DLP Reports results from its initial Metallurgical Study on its Aurora Property, Peru. High recoveries achieved (95.8% Cu, 86.4% Mo, 89.3% Ag) to saleable concentrates.
Cranbrook, British Columbia, (Newsfile Corp. – August 29, 2024) DLP Resources Inc. (“DLP” or the “Company”) (TSXV:DLP) (OTCQB:DLPRF) is pleased to report results from the initial metallurgical scoping study on its Aurora Project in southern Peru. The Company commissioned C.H. Plenge & Cia S.A. ("Plenge") in Lima, Peru to complete test work programs on three composites taken from the partially leached (M-1), copper enriched/mixed (M-2) and primary Mo-rich (M-3) zones. The test work reported:
1. Head Assays.
2. Mineralogy.
3. Recovery of copper, silver, and molybdenum by flotation.
4. Copper-Molybdenum separation by flotation.
Highlights are listed below, and detailed results highlighted in Tables 1-11.
Ian Gendall, President & CEO, commented: “Aurora has simple metallurgy that returns high recoveries of critical minerals, copper and molybdenum from standard flotation processes into highgrade concentrates free of deleterious elements. This first phase of metallurgical test work has confirmed high recoveries of copper (95.8%), molybdenum (86.4%) and silver (89.3%) in the rougher concentrate from the composite of partially leached, enriched/mixed and primary mineralized zones. These excellent recoveries for copper, molybdenum and silver at a time when molybdenum prices are at $30/lb, copper at $4.20/lb and silver at $29/oz, bode well for the economics of the project moving forward.”
Highlights
1. The major copper mineral is chalcopyrite followed by chalcocite while molybdenum is molybdenite. The main gangue is quartz followed by orthoclase and muscovite. Pyrite is the main sulphide gangue.
2. High recoveries for copper (“Cu”), molybdenum (“Mo”) and silver (“Ag”) in the rougher concentrate from the composite created from the partially leached (M1), copper enriched (M2) and primary Mo-rich (M3) zones were 95.8%, 86.4% and 89.3%, respectively. The primary grind was 150 microns and concentrate regrind of 20 to 44 microns.
3. The best conditions for maximum molybdenum, copper and silver recovery were determined and verified by Run 32-C with pH of 9.5, a primary grind of P80-133 microns using collectors consisting of - Xanthate SIBX (Z-14) 27 g/ t, A-208 11 g/ t, F. Oil 10g/ t, frother MIBC 17 g/t and a flotation time of 12 min. This gave recoveries of Ag-71.6%, Cu-97.4% and Mo-92.4%.
4. Copper molybdenum separation was successfully tested on a copper molybdenum concentrate obtained from a large, locked test .
5. A commercial grade molybdenum concentrate was floated for composite M-1 and assayed 52.6% molybdenum at 61% recovery. Similarly, for composite M-3 the concentrate assayed 49.7% molybdenum at 84% recovery from the feed. In both cases NaSH was used as depressant and the separation stages limited to four because of mass restrictions. Copper molybdenum separation was not tested for composite M-2. Additional testing for M-2 extending the cleaner flotation time to accommodate the slow floating molybdenum was recommended by Plenge
6. The projected metallurgical balances from lock cycle testing (“LCT”) for M-1 and M-2 were as follows:
a. Composite M-1 (partial leached zone) gave a bulk concentrate assaying 153g/ t silver,17.7% copper and 3.8% molybdenum with recoveries of 53.3%, 81.8% and 62.4%, respectively.
b. Composite M-3 (Primary Mo-rich) the bulk concentrate assayed 57.7 g/ t silver, 7.5 % copper and 28% molybdenum with recoveries of 61%, 85.6% and 89.8%, respectively. The low copper grade is due to the high molybdenum grade and recovery.
7. The average recovery to the bulk concentrate from the composite consisting of all three test composites, M-1 (partial leached zone), M-2 (enriched/mixed copper zone) and M-3 (primary Mo-rich zone) for silver, copper and molybdenum were 60.8%, 83.2% and 67.6%, respectively. The concentrate grades range from 17.7% to 29.5% copper and molybdenum from 1.5% to 28.0%.
