By-product and Metallurgical Process Development
18 November 2021
AfriTin Mining Limited
("AfriTin" or the "Company")
By-product and Metallurgical Process Development Programme
AfriTin Mining Limited (AIM: ATM), an African tech-metals mining company with a portfolio of mining and exploration assets in Namibia in tin, lithium and tantalum, with its flagship asset, the Uis Tin Mine ("Uis") in Namibia, is pleased to provide an update on its by-product and metallurgical process development programme.
▪ Density-based lithium beneficiation test work has achieved petalite concentrate grades in excess of 4% Li2O and within contaminant specifications for a typical saleable technical grade petalite product;
▪ The Company will proceed with the design and procurement of pilot lithium beneficiation facility;
▪ Test work successful in producing a high-grade, saleable specification tantalum concentrate (>24% Ta2O5); and
▪ The Company to proceed with the implementation of tantalum concentrating circuit.
Anthony Viljoen (CEO) Commented:
"The metallurgical test work results confirm the production potential of separate saleable lithium and tantalum concentrates. Implementation of these by-product streams could substantially transform the overall economics and unit cost of production for the current Phase 1 facility. More importantly, it provides an outstanding platform for the future large-scale Phase 2 facility with a planned production capacity of more than 8 times the current facility. By implementing the pilot phase development of these separate elements, the Company aims to take advantage of the burgeoning technology metals market by fast tracking the by-product streams into production.
We are encouraged by the rapid progress on our metallurgical test work programme in support of our goal of becoming a major player in the tech-metal mining sector."
The Company has embarked on an aggressive strategy to maximise returns by producing by-products and maximising processing throughput. The programmes to develop separate tantalum and lithium concentrate by-products are advancing to the piloting phase.
Lithium By-product Development:
Lithium oxide at Uis occurs primarily as the mineral petalite in the ore which is treated by the current processing facility. The occurrence of petalite is consistent throughout the mineral resource. The Company aims to produce a premium technical grade petalite concentrate. Although petalite contains comparatively less lithium than the more common spodumene (petalite has a theoretical limit of 4.9% Li2O), the low contaminant levels of technical grade petalite makes it suitable for the glass and ceramics market, therefore attracting a premium to the typical chemical grade spodumene concentrate. A technical grade petalite concentrate typically contains a minimum of 4.0% Li2O, a maximum of 0.05% Fe2O3 and alkali metal compounds (Na2O + K2O) of less than 1.0%. The Company is also investigating possible offtake routes in the battery materials market.
Test work to date focussed on processing several samples from the current plant feed and discard streams to produce petalite concentrates. Dense Medium Separation (DMS) test work on laboratory scale as well as piloting scale has achieved an upgrade in Li2O of 4 times and higher, with several samples producing grades above 4.0% Li2O and contaminant levels within technical grade specifications. The test work has been expanded to include milling and flotation as a method of further upgrade and maximising recovery of Li2O.
The Company will proceed with the design and procurement for a pilot petalite concentration plant. The process flow design of a petalite concentration circuit is planned as a combination of density separation, flotation and magnetic separation methods. The circuit will be fed with coarse discard material from the first stage of DMS in the current processing plant on a batch basis. The facility will have a processing capacity of 20 tonnes per hour and is intended as a pilot for an integrated full-scale petalite concentrate circuit (120 tonnes per hour).
The pilot plant is expected to cost GBP2.2 million, consisting of CAPEX and operating costs over the course of the pilot campaign. The plant will be funded from existing cash reserves. The Company plans to operate the plant for an initial period of 6 months, generating bulk product sales for the purpose of establishing a long-term offtake agreement. Results from this pilot will inform a bankable feasibility study for the integrated full-scale circuit. AfriTin is engaging with possible EPCM partners for the implementation of the pilot plant by Q2 of 2022, to be followed by the implementation of the full-scale petalite concentrate circuit.
Tantalum By-Product Development:
Tantalum at Uis occurs primarily within Columbite Group Minerals (CGM) which have a similar density to the tin bearing mineral cassiterite and is currently recovered as part of the tin concentrate. At present, the Company does not receive a credit for the contained tantalum within the tin concentrate. Therefore, the aim is to separate the tantalum bearing minerals from the tin concentrate and create a by-product at a typical saleable grade of 20% Ta2O5.
Magnetic separation is a proven technology for the separation of Ta-bearing CGM from non-magnetic minerals such as Cassiterite. Following the initial focus on wet magnetic separation techniques, recent work investigated dry magnetic separation techniques. Production of concentrates containing in excess of 24% Ta2O5 was achieved from separate samples submitted to two independent service providers using similar processing strategies and equipment.
Based on the above results, the Company will proceed with the implementation of a pilot beneficiation circuit to further process the currently produced tin concentrate employing dry screening and a high intensity dry electromagnetic separation to produce a separate tantalum concentrate. The circuit has an estimated capital cost of GBP0.3 million and will be funded from existing cash reserves. Construction of the circuit will be managed by AfriTin's in-house engineering team.
The pilot tantalum separation circuit will treat the entire stream of currently produced tin concentrate. The Company expects to progress seamlessly from the pilot phase to the final circuit configuration through process optimisation over a period of 6 months.
Glossary of abbreviations
Tin bearing mineral
Dense Medium Separation
Columbite Group Minerals, which is tantalum bearing
Elemental symbol for Lithium
Li → Li2O
Conversion factor of 2.153
Low iron lithium bearing silicate
Quality Assurance Quality Control
Elemental symbol for Tin
Elemental symbol for Tantalum
AfriTin Mining Limited
+27 (11) 268 6555
Anthony Viljoen, CEO
+44 (0) 20 7220 1666
WH Ireland Limited
Corporate Advisor and Joint Broker
H&P Advisory Limited
+44 (0) 20 7907 8500
Tavistock Financial PR (United Kingdom)
+44 (0) 20 7920 3150
About AfriTin Mining Limited
Notes to Editors
AfriTin Mining Limited is the first pure tin company listed in London and its vision is to create a portfolio of globally significant, conflict-free, tin-producing assets. The Company's flagship asset is the Uis Tin Mine in Namibia, formerly the world's largest hard-rock open cast tin mine.
AfriTin is managed by an experienced board of directors and management team with a current strategy to ramp-up production at the Uis Tin Mine in Namibia to 10,000 tonnes of concentrate in a Phase 2 expansion, having reached Phase 1 commercial production in 2020. The Company strives to capitalise on the solid supply/demand fundamentals of tin by developing a critical mass of tin resource inventory, achieving production in the near term and further scaling production by consolidating tin assets in Africa.