New LNG hub for miners to be online by October.
E25 managing director Justin Brown says deal is a landmark moment.
Renascor is in negotiations for the balance of PSG produced at Siviour.
Gunvor will take about 2700 tonnes of high-purity vanadium pentoxide each year.
Fenix will also buy Sinosteel's iron ore infrastructure at Geraldton's port.
The agreement adds to the offtake deals TNG already has in place.