29 Mar ALPHAMIN ANNOUNCES AN UPDATED MPAMA SOUTH MINERAL RESOURCE ESTIMATE AND THE DECISION TO COMMENCE WITH DEVELOPMENT
29 March 2022 – Alphamin Resources Corp. (AFM:TSXV, APH:JSE AltX, “Alphamin” or the “Company”), a producer of 4% of the world’s mined tin1 from its high-grade operation in the Democratic Republic of Congo, is pleased to announce an updated Mpama South Mineral Resource estimate and the decision to commence with the development of the Mpama South mine and processing plant.
- Mpama South updated Inferred Resource up 75% to 3.42Mt based on assays from 22 additional drillholes. Mpama South Mineral Resource now stands at:-
- 0.85Mt @ 2.55% Sn for 21.5kt contained tin in the Indicated category; and
- 3.42Mt @ 2.45% Sn for 83.7kt contained tin in the Inferred category
- Significant additional resource growth potential at Mpama South – drilling is on-going with considerable mineralisation intercepted beyond the updated Mineral Resource boundary
- Decision to commence with the development of Mpama South:-
- Targeted first tin production by December 2023
- Estimated annual contained tin production of 7,232 tonnes3 at an estimated AISC2 of US$15,188/t tin (Based on an assumed US$40,000/t tin price)
- Estimated annual EBITDA2 of US$187m3 at an assumed tin price of US$40,000/t
- Estimated capital development cost of US$116m providing a projected short payback in relation to annual EBITDA potential
- De-risked project execution with similar mining method, mining fleet and processing route as currently applied at Alphamin’s adjacent Mpama North Mine
- Capital development cost to be funded from cash reserves
- Mpama South’s development is expected to increase annual contained tin production from the current 12,000tpa to ~20,000tpa, approximating 6.6% of the world’s mined tin1
1Data obtained from International Tin Association Tin Industry Review 2020.
2This is a non-GAAP financial measure, is not standardized and may not be comparable to similar financial measures of other issuers. See “Use of Non-IFRS Financial Performance Measures” below for a further explanation of this performance metric and how it is calculated.
3Data obtained from Preliminary Economic Assessment study announced on 7 March 2022
Chief Executive Officer, Maritz Smith comments:
“The development of Mpama South as a brownfields expansion is expected to increase Alphamin’s annual tin production by 65% to a targeted 20,000t from FY2024. Tin and technology are inter-linked and consequently global demand for tin continues to increase despite constrained supply. This development decision and the resultant additional production expected by the end of 2023, positions us to deliver more tin into this widening market deficit.”
Mpama South Updated Mineral Resource Estimate
The updated Mineral Resource for Mpama South follows three weeks after the announcement of the maiden Mineral Resource in the Company’s announcement of 7th March 2022. The update is based on the receipt of assays for a further 22 drillholes to the original 79 drillholes on which the Maiden Mineral Resource estimate was based.
The updated Mineral Resource presented in Figure 1 closely follows the spatial position of reported assays which Alphamin presented in its 22nd March 2022 Company announcement. This practice of regularly plotting intercepted visual cassiterite and assays in news announcements, as an early indication of where Mineral Resources may potentially extend to and then following it up with regular Mineral Resource updates, is planned to continue during 2022.
Following the receipt of assays for the additional 22 drillholes, an updated Mineral Resource Estimate (MRE) for the Mpama South project was completed. The MRE, which now includes results from 102 drillholes, was estimated using the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Best Practice Guidelines (2019) and is reported in accordance with the 2014 CIM Definition Standards.
The Mineral Resource is classified into the Indicated and Inferred categories and is reported at a base case tin grade of 1.0%, which satisfies reasonable prospects for economic extraction. Mpama South Inferred Resources increased by 75% to 3.42Mt. The Mineral Resource Statement with an effective date of 28 March 2022 is presented in Table 1:-
Table 1: Updated Mpama South Mineral Resources effective 28 March 2022
4CIM Definition: An Indicated Mineral Resource is that part of a Mineral Resource for which quantity, grade or quality, densities, shape and physical characteristics are estimated with sufficient confidence to allow the application of Modifying Factors insufficient detail to support mine planning and evaluation of the economic viability of the deposit.
