Gold & Silver Operations
Success Story of Barrick Gold’s Buzwagi Mines in Tanzania
Barrick Buzwagi was considered a marginal project until a new process was introduced that allowed production of copper concentrates for sale and leaching of gold from scavenger flotation tailings. This new process was one of the key contributions that resulted in transforming the project economics. Direct leaching of Buzwagi ores was the initial concept for the project that did not work out well due to the presence of high secondary copper minerals leading to high cyanide consumption and a lower overall gold leach recovery. With this new concept, Buzwagi commenced commercial gold production in 2009 and has produced over one million ounce of gold to date. This Buzwagi success story was presented at the Cu2007 conference in Toronto, co-authored by Barun Gorain, Pierre Beaudoin, Peter Kondos, Jacques McMullen and Julie Shuttleworth
Barun Gorain with Buzwagi operators during plant commissioning
Barun Gorain in the Buzwagi Flotation plant
Kanowna Belle Operations, Western Australia
Barrick’s Kanowna Belle Operations during 2006 to 2012, was in the forefront of implementing new technologies. Responsible for implementing new technologies, as director at Barrick’s Strategic Solutions Group, a new program involving implementation of learnings from AMIRA’s P9 project was initiated embraced by Kanowna. A joint team involving Barrick’s AuTec and JKMRC P9 team led plant survey campaigns to optimize both comminution and flotation performance, which resulted in at least 10% mill throughout and 1-2% gold recovery improvements. This experience of collaboration of site personnel and corporate with external researchers (JKMRC in this case) was highly valuable.
Porgera JV, Papua New Guinea
Barrick’s Porgera JV is an integrated operations designed to treat refractory gold ores involving flotation, gravity, pressure oxidation, gold leaching and electrowinning to make gold dore’ on site. Having an experience working on projects at Porgera was no doubt enriching. Responsible for providing support to optimize recovery at Porgera, as director at Barrick’s Strategic Solutions Group, various projects were initiated involving comminution, flotation, process control and leaching involving Barrick’s AuTec and some technology providers, all these efforts resulted in at least 2% gold recovery improvements and other mill throughput benefits. The eagerness of embracing new technology by plant personnel, such as implementing Portage’s Expert Control, was indeed an important highlight for their success. This is an underlying theme that transcends all operations that are truly successful.
Cowal Gold Mines, NSW, Australia
Barrick’s Cowal Gold Mines was commissioned during 2006-2007. One of the key challenges was to operate Flash flotation and the Rougher flotation in sync with gravity gold recovery and the leaching plant. Optimization of plants like Cowal, required a holistic view to identify the optimum solution. Leading the plant recovery initiative involving Barrick’s AuTec, JKMRC and various technology players supported by site personnel was an important learning experience on how to implement solutions. Just finding a solution is not sufficient but Technology Transfer involving site personnel was key to success. Installation of froth cameras along with development of advanced process control strategy to optimize flotation recovery was an important development. Grinding optimization along with better operation of gravity, flash flotation and regrind circuits were immensely beneficial to plant improvements. Again, another example of site playing a key role in implementing solution resulting in plant improvements.
Pueblo Viejo (PV) JV, Dominican Republic
PV is a flagship joint venture operated by Barrick and is regarded as one of the complex refractory gold ores treated using whole ore pressure oxidation (autoclave) technology. One of the key experiences gained during 2012 to 2016 at PV was the development of a solution to remove total carbonaceous matter (TCM) to reduce the preg-robbing behavior of the double refractory ores. This is no easy task considering the severe locking of TCM with gold bearing sulfides. A novel technology was developed, tested at AuTec and validated using a major pilot campaign at PV involving Eriez Technologies that was successfully completed. The key learning from this partnership is that development of new technologies is possible only if there is a burning platform and a strong alignment between corporate, operations and technology partners.
Pascua Lama Operations, Chile & Argentina
The AMBS technology is now successfully operating at Antofagasta’s Esperanza (now Centinela) operation using raw sea water and at Barrick’s Jabal Sayid operations using municipal waste-water. The advantage of AMBS is that this technology can handle high saline or brackish water in copper flotation process which also helps to improve moly recovery. This success promoted Barrick to test AMBS for the complex Pascua Lama copper-gold-silver ores where conventional processes pose severe challenges in recovery and in obtaining concentrate quality. After successful validation of AMBS in bench, various piloting campaigns were carried out in Chile that showed significant improvements in metallurgical performance. Details of AMBS technology in the link below:
https://www.barrick.com/news/news-details/2016/new-tech-uses-salt-or-brackish-water-to-process-copper-concentrate/default.aspx
Barrick’s Cortez Mining Operations, Nevada
The success of Barrick can be traced to its innovation culture since its early days when the company embraced pressure oxidation to treat the refractory gold ores at Goldstrike. Since then many innovations such as AMBS, and Thiosulfate leaching have been developed and commercialized at Barrick. With the advent of the digital era, Barrick was in a forefront embracing digitization especially at its underground mining and process plant operations. The opportunity to develop a digital framework as part of Barrick’s digital and innovation team was a transforming experience. An advanced Mine to Mill initiative was launched as part of this initiative involving innovative blasting, comminution and leaching using JKTech’s and other global expertise mainly to focus on maximizing mill throughput treating complex hard ores along with enhanced gold recovery. This is one of the few projects that is still ongoing at Cortez with an aim to optimize Mine to Mill operations. The key learning is that digitization is only an enabler, but when coupled with core knowhow could be a powerful force towards transformation and operational excellence.
New technology to Treat Double Refractory Carlin Ores
One of the key responsibilities at Barrick was to develop innovative technologies to treat the complex gold ores of the future (double and triple refractory ores). The innovative spirit of Barrick was an inspiration to the mining community at large and the opportunity to assist in developing technologies for future ore bodies is worthy of mention. Working with global centres-of-excellence along with AuTec provided a significant opportunity to build an inhouse R&D expertise that allowed development of a new process to remove preg-robbing carbon and arsenic bearing minerals from complex gold ores to maximize gold recovery. This know-how is immensely valuable as gold mining companies will need to treat these complex ore bodies in the future. Companies that have the knowhow will emerge as more successful.