8. For the master composite (M-1+M-2+M-3) roughly 70% of the value is represented by molybdenum, 27% by copper and 3% by silver therefore it may be considered a molybdenum ore.
9. No significant penalty or deleterious elements were found for both copper and molybdenum concentrate.
10. Further improvements in grade and recovery are foreseeable with further testing.
Metallurgical Scoping Study Summary
The metallurgical test work program at C.H. Plenge & Cia S.A. ("Plenge") in Lima, Peru included studies on three composite samples sent to the Plenge Laboratory Lima offices by DLP on October 25, 2023. The three composite samples were taken from ¼ diamond drill core and included, M-1 (~161kg), M-2 (~155kg) and M-3 (~149kg). These composite samples were taken from 7 drillholes totaling ~465kg and represented the following intervals:
1. M-1: Partial leached zone in mineralized porphyry from 24 to 121m,
2. M-2: Cu enriched/mixed zone in mineralized porphyry between 111 and 363m and,
3. M-3: Primary Mo-rich zone in mineralized porphyry from 478 to 988m.
The samples were selected from the Aurora porphyry copper-molybdenum-silver deposit to represent the mineralization, metal grades and lithology type for the initial metallurgical test work.
The test works main objective, was to obtain the following information on the three composite samples M-1, M-2 and M-3 and the master composite of all three.
1. Head Assays.
2. Mineralogy.
3. Recovery of Copper, Silver, and Molybdenum by flotation.
4. Copper Molybdenum Separation by flotation.
Sample Selection
The metallurgical samples were taken from seven of the thirteen drill holes drilled in 2013 and are listed in Tables 1 and 2 below. The samples were selected to represent the mineralization, metal grades and lithology type for the initial metallurgical test work.
Table 1. Sample intervals for composites M-1 (Partially leached mineralized porphyry) and M-2 (enriched/mixed mineralized porphyry).
| M-1 - Partially Leached (Mineralized Porphyry) | M-2 – Enriched/Mixed (Mineralized Porphyry) | ||||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| SAMPLE ID | Hole ID | From (m) | To (m) | Interval (m) | SAMPLE ID | Hole ID | From (m) | To (m) | Interval (m) | ||||||||||
| SAMPLE | From | To | Interval | SAMPLE | From | To | Interval | ||||||||||||
| ID | Hole ID | (m) | (m) | (m) | ID | Hole ID | (m) | (m) | (m) | ||||||||||
| Y330866 | A23-004 | 28.00 | 30.00 | 2.00 | Y330909 | A23-004 | 110.90 | 113.00 | 2.10 | ||||||||||
| Y330869 | A23-004 | 34.00 | 36.00 | 2.00 | Y330912 | A23-004 | 115.00 | 117.50 | 2.50 | ||||||||||
| Y330870 | A23-004 | 36.00 | 38.00 | 2.00 | Y330924 | A23-004 | 140.00 | 142.00 | 2.00 | ||||||||||
| Y330873 | A23-004 | 40.00 | 42.00 | 2.00 | Y330927 | A23-004 | 146.00 | 148.00 | 2.00 | ||||||||||
| Y330875 | A23-004 | 44.00 | 46.00 | 2.00 | Y330933 | A23-004 | 156.00 | 158.00 | 2.00 | ||||||||||
| Y330877 | A23-004 | 48.00 | 50.00 | 2.00 | Y330934 | A23-004 | 158.00 | 160.00 | 2.00 | ||||||||||
| Y330878 | A23-004 | 50.00 | 52.00 | 2.00 | Y330936 | A23-004 | 162.00 | 164.00 | 2.00 | ||||||||||
| Y330879 | A23-004 | 52.00 | 54.00 | 2.00 | Y330937 | A23-004 | 164.00 | 166.00 | 2.00 | ||||||||||
| Y330880 | A23-004 | 54.00 | 56.00 | 2.00 | Y330961 | A23-004 | 210.00 | 212.00 | 2.00 | ||||||||||
| Y330884 | A23-004 | 62.00 | 64.00 | 2.00 | Y330967 | A23-004 | 222.00 | 224.00 | 2.00 | ||||||||||
