Magnetic Resources streamlines flowsheet for 97.5% gold recovery

• MAU testwork at LJN4 shows 97.5% gold recovery using new deeper composite
• Results show smaller grind mill would reduce capex and opex
• Project is targeted to produce 150,000oz per annum

Special Report: Magnetic Resources has wrapped up testwork at its Lady Julie North 4 (LJN4) gold project in WA with a standout 97.5% recovery rate from a composite in a deeper section of the deposit’s underground resource.

LJN4 hosts a recently upgraded resource of 23.6Mt grading 2.04g/t for ~1.55Moz of gold and is the primary deposit at Lady Julie project that has an overall resource of 28.11Mt at 1.93g/t for 1.75Moz.

The latest test results show a spectacular increase over the potential recovery achieved with conventional gravity/leach of 88%, by adding two stage flotation and regrinding to 20 µm.

Magnetic Resources (ASX:MAU) said the 97.5% recovery in the deep altered ultramafic showed the increasing potential resource sizes within the central and northern high-grade core zones that were still open at depth.

That could increase the forecast annual production rate of 104,000oz and target of 150,000oz.

The company has also boosted project economics by optimising the float/grind stage of processing, highlighting that a smaller grind mill may be needed then originally envisaged, translating to reduced capex and opex.

When weighted by the relative contribution to the project mill feed, the average recovery for the project remains above 92%.

Streamlining at high gold prices

In an economic update from August 2024, Lady Julie is expected to produce at an annual rate of 104,000oz for eight years from an open pit to generate total EBITDA of $1.49bn using a $3200/oz gold price.

Development capex was estimated at $111.3m assuming a standalone 2.2Mtpa processing plant and three months pre-production activities while all-in sustaining costs are expected to be $1386/oz.

These estimates are now extremely conservative given the current gold spot prices over US$3000/oz, making it the perfect time to streamline the flowsheet – with even small improvements able to significantly boost project economics.

“Another set of very pleasing results yet again reinforcing the value inherent in the project,” managing director George Sakalidis said.

“The exceptional 97.5% recovery in the deep ultramafic is very positive given the recent results showing potential increasing resource sizes within the central and northern high grade core zones that are still open at depth.

“The gains in recovery at a time of strengthening gold price, vindicates the speedy approach taken to adopt and incorporate new ideas when a benefit is visualised.

“This work provides the confidence needed to complete the process plant design/costing incorporating the optimized flotation/fine grind solution.”

With this test program complete, the company could detail the sizing of components for the flotation and fine grinding circuit – closing out the design stage for the total plant – with the next step completing costings for the project’s feasibility study.

This article was developed in collaboration with Magnetic Resources, a Stockhead advertiser at the time of publishing.

This article does not constitute financial product advice. You should consider obtaining independent advice before making any financial decisions.