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Tuesday 16 January, 2018

Mineral & Financial

Investment Update

RNS Number : 9368B
Mineral & Financial Invest. Limited
16 January 2018
 

 

Minerals and Financial Investments Limited

 

Lagoa Salgada Positive Results From Mineralogical Tests

 

 

HIGHLIGHTS:

 

·     Encouraging mineralogical test results which point to relatively good expected metallurgical recoveries

·     Unexpected positive results from the tests on the Gossan with high tin assays of 2.25% (SnO2) by weight.

·     Indicated Tin content in the Gossan could significantly improve the economics of the deposit.

·     Within the massive sulphides - zinc is mostly as sphalerite.

·     The sum of the liberated and high grade sphalerite (zinc) averages 72%, which is a good liberation average in light of the grind size.

·     Lead is mostly as galena within the massive sulphide and has a relatively high liberation average of 62% on a first grind

·     The LS-1 Central Sector ore has very few contaminants and could improve the overall value of the LS-1 concentrate through blending.

 

George Town, Cayman Island - January 16 2018 - Mineral & Financial Investments is very pleased to announce its 49%-owned investment, TH Crestgate GmbH, a private Swiss-based investment company has released  the results of mineralogical tests on the LS-1 deposit at the 100%-owned Lagoa Salgada zinc-copper project in southern Portugal. The deposit's current resource is 4.5Mt, with a zinc equivalent grade of 8.2% (see RNS of August 27, 2015). A resource update is expected to be released shortly. The results partly delayed pending the completion of these mineralogical test results, which will be incorporated into the resource update document. The resource update is being completed by AGP Mining Consultants Inc. of Canada.

 

The Iberian Pyrite Belt (IPB) is home to some of the largest Volcanogenic Massive Sulphide (VMS) ore bodies in the world. The VMS ore bodies of the IBP have the potential to be both large and poly-metallic. These ore bodies are normally zinc, lead and copper rich, as is the Lagoa Salgada ore body, situated at the north-central edge of the IPB. VMS systems often have some paragenetic complexity, due to the different metals, mineralogy, size of particles and any contaminants. Metallurgy can be an important determinant of a project's economics on the IPB.

Jacques Vaillancourt, Chairman of Mineral and Financial, stated that -"These results from TH Crestgate were better than we had expected. Metallurgy is an important determinant of the economics of the Iberian Pyrite Belt ore bodies. The good liberation of the sphalerite and galena appears to match, and we believe it could perhaps exceed that of neighbouring major operating mines. Secondly, the major contaminant appears to be arsenopyrite, which can be preferentially excluded from the final concentrates. Thirdly, the ore from the Central Sector is very clean and could easily be blended into the LS-1 concentrate, which would serve to reduce any overall penalties from the smelters. Lastly, the big surprise was the presence of high-grade (2.25% Sn) tin in the Gossan. TH Crestgate had not initially asked ALS to assay for tin when testing the core from the 2017 drilling campaign. On the back of this result, a sample from LS-MS-01 has been resent to ALS for a secondary assay to confirm the presence of tin in the sample. "

 

TH Crestgate retained Empresa de Perfuração e Desenvolvimento Mineiro, S.A.
(EDPM) to complete a mineralogical analysis using an Automated Mineralogy by Mineral Liberation Analyzer (MLA). EDPM is an independent mining contractor and formerly owned by Almina, a private Portuguese company that owns the Aljustrel Mine, located in Portugal, which is the second largest mine in Portugal on the Iberian Pyrite Belt, after Neves Corvo (Lundin Mining). EDPM was selected because of their in depth knowledge and experience on the metallurgy of the IPB.

The tests were performed on samples from all 3 types of lithologies found in the Lagoa Salgada ore body: Gossan, Massive-Sulphides, and Stockwork mineralisation. The fifteen samples were from pulps of core samples from the 2017 drill program. These samples are representative of a first grind mill process (i.e. 60 microns (μm)). 

 

Sphalerite is the main zinc bearing mineral, usually representing 99% of the contained zinc. In general most of the sphalerite is liberated at the 60μm grain size. In each of the sphalerite samples liberation levels achieved ranged between 50% and 90% with an average of 63%, which is relatively high for the IBP, especially considering the grind size of 60μm. The sum of the liberated particles is considerably higher, reaching an average of 72% of the sphalerite.

 

The results by mineralization type reveal that the best theoretical recovery for the sphalerite will come from the stockworks, followed by the Massive Sulfide zones. The stockwork mineralization will require a smaller, likely secondary grind cycle. The sphalerite liberation in all the samples ranged from as high as 92.9% to a low of 36.8% with an average of 72%, from what is a first grind equivalency.