5CIM Definition: An Inferred Mineral Resource is that part of a Mineral Resource for which quantity and grade or quality are estimated on the basis of limited geological evidence and sampling. Geological evidence is sufficient to imply but not verify geological and grade or quality continuity.
Mineral Resources that are not Mineral Reserves do not have a demonstrated economic viability and require advanced studies and economic analysis to prove their viability for extraction.
The MRE for Mpama South does not include a substantial quantity of subsequent drilling containing characteristic high grade visual cassiterite. Around 30 additional drillholes and over ~10,000 metres beyond and within the limits of the updated MRE at Mpama South have been completed. Subsequent Mpama South MRE updates are expected to be released throughout the remainder of the drilling phases in 2022 and beyond as assays are received.
The MRE has been completed by Mr. J.C. Witley (BSc Hons, MSc (Eng.)) who is a geologist with 33 years’ experience in base and precious metals exploration and mining as well as Mineral Resource evaluation and reporting. He is a Principal Resource Consultant for The MSA Group (an independent consulting company), is registered with the South African Council for Natural Scientific Professions (SACNASP) and is a Fellow of the Geological Society of South Africa (GSSA). Mr. Witley has the appropriate relevant qualifications and experience to be considered a “Qualified Person” for the style and type of mineralisation and activity being undertaken as defined in National Instrument 43-101 Standards of Disclosure of Mineral Projects.
Preliminary Economic Assessment (PEA) Results on Mpama South
Summary results from the PEA announced on 7 March 2022 are tabulated below. The PEA was based on the maiden Resource estimate and excludes Resources from the updated MRE included in this announcement.
|Avg. Annualised ROM mined and processed||
|Avg. Annualised ROM grade||
|Avg. Annualised Contained tin produced||
|Avg. Annualised AISC per tonne contained tin sold (At US$40,000/t tin price)||
|Avg. Annualised AISC per tonne contained tin sold (At US$30,000/t tin price)||
|Avg. Annualised EBITDA (At US$40,000/t tin price)||
|Avg. Annualised EBITDA (At US$30,000/t tin price)||
|Development Capital Estimate||
* The outputs are based on 100% of the project. Alphamin indirectly owns 84,14% of the project.
The PEA is preliminary in nature, it includes Inferred Mineral Resources that are considered too speculative geologically to have economic considerations applied to them that would enable them to be categorized as Mineral Reserves. There is no certainty that the PEA results will be realized. Mineral Resources are not Mineral Reserves and do not have demonstrated economic viability, nor is there certainty that the Mineral Resource will be converted into Mineral Reserves.
Decision to commence with the development of Mpama South
PEA studies are conceptual in nature and are most commonly applied to projects at an early stage of exploration to conceptualise potential viability. A PEA is not a pre-feasibility or feasibility study and the Company does not purport the PEA results to be equivalent to a feasibility study. However, notwithstanding the very preliminary and conceptual nature of the PEA, based on the Company’s experience at Mpama North and knowledge base, including regarding underground conditions, the mining method and processing route, and the proximity and very similar characteristics of the deposits, the Company believes that Mpama South represents an immediately accessible adjacent Resource to the current producing Mpama North mine.
The Board has approved the commencement of development of Mpama South without delay taking account of:
- the opportunity to take advantage of the current and forecasted supply deficit in the tin market;
- the Company’s ability to self-fund its development from current and short-term forecasted cash reserves;
- the continued exploration success at Mpama South which has immediate potential for further resource extensions and successful conversion of inferred resources;
- the expected short payback on this capital investment;
- the potential significant value any additional production has to the operating profits of the Company in the near term.
The lead time to project completion and commissioning is estimated at 20 months with first tin production targeted by December 2023. The surface infrastructure and processing plant construction will be executed under an EPCM contract model, using contractors who are familiar with the Mpama North mine, and who have proven their competence at the mine to date. The underground mine development will be executed by a dedicated Alphamin mining team who will progress from developing the project to planned production mining.
Mr Jeremy Witley, Pr. Sci. Nat., B.Sc. (Hons.) Mining Geology, M.Sc. (Eng.), is a qualified person (QP) as defined in National Instrument 43-101 and has reviewed and approved the scientific and technical information relating to Mineral Resources contained in this news release. He is a Principal Mineral Resource Consultant of The MSA Group (Pty.) Ltd., an independent technical consultant to the Company.
