21 January 2022
Quarterly Activities and Cashflow Report for the period ending 31 December 2021
Boab Metals Limited (ASX: BML) ("Boab" or "Company") is pleased to provide the following activity and cashflow report for the quarter ending 31 December 2021. The quarter saw significant progress toward the development of the Company's 75% owned Sorby Hills Lead-Silver-Zinc Project ("Sorby Hills" or "the Project"), located in the Kimberley Region of Western Australia.
HIGHLIGHTS
- Updated Mineral Resource Estimate for Sorby Hills 47.3Mt at 4.1% Pb Eq (3.1% Pb, 35g/t Ag) and 0.4% Zn containing 1.47Mt Pb, 53Moz Ag and 0.21kt Zn, including:
- 14% increase in Measured and Indicated Resources versus the PFS Resource, and a 7% increase versus the April 2021 estimate; and
- Inaugural 1.0Mt Indicated Resource reported for the Beta Deposit.
- Sorby Hills DFS Metallurgical Test Work Results confirming:
- separate flotation of Oxidised and Fresh Ore will deliver significant uplift in metal recovery across the Life of Mine;
- Lead recoveries of up to 95% (Fresh Ore) and up to 90% (Oxidised Ore); and
- Silver recoveries of up to 87%Ag (Fresh Ore) and up to 92% (Oxidised Ore).
- Sorby Hills Site Visit Undertaken by NAIF and Commercial Banks.
- The Company has a cash balance of A$8.4M as at 31 December 2021 and is well funded to continue progressing Sorby Hills to a Final Investment Decision ("FID").
Boab Managing Director and CEO, Simon Noon, stated:
"The quarter has seen the Company put in place significant building blocks to support the Sorby Hills Definitive Feasibility Study and development of the Project. The updated Mineral Resource Estimate and Metallurgical Test Work will underpin our Mine Plan and Process Plant design and I am confident the results will have a positive impact on the Project Economics."
Upgraded Mineral Resource Estimate for Sorby Hills
Boab's Pre-Feasibility Study ("PFS") confirmed the Sorby Hills Project as a low-risk, high value project underpinned by a large near-surfacePb-Ag-Zn deposit comprising a Mineral Resource of 44.1Mt at 3.3% Pb, 38g/t Ag and 0.5% Zn (ASX release 2 June 2020), and Proved and Probable Reserves of 13.6Mt at 3.6% Pb, and 40g/t Ag (ASX release 25 August 2020).
On the back of the positive PFS results, a Phase IV drilling program was designed to primarily advance the Project towards DFS status. As such, the bulk of drilling metres (3,340m, 70%) were apportioned to collecting samples for metallurgical and geotechnical test work. The balance of the program was targeted at increasing geological confidence via infill drilling and testing potential shallow Resource extensions to the south of the Omega deposit (~1,460m, 30%).
An interim Mineral Resource update incorporating the results of the Phase IV drilling was released in April 2021 (ASX release 6 April 2021) and delivered 44.9Mt at 3.2% Pb, 0.5% Zn and 37g/t Ag.
Subsequently, a Phase V drilling program comprising an additional 59 diamond drill holes (5,284m) was completed with the objective of expanding the Sorby Hills Mining Inventory and supporting the opportunity to increase the 1.5Mtpa processing plant capacity proposed in the PFS.
The updated Mineral Resource Estimate (ASX release 17 December 2021) was undertaken by CSA Global and upgrades the PFS Mineral Resource Estimate via the inclusion of results from the Phase IV and Phase V drilling programs (Figure 1). A comprehensive breakdown of the Mineral Resource by Resource classification and deposit is shown in Table 1 and Table 2 below.
The Mineral Resource Estimate for Lead domains of the Sorby Hills deposit comprises 47.3Mt at 3.1% Pb, 0.4% Zn and 35g/t Ag (1% Pb cut-off).
The updated Mineral Resource Estimate has resulted in a 2.8 Mt (14%) increase in Measured and Indicated Tonnes of 2.8Mt (14%), 65kt contained Lead (9%) and 3.0Moz contained Silver (11%) versus the Mineral Resource Estimate that underpinned the PFS.
The increase in Resource quantity and confidence is expected to have a positive impact on the Sorby Hills Ore Reserve and DFS economics.
Metallurgical Test Work Program Delivers Enhanced Metal Recoveries
The DFS Metallurgical Test Work Program was launched on the back of a successful Phase IV drilling program with the primary objective of delivering robust results to underpin the Sorby Hills DFS ProcessPlant design criteria.
Approximately 1,420kg from 399m of half core was recovered from 35 HQ diamond holes drilled during the Phase IV and V programs and then combined and composited into Variability Samples, Schedule Composites and Master Composites.
Samples and Composites were utilised for a range of test work including: Flotation, Comminution, Mineralogy, Heavy Liquid Separation ("HLS"), Tailings Thickening, Concentrate Filtration and Concentrate Analysis. The DFS Metallurgical Test work Program builds upon a significant body of previous metallurgical test work undertaken by Boab since acquiring the Sorby Hills Project in 2018 and test work by others dating back to 1979.
Table 1: Updated Sorby Hills Mineral Resource Estimate - Pb Domains only.
