Iron ore miner and steelmaker Arrium has crashed to a full-year $1.9 billion loss, another victim of the collapsing iron ore market.

The result is a $2.2 billion downturn on last year's profit of almost $300 million.

The loss was driven by $1.8 billion worth of previously announced asset write-downs and restructuring costs primarily related to Arrium's South Australian mining business.

That restructuring has already seen hundreds of jobs go from Arrium's mines.

The underlying result - removing the impact of one-off items - was a $6.7 million loss, which was ahead of analysts' grimmer forecast of a $30-40 million loss.

The mining business saw the average price of its only commodity - iron ore - fall 41 per cent, from $US123 per tonne in 2014 to $US72 last year.

The iron ore division's earnings (before interest, tax, depreciation and amortisation) were hit even harder, declining from $600 million to just $90 million last year.

The company is undertaking a major restructuring of its operations - including the already announced closure of higher cost Southern Iron assets - with the aim of reducing its breakeven price to $U47 per tonne.

Iron ore is currently trading at about $US56 per tonne, but dived as low as $US44 per tonne last month.

The problems in the mining business more than overshadowed an improvement in Arrium's steelmaking arm.

In the past six months Arrium Steel became profitable for the first time since the GFC, although it still recorded a $33.2 million loss for the full year.

Domestic steel demand improved on the back of increased residential construction, particularly in high rise apartments and large commercial projects in New South Wales, pushing up sales volumes by 4 per cent.

Reporting season calendar

Arrium chief executive Andrew Roberts said he expected further improvement in the steel business as it benefited from a strong pipeline in major infrastructure projects, as well as a lower Australian dollar, lower raw material costs and increased efficiencies.

However Mr Roberts warned that this might be offset to a degree by on-going pressures from tumbling prices and margins in Asian steelmaking.

Mr Roberts said the company would continue to work on the strategic review it announced in June with the aim of improving the group's structure and cutting its debt.

"We commenced the strategic review of our business to assess options for providing an appropriate structure and level of debt in the low iron ore price environment," he added.

Mr Roberts said there had already been considerable interest in the market for the mining consumables business which produces material for grinding mined ore.

Arrium will not pay a dividend this year, having paid out 9 cents a share last year.

At 11:00am (AEST) Arrium's shares had bounced 4 per cent to 13 cents a share.

Mt Gibson Iron also swings to large loss

Fellow junior iron ore miner Mount Gibson also plunged deep into the red, posting a full-year $911 million loss.

The result was driven by significant asset write-downs totalling $945 million.

The result excluding those write-downs was a $17 million gross loss compared to last year's $173 million profit.

Mount Gibson chief executive Jim Beyer described the year as very challenging and disappointing.

"The large fall in iron ore prices and impacts of the seawall failure at Koolan Island resulting in very significant financial losses for the company and all shareholders," Mr Beyer said.

"However, our decisive and ongoing cost reduction and optimisation initiatives have been critical in helping to stabilise the business in the latter part of the year, and in turn preserve substantial financial capability and flexibility to adapt to the difficult conditions."

Despite managing to cut production costs by 19 per cent over the course of the year, Mount Gibson's average cost of goods sold is still around $62 per wet metric tonne, still well above the current market price of iron ore,.

Mount Gibson also abandoned its dividend, having paid out 4 cents a share last year.

At 11:30am Mount Gibson shares remained flat at 18.5 cents.