Abu Dabbab Tantalum
Introduction
The 44.5 million tonne Abu Dabbab tantalum-tin-feldspar deposit is located within the Central Eastern Desert in Egypt. The deposit is located about 16km inland from the western shore of the Red Sea. The deposit is covered by two Exploitation Leases (1658 & 1659) granted in the name of Tantalum Egypt JSC, a company incorporated in Egypt and owned 50% by the Egyptian Government via the Egyptian Mineral Resources Authority (EMRA) and 50% by Tantalum International Pty Ltd which is a 100% owned subsidiary of Gippsland Ltd.
Tantalum applications
Tantalum is a grey metal, classed as a refractory metal because it is resistant to chemical attack. For industrial use, its important properties are a high melting point, ductility which allows it to be drawn into wire, and malleability which allows sheets and tubes to be made. Once exposed to air, the metal is covered with a thin layer of oxide which allows it to resist fluids in the human body, and also acids and other corrosive liquids, in the chemical industry. It has a high dielectric, which makes it so valuable in capacitors for the electronics industry. Tantalum capacitors form an integral component in the production of mobile telephones, telecommunication infrastructure, laptop computers, auto-electrics plus still and video digital cameras.
Because of the metal’s resistance to corrosion it is used in chemical plant and equipment. Its high melting point (2,997°C) and low thermal coefficient of expansion make it a crucial component of jet engine turbine blades. As tantalum carbide, one of the hardest substances known to man, it is used for cutting tools.
Tantalum Market
The majority of the world’s tantalum is sold by way of long-term offtake agreements between the miner and the tantalum refiner/metal producer. Tantalum is not sold via a regulated market as is for gold, copper, zinc and tin. The global tantalum Ta2O5 market is estimated to be in the order of 5 - 7 million pounds per annum. Industry commentators suggest that the market is growing at a rate of about 7% per annum.
HC Starck GmbH, is generally considered to be the world’s leading tantalum concentrate consumer/processor followed (not in order) by Cabot Corporation (USA), Ulba OJSC (Kazakhstan), Mitsui-Kinzoku (Japan) and Ningxia Non-Ferrous Metals (China) plus various other Chinese groups.
Previous exploration
Tin-tungsten mineralisation at Abu Dabbab has been known since the 1940s but it was not explored until the early 1970s when a joint Soviet-Egyptian team, completed an extensive exploration programme. In the early 1990s the project was further explored by a joint venture between the Egyptian Government and Geominera Italiana. The previous work included 28 diamond drill holes, three adits, one crosscut, numerous trenches, surface sampling, bulk sampling and metallurgical tests. Gippsland carried out some re-sampling of the adits to verify the previous results, collected bulk samples totalling 43 tonnes which were used to conducted additional detailed metallurgical test work in Australia. Encouraged by the results of the test work, Gippsland commenced a Bankable Feasibility Study which was completed in October 2004 and updated in September 2008 by the international engineering Group Lycopodium Pty Ltd.
Geological setting
The Ta-Nb-Sn mineralisation of Abu Dabbab is represented by disseminated cassiterite and niobio-tantalite, hosted in a stock of apogranite. The apogranite at Abu Dabbab is leucocratic, holocrystalline, white grey to greenish blue and with manganese oxide spots and dendrites. It is mostly fine to medium grained and occasionally has a porphyritic texture.
The characteristic alteration processes in the apogranite are greisenisation, microclinisation, silicification and albitisation.
The shape of the host apogranite intrusion is generally ellipsoidal except in the north-western part where there is a narrow off-shoot, about 150m in length. The apogranite mass is elongate in an east-west direction with a maximum length of about 400m. Maximum width in a northeast-southwest direction is nearly 200m. The body extends about 130m above the level of the adits and has been intersected in drilling at a depth of 350m below the adits.
No significant disseminated mineralisation is present in the country rocks surrounding the intrusive mass, therefore the ore deposit limits correspond to the limits of the apogranitic body.
Resources
Abu Dabbab Mineral Resources (100g/t Ta2O5 cut-off)
Category Million Tonnes Ta2O5 (g/t) Sn grade(%)
Measured Mineral Resource
15.2
290
0.143%
Indicated Mineral Resource
17.3
250
0.078%
Inferred Mineral Resource
12
200
0.03%
Total Mineral Resource 44.5 250 0.09%
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