 

Galena is the main lead-bearing mineral, with the exception of the Gossan, where lead is distributed mostly in schultenite. Schultenite was found in very small percentages, and was found in only 2 samples, (Samples: MS-01-159 = 0.07%, and; MS-01-159 = 1.22%). The liberation of the Galena is very similar to the sphalerite. The un-liberated galena can be released by a smaller grind size, with some limitations. The Galena samples for the Stock-work mineralization, similar to the Sphalerite samples, will likely achieve the highest recoveries, followed by the Massive Sulfides. The Galena found in the Stringer zones is finer; regrinding may imply losses due to ultrafine particles. The Galena liberation (liberated particles and high grade[1]) in all the samples ranged from as high as 90.3% to a low of 22.3% with an average of 62%, from what is a first grind equivalency.

 

MODAL MINERALOGY FOR THE DIFFERENT LITHOLOGIES

see table 1 for detailed breakdown

http://www.rns-pdf.londonstockexchange.com/rns/9368B_-2018-1-15.pdf

 

MODAL MINERALOGY OF ALL SAMPLES

http://www.rns-pdf.londonstockexchange.com/rns/9368B_-2018-1-15.pdf

 

DIFFERENT LIBERATION BY COMPOSITION

Target mineral is in blue

http://www.rns-pdf.londonstockexchange.com/rns/9368B_-2018-1-15.pdf

 

SPHALERITE GRADE RECOVERY

Fissural Remobilization (i.e. Stock-work) Samples - Theoretical Grade-Recovery Curve

 http://www.rns-pdf.londonstockexchange.com/rns/9368B_-2018-1-15.pdf

 

SPHALERITE GRADE RECOVERY

Massive Sulfide Samples - Theoretical Grade-Recovery Curve

 http://www.rns-pdf.londonstockexchange.com/rns/9368B_-2018-1-15.pdf

 

SPHALERITE GRADE RECOVERY

Stringer Zone Samples - Theoretical Grade-Recovery Curve

 http://www.rns-pdf.londonstockexchange.com/rns/9368B_-2018-1-15.pdf

 

GALENA GRADE RECOVERY

Fissural Remobilization (i.e. Stockwork) - Theoretical Grade-Recovery Curve

 http://www.rns-pdf.londonstockexchange.com/rns/9368B_-2018-1-15.pdf

 

GALENA GRADE RECOVERY

Massive Sulfide Zone Samples - Theoretical Grade-Recovery Curve

 http://www.rns-pdf.londonstockexchange.com/rns/9368B_-2018-1-15.pdf

 

GALENA GRADE RECOVERY

Stringer Zone Samples - Theoretical Grade-Recovery Curve

 http://www.rns-pdf.londonstockexchange.com/rns/9368B_-2018-1-15.pdf

 

 

EDPM's analysis by metal determined that the metals of primary interest (zinc, lead, copper, silver and gold) are associated, mainly, with mono-mineralic crystallizations, with good percentages of liberated + high-grade particles from a ~60μm grind and some high-purity ores that may allow a blending to increase the quality of a future concentrate.

Zinc: Within the "LS-1" ore body massive sulfides zone, the zinc is (~99%) hosted in sphalerite. Within the "Central Sector" the majority of the zinc is hosted in carbonates (smithsonite). The LS-1 Central Sectors ore is particularly distinguished by the lower concentrations of Mercury (Hg) and would likely become an important blending asset, creating a more valuable and saleable concentrate.

The sum of the liberated and high-grade sphalerite particles is considerably high (considering the grind size) reaching an average of 72% of the total sphalerite. Plus, an important fraction of the un-liberated sphalerite is incorporated in the coarser particles that might be simply liberated a secondary grind stage.

Lead: The lead is practically exclusively hosted as galena, with the exception of the lead found in the Gossan (i.e. schultenite). The liberation of the galena at an average 60μm grind is very similar to the sphalerite.  The portion of the liberated and high-grade galena particles is high with an average of 62% in this simulated 60μm first grind. Galena is finer than sphalerite and would require a smaller grind for a higher liberation measure.

 

Copper:  Most of the copper is distributed as chalcopyrite and chalcocite on the higher Cu grade samples (Stringer, Stockwork and Gossan). Within the massive sulphides there are some other copper minerals e.g. enargite, tetrahedrite and kesterite.

Silver: The EDPM work reveals a very important feature about the silver mineralization. The report reveals that the silver is essentially linked to the galena. This is positive, inasmuch as the galena concentrates will carry most of the recoverable silver and this would improve payability for the silver in the concentrate overall. In the IPB silver can often be associated with other minerals which makes it much more difficult to recover and/or be paid for. Within the Gossan, the silver was identified in native metal, along with gold.

Gold: Due to the naturally fine size of gold, little information was expected from the EDPM report, however it was found with silver, in the Gossans.

