From fast-track ramp-up to lifecycle support at Merdeka’s Pani Gold Project

Located in Indonesia’s Gorontalo province, the Pani Gold Project is set to become one of the country’s largest primary gold mines. Operated by PT Merdeka Gold Resources, a subsidiary of PT Merdeka Copper Gold Tbk, the project has ore reserves of 203.1 million tonnes, including 5.2 million ounces of gold and 5.5 million ounces of silver. Using large-scale heap leach processing, Pani achieved first gold production in Q1 2026, with heap leach irrigation beginning in January 2026 and confirming operational readiness ahead of schedule. 

Metso and Merdeka Copper Gold have partnered for more than 10 years, beginning with earlier projects such as Tujuh Bukit and Wetar. Through this long-term relationship, the teams have built a strong understanding of Merdeka’s operating priorities, technical requirements and project execution needs. Metso was involved from the early stages of the Pani project, supporting feasibility studies, metallurgical testing and process design. 

A robust circuit for a fast-track ramp-up

Pani is engineered for an initial heap leach capacity of 8 Mtpa, requiring a robust crushing and screening circuit capable of processing variable open-pit ore while maintaining stable, continuous throughput. With low-grade ore, efficient size reduction and consistent feed preparation are critical to supporting downstream agglomeration, heap leach performance and gold recovery. 

The project also needed to reach operational readiness within an aggressive commissioning timeline. This placed added emphasis on reliable equipment selection, aligned engineering, fast-track supply and strong site support during installation and start-up.

An integrated crushing and screening solution 

To meet these operating requirements, Metso supplied an integrated crushing and screening circuit designed to support high reduction ratios, consistent throughput, high availability and low maintenance costs. The solution included an Apron Feeder to support reliable material flow from the start, followed by a Nordberg® C160 jaw crusher for primary crushing. Secondary and tertiary crushing were handled by Nordberg® HP900 cone crushers, supported by vibrating grizzly and screening equipment for effective classification. At every step, the process was optimised to achieve efficient reduction and a target particle size distribution for downstream processing. 

Designing reliability into the circuit before start-up 

Metso drew on global field experience and data from comparable installations to optimize the circuit before installation. These reliability-focused design improvements helped increase component durability, support long-term mechanical reliability and reduce the risk of unplanned downtime.  

Early collaboration 

This early collaboration and engineering input also helped align the flowsheet, equipment selection and installation approach, supporting faster commissioning and a smoother transition into operation. For Merdeka, this collaboration helped reduce operational risk and build a stronger foundation for stable performance during ramp-up.

Installation and commissioning support 

Customer feedback highlighted the value of Metso’s on-site support during installation, particularly in assisting with installation sequence planning and coordinating key activities across the crushing and screening circuit. Metso’s support during testing and commissioning helped the site address issues quickly, mimize commissioning uncertainty and move more smoothly into operation. 

Stable ramp-up supports early production performance 

The plant began operations in January 2026 and has demonstrated a steady, stable ramp-up. Throughput has increased to approximately 20,000 tonnes per day, with plant availability reaching up to 85%. Despite highly variable feed ore, gold recovery has reached around 70% during this phase, supported in part by stable and consistent crushed feed preparation for the leach pad. 

Reliability beyond commissioning with lifecycle support 

Reliability and aftermarket support remain critical priorities for Merdeka as Pani continues to ramp up. Through its inventory agreement with Metso, Pani has preferential access to critical spare parts, supported by planning guidance from Metso and supply through the Surabaya Service Centre. This helps reduce the risk and duration of unplanned downtime and supports more reliable long-term operation. 

The Pani Gold Project demonstrates how early collaboration, fit-for-purpose equipment selection and strong lifecycle support can help reduce risk in fast-track mining projects. By combining an integrated crushing and screening circuit with installation support, commissioning assistance and ongoing spare parts planning, Metso has helped Merdeka build a more reliable foundation for ramp-up, production stability and long-term operational performance. At Pani, that foundation is helping turn fast-track delivery into sustained operational confidence.