The research, which factors in publically-available information on deals greater than US$1 million, showed some $2.3 billion was invested last year across the sector in 60 deals. This was up from $1.75 billion across 30 transactions in 2016.

While 2017 was heralded as an "encouraging year" by BLP, the level of investment was still down on its 2015 peak of $3.2 billion from 119 deals. That year, PE funds upped their stakes in mining companies experiencing distressed situations.

Copper was the commodity of choice in 2017 accounting for 70% of investment by value, with gold, which had been the most popular commodity in the previous three years, second choice. Battery minerals was in third position.

Africa was the most popular destination, with 45% of the funds invested going into entities tied to the young continent. Australia was second with $423 million going into the country, while North America, with $350 million, was third.

Just over half of all transactions by value - 55% - were acquisitions, while strategic stakes accounted for 40%. The remaining 5% was tied to increasing stakes in projects or companies.

"In the last four years, whilst acquisitions have remained relatively static, there has been a marked switch from increasing stakes, commonly to protect investments in distress situations, to acquiring strategic stakes," Alexander Keepin, the author of the report and mining head at BLP, said.

"This refects the recovery in the sector generally and also the second wave of fundraising by the mining private equity funds themselves, leading them to seek more new investments."

Keepin saw PE investments rising further in 2018.

"Given the strength of prices and recent fundraisings by mining private equity firms, strategic stakes are expected to continue to be the most popular form of investment," he said.