The mining industry that faced a tough year in 2015 because of factors such as the China slowdown will continue to face the heat in the current year as well, according to Mine 2016, a report on the sector by accounting firm, PwC. The 13th annual review of the top trends in the global mining industry revealed that 2016 will affect miners because of an uncertain global economy and high levels of debt.

The report revealed that the top 40 miners in the world reported a collective loss of $27bn (£18.65bn, €23.78bn) in 2015 and that their combined market capitalisation had fallen by 37% to $494bn. The market cap of a few companies were said to be even below their net book value, the value at which a company carries an asset on its balance sheet, according to the report.

Chris Dodd, PwC Australia mining leader, said there could be more pain to come for miners in terms of impairments, meaning the permanent reduction in the value of a company's asset, normally a fixed asset. He said this was because the market capitalisation of 15 of the top 40 mining companies had fallen below their book values, up from 12 in 2014.

"A 25% year-on-year decline in commodity prices had the top 40 chasing even the most incremental productivity improvements, with many turning to asset sales in the fight for survival. Investors punished the group for what they perceived to be poor investment and capital management decisions, and in some cases a feeling that the benefits of the boom had been squandered," Dodd explained.

"Mining is a cyclical game and different industries ultimately attract the investors they deserve. Hopefully those investors who are getting on board now are taking a long-term view. However if the current short-term focus continues that will ultimately curtail the capital that's available for investment, and constrain options for growth", Dodd added.

The report was, however, not all negative. It said, "Whilst the industry continues to face significant economic headwinds, there is still a long term positive outlook." It even praised some miners for achieving some success in their cost cutting drive in the face of the downturn. It added that the top 40 miners seemed to have worked in a smarter and more productive way in an effort to increase volume growth from existing facilities at a lower cost.