Rio Tinto's Guinean unit has reached an agreement with its joint venture partners including China's Baowu on the development of infrastructure for the Simandou iron ore mine in southeast Guinea.

A Rio Tinto spokesperson said they have inked a new non-binding term sheet with Baowu Resources as the next step towards achieving the shareholder agreement, cost estimates, and regulatory approvals required to advance the program. However, the companies didn’t disclose any details on the terms of the agreement.

Simandou is the largest undeveloped project of iron ore in the world, and iron ore is a key raw material for stainless steel.