Much is being talked about the ‘graphite boom’ and one company moving quickly forward is Lincoln Minerals, which has appointed Parsons Brinckerhoff to undertake an immediate scoping concept study for its wholly owned Koppio-Kookaburra Gully graphite project in the southern Eyre Peninsula region of South Australia. Both targets, which adjoin each other, have existing graphite Inferred Resources. The study will estimate capital costs, maintenance costs and operating costs to a Class 4 (concept study) standard for one or more mines in the Koppio-Kookaburra Gully area feeding into a single processing plant.
The study will include estimates for the processing plant, civil works including roads, water and electrical power and will take about four weeks to complete.
Aerial electromagnetic (EM) surveys were completed earlier this month over the Koppio, Kookaburra Gully, Pernella and Cockabidnie-Campoona Syncline areas on Eyre Peninsula. Lincoln is currently awaiting processed data and maps from these surveys (expected in about four to six weeks) to help delineate additional exploration drilling targets within the highly conductive graphite horizons.
The Koppio-Kookaburra Gully project area is ideally located just 35 km from the port of Port Lincoln and includes a number of historic graphite deposits and prospects including the historic Koppio graphite mine, Kookaburra Gully and Pernella.
Bulk samples of flake graphite from the Koppio mine and Kookaburra Gully are currently undergoing metallurgical testwork in Germany and Austria and have been assayed at grades ranging up to, respectively, 32.0% and 28.6% TGC (Total Graphitic Carbon).
An Exploration Work Approval has been received for proposed drilling by Lincoln at Koppio and Kookaburra Gully when weather and ground conditions permit.
The Koppio mine and Kookaburra Gully deposits comprise high grade flake graphite (medium to coarse flake) Inferred Mineral Resources and exploration targets equal to or better than many operating graphite mines around the world. Inferred Mineral Resources: Kookaburra Gully 880,000 t @ 11.5% C and Koppio mine 57,000 t @ 13.1% C
Exploration Targets, including above resources: Kookaburra Gully 900,000 t to 1.8 Mt @ 10-15% C and Koppio mine 105,000 t to 1.04 Mt @ 10-15% C.
Metallurgical testwork undertaken in the early 1980s by Warman International for Pancontinental Mining showed that Kookaburra Gully mineralisation was readily amenable to concentration by metallurgical processes including size classification, flotation and gravity concentration. Premium flake product (>150 micron) can be produced at grades in excess of 90% TGC without reverting to chemical leaching. Fine amorphous graphite can also be produced at grades better than 80% TGC. Total graphite recovery in this test work was about 5% by weight of feed with the coarser >150 micron concentrate averaging 2-3% of feed.