Precious metals including gold, platinum and palladium remain in residue throughout the leaching process and are recovered from the residue via flotation. A weighted precious metals recovery from the leach residue of 90.9%, 82.6%, and 88.1% for Maturi Bulk #1; 88.2%, 52.5%, and 78.8% for Maturi Bulk #2; and 75.0%, 75.0% and 75.0% for Maturi Ni-Cu was achieved for gold, platinum, and palladium respectively.
Compositions of the flotation products for each concentrate processed are presented in Table 2.
Table 2 - Precious Metals Flotation Concentrate Product S (t) S[o] Au Pt Pd Concentrate % % g/t g/t g/t Maturi Bulk #1 85.8 81.4 6.1 11.0 33.0 Maturi Bulk #2 93.8 91.4 4.1 5.3 19.8 Maturi Ni-Cu 97.0 94.6 2.5 6.8 21.4
Although not integrated within the pilot plant flowsheet, bench testwork was performed to further upgrade the material to elemental sulphur and a separate Precious Metals cake using sulphur melting. The grade of the Precious Metals cake for the Maturi nickel-copper concentrate would be approximately 225 g/t assuming the cake retained an elemental sulphur grade of 45%.
Further metallurgical testing will be conducted during pre-feasibility in order to optimize the selected process and flowsheet design.Tom Pugsley, Director of Duluth Metals is the Qualified Person for Duluth Metals in accordance with NI 43-101 of the Canadian Securities Administrators, and is responsible for the review of the technical content of this press release. About Duluth Metals Limited Duluth Metals Limited is committed to acquiring, exploring and developing copper, nickel and platinum group metal (PGM) deposits. Duluth Metals has a joint venture with Antofagasta plc on the Twin Metals Minnesota Project, located within the rapidly emerging Duluth Complex mining camp in north-eastern Minnesota. The Duluth Complex hosts one of the world's largest undeveloped repositories of copper, nickel and PGMs, including the world's third largest accumulation of nickel sulphides, and one of the world's largest accumulations of polymetallic copper and platinum group metals. Aside from the joint venture, Duluth Metals retains a 100% position on approximately 40,000 acres of mineral interests on exploration properties adjacent to and nearby the Twin Metals Minnesota LLC joint venture. About Twin Metals Minnesota LLC