Perpetua Resources will receive $8.5 million for all the silver expected to be mined as part of its Stibnite Gold Project, the Boise mining company announced last week.The silver was sold to the Franco-Nevada Corporation, a Toronto mining company, through an agreement that nets Perpetua $8.5 million in cash.The $8.5 million will be used to pay for the company’s general corporate expenses, Perpetua President and CEO Jon Cherry said.The sale leaves Perpetua with about $80 million in on-hand funding to pay for expenses related to permitting the company’s proposed gold and antimony mine near Yellow Pine, said Perpetua CFO Jessica Largent.“We will continue to evaluate various financing options that unlock shareholder value as we receive permits for our world-class project and transition towards construction,” Largent said.Silver makes up less than 1% of Perpetua’s estimated $6 billion in mineral reserves at Stibnite, which include 4.8 million ounces of gold and 115 million pounds of antimony.Plans call for gold, silver and antimony to be extracted from three open pit mines totaling about 473 acres at Stibnite.Perpetua is currently awaiting the release of a draft decision on the project by the Payette National Forest, the lead permitting agency for the federal review process.A draft decision is currently slated for release this spring, with a final decision expected by the end of the year, according to an April 1 project update issued by the Payette.Overall, Perpetua has spent more than $300 million on its Stibnite proposal since exploration began in 2011.The company has received $75 million in the last two years from the U.S.