Mr. Clive Brown, Pr. Eng., B.Sc. Engineering (Mining), is a qualified person (QP) as defined in National Instrument 43-101 and has reviewed and approved all scientific and technical information other than relating to the mineral resources contained in this news release. He is a Principal Consultant and Director of Bara Consulting Pty Limited, an independent technical consultant to the Company.
FOR MORE INFORMATION, PLEASE CONTACT:
Alphamin Resources Corp.
Tel: +230 269 4166
CAUTION REGARDING FORWARD LOOKING STATEMENTS
Information in this news release that is not a statement of historical fact constitutes forward-looking information. Forward-looking statements contained herein include, without limitation, statements relating to the results of the Mpama South PEA, including estimated development costs, estimated quantities of materials to be mined and processed, estimated grades, metallurgical recoveries and quantities of tin to be produced, and estimated costs of production and EBITDA, estimated time for mine construction, the merit and potential viability of the project, estimated Mineral Resources for Mpama South, development of a mine at Mpama South and anticipated exploration activities and outcomes. Forward-looking statements are based on assumptions management believes to be reasonable at the time such statements are made. There can be no assurance that such statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, readers should not place undue reliance on forward-looking statements. Although Alphamin has attempted to identify important factors that could cause actual results to differ materially from those contained in forward-looking statements, there may be other factors that cause results not to be as anticipated, estimated or intended. Factors that may cause actual results to differ materially from expected results described in forward-looking statements include, but are not limited to: uncertainties inherent in estimates of Mineral Resources, mine development and operating costs, mining volumes, grades and processing recoveries, particularly in light of the very early stage at which some of these estimates are being made, global economic uncertainties, volatility of metal prices, uncertainties with respect to social, community and environmental impacts, uninterrupted access to required infrastructure, adverse political geopolitical events, impacts of the global Covid-19 pandemic on mining, global supply chain issues which may cause longer lead-times to procure critical equipment and consumables which may delay project implementation as well as those risk factors set out in the Company’s Management Discussion and Analysis and other disclosure documents available under the Company’s profile at www.sedar.com. Forward-looking statements contained herein are made as of the date of this news release and Alphamin disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or results or otherwise, except as required by applicable securities laws.
USE OF NON-IFRS FINANCIAL PERFORMANCE MEASURES
This announcement refers to the following non-IFRS financial performance measures:
EBITDA is profit before net finance expense, income taxes and depreciation, depletion, and amortization. This measure assists readers in understanding the cash generating potential of the project including liquidity to fund working capital, pay taxes, service debt, and funding capital expenditures and investment opportunities.
This measure is not recognized under IFRS as it does not have any standardized meaning prescribed by IFRS and is therefore unlikely to be comparable to similar measures presented by other issuers. EBITDA data is intended to provide additional information and should not be considered in isolation or as a substitute for measures of performance prepared in accordance with IFRS.
This measures the costs to produce a tonne of contained tin plus the capital sustaining costs to maintain the mine, processing plant and infrastructure. AISC includes mine operating production expenses such as mining, processing, administration, indirect charges (including surface maintenance and camp and tailings dam construction costs), smelting costs and deductions, refining and freight, distribution, royalties and product marketing fees. AISC does not include depreciation, depletion, and amortization, reclamation expenses, borrowing costs and exploration expenses. Contractual product marketing fees terminate in August 2024, following which date zero marketing fees have been included in estimated AISC and EBITDA.
Sustaining capital expenditures are defined as those expenditures which do not increase contained tin production at a mine site and excludes all expenditures at the Company’s projects and certain expenditures at the Company’s operating sites which are deemed expansionary in nature.
