Highlights
- Phase 3 testing included 45 new variability composites testing the full range of rock types, gold (“Au”) grades and ore types encountered across Black Pine.
- Aggregate results support a simple, low capital, low operating cost, Run-of-Mine (“ROM”) heap leach processing route for Black Pine ores.
- Gold extractions are consistent with previous metallurgical programs, with >80% of the leachable gold extracted within 10 days and final column leach gold extractions ranging up to 94.8%:
- Phase 1 bulk sample column test results: 78.9% weighted average gold extraction, ranging up to 92.8%1
- Phase 2 variability composite column tests: 82.1% weighted average gold extraction, ranging up to 94.5%1
- Historical column tests from bulk samples and drill core composites: 80.8% weighted average gold extraction.
1 See press releases dated
All metallurgical work at Black Pine has been supervised by
- Forty-five column leach tests produced a weighted average* 80.8% gold extraction, with a range from 44.5% to 94.8% gold extraction. See Table 1, below, or click here: https://libertygold.ca/images/news/2021/October/Gold_Extraction_Data.pdf
- Gold extraction was rapid, with >80% of the leachable gold extracted within the first 10 days of column leaching. See Figure 1, below or click here: https://libertygold.ca/images/news/2021/October/Cumulative_Leach_Curves.pdf
- Percent gold extraction is well-correlated with head grade, with the highest-grade composites returning the higher extraction numbers. Of the 45 column tests:
- 18 column tests were conducted on material below 0.5 grams per tonne (“g/t”) Au, and returned weighted average 71.8% gold extraction
- 10 column tests were conducted on material between 0.5 g/t Au and 1.0 g/t Au and returned weighted average 79.0% gold extraction
- 17 column tests were conducted on material above 1.0 g/t Au, and returned weighted average 82.3% gold extraction
- For further details see the grade recovery curve in Figure 2 or click here: https://libertygold.ca/images/news/2021/October/Grade_Recovery_Curve.pdf
- Phase 4 metallurgical test work has commenced on 15 PQ drill core composite samples of lower-grade Black Pine mineralization, in the range 0.10 g/t Au to 0.20 g/t Au. Further PQ core drilling has commenced in support of a Phase 5 metallurgical program, considered at this time to be sufficient to support a future feasibility study at Black Pine, targeting the recent Rangefront D-4 discovery,
Discovery Zone ,F Zone ,CD Extension and E Zone .
*Weighted average gold extraction is obtained using the following equation: (composite head grade (grams/tonnes) multiplied by extraction (%) for all head grades)/sum of all head grades. Using arithmetic averages tends to over-represent low grade composites and under-represent high grade composites. The arithmetic extraction average of the 45 column tests is 76%.
