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. FLSmidth is the only company in Africa capable of providing a complete end-to-end gold extraction solution drawn from in-house technology.This know-how and equipment derives 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 located 300 kilometres north of Windhoek, Namibia, between the towns of Otjiwarongo and Otavi, and will rank as the country'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 metre diameter thickeners (one pre-leach and one tailings) with a bolted tank design; one carbon fines and one sludge filter and four electrowinning cells. FLSmidth will provide installation and commissioning supervision on-site, as well as post commissioning support from its Johannesburg operations.

FLSmidth’s gMAX cyclones focus on minimising 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 ball mill circulating load treated by gravity,” Dave Capstick, FLSmidth business development manager, 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 underway. The electrowinning cells and standby units are about to be shipped.

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 operating customers who are planning 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 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 the addition of 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. While this offering incorporates individual components, it also presents world class capabilities in terms of combining these components into customer-specific integrated gold room and plant packages.