RACA Journal September 2023 | Page 40

Project

Methodologies used to implement energy reductions included :

• A horizontal spray chamber BAC design was selected for minimum air resistance

• High thermal performance cooling towers with low internal resistance

• Plant room adjacent to the BAC for minimum hydraulic and thermal losses

• High efficiency single-stage centrifugal refrigerant compressors ( with efficient part load control )

• Process system design to maximise plant coefficient of performance ( COP )

Andhee explains that considering the extreme temperatures in the plant room , which often reached 40-43 ° C , special measures were taken to maintain optimal working conditions . An air-conditioned booth was constructed to house the York Optiview Panel , which controls the HVAC system . This step ensured that the delicate network cards and equipment inside the booth remained cool and prevented potential heat-related issues .

“ Energy efficiency was a key consideration throughout the project . The team implemented various strategies to minimise energy consumption and associated costs . For example , the design included a horizontal spray chamber air cooler , which reduces air resistance and eliminates the need for large fans . Additionally , a high thermal performance cooling tower with low internal resistance was selected to efficiently dissipate heat . By positioning the refrigeration machine adjacent to the bulk air cooler , the team minimised thermal losses and reduced energy wastage during longdistance cooling operations ,” he adds .

BBE Projects is currently working on the Gara South Refrigeration plant that will be commissioned later this year , and the project is on track for completion in the third quarter of 2023 . Once complete , the refrigeration system will enable mining in the largely untapped southern area of the orebody , extending the life of the mine significantly .

CLIENT BACKGROUND Société des Mines de Loulo ( SOMILO ) SA is an exploration and mining company and the owner of the Loulo gold mine , which in turn is owned 80 % by Barrick Gold and 20 % by the state of Mali .

Gold potential was first recognised by the Syndicat Or joint venture between the Malian Direction Nationale de la Géologie et des Mines and the French Bureau de Recherches Géologiques et Minières ( BRGM ). The Gara gold deposit was discovered in 1981 by the Syndicat Or joint venture . In 1992 , BHP Minerals Mali entered into an agreement with Société des Mines de Loulo for a joint venture that developed the Gara deposit into a mineral resource that was deemed sub-economic at the time .

During 1996 , Randgold Resources acquired BHP Minerals Mali and undertook additional regional exploration , which resulted in the discovery of Yalea in 1997 , the second of two deposits that make up Loulo Mine . In 2003 , a feasibility study was undertaken at Loulo on a 12 Mt at 3.60 g / t Au for 1.4 Moz Ore Reserve , which led to the construction of an open pit mine in 2004 . Production from Loulo mine started in 2005 as an open pit operation . The Loulo underground mine passed through the feasibility study stage in 2005 , with development beginning in 2006 . The first gold produced from Yalea underground was in 2008 and Gara underground in 2011 .

Randgold Resources merged with Barrick Gold in 2018 / 19 . This mega-merger created the world ’ s biggest gold miner by market capitalisation . The merger was required to pool the companies ’ resources to stay competitive in the industry . RACA

Project name : LIST OF PROFESSIONALS : Owner ( Mine ) Developer Architect / Designer Project manager

Consulting engineer

Contractors

HVAC and associated product suppliers

RACA Journal I September 2023 www . refrigerationandaircon . co . za