Hummingbird Resources provides 2021 reserve update
Published by Jessica Casey,
Global Mining Review,
Hummingbird Resources plc has provided an updated JORC-compliant company reserve statement, which includes a maiden reserve for the Kouroussa mine in Guinea.
Hummingbird's updated reserves total 1.12 million oz of gold (Au), a 438 600 oz increase to the previous company reserve statement in October 2019 of 672 000 oz.
2021 company reserve highlights:
Company reserve update
- Updated company reserves as of 30 June 2021 total 1.12 million oz at 3.03 g/t), comprising:
- Yanfolila mine in Mali: 705 800 oz at 2.57 g/t, being a net increase of 29 700 oz, including depleted reserves from mining since the previous company reserve statement in October 2019.
- The Yanfolila mine reserves include both opencast reserves on six deposits totalling 503 600 oz at 2.3 g/t (including stockpiles) and a maiden underground reserve at Komana east (KEUG) of 202 200 oz at 3.64 g/t.
- Kouroussa mine in Guinea: 408 900 oz at 4.38 g/t establishing a maiden reserve at that asset.
- These reported reserves for both Yanfolila and Kouroussa have upside potential as they do not include the 2021 drilling campaign of ~68 000 m (~44 000 m at Yanfolila and ~24 000 m at Kouroussa). The results of this year’s drilling campaign will be included in the 2022 updated company resource and reserve statements, scheduled to be released in 2Q22.
Yanfolila Mine, Mali
- The majority of the JORC compliant Yanfolila reserves increase has come from two key future mining deposits, including the new underground reserves at KEUG and the maiden opencast reserves at the Sanioumale East deposit (SE).
- Identification of reserves at both deposits are a result of the company’s investment and focus on exploration in 2020 with a total of ~21 000 m being drilled, with potential for further increases in reserves with a total of ~41 000 m being drilled in 2021 at Yanfolila, but which is not included in this reserve statement. The new reserves at Yanfolila from these deposits are split as follows:
- KEUG: 202 200 oz at 3.64 g/t.
- SE: 100 300 oz at 2.64 g/t.
Kouroussa Mine, Guinea
- Kouroussa's maiden opencast reserve of 408 900 oz at 4.38 g/t, was from the main and largest deposit called Koekoe (KK). The reserve is supported by the JORC compliant resource statement as completed by independent mining consultancy company, Mining Plus, in May 2020.
- As stated above, there is upside potential to the Kouroussa maiden reserve number in the 2022 company resource and reserve statements with the inclusion of the 2021 infill drilling campaign of ~24 000 m. Further, the company expects the largest of the three other key deposits at Kouroussa, called Kinkine, to have a maiden reserve in the 2022 company resource and reserve statements.
Dugbe Mine, Liberia
The company’s Dugbe mine in Liberia is not included in this year's company reserves statement. As per the release on 22 November 2021, the company’s earn-in partners on Dugbe, Pasofino Gold Ltd released an updated mineral resource estimate (MRE) of 4.0 million oz, including 3.4 million oz is in the measured and indicated category. The company will provide a more detailed update on Dugbe reserves once Pasofino completes the definitive feasibility study (DFS) scheduled for completion by 2Q22, providing further significant upside potential for the company’s resource and reserves profile.
Dan Betts, CEO of Hummingbird Resources, commented: “Our exploration strategy in 2020 has delivered JORC compliant reserves, extending Yanfolila’s LOM and delivering a maiden reserve at Kouroussa, our low cost/high margin operation which will more than double Hummingbird’s future gold production scheduled for first gold pour the end of 2Q23. This year’s exploration campaigns were three times larger in terms of metres drilled than those in 2020, with the focus to further increase our company reserve and resource base in order to achieve the company’s ambition of having LOMs in excess of 10 years from our assets.
“The results of these programmes will form the basis of the 2022 company resources and reserve updates, which are scheduled to be released in 2Q22 where we see further upside potential from the current company reserves of 1.12 million oz. Further, reserves upside is expected from our Dugbe mine in Liberia once the DFS is completed by earn-in partners Pasofino given the material 4 million oz resource base, of which 3.4 million oz is in the measured and indicated category.”
Anthony Kocken, COO of Hummingbird Resources, added: “Significant company resources have been focused on adding to the mineral inventory as we work towards our goal of a 10 year LOM at our assets. The geological, exploration, and technical teams within Hummingbird and our business partners have worked efficiently and effectively to produce positive results and we look forward to the significant drilling investment in 2021 (approximately 68 000 m) to further progress the Hummingbird reserves base as the foundation to future growth and value creation.”
2021 company reserve summary
Yanfolila, Mali Reserves
The Yanfolila gold mine is located within the Yanfolila exploitation permit area. The permit area contains the following six deposits that are being included within the 2021 company reserve statement:
- Komana East (KE).
- Komana East Underground (KEUG).
- Komana West (KW).
- Gonka (GK).
- Sanioumale West (SW).
- Sanioumale East (SE).
KE and KEUG
The KE deposit, with a current reserve of 99 200 oz, is currently being mined as an opencast and has been the principal source of ore to the process plant since the operation commenced in December 2017. Delineation of the gold mineralisation at KE has been limited previously by the lack of drilling, with limited drilling piercing the ore body below 0 mRL or 400 m below surface.
