Metallurgical coal is an essential material in steel production. The metallurgical coal product of PT Maruwai Coal (“MC” or the “Company”) is a hard coking coal with strong coking characteristics and a crucible swelling number (CSN) of 9 (on a scale of 1 to 9), making it highly suitable for use in coke blending applications.

MC’s coking coal, Enviromet, features ultra-low ash and low phosphorus content, enabling lower waste generation and contributing to the production of stronger steel products. The high vitrinite content of Enviromet provides excellent reactivity and plasticity characteristics when blended with other coals. Its high-quality product and operational excellence have earned MC a prestigious reputation among leading customers across Asia, particularly in Japan, India, China, South Korea, and Indonesia.

The metallurgical coal resources and reserves within MC’s Coal Contract of Work (PKP2B) area were calculated based on the coal resource and reserve estimation report conducted in August 2021 using the principles of the JORC Code 2012. This demonstrates MC’s ability to generate sustainable economic performance and contribute to the nation through its operations. MC’s coal resources are classified into Measured, Indicated, and Inferred Resources. As of the end of 2025, MC had total coal resources of 108.7 million tons and reserves of 87.9 million tons.

MC’s mining operations are carried out using conventional truck-and-shovel methods by PT Saptaindra Sejati (SIS), which is also a subsidiary of PT Alamtri Resources Indonesia Tbk. MC’s operations are also supported by the Lampunut Coal Handling and Preparation Plant (CHPP), which has a feed capacity of 525 tph and is one of the largest CHPP facilities in Indonesia. CHPP plays a role in reducing coal ash content through a washing process applied to coal with high ash content, allowing the ash level to be reduced to 4.5%.

The following is the flow of MC's coal from pit to port: