The placing involved 92.5 million new ordinary shares and commitments to subscribe for 35.8 million ordinary shares at a placing price of 9p each.
Major Savannah shareholder Al Marjan Limited also sent a letter of intent for a further £1 million, bringing proceeds up to £12.5 million.
Savannah said the aggregate placing and subscription shares represented 15.5% of the company's enlarged share capital.
Savannah CEO David Archer said the fundraising meant the company was welcoming a number of new significant UK institutional shareholders.
"The net funds raised will enable us to advance our project in Portugal through a feasibility study, with a view to making a final development decision early next year," he said.
Savannah hopes to start construction of the project in the June 2019 quarter, just months after it finishes a feasibility study.
Savannah's shares dropped 12.05% Thursday to 9.72p.