Geita

Overview

The Geita gold mine is located in the Lake Victoria goldfields of the Mwanza region of Tanzania, about 120km from Mwanza and 4km west of the town of Geita. The mine is wholly owned and managed by AngloGold Ashanti.

The Geita gold deposit is an Archaean mesothermal orebody, largely hosted in a banded ironstone formation. It is a multiple open pit operation with underground potential and is currently serviced by a 5.2Mt per annum CIL processing plant. 

Location

The Geita open-pit mine is situated in north-western Tanzania approximately 90 kilometers from the regional capital of Mwanza and 20 kilometers south of Lake Victoria in an area known as the Lake Victoria Goldfields.

Geita covers some 373 sq km of prospecting licenses with the inclusion of the Nyamulilima Hill license (Anglogold) into the joint venture. Within this area a special mining license has been granted covering 114 sq km. (Dec/02).

Nyamulilima Hill is located south of Lake Victoria, about 9 miles south of the Geita project.

Geology and Mineralization

Geita is found within the typical Archaen greenstone belt terrain of northern Tanzania and is one of a series of belts which form an outer oval shaped arc consisting predominantly of banded ironstone formations and intermediate to felsic volcanics.Gold mineralisation is generally associated with these thick ironstone formations which often rise above the plains to form a series of distinct ridges.To date, resources have been outlined on a number of deposits including Geita Hill, Lone Cone, Nyankanga, Kukuluma and Matandani.

Gold is associated with pyrite mineralization and is hosted in a thick sequence of banded ironstone formation which forms a prominent northeast trending ridge.

Mining & Operation

The turnaround at Geita resulted in gold production increasing by 31% to 357,000oz in 2010. Significant quarterly improvements were achieved during the first half of the year, with gold production rising from 84,000oz in the first quarter to 90,000oz in the second quarter. Output was hampered during the third quarter as a result of a major planned plant shutdown to replace the SAG mill discharge end-plate and to rebuild the crusher dump-pocket. Production was also supported by improved grades from Nyankanga pit, which delivered an average grade of 3g/t.

Total cash cost for the year improved by 19% to $777/oz, mainly as a result of lower reagent costs, as well as a reduction in general and engineering stores. The favourable movement in costs was partially offset by the deferred stripping charge.

Processing

The Geita mine comprises a crusher, SAG and ball mill grinding circuit, a gravity circuit and a 14-tonne stripping plant.

Multi-pit operation, with a 6 million tpa CIL plant gold mine. 

Environment & Community

Design work was completed on the Geita Town Water Supply Project, which will be built in 2011. This project, which will draw water from the Nyankanga dam on the mine’s lease area, will include transfer pumping, a treatment and storage system and will deliver water at a rate of 4,800 cubic metres per day to the town. 

Cyanide management has been enhanced with the completion of the plant tailings dilution circuit. Improved control may be expected once the second oxygen injection system on the conditioning tanks is satisfactorily commissioned at the beginning of 2011. 

The key requirements of the cyanide code have now been met and the main remaining objective is to achieve compliance with the code requirement that weak acid dissociable (WAD) cyanide levels in the tailings slurry should not exceed 50 parts per million for a period of three to six months. This will be the objective for the first two quarters of 2011. 

ISO 14001 environment certification was maintained in 2010.