Risks relating to Mineral Resource Estimates
The figures for Mineral Resources contained in this news release are estimates only and no assurance can be given that the anticipated tonnages and grades will be achieved, that the indicated level of recovery will be realized or that the Mineral Resources could be mined or processed profitably. There are numerous uncertainties inherent in estimating Mineral Resources, including many factors beyond the Company’s control. Such estimation is a subjective process, and the accuracy of any resource estimate is a function of the quantity and quality of available data and of the assumptions made and judgments used in engineering and geological interpretation. Short-term operating factors relating to the Mineral Resources, such as the need for orderly development of the ore bodies or the processing of new or different ore grades, may cause the mining operation to be unprofitable in any particular accounting period. In addition, there can be no assurance that metal recoveries in small scale laboratory tests will be duplicated in larger scale tests under on-site conditions or during production. Lower market prices, increased production costs, the presence of deleterious elements, reduced recovery rates and other factors may result in revision of its resource estimates from time to time or may render the Company’s resources uneconomic to exploit. Resource data is not indicative of future results of operations. If the Company’s actual Mineral Resources are less than current estimates or if the Company fails to develop its resource base through the realization of identified mineralized potential, its results of operations or financial condition may be materially and adversely affected.
Neither the TSX Venture Exchange nor its regulation services provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this news release.
Appendix 1: SAMPLE PREPARATION, ANALYSES AND QUALITY CONTROL AND QUALITY ASSURANCE (QAQC)
After receipt of diamond drill core from the drillers at the drill rig in marked core trays, core was transported to the Company’s core shed by the site geologist for logging and sampling. After sample mark up, lithological and geotechnical logging and photography, the core was split longitudinally in half using a water-cooled rotating diamond blade core saw. The cut core was replaced into the core tray with the half to be sampled facing upward. The Archimedes method of weight in air vs weight in water was used to provide relative density measurements on the whole length of the half core that was to be sampled and then replaced in the core trays.
Air dried samples were placed in pre-numbered sample bags together with pre-printed numbered sample tickets, which were cross-checked afterwards to prevent sample swaps. Sample bags were sealed using a plastic cable tie and then placed into poly-weave sacks which were in turn sealed with plastic cable ties. Each poly-weave sack was marked with a number and the sample numbers contained within, ready for delivery to the on-site Alphamin-Bisie laboratory (managed by Anchem) for sample preparation.
At the laboratory, samples were first checked off against the submission list supplied and then weighed and oven dried for 2 hours at 105 degrees Celsius. The dried samples were crushed by jaw crusher to 75% passing 2mm, from which a 250g riffle split was taken. This 250g split was pulverised in ring mills to 90% passing 75μm from which a sample for analysis was taken. Samples were homogenised using a corner-to-corner methodology and two samples were taken from each pulp, one of 10g for on-site laboratory preliminary assaying and another 150g sample for export and independent accredited 3rd party laboratory assaying.
For the initial on-site laboratory assay, 10 grams of pulverised sample is mixed with 2 grams of binder before press pellet preparation at 20t/psi for 1 minute. Press pellets are analysed in a desktop Spectro Xepos XRF analyser, twelve at a time, for Sn, Fe, Zn, Cu, Ag, Pb and As along with a standard, duplicate and blank. The analytical method conducted on the pressed pellet has an expected 10% precision and an upper detection limit of 70,000ppm and lower detection limit of 500ppm. Over-limit samples are titrated by wet chemistry with an upper limit validation of 70% Sn. The on-site laboratory assays are merely an exploration tool and were not used for reporting the exploration results or Mineral Resource estimation, which are based solely on the ALS assays.
The 150g sample is packaged in sealed paper sample envelopes and packed in a box for export in batches of approximately 500 samples and prepared for export authorisation with national authorities. Once authorisation is received, samples are air-couriered to ALS Global in Johannesburg South Africa, a subsidiary of ALS Limited, which is an independent commercial analytical facility. ALS operations are ISO 9001:2015 certificated and the Johannesburg office is ISO 17025 accredited for Chemical Analysis by SANAS (South African National Accreditation System, facility number T087), although the accreditation does not extend to the methods used for tin.
Received samples at ALS Johannesburg are checked off against the list of samples supplied and logged in the system. Quality Control is performed in the way of sieve tests every 50 samples and should a sample fail, the preceding 50 samples are ground in a ring mill pulveriser using a carbon steel ring set to 85 % passing 75μm. Samples are analysed for tin using method code ME-XRF05 conducted on a pressed pellet with 10% precision and an upper limit of 5,000ppm. The over-limit tin samples are analysed as fused disks according to method ME-XRF15c, which makes use of pre-oxidation and decomposition by fusion with 12:22 lithium borate flux containing 20% Sodium Nitrate as an oxidizing agent, with an upper detection limit of 79% Sn.
