Ora Banda positions for stronger, consistent Davyhurst gold production through enhancements


Ora Banda Mining Ltd (ASX:OBM) continues to ramp up operations at Davyhurst Gold Project in Western Australia supported by performance improvements from a number of top-down, bottom-up measures.

These have enabled Ora Banda to enhance drilling, blasting, mining and processing activities while remaining within annual guidance of 80,866 ounces.

Particularly encouraging for the company has been a measurable improvement this month in the weekly performance of Davyhurst’s milling and crushing circuits.

Gold production for the week starting August 23 increased to 1,164 ounces of refined gold with production this week expected to increase further to around 1,289 ounces of fine gold.

“Step change”

Ora Banda’s managing director Peter Nicholson said: “It is most pleasing to see the step-change in our plant’s performance and throughput. It is testament to our team and their hard work that all the action plans are being executed with successful outcomes.

“With clear plans in place to address the remaining limiting factors and exciting exploration results to follow up, we are now well placed for stronger, consistent production moving forward.”

Performance improvement measures have been aided by improved weather after extremely wet conditions in July hampered surface mining operations and led to road closures that delayed the delivery of mining fleet to the Missouri mine and the mobile crusher to the Davyhurst plant.

Processing plant

Ora Banda has improved the performance of the processing facility following the introduction of deeper material now being mined at Riverina with improved materials handling properties, coupled with a higher percentage of fresh rock available for blending.

Availability of the plant has also been improved through rectification measures that include,

Power outages:

A program of replacing power line insulators has been completed and the earth leakage trip sensitivity of the power station has been decreased, with only one subsequent power outage during a rain event.

Additionally, an independent specialist has been engaged to conduct a detailed fault-finding program during the next scheduled maintenance outage.

Given the process plant has had rain without losing power, and the Goldfields region is heading into a much drier part of the year, the company does not envisage any material issues with power supply in the coming quarter.

Crusher screen:

The company recently replaced screens in the SKALA double deck unit with softer panels that have higher self-cleaning properties. This has proven to be effective (combined with the increased primary blend) and the screen unit has not subsequently experienced throughput issues.


Along with the processing facility’s run time increases, other maintenance-related elements have been identified for correction and action plans implemented.

Currently, the back end of the plant can run at nameplate capacity, however, the crushing circuit is not yet matching that rate and this is largely being addressed by the additional feed generated via the mobile crushing unit.

OBM has ordered different sized screen panels (of the soft variety) to better balance the feed through the crushers in its three-stage circuit which is expected to fully resolve this issue and remove the requirement for the mobile crushing unit.

Independent review

In addition to these measures, Ora Banda has engaged Ausenco to undertake an independent review of the Davyhurst processing facility, including all aspects from spares held, maintenance procedures and practices through to operational improvement initiatives.

Mining operations

Mining at Riverina remains slightly ahead of schedule and this is similar are the Golden Eagle Underground site.

A diamond drill program of 3,650 metres testing the revised interpretation of mineralisation at Golden Eagle has been completed. Visually, nearly all holes intersected the target within metres of the planned intercepts.

Logging and assaying of the holes is ongoing, however, the company has further increased its confidence in the revised interpretation and the potential to extend mine life at Golden Eagle.

At Missouri open-pit mining continues although it is currently behind budget primarily due to the underperformance of blast hole drilling, which is impacting the ability to create broken ore stocks.

Ora Banda is working with the drilling contractor and there is an agreed action plan in place to address the issues being experienced, combining additional staff and drill rigs.

Mining of Missouri ore was about 30% behind schedule for the month of August with delays in earthmoving equipment arriving on site also being addressed.

The company estimates total Davyhurst gold production for the months of July and August to be 9,042 ounces.

On-site laboratory

The on-site preparation laboratory is scheduled to start operating on September 7, which will benefit the company by shortening assay turnaround times.

Construction of the new tailings storage facility (TSF) cell continues and earthworks are forecast to be completed in early October with piping and pumping to then be installed.

The TSF is forecast to be ready for use over a month before it is required.

Ora Banda’s cash and unsold bullion on hand at September 1 were $8.03 million and 1,298 ounces respectively with no debt.

After accounting for bullion, GST and creditors, the company has adjusted cash of $7.53 million.


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