Cornish Metals reports solid progress at South Crofty

The AIM-traded company said it had successfully installed the first submersible pump in the New Cooks Kitchen (NCK) shaft as part of the mine dewatering programme.

It said the pump, manufactured by KSB in Germany, is a specialist high-head 950 kW vertical submersible pump controlled by variable speed drives.

That, along with a second pump to be installed soon, would enable a pumping rate of 25,000 cubic meters per day to the mine water treatment plant (MWTP) as the water level dropped and the pumping head increased.

The first pump was lowered to a depth of 360 meters below the surface, suspended from 120 three-metre-long pipes forming a temporary rising main.

Once the water level reached the 360-metre depth, a permanent set of pumps would be installed, and the submersible pumps would be further lowered to about 700 metres below the surface for the second stage of the dewatering programme.

The installation of the second pump was expected to start by the end of June.

In addition to the pump installation, Cornish Metals said it was actively working on a feasibility study for South Crofty.

The metallurgical testwork programme, conducted by Wardell Armstrong International, was progressing well, with physical competency, characterisation, and gravity response testwork completed on the No.4, No.8, and Roskear lodes.

Cornish added that the mineralogy had been completed by Petrolab, with early gravity response results in line with previous operational results, indicating positive outcomes.

The first bulk composite sample from the metallurgical testwork programme has been sent to Germany for XRT ore sorter testing at TOMRA Sorting.

Fairport Engineering, responsible for the conceptual study of the processing plant design, layout, and cost, was meanwhile nearing completion of the second optimisation phase before moving on to the feasibility level design.

The final design of the processing plant would also consider potential future throughput expansions.

AGS Ground Solutions had completed the site investigation for the process plant footprint, while MiningOne had finished numerical modelling of the proposed underground mining methods and stope designs.

Results reportedly confirmed the historical operating data and suggested favourable ground conditions and excavation stability.

RobertsonGeo had meanwhile completed geotechnical televiewing on the majority of mining areas, validating previous known structural data, and core samples had been taken for laboratory testing.

Paterson & Cooke UK had initiated concept engineering on paste backfill options and physical testing, with preliminary results showing samples gaining sufficient strength at target densities.

Entech Mining and RSV Group were meanwhile collaborating to provide the method, costing, and schedule for refurbishment and recommissioning of NCK and Roskear shafts.

Piteau Associates had been engaged for hydrogeological works related to the feasibility study.

Furthermore, Cornish Metals' mine geological team was continuing to digitise and incorporate historic assay data into the South Crofty mineral resource model.

Recent work had focused on No.1 and No.2 lodes, and a new mineral resource estimate, incorporating those lodes along with data from the metallurgical drilling programme, was expected to be released by the end of the third quarter.

The company said its future efforts would concentrate on the ‘MING’ zone, located south of No.1 and No.2, and including the Main, Intermediate, North, and Great lodes.

“Activities at South Crofty continue at a good pace with the commencement of dewatering on-track for later this summer,” said chief executive officer and director Richard Williams.

“Good progress is also being made with many aspects of the feasibility study to examining the re-opening of South Crofty - initial results are very encouraging.

“The mine site team have also reached another important milestone with the installation of the first submersible pump into NCK shaft now underway.”

At 1245 BST, shares in Cornish Metals were up 4.44% at 11.75p.

Reporting by Josh White for Sharecast.com.