- Published: 26 October 2016
- Written by Editor
Osisko Reports Increased Gold Recovery Results at Marban
Table 1. Results of the 100 bottle-roll leaching tests on the Marban deposit.
Table 2. Results of the 35 bottle-roll leaching tests on the Norlartic deposit.
Six samples from the Marban deposit gave recovery results below 80% which are likely due to the presence of coarse gold grains. These samples are found in four of the five populations. Nevertheless, as previously established (see NioGold July 6, 2015 press release), the grade/recovery curve is near horizontal, signifying that the recovery does not decrease with lower grades. The Norlartic deposit samples show a much more homogeneous recovery and, similarly to Marban, show a flat grade/recovery curve. These gold cyanide leach test results are comparable to those obtained at the Canadian Malartic mine, located about 15 kilometers from the Marban project, for similar operating conditions utilized until 2015.
A total of 16 samples (10 from the Marban deposit and 6 from the Norlartic deposit) composed of PQ caliber core (diameter of 85 mm) were submitted for JK drop-weight tests, Bond low-energy impact tests, and Bond rod mill/Bond ball mill grindability tests.
- The results at different grind sizes are categorized as medium to very hard for the coarse sized fraction (CWI), moderately soft to moderately hard for the medium sized fraction (RWI) and soft to medium for the fine sized fraction (BWI). The Bond Ball mill grindability tests (work index) gave an average of 11.6 kWh/t for the Marban deposit and of 12.6 kWh/t for the Norlartic deposit.
The results of the grindability tests demonstrate that the rock quality would not be problematic for a SABC circuit type commonly used in open pit operations such as the Canadian Malartic Mine.
Table 3. Results of the 10 comminution tests on the Marban deposit.
Table 4. Results of the 6 comminution tests on the Norlartic deposit.
Quality Control and Qualified persons
The metallurgical testing program is designed and supervised by M. Christian Laroche, Ing. and M. Yan Ducharme, M.Sc., P.Geo. who are qualified persons as defined by the National Instrument 43-101. The metallurgical testing and the analyses were performed by SGS Mineral Services, Lakefield, Ontario. This news release was written, reviewed, and approved by M. Laroche and M. Ducharme.
About the Marban Project
The Marban Project is located in the Malartic mining camp in the Abitibi gold district of Quebec, Canada. The current in situ mineral resource estimate on the Marban, Norlartic and Kierens deposits is 38.2 Mt at a grade of 1.29 g/t Au for 1.59 Moz in the measured and indicated categories and 4.1 Mt at a grade of 1.47 g/t Au for 195,000 oz in the inferred category (see "Updated Mineral Resource Technical Report, Marban Block property, Quebec, Canada", dated July 28th, 2016 and filed on SEDAR). The Marban Project contains three past producing mines (Marban, Norlartic and Kierens) which collectively produced 585,000 ounces of gold between 1959 and 1992. The land package owned by Osisko in the heart of the Cadillac, Malartic and Val d'Or gold mining camps covers 125 km² and these camps currently host six producing gold mines, including the Canadian Malartic mine located near the Marban Project.