| Y330887 | A23-004 | 68.00 | 70.00 | 2.00 | Y330969 | A23-004 | 226.00 | 228.00 | 2.00 | ||||||||||
| Y330889 | A23-004 | 72.00 | 74.00 | 2.00 | Y330973 | A23-004 | 232.00 | 234.00 | 2.00 | ||||||||||
| Y330892 | A23-004 | 76.00 | 78.00 | 2.00 | Y330974 | A23-004 | 234.00 | 236.00 | 2.00 | ||||||||||
| Y330896 | A23-004 | 84.00 | 86.00 | 2.00 | Y330978 | A23-004 | 242.00 | 244.00 | 2.00 | ||||||||||
| Y330900 | A23-004 | 92.00 | 94.00 | 2.00 | Y330979 | A23-004 | 244.00 | 246.00 | 2.00 | ||||||||||
| Y330907 | A23-004 | 106.00 | 108.50 | 2.50 | Y330980 | A23-004 | 246.00 | 248.00 | 2.00 | ||||||||||
| Y331230 | A23-005 | 24.00 | 26.00 | 2.00 | Y330981 | A23-004 | 248.00 | 250.00 | 2.00 | ||||||||||
| Y331232 | A23-005 | 28.00 | 30.00 | 2.00 | Y330985 | A23-004 | 256.00 | 258.00 | 2.00 | ||||||||||
| Y331234 | A23-005 | 32.00 | 34.00 | 2.00 | Y330986 | A23-004 | 258.00 | 260.00 | 2.00 | ||||||||||
| Y331235 | A23-005 | 34.00 | 36.00 | 2.00 | Y330987 | A23-004 | 260.00 | 262.00 | 2.00 | ||||||||||
| Y331238 | A23-005 | 38.00 | 40.00 | 2.00 | Y331294 | A23-005 | 146.00 | 148.00 | 2.00 | ||||||||||
| Y331239 | A23-005 | 40.00 | 42.00 | 2.00 | Y331295 | A23-005 | 148.00 | 150.00 | 2.00 | ||||||||||
| Y331243 | A23-005 | 48.00 | 50.00 | 2.00 | Y331296 | A23-005 | 150.00 | 152.00 | 2.00 | ||||||||||
| Y331250 | A23-005 | 62.00 | 64.00 | 2.00 | Y331301 | A23-005 | 158.00 | 160.00 | 2.00 |
| Table 1 cont. M-1 - Partially Leached | Table 1 cont. M-2 – Enriched/Mixed | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| (Mineralized Porphyry) | (Mineralized Porphyry) | |||||||||||
| SAMPLE | Hole ID | From | To | Interval | SAMPLE | Hole ID | From | To | Interval | |||
| ID | Hole ID | (m) | (m) | (m) | ID | Hole ID | (m) | (m) | (m) | |||
| Y331251 | A23-005 | 64.00 | 66.00 | 2.00 | Y331302 | A23-005 | 160.00 | 162.00 | 2.00 | |||
| Y331252 | A23-005 | 66.00 | 68.00 | 2.00 | Y331303 | A23-005 | 162.00 | 164.00 | 2.00 | |||
| Y331269 | A23-005 | 98.00 | 100.00 | 2.00 | Y331304 | A23-005 | 164.00 | 166.00 | 2.00 | |||
| Y331270 | A23-005 | 100.00 | 102.00 | 2.00 | Y331313 | A23-005 | 182.00 | 184.00 | 2.00 | |||
| Y331274 | A23-005 | 108.00 | 110.00 | 2.00 | Y331618 | A23-006 | 91.00 | 93.00 | 2.00 | |||
| Y331593 | A23-006 | 38.00 | 40.00 | 2.00 | Y331623 | A23-006 | 99.00 | 101.00 | 2.00 | |||
| Y331595 | A23-006 | 42.00 | 45.00 | 3.00 | Y331636 | A23-006 | 125.00 | 127.00 | 2.00 | |||
| Y331596 | A23-006 | 45.00 | 47.00 | 2.00 | Y331639 | A23-006 | 131.00 | 133.00 | 2.00 | |||
| Y331597 | A23-006 | 47.00 | 49.00 | 2.00 | Y331671 | A23-006 | 191.00 | 193.00 | 2.00 | |||
| Y331598 | A23-006 | 49.00 | 51.00 | 2.00 | Y331675 | A23-006 | 199.00 | 201.00 | 2.00 | |||
| Y331603 | A23-006 | 58.00 | 60.00 | 2.00 | Y331693 | A23-006 | 231.00 | 233.00 | 2.00 | |||
| Y331607 | A23-006 | 69.00 | 71.00 | 2.00 | Y332488 | A23-008 | 343.00 | 345.00 | 2.00 | |||
| Y331610 | A23-006 | 75.00 | 77.00 | 2.00 | Y332492 | A23-008 | 351.00 | 353.00 | 2.00 | |||
| Y331611 | A23-006 | 77.00 | 79.00 | 2.00 | Y332846 | A23-009 | 325.00 | 327.00 | 2.00 | |||
| Y331621 | A23-006 | 95.00 | 97.00 | 2.00 | ||||||||
| Y331633 | A23-006 | 119.00 | 121.00 | 2.00 | ||||||||
| Total Metres | 81.50 | Total Metres | 76.60 |
Table 2. Sample intervals for composite M3 (primary – hypogene mineralized porphyry).
