Mount Burgess Mining N L : Clarification of ASX 10 February 2021 Announcement 11/02/2021 (pdf 224 KB)

11 February 2021

ASX CODE: MTB

Kihabe-Nxuu Polymetallic Zn/Pb/Ag/Ge/V Project

Analysis of Milled Size Fractions from Vertical Milling

On 10 February 2021 the Company released to the market information regarding test work conducted to investigate whether or not there was any concentration of mineralisation within certain vertically milled size fractions.

Subsequent queries raised indicate there to be some misunderstanding of the results of the test work.

Primary Purpose of Vertical Milling Test Work

The primary purpose of the Vertical Milling test work conducted by Energy Densification Systems (EDS) South Africa was to determine whether or not Vertical Milling could be applied effectively to the Nxuu Deposit ore. The test work showed that Vertical Milling produced very encouraging results to the extent that the required power consumption can be reduced by as much as 40%, compared to the amount of power required for conventional Ball/SAG/Rod mills.

Ancillary Test Work

Further test work was then conducted to determine whether the Vertical Milling process caused excessive concentrations of mineralisation within certain size fractions. Such concentrations would potentially require additional separation processes, thereby making further processing more complex.

Assaying of the vertically milled size fractions has confirmed that Vertical Milling does not produce excessive concentrations of mineralisation within particular size fractions. This confirms that the application of a standard separation process from the overall milled product for the recovery of metal or concentrate is practicable and less complex compared to dealing with concentrations of mineralisation within certain size fractions.

ACN: 009 067 476 8/800 Albany Hwy East Victoria Park

Western Australia 6101

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Forward Looking Statement

This report contains forward looking statements in respect of the projects being reported on by the Company. Forward looking statements are based on beliefs, opinions, assessments and estimates based on facts and information available to management and/or professional consultants at the time they are formed or made and are, in the opinion of management and/or consultants, applied as reasonably and responsibly as possible as at the time that they are applied.

Any statements in respect of Ore Reserves, Mineral Resources and zones of mineralisation may also be deemed to be forward looking statements in that they contain estimates that the Company believes have been based on reasonable assumptions with respect to the mineralisation that has been found thus far. Exploration targets are conceptual in nature and are formed from projection of the known resource dimensions along strike. The quantity and grade of an exploration target is insufficient to define a Mineral Resource. Forward looking statements are not statements of historical fact, they are based on reasonable projections and calculations, the ultimate results or outcomes of which may differ materially from those described or incorporated in the forward looking statements. Such differences or changes in circumstances to those described or incorporated in the forward looking statements may arise as a consequence of the variety of risks, uncertainties and other factors relative to the exploration and mining industry and the particular properties in which the Company has an interest.

Such risks, uncertainties and other factors could include but would not necessarily be limited to fluctuations in metals and minerals prices, fluctuations in rates of exchange, changes in government policy and political instability in the countries in which the Company operates.

Other important Information

Purpose of document: This document has been prepared by Mount Burgess Mining NL (MTB). It is intended only for the purpose of providing information on MTB, its project and its proposed operations. This document is neither of an investment advice, a prospectus nor a product disclosure statement. It does not represent an investment disclosure document. It does not purport to contain all the information that a prospective investor may require to make an evaluated investment decision. MTB does not purport to give financial or investment advice.

Professional advice: Recipients of this document should consider seeking appropriate professional advice in reviewing this document and should review any other information relative to MTB in the event of considering any investment decision.

Forward looking statements: This document contains forward looking statements which should be reviewed and considered as part of the overall disclosure relative to this report.

Disclaimer: Neither MTB nor any of its officers, employees or advisors make any warranty (express or implied) as to the accuracy, reliability and completeness of the information contained in this document. Nothing in this document can be relied upon as a promise, representation or warranty.

Proprietary information: This document and the information contained therein is proprietary to MTB.

Competent Persons' Statements:

The information in this report that relates to mineralogical and metallurgical test work results conducted on samples from the Nxuu Deposit fairly represents information and supporting documentation approved for release by Mr Chris Campbell-Hicks, Metallurgist, FAusIMM (CP Metallurgy),MMICA, Non-Executive Director of the Company, who reviewed the content of the announcement. Mr Campbell-Hicks has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity being undertaken to qualify as a Competent Person as defined in the 2012 Edition of the JORC Code and has consented to the inclusion in respect of the matters based on the information in the form and context in which it appears.

