Optimizations to increase throughput and recovery rates

Expansion and restart of a gold operation in Brazil
Godofredo Viana, Brazil
2017 - 2019
Equinox Gold
Industry Sector
Industrial; Minerals & Metals
Service Area
Project Delivery; Process Plants
EPC/EPCM Contracting; Gold Processing Plants

The Aurizona Gold Project was constructed in 2010 and successfully operated for four years treating saprolitic ores.

On September 2015, all mining and processing operations were suspended and all facilities were placed on care and maintenance status. In November 2016, a 3rd party contractor completed a pre-feasibility study of the project to finish the upgrade in order to process various types of mill feeds at a nominal rate of 8,000 t/d.

Client requirements

In 2017, Ausenco was selected to provide EPCM services for the execution of the process plant upgrades.  The main design work included an upgrade of the comminution circuit to allow the processing of various mill feeds at a nominal processing rate of 8,000 tpd.

Project solutions and approach
Ausenco integrated the upgrades into the existing facilities, including the crushing, grinding and reagents, along with new processing circuits. The former CIL circuit was converted to a hybrid leach/CIP circuit to enhance gold recovery. 

This brownfield project used new and refurbished equipment to increase throughput and recovery rates, resulting in an economically viable plant. First gold was poured in May 2019

Outcomes and achievements

  • Optimization of flowsheet and site layout for new expansion circuits within the existing plant footprint to make the process feasible.
  • Processing plant restarted successfully in May 2019, achieving nameplate capacity of 8,000 tpd shortly after.
  • Developed a strong on-site safety culture through implementation of site- specific training, auditing and reporting systems.
  • Successfully navigated the logistics and equipment delivery despite significant rainfall and short dry season.
  • Over 1.3 Million man-hours LTI free achieved.