Table 1: Results, Liberty Gold Phase 3 Variability Composite Testing
Phase 3 Metallurgical Testing | Fine Bottle Roll | Coarse Bottle Roll | Column Tests | ||||||||||
Feed Target P80 (75µm) | Feed Target P80 (1,700µm) | ||||||||||||
Drill Hole ID | Deposit Area | Actual Feed P80 (µm) | Calc Hd Au (g/t) | Direct Leach Gold Extracted (%) | Actual Feed P80(µm) | Calc Hd Au (g/t) | Carbon in Leach Gold Extracted (%) | Actual Feed P80 (µm) | Calc Hd Au (g/t) | Gold Extracted (%) | Actual Feed P80(mm) | Calc Hd Au (g/t) | Gold Extracted (%) |
BP190-#30 | D1 | 56 | 0.29 | 65.1 | 58 | 0.33 | 68.5 | 1,470 | 0.22 | 49.7 | 11.3 | 0.21 | 47.4 |
BP190-#31 | D1 | 56 | 0.46 | 69.9 | 38 | 0.46 | 77.3 | 1,590 | 0.40 | 69.3 | 24.0 | 0.40 | 70.5 |
BP190-#32 | D1 | 65 | 0.62 | 84.4 | 38 | 0.66 | 87.2 | 1,650 | 0.62 | 82.3 | 12.6 | 0.66 | 82.7 |
BP190-#33 | D1 | 51 | 0.49 | 84.7 | 54 | 0.51 | 89.5 | 1,340 | 0.46 | 86.5 | 12.5 | 0.46 | 89.0 |
BP190-#34 | D1 | 38 | 0.76 | 73.1 | 46 | 0.77 | 83.4 | 1,410 | 0.80 | 76.3 | 23.8 | 0.76 | 78.5 |
BP190-#35 | D1 | 48 | 0.35 | 79.3 | 62 | 0.41 | 86.5 | 1,340 | 0.41 | 82.7 | 23.9 | 0.38 | 80.9 |
BP190-#36 | D1 | 71 | 3.68 | 84.0 | 62 | 3.80 | 89.6 | 1,410 | 3.69 | 83.3 | 10.9 | 3.99 | 87.0 |
BP197-#37 | D3 | 46 | 1.44 | 71.3 | 60 | 1.73 | 77.2 | 1,490 | 1.46 | 78.6 | 27.9 | 1.31 | 78.4 |
BP197-#38 | D3 | 64 | 0.25 | 77.6 | 51 | 0.24 | 83.6 | 1,240 | 0.23 | 80.5 | 24.5 | 0.24 | 76.7 |
BP197-#39 | D3 | 59 | 0.68 | 87.9 | 63 | 0.71 | 90.5 | 1,510 | 0.66 | 87.4 | 22.5 | 0.69 | 85.3 |
BP197-#40 | D3 | 53 | 2.08 | 89.9 | 52 | 2.22 | 92.5 | 1,810 | 2.11 | 88.4 | 13.7 | 2.01 | 88.9 |
BP197-#41 | D3 | 65 | 0.53 | 77.3 | 65 | 0.57 | 84.2 | 1,800 | 0.53 | 78.0 | 24.2 | 0.51 | 72.7 |
BP197-#42 | D3 | 57 | 1.25 | 85.9 | 56 | 1.31 | 91.2 | 1,770 | 1.24 | 88.0 | 11.8 | 1.16 | 86.5 |
BP197-#43 | D3 | 59 | 0.38 | 68.7 | 66 | 0.41 | 86.2 | 1,490 | 0.42 | 72.3 | 22.6 | 0.34 | 76.1 |
BP207-#44 | D2 | 60 | 0.22 | 67.8 | 63 | 0.25 | 76.2 | 1,780 | 0.25 | 70.6 | 12.6 | 0.25 | 62.6 |
BP207-#45 | D2 | 59 | 1.29 | 74.4 | 61 | 1.41 | 79.9 | 1,710 | 1.29 | 71.4 | 22.1 | 1.35 | 80.2 |
BP207-#46 | D2 | 60 | 0.85 | 76.6 | 66 | 0.88 | 86.5 | 1,280 | 0.85 | 76.6 | 8.9 | 0.73 | 82.5 |
BP207-#47 | D2 | 54 | 2.68 | 32.6 | 54 | 2.80 | 59.3 | 1,320 | 2.70 | 28.2 | 12.5 | 2.77 | 44.5 |
BP207-#48 | D2 | 54 | 4.07 | 83.2 | 53 | 4.12 | 86.1 | 1,400 | 3.98 | 79.4 | 24.7 | 4.75 | 80.4 |
BP207-#49 | D2 | 63 | 1.31 | 79.2 | 42 | 1.38 | 84.3 | 1,610 | 1.33 | 77.5 | 24.3 | 1.47 | 80.2 |
BP214-#50 | D2 | 60 | 0.30 | 79.0 | 53 | 0.29 | 82.1 | 1,740 | 0.30 | 74.7 | 11.6 | 0.28 | 76.0 |