Mr Campbell-Hicks has for a number of years whilst working with Coffey Mining and other consultancies and companies made contributions to numerous Scoping Studies, Pre-feasibility Studies and Feasibility Studies under the 2004 JORC Code, the 2012 JORC Code and the Canadian National Instrument (NI 43-101). As such he qualifies as a Competent Person for reporting on matters pertaining to metallurgy, process engineering and interpretation of test work results and data for the establishment of Design Criteria for such studies.

The following extract from the JORC Code 2012 Table 1 is provided for compliance with the Code requirements for the reporting of drilling results.

Section 1 Sampling Techniques and Data (Criteria in this section apply to all succeeding sections).

Criteria	JORC code explanation	Commentary
Sampling techniques	Nature and quality of sampling (eg cut channels, random chips, or specific specialised industry standard measurement tools appropriate to the minerals under investigation, such as down hole gamma sondes, or handheld XRF instruments, etc). These examples should not be taken as limiting the broad meaning of sampling. • Include reference to measures taken to ensure sample representivity and the appropriate calibration of any measurement tools or systems used. • Aspects of the determination of mineralisation that are Material to the Public Report. • In cases where 'industry standard' work has been done this would be relatively simple (eg 'reverse circulation drilling was used to obtain 1 m samples from which 3 kg was pulverised to produce a 30 g charge for fire assay'). In other cases more explanation may be required, such as where there is coarse gold that has inherent sampling problems. Unusual commodities or mineralisation types (eg submarine nodules) may warrant disclosure of detailed information.	Mount Burgess Mining Diamond Core Holes HQ Diamond Core was marked and collected in sample trays, visually logged and cut in half. Samples were collected as nominal 1m intervals but based on visible geology with minimum samples of 0.3m and maximum samples of 1.3m. Half of each core was retained on site in core trays and the other half was double bagged and sent to Intertek Genalysis Randburg, South Africa where they were crushed. A portion of each intersection sample was then pulverised to p80 75um and sent to Intertek Genalysis for assaying via ICPMS/OES for Ag/Co/Cu/Ga/Ge/In/Pb/V/Zn. Mount Burgess Mining Reverse Circulation Holes Individual meters of RC drill chips were bagged from the cyclone. These were then riffle split for storage in smaller bags, with selected drill chips being stored in drill chip trays. A trowel was used to select drill chip samples from sample bags to be packaged and sent to Intertek Genalysis, Randburg, South Africa where they were crushed. A portion of each intersection's sample was then pulverised to P80 75um and sent to Intertek Genalysis, Maddington, WA, for assaying via ICP/OES for Ag/Co/Cu/Pb/Zn. Mount Burgess Mining Diamond Core Samples submitted for Metallurgical Test Work The remainder of the crushed samples were then sent from Intertek Genalysis Randburg to Intertek Genalysis Maddington, Western Australia where they were then collected by the Company for storage. Samples from various intersections from six drill holes NXDD030, NXDD033, NXDD037, NXDD039, NXDD040 and NXDD043, as shown in Figure 1 of the Company's announcement of 28 May 2019 to ASX, were selected by the Company for submission for sensor sorter metallurgical test work. These samples were chosen to determine if Sensor Sorter X-ray Test Work developed by STEINERT could be used to pre-concentrate zinc, lead, silver, germanium and vanadium pentoxide mineralization prior to milling and flotation. Results of the +4mm STEINERT Metallurgical Test Work were reported on 20 August 2019.
Drill type (eg core, reverse circulation, open-hole hammer, rotary air blast, auger, Bangka, sonic, etc) and details (eg core diameter, triple or standard tube, depth of diamond tails, face-sampling bit or other type, whether core is oriented and if so, by what method, etc).	Mount Burgess Mining Diamond Core Holes HQ diameter triple tube was used for diamond core drilling. As all holes drilled into the Nxuu deposit were vertical holes the diamond core was not orientated. Mount Burgess Mining RC Hole One vertical RC hole was drilled into the Nxuu Deposit mineralised zone.
Drill sample recovery	Method of recording and assessing core and chip sample recoveries and results assessed. • Measures taken to maximise sample recovery and ensure representative nature of the samples. • Whether a relationship exists between sample recovery and grade and whether sample bias may have occurred due to preferential loss/gain of fine/coarse material	Mount Burgess Mining Diamond Core and RC Holes Sample recoveries were in general high and no unusual measures were taken to maximise sample recovery other than the use of triple tube core for diamond core drilling. Mount Burgess believes there is no evidence of sample bias due to preferential loss/gain of fine/coarse material.