Indium / selenium: The low concentration levels of Indium (In) and Selenium (Se) make it difficult to fully analyses the metals using Energy- dispersive X-ray Spectroscopy (EDS). Nevertheless, the indium is correlated with the sphalerite, indicating that the zinc concentrates may end up with high-levels of indium. An unusual feature of the Gossan is that it carries Selenium.

Tin: Historical drill assays at Lagoa Salgada identified the presence of tin (Sn). Moreover, the presence of tin is a known feature of several of the IBP VMS systems (e.g. Neves Corvo). However, the Gossan hosted unusually high levels of tin as cassiterite with one grade of ~2.25% SnO2 reported. For the most part, the cassiterite is liberated or associated with friable goethite. Samples from hole LS-MS-01 have been resent to ALS for re-assay following this discovery as tin was not one of the metals that ALS initially assayed for in the 2017 drill campaign.   

            Deleterious metals:  There were no new issues of deleterious metals identified within the EDPM report. The assays identified the known presence of Hg and Cd associated with sphalerite. There is now clear evidence that a "clean" zinc concentrate could be produced from the mineralization found in the Central Sector of the LS-1 deposit allowing for reduction in the average level of contaminants in any blended concentrate. Within the massive sulfide arsenic appears mostly as arsenopyrite, and not present in high concentrations in the main zinc or lead bearing minerals. With the removal, segregation and disposal of the arsenopyrite most part of the As and Sb will be removed. This means that any Zn, Pb, or Cu concentrates produced from LS-1 would not have significant penalties applied by smelters.

ASSET DESCRIPTION

 

The Lagoa Salgada resource is centred on one gravimetric anomaly called LS-1. There are a total of 17 gravimetric anomalies on the property. These anomalies remain to be fully tested. A petrographic study undertaken by TH Crestgate focused on the LS-1 area of the Lagoa Salgada property and also indicated the presence of anomalously high levels of indium in sphalaritic zones of mineralization. The ore body is composed of a stock work zone (LS-1 Central Sector) - a more than 700m thick volcano-sedimentary complex - and a massive sulfide lens in the northwest. It is covered by more than one hundred meters of sediments of the Sado-Tertiary basin.

 

The historical, Canadian Institute of Mining (CIM) compliant, resource estimate, located on LS-1, completed in 2012 by Paul Daigle, P.Geo, is summarized below:

 

Category

LS-1 Resource Summary

 

LS-1 Sector

 

Tonnes

 

Mineral

 

Grade

Contained Metal

 

Units

 

 

Indicated

 

 

2,942,000

Pb (%)

2.94

190,686,436

Lbs.

Zn (%)

3.40

220,521,729

Lbs.

Cu (%)

0.34

22,052,173

Lbs.

Ag (g/t)

54.72

5,175,824

Oz.

Au (g/t)

0.82

77,562

Oz.

 

 

Inferred

 

 

1,554,000

Pb (%)

2.50

85,648,710

Lbs.

Zn (%)

1.80

61,667,071

Lbs.

Cu (%)

0.35

11,990,819

Lbs.

Ag (g/t)

51.00

2,548,073

Oz.

Au (g/t)

0.78

38,971

Oz.

 

 

Total

 

 

4,496,000

Pb (%)

2.79

276,335,146

Lbs.

Zn (%)

2.85

282,188,800

Lbs.

Cu (%)

0.34

34,042,992

Lbs.

Ag (g/t)

53.43

7,723,897

Oz.

Au (g/t)

0.81

116,532

Oz.

           Source: Tetra-Tech Wardrop

 

References in this announcement to exploration results and resource updates have been approved for release by Joao Barros, BSc (Engineering), MSc (Geology), who has more than 14 years of relevant experience in the field of activity concerned. Mr. Barros is a Member of the Portuguese Engineers Association. Mr. Barros is employed by Redcorp Empreedimentos Mineiros, Lda., a wholly owned subsidiary of TH Crestgate GmbH, and has consented to the inclusion of the material in the form and context in which it appears.

 

This report should be seen as indicative of possible mineral content and not definitive, as the sample group is insufficient to arrive at any economic conclusions.

 

 

 

For more information:           

Katy Mitchell, WH Ireland Group Limited                                               +44 161 832 2174

Jon Belliss, Beaufort Securities Limited                                                   +44 207 382 8300

Jacques Vaillancourt, Mineral & Financial Investments Ltd.                     +44 780 226 8247



[1] The "high-grade particles" are from the "75%< x <90%" liberation class (see table 2). Usually these particles are not considered "liberated" but as they carry, at least, 75% of the mineral of interest they use to go directly to the concentrate, without need of regrind.


This information is provided by RNS
The company news service from the London Stock Exchange
 
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