II. CESL™ TESTINGThree concentrates from the Twin Metals project were successfully processed through Teck's hydrometallurgical research facility utilizing the CESL™ process for approximately a six week period in Q1 of 2013. The concentrates processed through the pilot plant consisted of three different concentrates from the Twin Metals resource. The first concentrate was a bulk concentrate (all metals floated in one concentrate) made from a mixed sample of material from the Maturi and Birch Lake deposits. The second concentrate was a bulk concentrate made from material derived from the western portion of the Maturi deposit. The third concentrate was a nickel concentrate derived as one of two products from the ALS flotation pilot plant during the period when a separate copper and nickel concentrate was being produced from ore from the western portion of the Maturi deposit. The concentrate characteristics were:
- Maturi Bulk #1 - produced from Maturi East and Birch Lake deposits (17.0 % Cu, 3.7 % Ni and 20.4 g/t TPM (Total Precious Metals or TPM = Platinum+Palladium+Gold));
- Maturi Bulk #2 - produced from Maturi West deposit (15.5 % Cu, 4.1% Ni and 9.0 g/t TPM);
- Maturi Ni-Cu - produced from Maturi West deposit after separation of a high grade Cu concentrate ( 6.9 % Cu, 8.0 % Ni and 10.6 g/t TPM).
Table 1: Maturi Metal Recoveries from Concentrate Concentrate Metal Recovery % Cu % Ni Maturi Bulk #1 93.7 96.1 Maturi Bulk #2 Maturi Ni-Cu 91.2 97.6Recovery of Precious Metals from CESL™ residue