Logging	Whether core and chip samples have been geologically and geotechnically logged to a level of detail to support appropriate Mineral Resource	Mount Burgess Mining Diamond Core Holes and RC Hole Holes were logged in the field by qualified Geologists on the Company's log sheet template and of sufficient detail
estimation, mining studies and metallurgical studies. • Whether logging is qualitative or quantitative in nature. Core (or costean, channel, etc) photography. • The total length and percentage of the relevant intersections logged.	to support future mineral resource estimation: Qualitative observations covered Lithology, grain size, colour, alteration, mineralisation, structure. Quantitative logging included vein percent. SG calculations at ~5m intervals were taken in the DD holes. All holes were logged for the entire length of hole. Logs are entered into MTBs GIS database managed by MTB in Perth.
Sub-sampling techniques and sample preparation	If core, whether cut or sawn and whether quarter, half or all core taken. • If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet or dry. • For all sample types, the nature, quality and appropriateness of the sample preparation technique. • Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples. • Measures taken to ensure that the sampling is representative of the in situ material collected, including for instance results for field duplicate/second-half sampling. • Whether sample sizes are appropriate to the grain size of the material being sampled	Mount Burgess Mining Diamond Holes and RC Hole HQ Core was sawn in half on site. Half of each core was retained on site in core trays and the other half was double bagged and labelled noting Hole# and interval both within the bag and on the bag. Sample bags were then placed in larger bags of ~40 individual samples and the larger bags also labelled describing the contents. Field duplicates were inserted at regular intervals. Core Retained on Site In November 2020: • ½ HQ diamond core amounting to 688 kg from 14 drill holes from the Nxuu Deposit was sent to EDS South Africa to conduct Vertical Milling Test work. Results from this test work were released to the market on 3 December 2020. • 330 kg of ½ HQ diamond core from 10 drill holes from the Nxuu Deposit was sent to STEINERT Australia to conduct bulk sensor sorter x-ray test work to verify initial test work reported to the market 20 August 2019. • 6-10 kg of ½ HQ diamond core from three Kihabe deposit drill Holes were sent to Naples University to conduct mineralogical test work to determine the host minerals for Vanadium and Germanium. All samples were assayed for Ag/Co/Cu/Ga/Ge/In/Pb/V/Zn. All RC sample bags were labelled with drill hole number and sample interval and collectively stored in larger bags with similar reference. Drill chip trays were all stored separately. All samples were assayed for Ag/Co/Cu/Pg/Zn.
Quality of assay data and laboratory tests	•The nature, quality and appropriateness of the assaying and laboratory procedures used and whether the technique is considered partial or total •For geophysical tools, spectrometers, hand-held XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibration factors applied and their derivation etc. • nature of quality control procedures adopted (e.g. standards, blanks, duplicates, external laboratory checks ) and whether acceptable levels of accuracy (i.e. lack of bias) and precision have been established.	All Mount Burgess Samples All samples, when originally assayed, were sent to Intertek Genalysis Perth, for assaying according to the following standard techniques: Diamond Core Samples (a) Ore grade digest followed by ICP - OES finish for Silver, Lead, Vanadium & Zinc (b) Nitric acid/hydrofluoric acid specific digest for Germanium and Indium (c) Also 4 acid digest for silver, lead, zinc, germanium and gallium followed by AAS RC Samples Ore grade digest followed by ICP-OES for Ag/Co/Cu/Pb/Zn All samples submitted for the Steinert Test Work, once separated through the Sensor Sorter X-ray process, were then submitted to NAGROM Laboratories for the upgraded concentrates to then be assayed by mixed acid digest with ICP finish for Vanadium, Lead, Zinc and Silver. Mount Burgess quality control procedures include following standard procedures when sampling, including sampling on geological intervals, and reviews of sampling techniques in the field. The current laboratory procedures applied to the Mount Burgess sample preparation include the use of cleaning lab equip with compressed air between samples, quartz flushes between high grade samples, insertion of crusher duplicate QAQC samples, periodic pulverised sample particle size (QAQC) testing and insertion of laboratory pulp duplicates QAQC samples according to Intertek protocols.