buzwagi gold mine, shinyanga - mining technology | mining news and views updated daily
Buzwagi Gold Mine is situated six kilometres south-east of the district of Kahama in the Shinyanga region, United Republic of Tanzania. The mine is 100% owned and operated by African Barrick Gold (ABG), a subsidiary of Barrick Gold Corporation.
ABG purchased the Buzwagi mine in 2000. The feasibility studies of the mine were completed in 2006. The development of the mine began in 2007 and was completed in 2009. The mine commenced operations in May 2009 and is expected to be shut-down in 2022.
The Buzwagi mine produced 196,541oz of gold in 2011, which was six percent higher compared to the production in 2010. The failure of the semi autogenous grinder (SAG) motor at the mines processing facility in May 2011 caused the production levels to fall by 15,000oz of gold.
The Buzwagi gold mine lies in a fleece-hosted quartz-veined deposit which comprises of porphyritic granite. Proven and probable reserves at the mine as of December 2011 stand at 61.4 million tons (Mt) graded at 1.47g/t Au (2.9Moz gold equivalent) alongside 0.114% Cu (154Mlbs copper equivalent).
Buzwagi has been developed as an open-pit mine and is being mined using a truck and shovel method. Extraction of the ore includes drilling, blasting, loading and hauling. The infrastructure being used for mining encompasses three excavators, Komatsu shovels, dozers, front-end loaders, 15 haul trucks and three blast hole drill rigs.
The ore extracted is transported to the processing facility by 150t capacity haul trucks. The processing plant can treat 12,000 tons of ore each day. It features two Knelson KC-XD48 concentrators, CS2000 ACACIA reactors, a primary jaw crusher, a SAG mill and a flotation and carbon-in-leach circuit.
The run of mine ore is broken down to a high degree of fineness in a primary jaw crusher. The crushed ore is transferred to the SAG mill for grinding. The ground ore is conveyed to the Knelson KC-XD-48 concentrators and CS2000 ACACIA reactors to produce oxide ore.
The oxide ore is treated by the gravity, flotation and carbon-in-leach (CIL) circuit. It is transferred to the cyanide leach tanks containing leach solution to generate pregnant solution. The solution is moved to the adsorption tanks where the gold attaches to the surface of the carbon. The gold is separated from carbon in a gravity and floatation circuit. The solution is transferred to the tailing storage facility for reuse.
Vacon supplies variable speed AC drives totalling eight megawatts, ranging from the small three-amp Vacon NXS units up to the largest 1,500-amp Vacon NXC units to render speed control. The company also provided two 1,500-KVA 12-pulse transformers and ten soft starters.