Method code ME-ICP61 (HF, HNO3, HClO4 and HCl leach with ICP-AES finish) is used for 33 elements including base metals. ME-OG62, a four-acid digestion, is used on ore grade samples for lead, zinc, copper and silver. Both methods are accredited by SANAS.
The program is designed to include a comprehensive analytical quality assurance and control routine comprising the systematic use of Company inserted standards, blanks and field duplicate samples, internal laboratory standards and analysis at an accredited laboratory. The pulps were accompanied by blind QAQC samples inserted into the sample stream by the Alphamin-Bisie geologists. These comprised blank samples, certified reference materials and pulp duplicates each at an insertion rate of approximately 5%.
The QAQC results demonstrate that the assay results are both accurate and precise with an insignificant amount of contamination (in the order of 10pmm Sn on average) and negligible sampling errors.
Laboratory verification work was conducted by check assays conducted at SGS South Africa (Pty) Ltd. This included 105 check samples submitted in November 2021. These samples comprised duplicated pulps from the maiden resource drillholes derived from the sample preparation at the on-site laboratory. CRMs and blanks to an appropriate level also formed part of the 105-sample submission. Check assay results showed that there was a near zero overall bias and that inter-lab precision, after removal of <0.10% Sn samples ,was ~85% within 10% error and ~95% within 20% error. Given the nature of high-grade tin variability and previous knowledge of umpire check exercises at the operation, these results are considered acceptable.
Appendix 3: Checklist of Assessment and Reporting Criteria
|Drilling techniques||All drillholes were diamond drill cored and drilled from surface (most intersections drilled using NQ size), holes drilled orientated in an east-west direction were angled between -60° and -70°. Holes collared in the west were drilled out in fan patterns into the side of a hill and angled between 0° and minus 35°.|
|Logging||All of the drillholes were geologically logged by qualified geologists. The logging is of an appropriate standard for grade estimation.|
|Drill sample recovery||Core recovery in the mineralised zones was observed to be very good and is on average 97%.|
|Sampling methods||Half core samples were collected continuously through the mineralised zones after being cut longitudinally in half using a diamond saw. Drillhole samples were taken at nominal 1 m intervals, which were adjusted to smaller intervals in order to target the cassiterite vein zones. Lithological contacts were honoured during the sampling. MSA’s observations indicated that the routine sampling was performed to a reasonable standard and is suitable for evaluation purposes.|
|Quality of assay data and laboratory tests||At the on-site ABM laboratory (managed by Anchem), samples were first checked off against the submission list supplied and then weighed and oven dried for 2 hours at 105 degrees Celsius. The dried samples were crushed by jaw crusher to 75% passing 2mm, from which a 250g riffle split was taken. This 250g split was pulverised in ring mills to 90% passing 75μm from which a sample for analysis was taken. Samples were homogenised using a corner-to-corner methodology and two samples were taken from each pulp, one of 10g for on-site laboratory assaying and another 150g sample for export and independent accredited 3rd party laboratory assaying.
Received samples at ALS Johannesburg are checked off against the list of samples supplied and logged in the system. Quality Control is performed by way of sieve tests every 50 samples and should a sample fail, the preceding 50 samples are ground in a ring mill pulveriser using a carbon steel ring set to 85 % passing 75μm. Samples are analysed for tin using method code ME-XRF05 conducted on a pressed pellet with 10% precision and an upper limit of 5,000ppm. The over-limit tin samples are analysed as fused disks according to method ME-XRF15c, which makes use of pre-oxidation and decomposition by fusion with 12:22 lithium borate flux containing 20% Sodium Nitrate as an oxidizing agent, with an upper detection limit of 79% Sn.
Prior to the 2021 drilling the assays were also conducted at ALS Global in Johannesburg where samples were analysed for tin using fused disc ME-XRF05 with 10% precision and an upper limit of 10 000 ppm. This was reduced to 5,000 ppm from 2014 onwards. Over limit samples were sent to Vancouver for ME-XRF10 which uses a Lithium Borate 50:50 flux with an upper detection limit of 60% and precision of 5%.
