In this 7-minute Exploration Update Managing Director Mike Schwarz discusses:
• the insights from the recent Benchmark Minerals’ Battery Metals conference in Perth
• how the huge exploration target at Sugarloaf Prospect was defined
• the details of the new Lacroma Graphite Prospect
• iTech’s plans and timelines for increasing the overall resource at the Campoona Graphite Project
- Extensive drill target defined at Lacroma Graphite Prospect on the Eyre Peninsula
- A 12 km long airborne electromagnetic anomaly maps an extensive graphitic horizon on EL6634
- iTech has modelled a first stage drill target in the northern 6 km of the anomaly from electromagnetic sections and drill holes
- Drilling has confirmed the anomaly is caused by thick graphite mineralisation with drill hole WG021 intersecting 60m @ 6.8% total graphitic carbon (TGC)
- Preliminary metallurgy of dill hole WG021 demonstrates that a high-grade graphite concentrate of >90% TGC with recoveries of ~83% can be achieved using the same flowsheet established for the Campoona Graphite Deposit
- Landowner approvals are in place and government drilling approvals have been submitted to commence drilling in the next few months
- The Lacroma Prospect is in addition to the Company’s recently announced exploration target at the Sugarloaf Graphite Prospect of 158-264 Mt @ 7-12 % TGC (see ASX Release 19 September 2022)
Lacroma Graphite Prospect
The Lacroma Graphite Prospect is located approximately 45 km north-west of Cleve on the central Eyre Peninsula and <20 km from iTech’s proposed graphite processing plant for the Campoona Spherical Graphite Project. The graphite at this location occurs within the Paleoproterozoic Hutchison Group Metasediments and is likely to have formed from organic rich stratigraphic horizons metamorphosed during regional upper greenschist to lower amphibolite facies metamorphism during the Kimban Orogeny. The western Lacroma graphite rich horizon forms a north-south trending structure with a shallow easterly dip. As the structure falls to depth to the east, it is thrust back to surface along a north- south fault to form the eastern Lacroma Target, as interpreted from drilling and detailed airborne and ground-based electromagnetics (Figure 2.)
The Lacroma drill target has been defined from a series of east-west conductivity sections spaced at 400m intervals and derived from a TEMPEST airborne electromagnetic survey flown in 2012. Historical drilling, in the same year, tested the source of the conductivity anomaly and confirmed it was caused by significant thicknesses of graphite mineralisation. Of 4 holes designed to test the Lacroma target, WGC021, was correctly located to test the bulk of the conductivity anomaly. This drill hole returned 60 m @ 6.8% TGC from 74-134m downhole with a higher-grade interval of 21m @ 9% TGC from 100- 121m downhole. Drill holes WG022-24 were drilled approximately 600 m to the north and intersected variable amounts of graphite mineralisation confirming that the eastern conductivity anomaly is caused by a north-south trending graphite rich horizon dipping gently to the east. No drilling has intersected the western conductivity anomaly and this target remains untested.
Figure 2. Plan view of the Lacroma Graphite Prospect – Eyre Peninsula, South Australia
In 2015, Archer Materials undertook preliminary metallurgical test work, on sample from drill hole WG021, to determine if a suitable concentrate could be made by using the flow sheet developed for the Campoona Graphite Deposit. The program included four rougher and cleaner tests and two rod mill work index determinations on a 50 kg sample. From a 9% TGC head assay a concentrate of 90.7% TGC with 83% recovery, via simple flotation, was achieved with room for improvement in both grade and recovery with further optimisation.
iTech is planning to drill test the Lacroma Graphite Prospect in the coming months. Landowner consent has been obtained to commence drilling in December once crops have been harvested. Applications for approval to drill have been submitted to the government and are expected to be received within 4-6 weeks. A suitable reverse circulation drill rig has been secured to complete the program. iTech will concentrate on drill testing the Lacroma West initially, as graphite mineralisation has already been confirmed by historical drilling and appears to be over a relatively over a large area according to the conductivity cross sections. Several test holes will be drilled into Lacroma East to confirm the anomaly is caused by graphite and determine the depth to mineralisation. The program is expected to take up to 6 weeks to complete and will be run in conjunction with drill testing the Sugarloaf Graphite Exploration Target approximately 20 km to the southwest.