| M3 – Primary/Hypogene (Mineralized Porphyry) | |||||||||
|---|---|---|---|---|---|---|---|---|---|
| SAMPLE ID | Hole ID | From (m) | To (m) | Interval (m) | |||||
| From | To | Interval | |||||||
| SAMPLE ID | Hole ID | (m) | (m) | (m) | |||||
| Y331111 | A23-004 | 497.00 | 499.00 | 2.00 | |||||
| Y331112 | A23-004 | 499.00 | 502.00 | 3.00 | |||||
| Y331117 | A23-004 | 510.00 | 512.00 | 2.00 | |||||
| Y331118 | A23-004 | 512.00 | 514.00 | 2.00 | |||||
| Y331123 | A23-004 | 520.00 | 522.00 | 2.00 | |||||
| Y331468 | A23-005 | 478.00 | 480.00 | 2.00 | |||||
| Y331469 | A23-005 | 480.00 | 482.00 | 2.00 | |||||
| Y331470 | A23-005 | 482.00 | 484.00 | 2.00 | |||||
| Y331477 | A23-005 | 496.00 | 498.00 | 2.00 | |||||
| Y331478 | A23-005 | 498.00 | 500.00 | 2.00 | |||||
| Y331830 | A23-006 | 500.00 | 502.00 | 2.00 | |||||
| Y331833 | A23-006 | 506.00 | 508.00 | 2.00 | |||||
| Y331836 | A23-006 | 512.00 | 514.00 | 2.00 | |||||
| Y331848 | A23-006 | 534.00 | 536.00 | 2.00 |
| Table 2 cont. M3 – Primary/Hypogene | ||||||
|---|---|---|---|---|---|---|
| (Mineralized Porphyry) | ||||||
| SAMPLE ID | SAMPLE ID | Hole ID | From | To | Interval | |
| (m) | (m) | (m) | ||||
| Y331849 | A23-006 | 536.00 | 538.00 | 2.00 | ||
| Y332559 | A23-008 | 480.00 | 482.00 | 2.00 | ||
| Y332561 | A23-008 | 482.00 | 484.00 | 2.00 | ||
| Y332609 | A23-008 | 574.00 | 576.00 | 2.00 | ||
| Y332612 | A23-008 | 580.00 | 582.00 | 2.00 | ||
| Y332636 | A23-008 | 626.00 | 628.00 | 2.00 | ||
| Y332649 | A23-008 | 650.00 | 652.00 | 2.00 | ||
| Y332672 | A23-008 | 694.00 | 696.00 | 2.00 | ||
| Y333505 | A23-010 | 789.00 | 791.00 | 2.00 | ||
| Y333506 | A23-010 | 791.00 | 793.00 | 2.00 | ||
| Y333508 | A23-010 | 795.00 | 797.00 | 2.00 | ||
| Y333509 | A23-010 | 797.00 | 799.00 | 2.00 | ||
| Y333513 | A23-010 | 803.00 | 805.00 | 2.00 | ||
| Y333514 | A23-010 | 805.00 | 807.00 | 2.00 | ||
| Y333515 | A23-010 | 807.00 | 809.00 | 2.00 | ||
| Y333517 | A23-010 | 811.00 | 813.00 | 2.00 | ||
| Y333520 | A23-010 | 817.00 | 819.00 | 2.00 | ||
| Y333524 | A23-010 | 825.00 | 827.50 | 2.50 | ||
| Y333528 | A23-010 | 835.00 | 837.50 | 2.50 | ||
| Y333596 | A23-010 | 964.00 | 966.00 | 2.00 | ||
| Y333597 | A23-010 | 966.00 | 968.00 | 2.00 | ||
| Y333602 | A23-010 | 976.00 | 978.00 | 2.00 | ||
| Y333605 | A23-010 | 982.00 | 984.00 | 2.00 | ||
| Y333607 | A23-010 | 986.00 | 988.00 | 2.00 | ||
| Y333994 | A23-011 | 726.00 | 728.00 | 2.00 | ||