ME-ICP61, HF, HNO3, HCL04 and HCL leach with ICP-AES finish was used for 33 elements including base metals. ME-OG62, a four-acid digestion, was used on high grade samples for Pb, Zn, Cu & Ag.
External quality assurance of the laboratory assays for the Alphamin samples was monitored. Blank samples (223), certified reference materials (310) and duplicate samples (277) were inserted with the field samples accounting for approximately 11% of the total sample set.
The QAQC measures used by Alphamin revealed the following:
|Verification of sampling and assaying||The mineralisation in thirteen of the drillholes completed in 2021 at Mpama South were visually verified during a site-visits by the QP in August 2021 and several of the initial drillholes were examined during earlier site visits to Bisie. The QP observed the mineralisation in the cores and compared it with the assay results. It was found that the assays generally agreed with the observations made on the core. Core photos from the drilling programme have regularly been provided to the QP for inspection.
105 pulp duplicates were sent to SGS (Johannesburg) in November 2021 for confirmation assaying.
|Location of data points||The drillhole collar positions were surveyed using a differential GPS.
Downhole surveys were completed using a multishot down-hole survey instrument (Reflex EZ-Track), or north seeking gyro (Reflex EZ-Gyro / Reflex Gyro Sprint-IQ).
|Tonnage factors (in situ bulk densities)||Relative density measurements were made on the majority of recent drillhole samples using the Archimedes Principle of weight n air versus weight in water. A regression formula of tin grade against relative density was developed and applied to the samples that did not have direct measurements. The assigned specific gravity was interpolated into the block model using ordinary kriging.|
|Data density and distribution||A total of 107 holes were drilled in Mpama South. Holes were drilled steeply from east to west, along section lines spaced approximately 60 m to 80 m apart. Several sets of holes were drilled in a fan pattern into the side of a steep hill, with orientations spanning from the northeast to the southeast (from azimuth 045° to 125°). These drillholes fans intersect the mineralisation 25 m to 40 m apart in most of the Mineral Resource area.|
|Database integrity||Data was provided as Excel files. MSA completed spot checks on the database and is confident that the Alphamin database is an accurate representation of the original data collected.|
|Dimensions||The mineralisation consists of seven zones, with a total extent of 1 110 m along strike. The two main zones are MZ1 which has a strike length of 900 metres and 350 m down-dip and MZ2, with a strike length of 650 m and 350 m down-dip, accounting for 88% of the Mineral Resource.
The zones occurring in the footwall and hangingwall of the MZ1 and MZ2 tend to be narrower and irregular in shape with strike lengths from 100 m to 300 m. MZ6, which is located to the south has a strike length of 270 m and a dip length of 110 m.
|Geological interpretation||The mineralised intersections in drill core are clearly discernible. The Mineral Resource is interpreted to occur as irregular tabular mineralised zones, dipping 65-70° to the east, containing several narrow veins and disseminations of cassiterite. The mineralised zones are hosted in chlorite schist that is the result of intense hydrothermal alteration associated with a fracture system.
The two main zones of the Mineral Resource (MZ1 and MZ2) are continuous for almost 900 m, with average thicknesses of 4.1 m and 3.4 m respectively. However, the thicknesses of these two zones vary from as little as 1 m, up to 14 m thick.
Three smaller zones (MZ3 to MZ5) occur in the footwall of the main mineralisation which progressively become narrower, moving away from the main zone. MZ3 thickness ranges from 1 m to 9 m with an average thickness of 1.5 m. MZ4 has an average thickness of 1 m, attaining a maximum thickness of 5 m. MZ5 has an average thickness of 1.2 m, ranging from 1 m to 5 m. All zones become narrower along the edges, where they pinch-out.
A small, narrow zone (MZ7) occurs in the hangingwall of the main mineralisation with an average thickness of 0.5 m and a maximum thickness of 4 m.
MZ6, which occurs to the south, tends to be lower in grade and has an average thickness of 4 m, ranging from 1 m up to 9 m.
