Name: Mimosa mine.

Location: It is located in the Wedza geological complex on the Zimbabwean Great Dyke, 20 km west of Zvishavane and 150 km east of Bulawayo.

Controlling Company: Mimosa is a 50:50 joint venture between Impala Platinum (Implats) and Aquarius Platinum.

Brief History: Mimosa was acquired by Zimasco from Union Carbide in 1993. Zimasco piloted platinum mining in Zimbabwe by resuscitating the operation and steadily increasing production to 1 000 t/d achieved in 1998. In July 2001, Implats acquired a 35% stake in Mimosa for R246-million. This stake was increased to 50%, with a further acquisition of 15% in August 2002. Aquarius acquired a 50% stake in Mimosa during the same year.

Brief Description: Mimosa comprises a mechanised shallow underground mine and a concentrator plant.

Geology/Mineralisation: The Great Dyke is a layered complex similar to that of the Bushveld Complex in South Africa. It extends for 550 km and has a maximum width of 11 km.

The stratigraphy is broadly divided between a lower ultramafic and an overlying mafic sequence. The ultramafic sequence hosts the P1 pyroxenite, which in turn hosts the economic platinum-group-metal- (PGM-) bearing main sulphide zone (MSZ). The MSZ is a continuous layer generally between 2 m to 3 m thick. Optimal mineralisation varies.

Mimosa has a well-defined grade profile, where peak base metal and PGM values are offset vertically, with palladium dominant at the base, platinum in the centre, and nickel towards the top.

Reserves: Total attributable mineral reserves as at June 30, 2014, were estimated at 11.3-million tonnes grading 3.37 g/t platinum, palladium, rhodium and gold (4E) and 3.6 g/t platinum, palladium, rhodium, iridium, ruthenium and gold (6E).

Resources: Total attributable mineral resources as at June 30, 2014, were estimated at 64.6-million tonnes grading at 3.65 g/t 4E and 3.89 g/t 6E.

Products: 4E and 6E.

Mining Method: The bord and pillar mining is used, with stoping widths averaging about 2 m. Mining bords advance along the strike.

Major Infrastructure and Equipment: The mining cycle involves mechanised support drilling and installation, mechanised face drilling, charging and blasting, and mechanised lashing onto a conveyor network to an underground bunker. From the bunker, ore is conveyed to a surface stockpile.

Mimosa has a concentrator plant on site where initial processing is done. Concentrate is transported by road to Implats’ Mineral Processes, in Rustenburg, in the North West, in terms of a life-of-mine offtake agreement with Impala Refining Services.

Contact Person: Group corporate relations manager Alice Lourens.

Contact Details:
Implats,
tel +27 11 731 9000,
fax: +27 11 731 9254,
email Alice.Lourens@implats.co.za, and
website http://www.implats.co.za.