Who We Are
We are a group of experienced geology and mining professionals who have collaborated to deliver the best to the mining industry. Our expertise ranges from prospecting to mine closure with special emphasis on ESG. We understand the requirement of the fast-changing mining world on the verge of next Industrial Revolution.
In HDJ we believe in power of teamwork and commitment. Our highly motivated professionals and associates provide focused advice and solutions to clients globally for Coal, Nickel, Gold, Bauxite, Tin, Iron, Phosphate, Mineral Sand and more. Several HDJ team members hold “competent person” status for several local and international codes.
With extensive technical knowledge and field experience, we offer services including geological and geophysical data acquisition, due diligence, technical studies (pre-feasibility/feasibility/ITR), optimisation, mine planning, resource classification, JORC/KCMI Reporting, Valuation of coal and mineral asset (VALMIN), mine operation management and searching for coal/ mineral blocks for investors.
Our Background
HDJ was established in 2022, but experienced a period of limited activity until April 2025. With the appointment of Debdutta Ganguly as President Director, HDJ underwent significant revitalisation. A focused team was assembled, and proactive engagement with prospective clients resulted in the acquisition of key projects.
HDJ currently operates with all necessary licenses, enabling the company to legally provide exploration and mining consultancy services throughout Indonesia and with a team experienced across multiple commodities and geographies, HDJ is well-positioned to support projects globally.
Vision
HDJ will lead globally as a trusted leader in geology, mining, and support services, pioneering innovative and sustainable solutions, while upholding strong ethical and responsible practices.
Mission
HDJ delivers precise, timely, and expert-driven practical solutions from exploration to closure. We drive innovation, foster collaborative partnerships, and prioritise responsible practices that ensure environmental stewardship, social responsibility, and sound governance.
Our Team
HDJ Indonesia is led by a team of highly qualified professionals with extensive experience in geology,
mining engineering, environmental management, and project development
Yudi Suherlan
Results-driven Principal Geologist with more than 22 years of extensive experience in mapping, geological assessment and resource estimation.
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Debdutta Ganguly
Debdutta Ganguly has over 20 years of international experience in both open-pit and underground mining.
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James Hitt
With over 40 years of experience in surface coal mining, specializing in mine planning, evaluation, budgeting, environmental compliance, and economic assessment.
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Rahaman Siddique
Sid is a data science and simulation expert with over 10 years of experience helping organisations in pharma, consumer goods,
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Buldansyah
Senior geologist with extensive experience in gold exploration and mining. Proven track record in geological mapping, resource estimation,
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Edy Hidayat
Edy Hidayat is a geologist with a Bachelor’s degree in Geological Engineering from Universitas Pakuan Bogor.
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Winda Kartikasari
Bachelor of Engineering (Geological Engineering)
Winda Kartikasari is a Geological Engineering graduate with experience in mineral exploration, nickel resource estimation,
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Reinhard Bresman Cristoper
Bachelor of Engineering (Geological Engineering)
Reinhard Bresman is a marketing professional with a geological engineering background and five years’ experience in mining and mineral analysis.
MoreOur Commitment
At the heart of our values are integrity, innovation, and a dedication to building strong, lasting relationships with our clients. We are committed to delivering top-tier mining consultancy services in Indonesia, ensuring that every project we undertake is executed with precision and professionalism. Our team of experts combines years of industry experience with cutting-edge techniques to provide reliable and sustainable solutions tailored to your needs.
Beyond delivering results, we prioritize developing trust and maintaining open, long-term relationships with our clients, supporting them throughout their mining journey. With us, you can be confident that your vision will not only be realized but also nurtured with care, collaboration, and unwavering support.