual pound of production, and upwards.

Brock said projects such as Goro, Vale's nickel project on the South Pacific island of New Caledonia, started off with a capital estimate of $1.5 billion that was now looking at closer to $5.5 billion.

Further, MiningJournal.com reported in April that contractor underperformance and hyper-inflation of costs, including labour and materials, pushed the total capital cost of Xstrata's Koniambo ferronickel project, also in New Caledonia, to $5 billion from the $3.85 billion estimated when the project was approved and a 2004 estimate of $2.2 billion.

Therefore, Brock, said, "these high costs are real". He contrasted these examples with figures from a study Direct Nickel did with Aker Solutions out of Toronto which showed its capital costs will be in the range of $12.50/annual pound.

"We can claim that because our materials of construction are primarily stainless steel; and our process is low temperature, lower pressure and therefore overall simpler, which translates into lower costs," he said.

Operating costs are also lower.

"Sulphides and other laterite deposits are probably running into $5-8/lb, and you'd all know there are an awful lot of companies that are on the borderline at the moment with their nickel production costs," Brock added.

"Using this Aker study, we believe our costs will be around the $2-2.20/lb, which are straight operating costs, excluding any by-product credits from cobalt etc."

Trench noted that the price of energy is the key cost driver for ferronickel and nickel pig iron operations, which are very susceptible to movements in the LME nickel price.

While Trench believes nickel laterites "are actually the future of the nickel industry in volume terms as opposed to sulphides", he cautioned that laterites are classic "concave" resource assets in value terms - meaning that until they are developed, laterites have limited market value in the ground.

Underground sulphide mines, meanwhile, need constant focus as to their near-mine exploration potential in order to replenish ore reserves.

"As such they are completely different investment propositions to other portfolio assets such as iron ore, coal and copper porphyries held by diversified miners," Trench added.