| Y334008 | A23-011 | 752.00 | 754.00 | 2.00 | ||
| Y334017 | A23-011 | 768.00 | 770.00 | 2.00 | ||
| Y334025 | A23-011 | 784.00 | 786.00 | 2.00 | ||
| Y334035 | A23-011 | 804.00 | 806.00 | 2.00 | ||
| Y334048 | A23-011 | 828.00 | 830.00 | 2.00 | ||
| Y334072 | A23-011 | 874.00 | 876.00 | 2.00 | ||
| Y334102 | A23-011 | 930.00 | 932.00 | 2.00 | ||
| Y334114 | A23-011 | 954.00 | 956.00 | 2.00 | ||
| Total Metres | 102.00 |
Table 3: Diamond drill holes used for the Initial Metallurgical Test Work.
| Hole | Easting | Northing | Elevation | Length | Azimuth | Inclination |
|---|---|---|---|---|---|---|
| ID | m | m | m | m | Degrees | Degrees |
| A23-004 | 189,793 | 8,566,268 | 2638 | 700.90 | 140 | -70 |
| A23-005 | 189,740 | 8,566,258 | 2628 | 693.4 | 140 | -70 |
| A23-006 | 189,612 | 8,566,230 | 2628 | 708.55 | 140 | -70 |
| A23-008 | 189,631 | 8,566,045 | 2722 | 703.65 | 120 | -70 |
| A23-009 | 190,135 | 8,565,722 | 2966 | 790.55 | 340 | -70 |
| A23-010 | 190,079 | 8,565,708 | 2965 | 1002.55 | 340 | -70 |
| A23-011 | 189,970 | 8,565,440 | 2760 | 1081.70 | 025 | -70 |
Notes to Table 3: The coordinates are in WGS84 and 19S Datum.
Figure 1. DLP Project areas in Peru with Aurora Project Shown.
Figure 2. Metallurgical drill holes shown with grey circle with red outline.
The head grades for each composite M1, M2 and M3 and the combined master composite are shown in Table 4 below.
Table 4. Head Grade of Composites M-1-Partially leached, M-2-Enriched/Mixed and M-3-Primary Mo-rich and Master Composite.
The three composites represent copper molybdenum ore whose average head grade is silver 3.5 g/t, copper 0.30% and molybdenum 0.10%.
Table 5. ICP-OE Multielement (4-acid partial digestion) on Composite Samples M1, M2, M3 and Master Composite
For the master composite, roughly 70% of the value is represented by molybdenum, 27% by copper and 3% by silver therefore it may be considered a molybdenum ore.
Rougher Flotation Testing
Master Composite (M.C)
A Master Composite, M.C. , was prepared by blending equal parts of each of the three composites, M-1, M-2, and M-3.
Rougher reagent collection and dosage was explored by seven flotation kinetics tests. The tests were run at fine grind of P80=106 μ to reduce mineral liberation effects. All tests were run at pH=9.5 using 10 g/ t Fuel Oil as molybdenum collector.
A set of 31 kinetic flotation rougher tests were per formed to optimize rougher flotation using design of experiments (D.O.E).
