Ore type changes at this plant necessitated the conversion of an existing resin-in-leach gold recovery process to a carbon-in-leach process. We carried out detailed engineering design which included making the necessary modifications to the existing leach circuit equipment, rerouting the tailings disposal and reclaim water circuits, installing new reagent addition and CN destruction circuits, and adding the ancillary equipment required to support the amended flowsheet.

The industrial mineral concentrator has historically suffered sub-optimal flotation performance at two parallel processing plants. We optimised the grinding and flotation circuits to reduce overgrinding and the associated grinding costs, increase overall recovery, and minimise product loss to tailings. The new process flow incorporated a coarsened grind by moving from primary and secondary grinding to a primary grind and concentrate re-grind configuration. We reconfigured flotation tailing recycle streams to improve gangue liberation and maintain concentrate grade while increasing recovery.

Yamana’s Cerro Moro processing facility wanted to investigate which upgrades were required to roughly double the plant’s capacity while processing lower grade ore. Through data analysis, test work review, and process modelling, we successfully completed a conceptual study identifying low-cost options for plant expansion.

Yamana subsequently engaged us to conduct a PFS level study and necessary preliminary work including design and management of the metallurgical test campaign, audit of existing plant circuits, and trade off studies evaluating expansion approach and optimal throughput target required to support PFS engineering.

Yamana Gold’s Jacobina processing facility was undertaking detailed engineering with another engineering firm to allow an increased plant capacity and engaged us to conduct a review of the proposed design of the comminution circuit. In our review of design parameters and operational data, it was determined that many of the expansion targets could be satisfied with existing equipment.

Yamana then engaged us to conduct an audit to confirm the review findings and to manage the expansion by heading a steering committee responsible for overseeing the project to ensure achievement of the site’s low-capital expansion goals. Through auditing and debottlenecking efforts, we have helped the site team to increase from roughly 7500 tpd to 9000 tpd.

The off-gas dry handling system at this smelter was a bottleneck that resulted in substantial downtime due to maintenance and shutting the furnace before the dust could be removed manually from the collection drop box.

We were tasked with converting the dry handling process to a continuous wet handling system by developing a circuit to deal with the dust as well as to do proof-of-concept tests to produce a pelletised product. The process test work included open channel flow, vibrating screens, thickening, pelletising, bulk flow properties, and drying circuit tests and provided the basis for the wet handling system.