The Maldorky iron ore deposit lies approximately 28 km south of the Barrier Highway and the Transcontinental Railway, 300km east of Port Pirie and one hour drive west of Broken Hill. It was discovered by Havilah geologists during 2010 as the result of drilling a prominent magnetic anomaly associated with poorly outcropping Braemar Iron Formation. Following completion of 51 drillholes and demonstration of good continuity of mineralisation, a JORC Indicated Resource of 147 million tonnes of 30.1% Fe at a cut-off grade of 18% Fe was estimated.
The deposit owes its existence to thickening of the iron formation horizon under the combined influences of extreme shearing and drag folding at this particular locality. Overburden is generally thin to absent and the orebody is typically at least 100 metres thick over most of the area.
Havilah has built a 3D geological model of the Maldorky orebody, which shows it to be a thick, largely horizontal slab of massive iron ore as shown below.
Based on a resource block model, a 3 stage open pit mine was designed by a consultant mining engineer using sophisticated open pit optimization software. This mine design has a low life-of-mine waste:ore ratio of 0.19 due to the flat nature of the orebody and the minimal volumes of internal waste.
The favourable mining economics for the Maldorky deposit, the above average grade (compared with other Braemar region iron ore deposits) and positive logistical factors prompted Havilah to apply for a mining lease. The mining lease application is at an advanced stage, with the supporting documentation having been accepted by the regulators and having passed the public consultation phase.
SIMEC Mining (an affiliate of the GFG Alliance) had undertaken due diligence on Maldorky, with the objective of evaluating the commercialisation potential. The project has a continuous, heavy duty rail link to the Spencer Gulf ports of Whyalla and Port Pirie (and Port Waratah and Port Kembla in the east).
SIMEC Mining’s test work on Maldorky iron ore samples showed that the targeted product grade of 65% Fe can be achieved for a 40% product yield and an overall 85% Fe recovery with conventional processing methods.