Feb 1 2011
Hana Mining Ltd. (TSX VENTURE:HMG)(FRANKFURT:4LH) has announced results on the first locked cycle tests on sulphide material from the Chalcocite Zone at the Ghanzi Project.
The results show that the copper mineralization at the Chalcocite Zone sulfide mineralization is highly amenable to conventional flotation recovery technology.
Highlights of recent metallurgical results:
- Initial locked cycled tests, at a coarse grind size of 150 microns, show a copper recovery of 79.9%.
- The tests also show a final copper concentrate grade of 52.5%.
- Metallurgical work on applying conventional flotation technology on oxide and transitional material from the Banana Zone is ongoing.
- Metallurgical work on leaching on oxide material from the Banana Zone and material from the Chalcocite Zone is also ongoing.
Discussion of Results:
The preliminary metallurgical testing program was designed to determine the grinding and flotation characteristics of a Chalcocite Zone sulphide mineralization sample which is indicative of the current Ghanzi NI 43-101 compliant resource estimate. At a cut-off grade of 0.30% Cu, the Chalcocite Zone contains approximately 1.6 billion pounds of copper and 18.5 million ounces of silver from 161.1 million tonnes of mineralized material grading 0.45% Cu and 3.6 g/t Ag (Inferred Resources).
The test data will be used to develop a process flow sheet, to identify further testing requirements and to develop capital and operating costs for the Preliminary Economic Assessment (PEA) which is scheduled to be completed by the end of Q1 2011.
Mineralized material submitted for testing came from composite material from a 28 metre (61 to 99 metres) interval from drill hole HA-104DM which is located at the Chalcocite Zone.
In the Chalcocite Zone, sulphide composite chalcocite represents approximately 97% of the copper mineralization. Approximately 56% of the copper minerals are liberated at a coarse grind size of 150 microns, while copper minerals which are not liberated are mostly associated with silicates. Acid soluble copper represents 13% of the total contained copper.
Initial locked cycle metallurgical tests on the sulphides from the Chalcocite Zone show that the mineralized material is highly amenable to conventional flotation methods resulting in a copper recovery of 79.9%. The testing also showed that conventional flotation can produce a high grade concentrate, with average grades of 52.5%. For comparison, most conventional copper sulphide mining and milling operations produce a product with concentrate grades of 25% to 30% copper. At the Banana Zone the average concentrate grade, as determined from initial locked cycle tests, was found to be 43.55% copper. Therefore, the Chalcocite Zone will produce a very high quality product that should elicit considerable interest from global copper smelters.
Development Update:
The following engineering and consultation activities are ongoing to fulfill the goal of completion of a PEA in Q1 2011:
- Preliminary mine open pit modeling is being carried out using the December 2010 resource. A revised model will be completed and incorporated into the upcoming PEA which is expected to be completed in Q1 2011;
- Metallurgical work (column leaching) has been completed by Metcon Research in Tucson, Arizona, on the Chalcocite Zone and the oxide portion of the Banana Zone. Results are expected to be available soon;
- New personnel appointments will be announced shortly;
- Stefanutti Stocks Mining Services of Johannesburg, South Africa have provided a preliminary tailing impoundment design for the project which will be incorporated into the PEA.
Hana Mining's CEO and Chairman, Marek Kreczmer, commented as follows:
"We are very pleased with the metallurgical results from the Chalcocite Zone which show that copper mineralization can be recovered using standard flotation technology producing superior concentrate grades. If the leaching tests, which are still ongoing, are also positive, then we will be fortunate to have a couple of options for recovering copper at this zone. We believe that this flexibility in recovering copper adds value to the Ghanzi Project. Given the positive metallurgical results, combined with the large growing resource base, shallow dip and likelihood of a low strip ratio, the Chalcocite Zone is beginning to show incredible potential as a possible source of mineralized material to a centrally located processing (milling and flotation) plant."
Qualified Person and Quality Assurance/Quality Control
Metallurgical test work was carried out by MINTEK of Johannesburg, South Africa under the supervision of Arthur H. Winckers & Associates Mineral Processing Consulting.
Mr. Arthur Winckers, P.Eng., Consulting Mineral Processing Engineer for Hana, is the qualified person as defined in NI 43-101 and has reviewed the technical information in this press release.
The Ghanzi Project is located in the center of the Kalahari Copper Belt in northwestern Botswana. The Ghanzi property covers 2,169 square kilometres, and contains sediment-hosted copper-silver deposits with a demonstrated cumulative tested strike length of 70 kilometres. This favorable geology extends over an estimated strike length of 600 kilometres. Hana Mining released results of its most recent NI 43-101 compliant resource estimate for the Ghanzi Project on December 20, 2010, announcing an Indicated mineral resource of 762 million pounds of copper and 16 million ounces of silver from 37.4 million tonnes at a grade of 0.93% copper and 13.4 g/t silver. All of the Indicated resources are from the Banana Zone. The resource estimate also includes 5.6 billion pounds of copper and 85.4 million ounces of silver from 423.9 tonnes. This Inferred mineral resource estimate consists of 225.4 million tonnes grading 0.64% Cu and 8.1 g/t Ag in the Banana Zone, 20.7 million tonnes grading 1.23% Cu and 8.7 g/t Ag in Zone 5, 16.7 million tonnes grading 0.86% Cu and 4.0 g/t Ag in Zone 6, and 161.1 million tonnes grading 0.45% Cu and 3.6 g/t Ag in the Chalcocite Zone; all at a cut-off grade of 0.30% Cu.
The Banana Zone exhibits certain areas of higher grade Cu and Ag mineralization, particularly between sections 49700 to 52000 on the North limb and sections 63000 to 71000 on both the North and South limbs, which represent an opportunity to locate starter pits and mine initial tonnages at higher than average grades. These higher grade pockets tend to be well within open pit depth parameters and represent opportunities to improve early cash flow and overall returns in development.
The project will benefit from proposed rail and power infrastructure expansions, along with proximity to local population centers and workforce. A feasibility study is currently underway (funded by the World Bank and the governments of Botswana and Namibia) to support completion of a rail line link that would connect Botswana with the Namibian port of Walvis Bay, on the Atlantic coast. The closest existing railhead to port is at Gobabis, in Namibia, approximately 550 km from our property. Construction has begun on the 600MW expansion of the government-owned Moropule Power Plant, having secured US$825 million project funding in May 2009. The Ghanzi Copper-Silver Project is currently accessed by the paved Trans-Kalahari highway, which passes within 15 km of the property.
The Ghanzi property is one of Africa's premier future copper-silver resources.