Best conditions for rougher flotation were test 32C at:
- pH=9.5
- Primary Grind P80= 133 μm
Collectors Xanthate SIBX (Z-14) 27 g/ t
A-208 11 g/ t
F. Oi l 10g/ t
Frother MIBC 17 g/ t
Flotation Time of 12 min
Table 6. Design of Experiment (DOE) Optimized Rougher Conditions
The average rougher concentrate recovery for silver, copper and molybdenum were 89.3%, 95.8% and 86.4%, respectively (Table 7). The average mass pull was 6.3%. The flotation circuit and reagents used is typically encountered in the copper molybdenum mining industry. The primary grind was 150 microns and concentrate regrind of 20 to 44 microns.
Note: - Mass Pull = flowrate of solids reporting to the concentrate.
Copper molybdenum separation was successfully tested on a copper molybdenum concentrate obtained from a large, locked test . The copper bulk concentrate and recoveries are slightly different due to the lower bulk concentrate grade.
Table 7. Rougher Concentrate Metallurgical Balance Locked Cycle Test (LCT)
Notes to Tables 6 and 7
- Recoveries=Distribution (%), percentage of metal reporting to each concentrate relative to the metal content of the feed to the concentrator.
Locked Cycle Test (LCT) Flotation Tests Concentrate
LCT Conditions
- Grind P80 = 150 μm
- Regrind P80 = 44 μm
- %Solids 33%
- Reagent Rgh. PAX 8 g/ t
- SIBX 12 g/ t
- AP 208 11 g/ t
- F.O. 10 g/ t
- pH Rougher 9.5
- Cleaners 10.5
- Flotation Time Rougher 8 min
- 1st Clean 6 min
- Clean Scavenger 4 min
- 2nd Clean 4 min
- 3rd Clean 4 min.
The projected metallurgical balances from lock cycle testing for Composite M-1 (partially leached zone) gave a bulk concentrate assaying 153 g/ t silver, 17.7% copper and 3.8% molybdenum with recoveries of 53.3%, 81.8% and 62.4%, respectively.
For Composite M-3 the bulk concentrate assayed 57.7 g/ t silver, 7.5 % copper and 28% molybdenum with recoveries of 61%, 85.6% and 89.8%, respectively. The low copper grade is due to the high molybdenum grade and recovery.
The LCT for composite M-2 stabilized for copper however not for molybdenum therefore the projected metallurgical balance is not posted. The values reported are based on a six-cycle lock flotation test but assume that all intermediate products reported to tails and are therefore on the conservative side with some loss of copper recovery. The bulk concentrate assayed 234.2 g/t silver, 29.5% copper and 1.52% molybdenum with recoveries of 68%, 82.1% and 50.5%, respectively. The concentrate mass pull was 1.74% (Table 8).
Table 8. Combined Metallurgical Balance M-2
Notes: Copper reached stability, however molybdenum did not, building up in the cleaner circuit. It is possible that the cleaner flotation times were too short for the slow floating molybdenum preventing it from reaching stability. No molybdenum separation was per formed for M-2 because the locked test didn’t reach stability.
Recoveries=Distribution (%), percentage of metal reporting to each concentrate relative to the metal content of the feed to the concentrator.
- Conc Cu-Mo : Cu-Mo concentrate
- Midl 2, 3 + Cl Scv Conc : Middlings 2 and 3 plus cleaner scavenger concentrate
- Cl Scv Tail : Cleaner scavenger tail
- Rgh Conc : Rougher concentrate
- Rgh Tails : Rougher Tails
The average recovery to the bulk concentrate for silver, copper and molybdenum were 60.8%, 83.2% and 67.6%, respectively. The concentrate grades range from 17.7% to 29.5% copper and molybdenum from 1.5% to 28.0%. The average concentrate mass pull is 1.11%, equivalent to a Recovery of 90.09%.
Copper Molybdenum Separation Open Circuit
A commercial grade molybdenum concentrate was floated for composite M-1 and assayed 52.6% molybdenum at 61% recovery. Similarly, for composite M-3 the concentrate assayed 49.7% molybdenum at 84% recovery from the feed. In both cases NaSH was used as depressant and the separation stages limited to four because of mass restrictions. Copper molybdenum separation was not tested for composite M-2.