Classification by | Grade | Pb | Contained Metal | ||||||
Mt | Pb | Zn | Ag | Pb | Zn | Ag | Pb Eq. | ||
Deposit | Eq. | ||||||||
% | % | g/t | % | kt | kt | koz | kt | ||
A | |||||||||
Inferred | 0.6 | 5.3% | 1.0% | 23 | 6.0% | 31 | 6 | 427 | 35 |
Sub Total | 0.6 | 5.3% | 0.1% | 23 | 6.0% | 31 | 6 | 427 | 35 |
B | |||||||||
Measured | 1.4 | 3.8% | 0.3% | 19 | 4.3% | 52 | 4 | 859 | 60 |
Indicated | 1.3 | 3.4% | 0.3% | 21 | 4.0% | 44 | 4 | 862 | 52 |
Sub Total | 2.7 | 3.6% | 0.3% | 20 | 4.2% | 97 | 8 | 1,720 | 112 |
Omega | |||||||||
Measured | 8.5 | 3.3% | 0.4% | 37 | 4.3% | 279 | 32 | 9,995 | 366 |
Indicated | 5.8 | 3.5% | 0.4% | 34 | 4.4% | 205 | 25 | 6,331 | 259 |
Inferred | 2.9 | 2.7% | 0.4% | 26 | 3.4% | 76 | 13 | 2,414 | 97 |
Sub Total | 17.2 | 3.3% | 0.4% | 34 | 4.2% | 566 | 71 | 18,948 | 730 |
Norton | |||||||||
Measured | 2.8 | 4.1% | 0.3% | 75 | 6.2% | 112 | 9 | 6,668 | 170 |
Indicated | 2.1 | 3.2% | 0.5% | 38 | 4.3% | 68 | 11 | 2,617 | 91 |
Inferred | 16.2 | 2.5% | 0.5% | 27 | 3.2% | 402 | 75 | 14,039 | 523 |
Sub Total | 21.1 | 2.8% | 0.4% | 34 | 3.8% | 590 | 96 | 24,090 | 799 |
Alpha | |||||||||
Indicated | 0.7 | 2.6% | 0.5% | 41 | 3.8% | 18 | 4 | 923 | 26 |
Inferred | 0.8 | 3.6% | 1.2% | 86 | 6.0% | 27 | 9 | 2,052 | 44 |
Sub Total | 1.5 | 3.1% | 0.9% | 64 | 4.9% | 45 | 13 | 2,975 | 71 |
Beta | |||||||||
Indicated | 1.0 | 4.1% | 0.2% | 42 | 5.3% | 42 | 2 | 1,382 | 54 |
Inferred | 3.2 | 3.4% | 0.4% | 43 | 4.6% | 109 | 14 | 4,474 | 148 |
Sub Total | 4.2 | 3.6% | 0.4% | 43 | 4.8% | 151 | 17 | 5,856 | 202 |
Total Resource | |||||||||
Measured | 12.6 | 3.5% | 0.4% | 43 | 4.7% | 444 | 45 | 17,521 | 596 |
Indicated | 11.0 | 3.4% | 0.4% | 34 | 4.4% | 377 | 46 | 12,114 | 482 |
Inferred | 23.6 | 2.7% | 0.5% | 31 | 3.6% | 645 | 117 | 23,406 | 848 |
Total | 47.3 | 3.1% | 0.4% | 35 | 4.1% | 1,465 | 207 | 53,042 | 1,925 |
Note: Tonnes and Grade are rounded. Reported at a 1.0% Pb Cut-Off.
Discrepancy in calculated Contained Metal is due to rounding.
See Appendix 2 for Lead Equivalent calculation method.
Lead Equivalent calculation excludes Zinc.
Table 2: Sorby Hills Mineral Resource Estimate - Alpha Deposit Zn Domains only.
Classification | Mt | Pb | Zn | Ag | Pb | Zn | Ag |
by Deposit | % | % | g/t | kt | kt | koz | |
Alpha | |||||||
Indicated | 2.1 | 0.3 | 2.8 | 22 | 6 | 59 | 1,485 |
Inferred | 2.1 | 0.4 | 2.3 | 21 | 8 | 48 | 1,418 |
Sub Total | 4.2 | 0.5 | 2.5 | 22 | 15 | 107 | 2,971 |
Note: Tonnes and Grade are rounded. Reported at a 1.0% Pb Cut-Off.
Discrepancy in calculated Contained Metal is due to rounding.
Flotation Test Work
Metal recoveries adopted for economic modelling for the PFS comprised Lead: 94.9% (Fresh Ore)
and 84% (Oxidised Ore) and Silver: 78.2% (Fresh Ore) and 94.4% (Oxidised Ore).
The DFS test work program was designed to investigate and compare processing Oxidised Ore and Fresh Ore using both blended and separated ore processing strategies.
Table 3 below presents a summary of the Sorby Hills flotation performance estimates. The recoveries will be key inputs into the DFS mine design and Sorby Hills Reserve evaluation.
Flotation results confirm recoveries of:
- 78% to 95% (Fresh Ore) and 80% to 90% (Oxidised Ore) for Lead; and o 78% to 87% (Fresh Ore) and 88% to 92% (Oxidised Ore) for Silver.
Recovery estimates are based on the Schedule Composite test results, and for the specific deposit estimates, the average Variability Sample test performance for that deposit. These results incorporate modifications based on Locked-Cycle test work to account for closed circuit performance estimation and, in the case of separate Oxidised and Fresh Ore only recoveries, adjustments to account for operational inefficiencies associated with campaign style processing.
The separate flotation of Oxidised and Fresh Ore delivers an uplift in recovery over the Life of Mine versus the sequential treatment of an Oxidised / Fresh Ore Blend adopted in the Sorby Hills PFS and is anticipated to have a positive impact on Project economics.
Concentrate Analysis
A comprehensive assay was undertaken on Lead-Silver Concentrate produced from each locked cycle test. The results of these assays have been provided to potential off takers as part of the ongoingtender for Boab's share of the Sorby Hills Lead-Silver concentrate production.
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Boab Metals Ltd. published this content on 21 January 2022 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 21 January 2022 09:01:03 UTC.