GOLD EXTRACTION CAPABILITY FLSmidth’s supply includes two 20-m-diameter thickeners and two 20-m-diameter thickeners – one pre-leach and one tailings – with a bolted tank design
Global manufacturer and equipment supplier FLSmidth’s capabilities in the gold extraction arena will be showcased with the supply of equipment to Vancouver-based gold producer B2Gold’s Otjikoto gold project, in Namibia.
FLSmidth is the only company in Africa capable of providing a complete end-to-end gold extraction solution drawn from in-house technology.
This equipment is derived from FLSmidth’s Summit Valley range of modular plants and equipment for the extraction of gold and silver. The globally renowned Summit Valley offering includes the industry’s highest-capacity electrowinning cell used in precious metals recovery.
The Otjikoto gold project is 300 km north of Windhoek, between the towns of Otjiwarongo and Otavi, and will rank as Namibia’s second and biggest gold mine when it enters production before year-end.
The current mine plan is based on probable mineral reserves of 29.4-million tonnes to be mined over an initial 12-year period.
The order was placed with FLSmidth in the second quarter of 2013 and comprises 14 Krebs gMAX cyclones, four KC-QS48 Knelson concentrators reporting to a ConSep Acacia CS8000 intense cyanidation reactor, two 20-m-diameter thickeners – one preleach and one tailings – with a bolted tank design, one carbon fines and sludge filter, and four electrowinning cells. FLSmidth will provide installation and commissioning supervision on site, as well as post-commis-sioning support from its Johan-nesburg operations.
FLSmidth’s gMAX cyclones focus on reducing turbulence while maximising tangential velocity, significantly advancing cyclone performance. To achieve these two design criteria, the gMAX incorporates performance-enhancing improvements to the inlet head, cylinder section, cones and apex.
The company’s Quantum Series (QS) Knelson batch concentrator is highly configurable and uses a rotating assembly, incorporating the latest design in concentrate cone technology and advancements in the upper and lower frame.
“The low-grade Otjikoto ore contains significant gravity gold that can occur in relatively large nuggets, so maximum gravity effort is planned for recovery, with 100% of the ball mill circulating load treated by gravity,” FLSmidth business development manager Dave Capstick says.
The Krebs cyclones, Knelson concentrators and Acacia leach reactor were shipped to the mine site in October last year, followed by the filters, with fabrication of the thickeners complete and trial assembly under way.
Since FLSmidth acquired the Utah-based precious metals extraction business of Summit Valley five years ago, it has been actively marketing these products in Africa and achieving a steady penetration of this market. These technology solutions are directed at oper-ating customers who are plan-ning to expand their gold recovery circuits and those who want to improve their efficiencies, as well as those who are building new plants. There are also significant applications where customers are experiencing operating inefficiencies.
In 2013, the company received an order for a complete process flow solution, from elution through to electrowinning, for gold mining company Shanta Gold’s New Luika mine, in Tanzania. Here FLSmidth has designed a fully engineered solution to improve the efficiency of its process, together with an elution, carbon regeneration and electrowinning circuit to the plant.
The Summit Valley speciality product range is known worldwide, having been used in 24 countries on six continents over the last 18 years.