Tanah Bumbu, South Kalimantan, April 2026: PT Borneo Indobara (BIB), a subsidiary of PT Golden Energy Mines Tbk, continues to strengthen its commitment to sustainable mining practices through the implementation of auger mining as part of its strategy to optimize coal reserve utilization and improve operational efficiency. Auger mining is a method similar to large-diameter horizontal drilling (1.5–1.9 meters) on highwalls with specific slopes, allowing coal extraction without the need for additional overburden removal. The auger machine operates using a spiral system that penetrates the coal seam and continuously transports material to the surface, and is therefore still categorized as part of surface mining operations.
Implementation of this method at BIB began in the third quarter of 2025, focusing on pit areas that have reached mine-out conditions or have a high stripping ratio (SR) that makes it uneconomical to mine using conventional open-pit mining methods. Initial development was carried out in collaboration with a specialist auger mining contractor, PT Auger Sistem Indonesia (PT ASI), with stages including operational trials, geotechnical parameter validation, and panel and pillar design optimization. Over time, this method has become an integral part of BIB’s mine planning, contributing to an increase in mineable coal reserves.
By the end of April 2026, cumulative production from auger operations alone had reached approximately 190,900 tons. This achievement demonstrates a significant contribution to increasing the utilization of reserves previously unmined using conventional open-pit mining methods, thereby adding mineable reserves that can be incorporated into future mining plans.
From a financial perspective, the implementation of auger mining provides significant benefits through:
- Increased recovery factor, particularly for highwall reserves previously unmined using conventional open-pit mining methods.
- Reducing the need for overburden removal, thereby lowering operating costs
- Optimizing cost per ton, especially in areas with high SR
- Increasing the economic value of marginal reserves
From a sustainability perspective, auger mining positively contributes to ESG aspects, specifically:
- GRI 304 (Biodiversity): reducing the need for new land clearing
- GRI 305 (Emissions): reducing emissions from overburden removal activities
- Resource Efficiency: increasing optimal reserve utilization
- Good Mining Practice: reducing losses and enhancing coal resource conservation.
This method also supports the principle of coal conservation by utilizing remaining coal reserves on the final highwall, thereby reducing the potential for resource or reserve loss.
BIB’s Survey, Geotech & Exploration Department Head, Joko Santoso, stated that going forward, BIB will continue to develop the implementation of auger mining by increasing equipment productivity, optimizing geotechnical design, and integrating it into long-term mine planning. With this approach, auger mining is expected to become one of the pillars in supporting production performance, cost efficiency, and achieving the company’s sustainability targets.
