Bulyanhulu Gold Mine, Kahama, Shinyanga, Tanzania
Bulyanhulu Gold Mine is situated 55km south of Lake Victoria in the district of Kahama, in the Shinyanga Region of the United Republic of Tanzania. It is owned and operated by African Barrick Gold (ABG), a wholly owned subsidiary of Barrick Gold Corporation. Approximately 2,853 personnel were employed at the mine's site by December 2011.
The mine was purchased by ABG in June 1999. The first gold was poured in April 2001. Operations at the mine are expected to be shut-down by 2034. The electricity to the mine is supplied by the Tanzania Electric Supply Company Limited (TANESCO), via a 220kv overhead grid network which connects to the Shinyanga station.
Operations at the mine were temporarily suspended in March 2010, because of a rock fall incident which caused three mortalities.
Gold production rates at the Tanzanian mine, East Africa
The production at the Bulyanhulu mine in 2011 stood at 262,034oz, which was one percent higher when compared to 2010 production rates.
Shear hosted quartz-veined deposit geology at African Barrick Gold's project
The Bulyanhulu mine lies in the shear hosted quartz-veined deposit, which comprises of Archaean rock formations. It hosts mafic volcanic flows overlaid by a series of pyroclastics and ash tuffs. Argillite is hosted between the mafic and felsic rocks present at the mine.
The mine consists of five different deposits, namely the Main, East and West zones and Reefs 0 and 2.
The proven and probable reserves at the mine as of December 2011 were 28.1 million tons (Mt), graded at 11.73g/t Au (10.63Moz gold equivalent), 0.669% Cu and 9.38g/t Ag.
Gold mineralisation in reefs and underground trackless mining operations
Gold mineralisation occurs in the reefs or quartz veins which are steeply plunging towards north-west striking structures. The mineralisation extends to a strike length of five kilometres and two to three metres in width. The majority of the mineralisation is identified in Reef 1.
The gold is associated with distributed sulphides ore within the steeply dipping reefs. The mine hosts high grade gold and low grade copper and silver.
Bulyanhulu has been developed as an underground trackless mining operation. It is being mined using four mining methods, which include longhole sublevel stoping, conventional cut and fill stoping, mechanised drift and fill stoping and alimak stoping.
The mine has a crushing, grinding and floatation plant, tailings storage facility, water management ponds and appurtenant facilities. Other infrastructure being utilised for the mining encompasses drill jumbos, scoops, dump trucks, rail locomotives, utility vehicles, shovels, loaders, dozers and handheld equipment.
Processing of concentrates at the deposit south of Lake Victoria, in Kahama
The processing plant was commissioned in 2000 with an initial capacity of 2,500t of ore each day. It was expanded by SNC-Lavalin in 2001 to yield 4000t of ore a day. It is currently being operated at a rated capacity of 3,300t of ore each day. It extracts approximately 200gm to 240gm of gold for each ton.
The plant features a crushing and grinding circuit, gravity separation circuit, floatation circuit, tailings thickening and filtration circuit, paste backfill facility and tailings storage facility.
The run of mine ore is crushed and grinded in a crushing and grinding mill. The output of the mill is conveyed to the floatation and carbon-in-leach (CIL) circuit, which constitutes cyanide leach tanks to generate pregnant solution.
The solution is transferred to the adsorption tanks where the gold and other concentrates are hinged to the surface of carbon. The gold, copper and silver concentrates are detached from carbon in a gravity and floatation circuit. The copper and silver concentrates are sold to smelters in China and Japan. The solution is transferred from adsorption tank to the tailing storage facility for reuse.
Recovered gold is moved to the tailing thickener to generate gold precipitates. The gold precipitates are exported to the international smelters to produce pure gold dore bars through specialised processing.
Transport links to ABG's Tanzanian Bulyanhulu Gold Mine
The Bulyanhulu mine is accessible via a private airport and local unpaved roads which connect to the main highway near Kahama.