The nickel sulphide deposit at Trojan Mine occurs within a pile of ultramafic lavas subjected to a lower amphibolite grade of metamorphism and are characterised by lensoidal bodies of serpentinite. The lavas form part of the Upper Greenstones (Bulawayan Group) of the Mazowe greenstone belt. The serpentinite bodies are separated from each other by cherts, BIFs, graphitic shales and felsic volcanics. The footwall and hanging wall of the nickel bearing serpentinites are formed by komatiitic and tholeiitic basalts. A doleritic dyke cuts through the serpentinites and displays nickel sulphide along its sheared contact. The regional setting and deformation of the Harare-Bindura schist belt with thrusting and doming of the Chinamora batholith has given rise to the deformation imprint observed in host rocks at the mine. The general strike of the ore bodies is east–west and dip steeply (75° to 85°) to the north and this is controlled by the regional foliation trend. The two major ore bodies are the Main Orebody and the Hanging Wall Orebody. The massive and near massive ores occupy a narrow and discontinuous zone along the footwall of the Main Orebody and this is called the Footwall Massive Orebody. The Main Orebody is the largest, and averages 250m long and 30m wide. There are other smaller ore bodies such as Trojan Hill, Cardiff East and Cardiff Far East, with dimensions of 100m x 15m and 200m x 15m respectively. Drilling has outlined the Main Orebody to a depth of 1180m below surface ........

Trojan Mine employs a sub-level caving mining method to extract ore from the Main Orebody; and the Hanging Wall Ore body that are steeply dipping (some 75-85o) and separated by a barren zone some 50m in thickness. The ore bodies are accessed from drives installed in the foot wall on levels developed from a sub-vertical shaft system, from 7L to 35L (the lowest working level and some 1,130m below surface), that is used to hoist rock and transport men and material to the workplaces.

Main levels are installed at 60m intervals and comprise a tracked haulage. Sub-levels are installed at 15m intervals from a footwall ramp that is developed between main levels. Currently mining is being conducted between 29L and 31L and the average historical drop down rate is equivalent to some 35m vertical per year. This rate is forecast to increase as the future footprint of the ore body decreases. The stoping operation is fully trackless using long-hole drill rigs and LHDs for all cleaning. Development is partially mechanised with some hand held drilling but all cleaning is by LHD.

The Trojan Mine Re-deepening Project
Trojan Mine completed and successfully commissioned the Shaft Re-deepening Project during an almost 8-week long shutdown from March to April of 2021. The Shaft Re-deepening Project involved two major components, namely:

The Shaft Re-deepening and Tie-in. This was the deepening of the existing sub-vertical shaft by 244 metres, to enable access to ........

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Trojan Mine Concentrator (“TMC”) incorporates two stages of flotation each comprising roughing and scavenging in low volume conventional cells with concentrate cleaning and re-cleaning also in low volume conventional cells. In primary flotation, coarsely liberated and faster floating minerals are recovered at a relatively coarse grind of 50% passing 75 micron. Primary flotation tails are reground to approximately 65% passing 75 micron ahead of secondary flotation, where finer and slower floating minerals are recovered. Flotation concentrates are thickened and filtered using rotary vacuum filters ahead of road transport to the Bindura Smelter and Refinery (“BSR”). Flotation tails are separately thickened before being pumped to the current tailings dam facility.