BP214-#51 | D2 | 60 | 0.31 | 73.9 | 52 | 0.33 | 80.5 | 170 | 0.32 | 73.0 | 0.2 | 0.32 | 70.9 |
BP214-#52 | D2 | 65 | 1.00 | 62.1 | 71 | 1.02 | 69.4 | 1,650 | 0.97 | 58.9 | 23.5 | 0.92 | 67.1 |
BP214-#53 | D2 | 44 | 1.18 | 56.3 | 57 | 1.21 | 72.2 | 1,870 | 1.27 | 57.5 | 12.0 | 1.25 | 66.8 |
BP214-#54 | D2 | 52 | 4.95 | 88.2 | 67 | 5.77 | 91.0 | 1,340 | 5.51 | 90.8 | 11.1 | 5.86 | 92.2 |
BP214-#55 | D2 | 53 | 3.93 | 92.5 | 84 | 4.00 | 94.0 | 1,190 | 3.92 | 92.2 | 11.3 | 3.05 | 93.2 |
BP214-#56 | D2 | 34 | 2.28 | 73.8 | 51 | 2.34 | 77.8 | 1,270 | 2.42 | 73.7 | 12.5 | 2.22 | 76.1 |
BP222-#57 | D3 | 39 | 0.47 | 83.0 | 55 | 0.50 | 85.5 | 1,560 | 0.50 | 80.4 | 12.1 | 0.42 | 78.1 |
BP222-#58 | D3 | 53 | 0.25 | 37.4 | 54 | 0.30 | 68.7 | 1,690 | 0.28 | 49.7 | 25.3 | 0.28 | 51.3 |
BP222-#59 | D3 | 57 | 0.26 | 62.7 | 49 | 0.28 | 80.1 | 2,200 | 0.25 | 62.8 | 25.1 | 0.27 | 72.8 |
BP222-#60 | D3 | 54 | 0.63 | 82.4 | 53 | 0.74 | 84.9 | 1,650 | 0.62 | 85.1 | 11.2 | 0.66 | 91.7 |
BP222-#61 | D3 | 56 | 3.83 | 88.3 | 55 | 4.01 | 88.9 | 1,550 | 3.86 | 84.6 | 12.0 | 3.48 | 83.1 |
BP222-#62 | D3 | 53 | 1.96 | 83.3 | 52 | 2.08 | 90.1 | 1,760 | 1.92 | 78.8 | 23.4 | 1.82 | 78.2 |
BP222-#63 | D3 | 54 | 0.41 | 79.8 | 53 | 0.48 | 82.7 | 1,480 | 0.45 | 78.5 | 22.9 | 0.42 | 78.7 |
BP231-#64 | D3 | 53 | 0.26 | 47.1 | 49 | 0.28 | 70.9 | 1,610 | 0.27 | 49.1 | 23.2 | 0.29 | 49.1 |
BP231-#65 | D3 | 53 | 0.30 | 56.8 | 55 | 0.34 | 87.3 | 1,820 | 0.31 | 72.4 | 28.1 | 0.31 | 83.4 |
BP231-#66 | D3 | 71 | 0.73 | 83.6 | 72 | 0.75 | 88.4 | 1,490 | 0.71 | 82.2 | 21.4 | 0.71 | 83.5 |
BP231-#67 | D3 | 55 | 0.72 | 88.5 | 54 | 0.81 | 92.4 | 1,420 | 0.71 | 87.8 | 23.7 | 0.73 | 90.0 |
BP231-#68 | D3 | 60 | 2.64 | 93.9 | 62 | 2.69 | 95.7 | 1,430 | 2.55 | 94.3 | 10.6 | 2.59 | 94.8 |
BP242-#69 | 59 | 1.18 | 82.2 | 58 | 1.20 | 83.8 | 1,370 | 0.98 | 68.2 | 12.2 | 1.16 | 70.5 | |
BP242-#70 | 56 | 3.18 | 92.0 | 58 | 3.25 | 92.7 | 1,560 | 2.88 | 87.4 | 14.7 | 2.97 | 87.1 | |
BP242-#71 | 57 | 0.28 | 74.1 | 58 | 0.30 | 75.6 | 1,590 | 0.25 | 61.7 | 13.7 | 0.28 | 66.8 | |
BP242-#72 | 55 | 0.41 | 72.9 | 50 | 0.42 | 84.2 | 1,640 | 0.33 | 66.4 | 14.0 | 0.18 | 67.3 | |
BP242-#73 | 63 | 0.59 | 70.8 | 65 | 0.61 | 78.0 | 1,630 | 0.51 | 51.7 | 13.9 | 0.60 | 54.5 | |
BP242-#74 | 55 | 0.37 | 79.1 | 59 | 0.38 | 82.5 | 1,600 | 0.25 | 58.3 | 12.3 | 0.36 | 66.7 |
Figure 1: Cumulative Leach Curves Confirm Rapid Leach Kinetics
https://www.globenewswire.com/NewsRoom/AttachmentNg/0c85b714-93da-4567-9799-f1a493643584
Figure 2: Phase 3 Column Test, Grade Recovery vs. Au Extraction % *
https://www.globenewswire.com/NewsRoom/AttachmentNg/66552eb3-f6a1-4a23-88d6-88174dd28f57
*Transition Columns: BP207-#47, BP222-#58 & BP231-#64 are excluded in the above graph.
