The Batu Hijau Mine is one of Indonesia’s largest open-pit porphyry copper-gold deposits, located on Sumbawa Island, approximately 1,500 kilometres east of Jakarta.

Operated by PT Amman Mineral Nusa Tenggara (AMMAN), the mine uses conventional open-pit truck and shovel methods to extract and process its valuable ore resources.

AMMAN recognised that adopting advanced drilling and blasting technology was key to achieving the desired rock fragmentation.

By partnering with Orica, the company aimed to achieve better fragmentation, minimise cap rock, improve loading and hauling efficiency, and enhance safety while delivering stronger overall operational performance.

Orica’s 4D™ bulk system expands the range of energy available from Orica’s trusted bulk emulsion blends for wet, dry and dewatered holes. 4D™ enables customers to precisely tailor explosive energy to match changing geology.

Delivered using Orica’s 4D™ enabled Mobile Manufacturing Units (MMU™), the system does not require bulking agents or high-energy additives.

The trial followed a phased approach to evaluate 4D™:

• Phase One – Product Verification: Verifying and validating the product across several Relative Bulk Strengths (RBS) using small-scale tests.
• Phase Two – Energy Matched and Higher Energy Trials: Testing designs with energy levels to match and exceed the standard design in three to four side-by-side blasts.
• Phase Three – Modified Design Trials: Expanding drill patterns using Fortis™ 4D™ Extra-i with higher energy. This phase included side-by-side and full blasts in ore and waste to assess 4D™ performance against the standard product and validate the value proposition for expanded patterns.

From phase one to phase three, the mine fired 564 tonnes of Fortis™ 4D™ Extra-i product.

The collaboration between Orica and AMMAN successfully introduced Fortis™ 4D™, delivering several ongoing benefits over the three-month period.

• The 4D™ blasts achieved better fragmentation and bucket fill time without increasing cost.
• The average powder factor of 4D™ blasts was 2.9% lower than the benchmark blasts.
• Across 1,052 cycles, the 4D™ blasts recorded a 1.9% improvement in bucket fill time.
• 4D™ blasts delivered an 18.9% reduction in P80 size, decreasing from 250 mm to 203 mm, as measured using photogrammetric techniques.

The reduction in digging time shown in the trial results is indicative of improved fragmentation quality. This suggests that the 4D™ product delivered more favourable fragmentation outcomes than the baseline product, with the potential to improve overall excavation efficiency.

 

The authors express gratitude to the site Drill and Blast team for their support in preparing this case study. Special thanks to the Orica team for their assistance.

Authors: Ainun Hafidz, Budyanung Anindita, Rian Saerang, Sathio Zulkarnaen

Date: 22 April 2025