Highly Positive Gold Metallurgical Results


(“ECR Minerals”, “ECR” or the “Company”)




ECR Minerals plc is pleased to announce that the results of initial metallurgical testwork carried out on samples from the Company’s Sierra de las Minas gold project area in La Rioja Province, Argentina have been received and are highly positive. Detailed results of the programme are disclosed below.

Four samples of approximately 20kg each were sent to the ALS Ammtec laboratory in Perth, Western Australia, where they were prepared for analysis. Two samples were taken at the El Abra prospect and one sample was taken at each of the Maestro Agüero and Casas Viejas prospects. All samples were composed of surficial vein material and each sample was taken at a location visually judged to be representative of the exposed vein mineralisation at the prospect.

Head Assays

Gold, silver and copper assays for each sample were carried out, with gold assays carried out in duplicate. The results are shown in the table below.


Table 1
Head assays for all samples
Element Unit Sample ID
Maestro Agüero
El Abra
Casas Viejas
El Abra
Gold1 g/t 4.60/6.39 16.5 0.06 0.47
Gold2 g/t 7.56 37.8 0.05 0.36/0.20
Silver g/t 54.0 2.0/2.0 <2.0 <2.0
Copper g/t 4235 2825 4295 55


The four samples show high variability in gold grades, indicating the possible presence of coarse grained gold. Samples 3 and 4 returned substantially lower gold grades than were obtained by previous surface sampling at El Abra and Casas Viejas, however a wide range of grades is to be expected.


Cyanidation Leach Testwork

A 3kg subsample of each sample was prepared and passed through a Knelson gravity concentrator. In each case, the concentrate was subjected to an intensive cyanide leach over 24 hours and the leach residue was then filtered, washed and added to the gravity tailing before being subjected to a standard cyanide leach over 48 hours. Details of the gold extraction achieved from each sample by this process are presented in Table 2 below.


Table 2
Gold extraction results for all samples
Gold extraction (%) -
intensive leach on gravity concentrate and direct leach on gravity tail

Sample Gravity concentrate Total including gravity tail
1 - Maestro Agüero 41.18 86.16
2 - El Abra (Abejas) 69.04 99.42
3 - Casas Viejas 36.78 95.40
4 - El Abra (Riel) 76.16 97.78


Overall gold extraction was excellent, exceeding 95% in three out of four samples, with a relatively high proportion of gravity recoverable gold. Comminution requirements and reagent consumption were all within acceptable ranges.

Further testwork will be undertaken over the coming months to confirm these results and gather additional data. The results of testwork on surficial material are not necessarily indicative of metallurgical characteristics at depth, which will be evaluated using drill core samples when these become available. Drilling at the El Abra prospect remains scheduled to commence later this month.


Current Sampling Programme

A programme of sampling at surface and within historical underground workings commenced in January, with sample sites selected at multiple prospects within the project area, including El Abra. A number of samples have already been sent for assay and results are expected shortly. Additional samples will be sent for assay during February.


Patrick Harford, Managing Director of ECR Minerals plc, comments:

“We are delighted with these metallurgical results, which indicate that near surface gold bearing material from El Abra and other prospects at Sierra de las Minas can be processed by conventional methods to achieve high rates of recovery.

These results represent a significant step towards confirming the viability of our plan to mine and process high grade ore from the project area on a toll treatment basis, and discussions with a potential toll treatment partner have been initiated. ECR’s goal remains to commence small scale production operations at Sierra de las Minas before the end of the year and by doing so to develop an early cashflow from the project.”


About the Sierra de las Minas Project Area

ECR holds 100% of the exploration rights to the Sierra de las Minas project area and 100% of the exploitation rights to a number of prospects within it, including the El Abra prospect. Exploration rights for other prospects may be converted to exploitation rights by application to the government of La Rioja Province. The El Abra and Jazmin prospects are subject to a 2% net smelter return royalty from production. Commencement of mining activities is subject to receipt of the necessary environmental permissions from the provincial government.

The project area is located approximately 800km north west of Buenos Aires, the capital city of Argentina, and is the site of significant historical small scale gold mining. Access to the project area is possible via paved highways from the cities of Mendoza, San Juan and Cordoba. Local access is by paved and unpaved provincial routes.


About ECR Minerals plc

ECR is a mineral development company with interests in Argentina, the USA, Indonesia, Thailand and Australia.


For further information please contact:

ECR Minerals plc
Michael Silver, Chairman Tel: +44 (0) 20 7929 1010
Patrick Harford, Managing Director
Stephen Clayson, Director & Chief Financial Officer
Luca Tenuta, Non-Executive Director
Email:This email address is being protected from spambots. You need JavaScript enabled to view it.
Daniel Stewart & Company plc
Paul Shackleton/Tessa Smith/David Hart Tel: +44 (0) 20 7776 6550
Old Park Lane Capital plc
Michael Parnes Tel: +44 (0) 20 7493 8188
Blythe Weigh Communications
Ana Ribeiro Tel: +44 (0)20 7138 3204
Barry Kaplan Associates
Larry Kaplan Tel: +1 732 747 0702

The contents of this announcement have been reviewed by Trevor Neale B.App.Sc. (Geol.), MAIG, a geological adviser to the Company with more than 35 years of experience in the mining and exploration industry.

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