Metallurgical Program
Samples for this study were obtained through drilling of seven PQ core holes. Composites were selected through consideration of rock type, alteration and gold grade to achieve a wide range of ore types. Program details included:
- Forty-five coarse bottle roll tests (target of 80% passing 10 mesh or 1.7 millimeter (“mm”) particle size) produced a weighted average 78.7% gold extraction.
- Forty-five fine bottle roll tests (target of 80% passing 200 mesh or 75 micron particle size) produced a weighted average 80.1% gold extraction for direct leach, and 45 fine bottle roll tests produced a weighted average 85.7% for carbon in leach (“CIL”).
- Samples for bottle roll testing were milled/crushed respectively targeting 80% passing 200 mesh (75 microns) and 80% passing 10 mesh (1.7 mm) particle size. The direct leach samples were rolled/agitated in bottles in a 1.0 grams per liter (“g/l”) dilute sodium cyanide (“NaCN”) solution for 72 hours (for 200 mesh) or 144 hours (for 10 mesh). The 200 mesh (75 microns) CIL samples were rolled/agitated in bottles for 72 hours in a 1.0 g/l dilute NaCN solution, containing 20 g/l of activated carbon.
- Forty-five column tests targeted 80% passing 0.5 inch (12.7 mm) and 1 inch (25.4 mm) crushed material and produced a weighted average 80.8% gold extraction.
- The variability composites were leached continuously between 82 to 99 days, including two on/off cycles for last three weeks at the end. Crushed material was leached in 10.2 mm and 15.2 mm columns irrigated by low strength (0.50 g/l) NaCN solution.
- Gold extraction is relatively insensitive to particle size. Most composites can be projected to coarse particle sizes approximating run of mine conditions without significant loss of gold extraction.
- Results generated by this program are consistent with historical column test results generated by Noranda in 1988 prior to mining, as well as metallurgical testing by
Liberty Gold using large diameter columns and 300 kilogram bulk samples, and Phase 2 variability composite testing using drill core.
For a map showing locations of drill holes used for metallurgical testing, see Figure 3, below, or click here: https://libertygold.ca/images/news/2021/October/BlackPineMet3PRmap.pdf.
Composites were assembled in
Figure 3: Locations of Drill Holes Used for Phase 3 Metallurgical Study
https://www.globenewswire.com/NewsRoom/AttachmentNg/71a118f9-186e-4892-ba50-66e0e85f9fd5
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Drill composites were calculated using a cut-off of 0.20 g/t. Drill intersections are reported as drilled thicknesses. True widths of the mineralized intervals vary between 30% and 100% of the reported lengths due to varying drill hole orientations but are typically in the range of 60% to 80% of true width. Drill samples were assayed by ALS Limited in
All statements in this press release, other than statements of historical fact, are "forward-looking information" with respect to
Such forward-looking information, involves known and unknown risks, which may cause the actual results to be materially different from any future results expressed or implied by such forward-looking information, including, risks related to the interpretation of results and/or the reliance on technical information provided by third parties as related to the Company’s mineral property interests; changes in project parameters as plans continue to be refined; current economic conditions; future prices of commodities; possible variations in grade or recovery rates; the costs and timing of the development of new deposits; failure of equipment or processes to operate as anticipated; the failure of contracted parties to perform; the timing and success of exploration activities generally; timing of any preliminary economic assessments or feasibility assessments; scalability of metallurgical results, delays in permitting; possible claims against the Company; labour disputes and other risks of the mining industry, including impacts from the pandemic of the novel coronavirus (COVID-19); delays in obtaining governmental approvals, financing or in the completion of exploration as well as those factors discussed in the Annual Information Form of the Company dated
Although
Figure 1
Cumulative Leach Curves Confirm Rapid Leach Kinetics
Figure 2
Phase 3 Column Test, Grade Recovery vs. Au Extraction % *
Figure 3
Locations of Drill Holes Used for Phase 3 Metallurgical Study
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