IGO has been undertaking a strategic review in an attempt to revaluate its resources.
The world's largest producer of iron ore shipped 80.3 million tons of the steel-making commodity in the quarter.
The solar farm could displace up to 11% of natural gas currently used for generation across Rio's integrated mining operations in the Pilbara.
Streaming deal will help SolGold finance feasibility studies, secure permits and later begin construction of the Cascabel copper-gold mine.