A three-dimensional wireframe model was created for the seven zones of mineralisation based on a grade threshold of 0.40% Sn. The MZ1 and MZ2 make up the main zone, which are the most consistent zones and occur within a persistent chlorite schist. Narrower less continuous zones occur above and below the main zone within chlorite-mica schists.
|Domains||The mineralisation was modelled as seven tabular zones containing irregular vein style mineralisation. A hard boundary was used to select data for estimation in order to honour the sharp nature of vein boundaries.|
|Compositing||Sample lengths were composited to 1 m by length and density weighting.|
|Statistics and variography||Statistics for the seven estimation domains show distributions that are positively skewed with coefficients of variation (CV) ranging from 1.33 to 1.97, the only exception being domain MZ7 which shows lower variability due to very few composites resulting in a CV of 0.79.
The two main zones (MZ1 and MZ2) have similar average tin grades (2.30% and 2.07% respectively). The smaller, footwall zones (MZ3 to MZ5) are higher in tin grade with averages ranging from 2.4% to 4.11% while MZ6 and MZ7 are lower in tin grade, with an average of 0.57% and 1.05% respectively.
Normal Scores semivariograms were calculated in the plane of the mineralisation, down-hole and across strike. Variograms were modelled for tin, with a range of 40 m within the plane of mineralisation and with a range of 3 m across the structures.
|Top or bottom cuts for grades||Top caps were applied to outlier values, identified as breaks in the cumulative, probability plots.|
|Data clustering||Data clustering occurs where the fan drilling, collared on the western side of the deposit, intersect the surface drilling collared in the east, resulting in a data spacing of 25 m to 40 m towards the centre of the deposit. Outside of this area, the grid spacing becomes more regular, 60m to 80 m along strike and 50 m down-dip.|
|Block size||A rotated block model with a parent cell of 10 mX by 10 mY by 2 mZ was used. Sub-celling was used to divide the parent cells to a minimum sub-cell of 1 mX by 1mY by 0.2 mZ to closely fit the narrow portions of the vein structures|
|Grade estimation||Tin, copper, lead, zinc, silver, arsenic and density were estimated using ordinary kriging. A minimum number of 5 and a maximum of 10 one metre composites were required for the tin and density estimates. A minimum of 5 and maximum of 8 composites were used for the other elements.
Estimation was carried out in three passes, with the first pass using search volumes coinciding with the variogram ranges. A second pass estimate expanded the search volumes by a factor of 1.5 to estimate blocks where insufficient samples were present for an estimate in the first pass. Where blocks remained un-estimated from the first two passes, a third pass, using an expansion factor of 10 was used to ensure all blocks in the model received a grade and density estimate.
Dynamic Anisotropy was used to orientate the search volumes to the strike and dip of the individual mineralised zones.
|Resource classification||Indicated Mineral Resources were declared where the drillhole spacing is approximately 40 m and where the geological model has low variability. The remainder of the interpreted model was classified as Inferred Mineral Resources, corresponding to areas informed by drilling spaced 50 m to 80 m apart with a maximum extrapolation of 20 m from the nearest drillhole.|
|Mining cuts and cut-off grade assumptions.||A minimum of 1 m was applied to the mineralisation model. The thickness, grade and steep dip implies that the Mineral Resource can be extracted using established underground mining methods similar to those applied at Mpama North.
A 1% cut-off grade was applied based on the Mpama North costs and prevailing tin price.
Isolated blocks above cut-off grade in dominantly low-grade areas of the model were not included in the Mineral Resource
|Metallurgical factors or assumptions||The tin mineralisation occurs as cassiterite, an oxide of tin (SnO2). At Mpama North gravity separation is used to produce a tin concentrate. The Cu, Zn and Pb mineralisation occurs as sulphides, which are removed by flotation to create the cassiterite product. It is assumed that similar processes will be used to process the Mpama South mineralisation.|
|Legal aspects and tenure||Alphamin through its wholly owned DRC subsidiary, Alphamin Mining Bisie SA, has a Mining License PE 13155 which includes the Bisie Tin Mine. Alphamin has an 84.14 percent interest in ABM. The Government of the Democratic Republic of Congo (GDRC) has a non-dilutive, 5% share in ABM.|
|Audits, reviews and site inspection||The following review work was completed by MSA: