The agreement is still awaiting approval from the DRC government.

"The weak mining market has helped Chinese companies buy overseas assets and increase their international footprint," Wei said. "There is great potential for the country's miners and steel producers to expand further."

Big three iron ore giants

Name: Vale SA

Founded: 1942

Entered China: 1973

Headquarters: Rio de Janeiro, Brazil

Number of employees worldwide: About 200,000

Global revenue in 2014: $38.24 billion

Name: Rio Tinto Plc

Founded: 1873

Entered China: 1973

Headquarters: London, UK

Number of employees worldwide: About 60,000

Global revenue in 2014: $47.66 billion

Name: BHP Billiton Limited

Founded: 1885

Entered China: 1973

Headquarters: Melbourne, Australia

Number of employees worldwide: About 47,000

Global revenue in 2014: $67.21 billion