Redcorp - Lagoa Salgada Metallurgical Test Results

RNS Number : 4802L

Mineral & Financial Invest. Limited

13 September 2021

 

Redcorp completes Phase 2 metallurgical testwork program at LAGOA SALGADA VMS PROJECT IN PORTUGAL

Highlights:

· Lagoa Salgada Metallurgical Test Results Support Use of a Conventional Polymetallic Process Flowsheet

· Flowsheet Indicate that Three (3) Saleable Concentrates Capable of Recovering Copper, Lead, Zinc, Gold, And Silver.

· Metal Recoveries Continue to Improve with additional testing

· Consultants State that they Believe That Metal Recoveries Will Be Equal or Better Than Average in the Iberian Pyrite Belt

· Full Pilot Metallurgical Test Expected in Q1-2022

George Town, Cayman Islands - September 13, 2021 - Mineral and Financial Investments Limited (LSE-AIM: MAFL) ("M&FI" "MAFL" or the "Company") is delighted to provide an update on one of its investee companies - Redcorp ("Redcorp" or the "Company"). The program is funded and guided by Ascendant Resources (Ascendant), which owns 25% of Redcorp, as part of Ascendant's previously announced earn-in agreement with Mineral and Financial (please refer to RNS of August 1, 2018 which has been amended see announcement dated 1 July 2020).

M&FI is pleased to announce results from Redcorp's Phase 2 metallurgical test work program, conducted by Grinding Solutions Limited (GSL), a UK mineral processing services company with strong technical knowledge of mineral processing of Iberian Pyrite Belt ("IBP") ores and has been guided by Micon International, who was responsible for the metallurgical results validation on material from both the massive sulphide and stockwork ores from the Venda Nova North and South Zones, at its Lagoa Salgada VMS project located in Portugal. 

In addition to supplementing further information regarding metal recoveries and concentrate grades, the Phase 2 metallurgical test work results support the use of a conventional polymetallic process flowsheet capable of recovering copper, lead, zinc, gold, and silver in three saleable concentrates. Flotation tailings will be leached for additional gold and silver values and t in will be recovered from processing the tailings material by flotation.

It should be noted that due to limited availability of fresh core, the testing material utilized was approximately 2 years old and highly oxidized which had a negative impact limiting results.  Grinding Solutions Ltd. is confident that with further work on fresh core, recovery expectations will be in line with or better than the average seen at existing mines on the Iberian Pyrite Belt. 

Jacques Vaillancourt, President & CEO of Mineral and Financial Investments stated, " We are very pleased that the test work completed by Grinding Solutions for Redcorp and Ascendant continued to show improved results as compared to previous results despite having less than ideal material.  We are also pleased that Grinding Solutions are confident in achieving at least benchmark recoveries for the IBP at Lagoa Salgada.  Enhanced testing developed a more robust and flexible flow sheet that could handle variability throughout the orebody and if encountered, also efficiently process oxidized fresh feed. They will continue to look for improvements with continued testing, which is likely to culminate in a full pilot test in Q1 2022. The testing of oxidized samples has been very helpful to fully understand the behavior of ore characteristics at Lagoa Salgada on an industrial scale and the results achieved in the Phase 2 test work program continues to provide the confidence necessary to initiate a full feasibility metallurgical test program in Q1 2022" .

The second stage of metallurgical testing was undertaken on samples with more representative head grades of the overall resource in order to determine the conformity of the results (head grades shown in Figure 1). As noted above, fresh core was not available and samples used for the test work had been in non-refrigerated storage for approximately 2 years (at a crush size of 2mm). As a consequence, the samples had been highly oxidized and this was confirmed when undertaking initial milling trials where pH level reductions were seen differing from trials carried out on previously tested fresh feed. Further evidence was seen in EDTA extraction tests that indicated free Cu, Pb, Zn ions present which would lead to mineral activation during flotation. Flowsheet and reagent scheme modifications were made to both the Massive Sulphide and Stock Work resulting in comparable results with the initial testing. In general, a decrease in grade but increase in the mineral recovery was observed.

Head grades of samples tested

 (Figure 1 )

Sample	Head Assay
	Cu %	Pb %	Zn %	Fe %	S %	Sn %	Au g/t	Ag g/t
MS Phase 1 Work	0.35	3.01	2.94	33.86	46.67	0.17	0.89	70.53
SW Phase 1 Work	1.81	5.11	6.82	14.78	9.29	-	0.15	64.43
MS Phase 2 Work	0.23	4.70	5.19	31.35	36.45	0.16	-	-
SW Phase 2 work	0.43	0.80	1.65	8.67	3.17	-	-	-

Grades and recoveries achieved across both test work phases

(Figure 2)

Sample		Assay							Recovery
		Mass %	Cu %	Pb %	Zn %	Sn %	Au g/t	Ag g/t	Cu	Pb	Zn	Sn	Au	Ag
Phase 1 MS Sample	Pb Conc.	3%	1.06	33.39	10.8	0.11	1.67	313.8	10%	37%	12%	2%	6%	15%
	Zn Conc.	4%	1.09	5.26	42.36	0.16	0.81	144.1	13%	7%	61%	4%	4%	9%
	Tailings	92%	0.29	1.82	0.86	0.17	0.86	58.42	77%	56%	27%	94%	90%	77%
Phase 1 SW Sample	Cu Conc.	5%	24.64	16.44	12.07	-	0.38	321.57	62%	15%	8%	-	11%	23%
	Pb Conc.	8%	6.90	48.99	15.77	-	0.19	460.86	30%	75%	61%	-	10%	56%
	Zn Conc.	8%	1.00	1.79	53.15	-	0.12	84.03	4%	3%	27%	-	6%	10%
	Tailings	80%	0.10	0.51	1.15	-	0.14	9.29	5%	8%	13%	-	72%	12%
Phase 2 MS Sample	Pb Conc.	9%	0.53	33.39	10.8	0.11	1.67	313.8	20%	43%	8%	3%	11%	19%
	Zn Conc.	10%	0.35	5.26	42.36	0.16	0.81	144.1	15%	12%	66%	10%	11%	11%
	Tailings	82%	0.18	1.82	0.86	0.17	0.86	58.42	65%	46%	26%	87%	77%	70%
Phase 2 SW Sample	Cu Conc.	1%	21.45	13.02	10.80	-	-	-	69%	22%	9%	-	-	-
	Pb Conc.	0%	10.89	17.27	10.77	-	-	-	10%	9%	3%	-	-	-
	Zn Conc.	2%	2.50	14.01	40.66	-	-	-	13%	39%	54%	-	-	-
	Tailings	96%	0.03	0.25	0.58	-	-	-	7%	30%	34%	-	-	-

Metallurgical testing showed that despite the oxidized sample, comparable performance could be achieved and allowed for the development of a more robust and flexible circuit that could handle variability throughout the orebody and if encountered, oxidized fresh feed.

It should be noted that reported numbers are calibrated results from Portable X-ray Fluorescence analysis (pXRF) results with confirmation via wet chemical assays expected soon. The grades and recoveries will then be updated with an increased level of confidence; however, they are not expected to change materially.

The locked cycle results from the massive sulphide materials showed that grade was sacrificed for recovery in the second set of more oxidised samples, and clean concentrates were more challenging to achieve due to the "free" ions in solution. This issue was also identified in the stockwork sample where lead (Pb) deportment compromised both the lead and the zinc concentrate grades and recoveries. Further test work in reducing this difficulty is currently underway.

It should be noted that the second set of samples received do not represent the whole orebody, but some specific sections of the North and South Zones, that were important to evaluate. Based on the results from the two phases of test work undertaken at Grinding Solutions, Grinding Solutions are confident that comparative performance could be achieved to projects working on similar ore bodies in the IPB, thus supporting recovery and concentrate grade assumptions used in the PEA. Further and continuous testing on fresh representative samples from drilling will be required to confirm this.  Ascendant plans to undertake additional test work going forward. The following table summarizes the results and the assumptions planned to be used in the upcoming PEA.

Results Summary

(Figure 3)

Metallurgy
Oxide
Copper recovery				0%
Zinc Recovery				0%
Lead Recovery				65%
Silver Recovery				66%
Gold Recovery				86%
Tin Recovery				40%
Massive Sulphide
Copper recovery				25%
Zinc Recovery				80%
Lead Recovery				65%
Silver Recovery (In Lead Concentrate)				35%
Silver Recovery (In Zinc Concentrate)				20%
Silver Recovery (Leach )				20%
Gold Recovery (In Lead Concentrate)				10%
Gold Recovery (Leach)				65%
Tin Recovery				30%
Stockwork
Copper recovery				80%
Zinc Recovery				80%
Lead Recovery				75%
Silver Recovery (In Lead Concentrate)				40%
Silver Recovery (In Zinc Concentrate)				20%
Silver Recovery (Leach )				20%
Gold Recovery (In Lead Concentrate)				10%
Gold Recovery (Leach)				65%
Tin Recovery				0%
Concentrate
Cu Concentrate Grades
	Oxides		% Cu	25%
	Massive Sulphides		% Cu	25%
	Stockwork		% Cu	25%
Zn Concentrate Grades
	Oxides		% Zn	48%
	Massive Sulphides		% Zn	48%
	Stockwork		% Zn	48%
Pb Concentrate Grades
	Oxides		% Pb	45%
	Massive Sulphides		% Pb	45%
	Stockwork		% Pb	45%
Sn Concentrate Grades
	Oxides		% Sn	30%
	Massive Sulphides		% Sn	30%
	Stockwork		% Sn	30%

Qualified Persons

Metallurgical test work is being carried out by Grinding Solutions Limited (GSL), a UK mineral processing services company with a strong technical knowledge on the mineral processing of the IBP ores and has been guided by Micon International, who was also responsible for the metallurgical results validation, resource determination and will act as the QP for the NI 43-101 preliminary economic assessment report to be completed by Ascendant.

The QPs have reviewed and approved the technical content of this news release.

Review of Technical Information

The scientific and technical information in this press release has been reviewed and approved by 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 16 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 75% owned subsidiary of M&FI, and has consented to the inclusion of the material in the form and context in which it appears.

FOR MORE INFORMATION:

Katy Mitchell, WH Ireland Limited                                               [phone]

Jon Belliss, Novum Securities Limited                                          [phone]

Jacques Vaillancourt, Mineral & Financial Investments Ltd.  [phone]

Dominic Baretto - Yellow Jersey PR Limited  [phone]

About Mineral and Financial Investments Ltd.

Mineral and Financial is a Cayman Island based London AIM listed investment company which focuses on investing in, as well as financing and advising of natural resource companies, with a particular focus on metals and mineral focused companies. For more information on Ascendant Resources, please visit our website at   www.mineralandfinancial.com  

 

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