However, in the last two years of exploration drilling by the company, testing for extensions below the base of the KE opencast has been conducted in order to develop underground mining potential. Per this year’s company reserve statement, the KEUG deposit has a reserve of 202 200 oz at 3.64 g/t. Specific timing in terms of when the KEUG will come into the future mine plans and the economics are being analysed but are not yet fully decided on. However, given the reserves as highlighted in this release and grade profile, the KEUG is expected to provide a key future base load production profile for the company in future years.
With the success of the previous two years exploration drilling proving up the KEUG, further work is being planned in 2022 that will target the down plunge extensions of the high grade zones to further give confidence to the long life and robust economics of an underground operation.
The KW deposit is made up of predominantly four opencast phases, of which three are nearing completion with the remaining fourth phase scheduled for mining in 2022, with a current reserve of 130 700 oz at a grade of 2.46 g/t. The deposit remains open at depth and along strike to the south, with planning in place to be tested in 2022.
GK deposit, contains 86 600 oz reserves at a grade of 2.86 g/t which are contained within the US$1500/oz pit design. The deposit has recently started to be mined and the company is currently evaluating GK as a potential underground mining operation. The company is also considering adding new reserves in 2022 by converting the large Indicated high-grade resource beneath the pit design to underground reserves.
SE deposit, located approximately 20 km from the process plant, reported a maiden opencast reserve of 100 300 oz at a grade of 2.64 g/t. SE has undergone a large resource infill and extension campaign of approximately 15 000 m in 2021, designed to increase the current deposit’s reported reserves number. The Sankarani Shear Zone, with mineralisation over 1.2 km of the 3 km long structure that also hosts the KE and GK deposits, is one of the geological structures in Mali the company sees potential for more future upside in both resources and reserves.
SW deposit, located some 25 km from the process plant, is a source of oxide ore for the current LOM at Yanfolila. Drilling in 2020 and 2021 continues to show that mineralisation is open at depth and to the North. Due to reclassification of resources for SW, the reserve was 12 600 oz lower than reported in 2019. Additional resource drilling completed in 2021 is expected to increase reserves to its original 2019 reserve number, or potentially greater.
The company has a focused plan on where the future reserves growth will come from to achieve its stated goal of a minimum 10-year LOM in reserves at Yanfolila. This updated company reserves statement highlights Hummingbird has a variety of sources to achieve this goal, including opencast, underground and under evaluation heap leach options.
Hummingbird commissioned CSA Global Pty Ltd, an ERM Group Company, to prepare a JORC-compliant ore reserve estimate for the Yanfolila gold mine opencast deposits, and Mining Plus to prepare a JORC-compliant ore reserve estimate for the Yanfolila KEUG deposit.
An ore reserve estimate of 6.8 million t at 2.3 g/t has been declared and classified as proved ore reserves of 0.9 million t at 1.23 g/t and probable ore reserves of 5.9 million t at 2.46 g/t ore reserve for the Yanfolila GoldMine, reported following the JORC Code (2012 Edition).
Kouroussa, Guinea reserves summary
The company acquired the Kouroussa Gold Mine in September 2020 and is in the construction stage, scheduled for first gold pour the end of 2Q23. The mining licenses are in the prolific, gold rich Siguiri Basin located within the West African nation of Guinea. Kouroussa currently hosts a MRE of 1.177 million oz comprising 7.4 million t at 3.54 g/t (indicated of 3.8 million t at 3.96 g/t and inferred of 3.6 million t at 3.09 g/t).
The Kouroussa mine is made up of four key known deposits where resources have been defined and reported in the May 2020 MRE. In this company reserve statement, the key deposit, Koekoe has a maiden reserve of 408 900 oz at 4.38 g/t. Only limited drilling at depth has been carried out however, in 2022, the company’s geology team is planning for further drill testing at depth to extend the known resources and reserves for this deposit.
The other three key deposits at Kouroussa, Kinkine, X-Vein and Bag-Farm-Junction, are all relatively smaller deposits to the main deposit Koekoe and are currently limited by the shallow nature of the drilling depths conducted so far. Collectively the three deposits comprise an additional +200 000 oz in resources (reported within a US$$1750/oz pit shell as used for resources), however with further geological study and analysis, future resource growth is scheduled to be tested in 2022 and beyond.
The company has been carrying out an infill drill programme in 2021 at Kouroussa of approximately +24 000 m focusing on converting the in-pit (contained within the US$1500/oz pit design) inferred to indicated resource base, of which there is approximately 200 000 oz.This 2021 drilling campaign will be included in the 2022 company resource and reserve statements scheduled for release in 2Q22.
Hummingbird requested CSA Global to provide an independent maiden ore reserve statement prepared by a competent person according to the Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves (JORC Code, 2012 Edition).
An ore reserve estimate of 2.9 million t at 4.38 g/t has been declared as a probable ore reserve for the Kouroussa Gold Project, reported in accordance with the JORC Code (2012 Edition).
Read the article online at: https://www.globalminingreview.com/mining/25112021/hummingbird-resources-provides-2021-reserve-update/
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