Parys Mountain – Positive Preliminary Results from Metallurgical Testwork

Parys Mountain – Positive Preliminary Results from Metallurgical Testwork

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4th December 2023


Anglesey Mining plc

(“Anglesey” or “the Company”)


Parys Mountain – Positive Preliminary Results from Metallurgical Testwork


Anglesey Mining plc (AIM:AYM), the UK minerals development company, is pleased to report that it has received preliminary results from the metallurgical testwork on the White Rock and Engine Zones at the Company’s Parys Mountain Cu-Zn-Pb-Ag-Au project, located on the Isle of Anglesey.


In June, the Company dispatched a 340kg sample to Grinding Solutions Limited (GSL) comprising a blend of material from both the White Rock and Engine Zones with a combined head-grade of 0.42% Cu, 3.60% Zn, 3.08% Pb, 49g/t Ag and 0.7g/t Au (10.8% ZnEq). The blend was 3.3 (White Rock) to 1.0 (Engine Zone), similar to the contribution that is expected to be delivered from the mine in the early years of production, prior to the Northern Copper Zone commencing.




  • Two pre-concentration methods were conducted – Dense Media Separation (DMS) undertaken by Pesco and X-Ray Transmission sorting (XRT) completed by TOMRA. One element of the testwork was to determine the optimal process to take forward into the Pre-Feasibility Study.
  • Both methods demonstrated that a successful pre-concentration stage would be applicable with the overall base metals only head-grade increasing from 7.5% ZnEq to 11.4% ZnEq from the DMS (+52%) and 11.7% ZnEq from the XRT (+55%) – results will be updated once the gold and silver numbers are finalised – the precious metals are expected to add 3-4% to the ZnEq grade. The preliminary results are tabulated below:


  Zn (%) Pb (%) Cu (%) ZnEq (%) Mass Rejection (%) Metal Loss (%)
Original Sample 3.6 3.1 0.42 7.5
DMS Results 6.4 3.8 0.60 11.4 35 5.2
XRT Results 6.4 3.7 0.70 11.7 29 3.0


  • Preliminary results from the locked-cycle flotation testwork demonstrated higher recoveries than those achieved in historical testing. These results are based on calibrated pXRF readings with the full wet chemistry expected over the coming 2-3 weeks. The results are tabulated below:


  Cu Concentrate Zn Concentrate Pb Concentrate Au Concentrate
  Cu Grade Recovery Zn Grade Recovery Pb Grade Recovery Au Grade Recovery
PEA Estimates 21.8 56 56.2 82 51.8 76 n/a 40
GSL Testwork 31.5 74 50.7 86 56.4 80 300 65
Difference   +32%   +5%   +5%   +63%


  • Testwork with regards to net acid generation, settling rates and contact leaching on the tailings is ongoing with results expected over the next 2-3 weeks. In addition, GLS will also be completing a diagnostic leach test on the final zinc tailings to ensure optimal recovery of gold.



Jo Battershill, Chief Executive of Anglesey Mining, commented: “We are very pleased by the preliminary results from the metallurgical testwork on the White Rock and Engine Zones, which have demonstrated that the assumptions used in the 2021 PEA are potentially on the conservative side. The results show that the overall metal recoveries appear to be better than expected, particularly for both copper and gold. It is also very positive to confirm that the Parys Mountain deposit is amenable to both DMS and XRT pre-concentration methods with the potential feed grade increased by over 50%.”

“Successful pre-concentration has many benefits ranging from increased feed grade into the processing plant, lower volumes of tailings for disposal and the potential to build smaller, lower cost processing infrastructure. We will now look to investigate the relevant capital and operating costs for each option to determine which is the most optimal route to move forward with in the planned Pre-Feasibility Study.”


About Anglesey Mining plc

Anglesey Mining is traded on the AIM market of the London Stock Exchange and currently has 420,093,017 ordinary shares on issue.


Anglesey is developing its 100% owned Parys Mountain Cu-Zn-Pb-Ag-Au deposit in North Wales, UK with a reported resource of 5.3 million tonnes at over 4.0% combined base metals in the Measured and Indicated categories and 10.8 million tonnes at over 2.5% combined base metals in the Inferred category.

Anglesey also holds an almost 50% interest in the Grängesberg Iron project in Sweden, together with management rights and a right of first refusal to increase its interest to 100%.  Anglesey also holds 12% of Labrador Iron Mines Holdings Limited, which through its 52% owned subsidiaries, is engaged in the exploration and development of direct shipping iron ore deposits in Labrador and Quebec.



For further information, please contact:

Anglesey Mining plc

Jo Battershill, Chief Executive – Tel: +44 (0)7540 366000

Andrew King, Interim-Chairman – Tel: +44 (0)7825 963700



Nominated Adviser & Joint Corporate Broker

Brian Garrahy / Daragh O’Reilly – Tel: +353 1 679 6363


WH Ireland

Joint Corporate Broker

Katy Mitchell / Harry Ansell – Tel: +44 (0) 207 220 1666


LEI: 213800X8BO8EK2B4HQ71

A .pdf version of the above RNS cab be viewed/downloaded by clicking HERE