Key Highlights from “Lock Cycle” Flotation Tests
- Excellent copper recoveries of 98.2% and 96.8% from a representative composite sample
- High-quality copper concentrate grades results of 27.0% and 29.6%
The results are an improvement over the figures included in the
Metallurgical Test Work Program Summary
A total of 34 diamond drill holes were used to create a spatially diverse composite sample (the “CBSP” composite) that intersected copper mineralized zones within the Corner Bay Mineral Resource estimate. The core material selected represented different rock types: semi and massive sulphides, quartz veins, diorite dyke, and fresh and altered anorthosite. The drill core was sampled by cutting a quarter split NQ core.
The CBSP composite was firstly compiled into a 202 kilogram sample with a grade of 2.20% Cu. The CBSP composite was then processed through the Steinert ore sorter and mixed with 26% of the unsorted underflow by-passed mineralized material to represent an overall sorted pre-concentrate mineralized material product. The CBSP composite resulted in a 123 kilogram sample with a grade of 3.31% Cu.
The composite sample was evaluated through lock cycle tests to determine the flotation metallurgical performance. The sample was prepared to a nominal grind size of 140 microns K80 in the rougher testing and then processed through a regrind size of approximately 37 microns K80 in the cleaner tests.
The sample responded consistently throughout the test work with excellent performance to conventional flotation processing methods and reagents. Two locked cycle tests were completed with varying retention times to determine the concentrate grade versus recovery. The tests resulted in concentrate grades of 27.0% Cu and 29.6% Cu and recoveries 98.2% and 96.8%, respectively (see Table 1).
Minimal amounts of deleterious elements (e.g. arsenic, antimony, bismuth, cadmium etc.) were present in the concentrate, indicative of the “clean” nature of the concentrate (see Table 2). These results showed the highly commercial quality of the concentrate in terms of salability and payment terms of smelters.
Table 1. Metallurgical Test Work Results
Composite / Test | Lock cycle test feed | Concentrate | Recovery | ||||||
CBSP (sorted mineralized material) | Cu % | Au g/t | Ag g/t | Cu % | Au g/t | Ag g/t | Cu % | Au % | Ag % |
Lock Cycle Test 1 | 3.31 | 0.30 | 9 | 27.0 | 1.82 | 68 | 98.2 | 72.1 | 86.4 |
Lock Cycle Test 2 | 3.28 | 0.55 | 10 | 29.6 | 3.24 | 72 | 96.8 | 62.6 | 76.9 |
Table 2. Impurity Element Content of Copper Concentrate
Composite / Test | Impurity Elements (ppm)1 | ||||||
CBSP (sorted mineralized material) | Arsenic (As) | Antimony (Sb) | Bismuth (Bi) | Cadmium (Cd) | Lead (Pb) | Mercury (Hg) | Zinc (Zn) |
Lock Cycle Test 1 | 22 | 3 | 4 | 10 | 102 | 1 | 735 |
Lock Cycle Test 2 | 10 | 3 | 3 | 10 | 88 | 1 | 777 |
1. | All analyses in parts per million (ppm). |
Technical Disclosure
All metallurgical test work referenced in this news release was completed by
Commercial certified standard material and blanks were inserted by BML into the sample chain accounting for 10% of the samples as part of the quality assurance and quality control (QA/QC) program.
Qualified Person
About Doré
Doré
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President and Chief Executive Officer | Vice President, Investor Relations |
Phone: (416) 792-2229 | Phone: (416) 219-2049 |
Email: ernest.mast@dorecopper.com | Email: laurie.gaborit@dorecopper.com |
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1. | Technical report titled "Preliminary Economic Assessment for the |
2. | Sources for historic production figures: Economic Geology, v. 107, pp. 963–989 - Structural and Stratigraphic Controls on Magmatic, Volcanogenic, and Shear Zone-Hosted Mineralization in the |
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Source: DORÉ COPPER MINING CORP
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