Germany’s KTI-Plersch was recently selected by Harmony Gold Mining to supply and install an ice cooling system at the Phakisa gold mine in South Africa. Phakisa gold mine has been using underground water chillers for bulk air cooling, as well as a 2,000 t/d surface ice plant for cooling of underground service water and for localised coolers closer to the working areas. However, Harmony required additional cooling capacity and chose KTI to supply a modular system of containerised ice makers. Two KTI ice plants with a capacity of 200 t/d each, were pre-fabricated at the KTI factory in Balzheim and cargo shipped from Hamburg to Cape Town.
Underground mines with depths reaching more than 2,400 m below the surface require extensive cooling to reduce the rock temperatures to less than 28°C. Adequately cooled air is essential for compliance with health and safety regulations, which also increases the productivity rate and reduces the injury rate. The KTI 400 t/d ice factory was erected in just ten days. The structural steel for the walkways and container supports was pre-manufactured and delivered to site ahead of time.
KTI says it has “made meaningful progress in demonstrating their ability to quickly and easily install massive ice systems.” The KTI plants at Harmony’s Phakisa gold mine have been operating almost without fault on a 24/7 basis since December 2013. Once the process was perfected, the nominal performance was exceeded by 10%, “showing that the system is reliable and economical.”
KTI believes it has introduced a “paradigm shift” in the application of surface ice making for deep-mine refrigeration and cooling, with each plant producing 220 t of ice with a 27°C water in-feed. The capital cost of an ice plant is below ZAR9000 per kilowatt, which is lower than alternative cooling means. The system installed at Phakisa is described as a breakthrough in terms of modular containerised ice making systems. As cooling demand underground increases, the system ensures swift installation and easy expansion. In addition, should it be required, these units can easily be moved to another location.
