Cone - AMPCO Minerals

About the Project

A remote gold ore mine site in the Asia Pacific region operates a crushing and screening plant that is preparing a crushed product for their heap leach operation. The site processes a highly abrasive and hard rock in a harsh continental climate with bitterly cold winters and short, warm summers, conditions that complicate maintenance, access, and uptime.

Reduced Circuit Efficiency

The abrasiveness and hardness of the ore accelerated wear and reduced efficiency across the existing circuit. The two mineral sizers used struggled to reliably process the material, limiting throughput and making it difficult to consistently achieve production targets.

A Circuit Redesign Strategy

The company engaged AMPCO Minerals to improve production performance and increase plant availability. AMPCO’s technical team partnered with site personnel to evaluate the existing equipment and operating conditions, then developed a two-phase circuit redesign focused on higher throughput, better system availability, and improved operational safety.

Phase 1 – Installation of a new primary crushing station.

Phase 1 established a new primary crushing station consisting of a GF6424 Grizzly Feeder, J65 Jaw Crusher, and a customized Fixed Stacking Conveyor.

  • The grizzly feeder provides consistent, controlled feed to the jaw crusher.
  • The J65 reduces hard rock to -280 mm for downstream processing and stockpiling. Its short toggle design, deep crushing chamber, and optimized nip angle support higher throughput and an effective reduction ratio.
  • The fixed stacking conveyor transfers the primary crushed ore to an intermediate stockpile.

Phase 2 – Rebuilding of the secondary and tertiary crushing circuits.

Phase 2 rebuilt the secondary and tertiary stages by replacing a secondary mineral sizer with a C65 Cone Crusher and adding a C50 Cone Crusher as a tertiary crusher. The mineral sizers could not efficiently handle the abrasive, competent ore, which resulted in a lower tonnage but also a coarser product and an overall lower system availability.

  • The new cone crushers feature a high pivot point and large eccentric throw to improve feed intake capacity and increase production.

In addition to the two cone crushers:

  • There was no space prior to the secondary cone to fit a screening station, but the existing secondary surge bin was modified to fit a new SLSP614-3G Scalping Screen, which despite its compact design, effectively handles the large feed size while screening out the -50mm fines in the feed prior to the secondary cone crusher to improve the overall system capacity.
  • Four customized Fixed Stacking Conveyors and an electrical control system was also included in the scope of the supply. The new control system was integrated with the existing plant PLC system.

The Upgraded Circuit in Action

With the installation of the J65 Jaw Crusher and replacement of two sizers with the C65 and C50 cone crushers, the upgraded circuit is better suited for abrasive hard rock, improving production tonnage, availability, and cost per ton. The grizzly feeder, scalping screen, and stacking conveyors support stable, continuous operation and help achieve the site’s production goals. The enhanced circuit is designed for 1,000 tph capacity and produces material -30 mm, well-suited for the heap leach operation.

 

For another look at AMPCO’s work in gold ore processing, see our Gold Mine Plant Project.