Gina Rinehart's Japanese iron ore partner, Marubeni, believes iron ore markets have bottomed out and prices for Australia's most lucrative export commodity will trend higher next year.

Speaking in Darwin on Tuesday, Marubeni's minerals and metals executive officer, Shinji Kawai said iron ore prices were poised to rise in 2015

"I think today's market is almost bottom," he said. "I think it is going up (next year). Toward the end of the year the price of iron ore is going up, no problem."

The benchmark price of iron ore for immediate delivery to the port of Qingdao in China surged 4.9 per cent to $US84.17 ($96.35) per tonne.

The share prices of Australia's key iron ore players leapt in response. Shares in Rio Tinto leapt 4 per cent to $60.72, while BHP Billiton stock was up 2.7 per cent to $33.47. Fortescue Metals Group shares rose 5.8 per cent to $3.66, after leaping 6 per cent on Monday.

The iron ore juniors enjoyed even more impressive gains. Mt Gibson Iron leapt 16.9 per cent to 52¢, while Atlas Iron rose 14.9 per cent 42.5¢ and BC Iron was up 13.1 per cent to $1.60.

Marubeni owns 15 per cent of the Roy Hill project which is 70 per cent owned by Ms Rinehart's Hancock Prospecting, and also involves Korea's Posco and Taiwan's China Steel Corporation as equity partners.

He said iron ore prices, which have slumped 40 per cent since the start of the year, were unlikely to top $US100 per tonne in 2015, but would definitely be higher than current prices.

Mr Kawai said he had no problem with BHP Billiton and Rio Tinto's plan to flood the market with iron ore, and his Marubeni colleague, Shinichi Kobayashi, said Roy Hill would not be affected by that strategy.

"Roy Hill is not a victim because Roy Hill is one of the most competitive iron ore mines in terms of cost competitiveness and quality," he said.

"We have 40 per cent of the lump iron ore which is very dear and the impurity is very low in general. So the quality and superiority of the Roy Hill is getting better and better."

Mr Kawai said Roy Hill could be exporting in August, 2015 rather than September, 2015 as planned.

"We are a bit ahead of schedule, the first ore will be shipped, the original schedule is September, 2015, but we expect to ship some a bit early," he said.

"At the end of September the construction had progressed to 60.9 per cent."

The jump in the iron ore price came after China's National Bureau of Statistics said on Monday that exports jumped 15.3 per cent in September from a year earlier. Imports rose 7 per cent, surprising many analysts who had predicted a fall.

"Ore inventory at mills has declined now to 24 days, providing the basis for a normal November-December restock," UBS commodities analysts Daniel Morgan said.

"How big might this be? In 2011 inventory at mills lifted from 27 [lifted] to 42 days; in 2012, 20 [lifted] to 38; and in 2013, 24 [lifted to] 37 days. But beyond this seasonal lift, robust low-cost supply growth and moderate demand growth equals a market share battle which will continue to weigh on prices in 2015."

The price of iron ore has plummeted in 2014 as large miners led by BHP Billiton, Rio Tinto and Vale have flooded the market with high quality product.

The supply glut has pushed the price low and also squeezed smaller producers who have higher cash costs and lower quality ore.

And iron ore prices are set to remain under pressure in the mid-term despite the overnight surge, Citibank commodities strategist Ivan Szpakowski said.

Citi is forecasting a moderate "pick-up" for the bulk commodity in the 2014 fourth quarter, with an average price of $US87 a tonne.

Mr Szpakowski said this would largely be driven by the machinery and infrastructure sectors in China, which make up 35 per cent of steel demand.

"We've always been bearish over the full-year for 2014 but thinking that the later part of the year would be stronger ... in terms of that price range, it is lower than we originally forecast," Mr Szpakowski said at the Citibank Investment Conference on Tuesday.

But for 2015 Citi is predicting a new rush of supply from large producers such as Vale, BHP and Rio which will drive the price back to $US80 a tonne.

When questioned about the "Chinese domestic production mystery" and whether or not local producers in China would exit the market due to the lower average price of iron ore, Mr Szpakowski said while research was inconsistent, he didn't think many had reacted yet but there would be an impact in China as it continues.

"We do expect that to occur, we do expect Chinese production to fall further in response to that," he said.