Unlock Mining Potential
Who we are
We are a team of experienced geology and mining professionals dedicated to providing top-notch services to the mining industry. Our expertise spans the entire mining lifecycle, from exploration to mine closure, with a strong focus on ESG.
At HDJ, we believe in teamwork and commitment, delivering expert solutions to clients, primarily in Indonesia and Southeast Asia, for commodities like Coal, Nickel, Gold, Copper, Bauxite, Tin, and Iron Sand. Many of our team members hold “competent person” status for various local and international codes. With deep local knowledge, we offer services in exploration, mine planning, geotechnical assessments, technical studies, JORC/KCMI reporting, asset valuation, and mine operation management.
Our 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.
Our Core Team
Yudi Suherlan
Director and Principal Geologist
Results-driven Principal Geologist with more than 22 years of extensive experience in mapping, geological assessment and resource estimation. Proven expertise in mineral exploration, data analysis, and project management. Strong track record of achieving successful outcomes in complex geological projects. Adept at collaborating with teams to enhance productivity and drive projects to completion. Committed to continuous improvement and professional development.
Debdutta Ganguly
President Director and Principal Mining Engineer
Debdutta Ganguly has over 20 years of international experience in both open-pit and underground mining. He has led major projects across Indonesia and India, with expertise in mine planning, reserve estimation, due diligence, and feasibility studies aligned with local and global reporting standards. A Registered Professional Engineer (PII), MAusIMM member, and accredited APEC and ASEAN Engineer, Debdutta combines technical excellence with strategic vision to deliver practical and compliant mining solutions.
James Hitt
Senior Advisor and Principal Mining Engineer
With over 40 years of experience in surface coal mining, specializing in mine planning, evaluation, budgeting, environmental compliance, and economic assessment. Experience includes work with major coal companies across the US, including in Alaska, New Mexico, and Wyoming, as well as international projects in India, Mongolia, Mexico, Indonesia, and Colombia. Has successfully led multidisciplinary teams and projects, driving operational efficiency and ensuring compliance with global environmental standards.
Rahaman Siddique
Data Science, AI & Simulation
Sid is a data science and simulation expert with over 10 years of experience helping organisations in pharma, consumer goods, manufacturing, and finance turn data into strategic advantage. He specialises in machine learning, AI roadmaps, and advanced simulation modelling using tools like AnyLogic, Simul8, and Pyomo. With a strong focus on decision intelligence and automation, Sid has supported 100+ organisations in optimising operations and solving complex business challenges.
Buldansyah
Senior Geologist
Senior geologist with extensive experience in gold exploration and mining. Proven track record in geological mapping, resource estimation, and feasibility studies. Skilled in managing exploration projects from inception to completion, ensuring compliance with industry standards. Strong analytical skills with a focus on optimizing resource recovery and minimizing environmental impact. Committed to driving successful outcomes through effective leadership and collaboration.
Edy Hidayat
Well Site Geologist
Edy Hidayat is a geologist with a Bachelor’s degree in Geological Engineering from Universitas Pakuan Bogor. His mining career spans several years across Indonesia. His previous roles include PJO for nickel mining in Southeast Sulawesi, Project Geologist for gold exploration in Central Papua, and General Manager in South Kalimantan. Edy’s experience also extends to project geologist roles in silica sand, quartz sand, and coal mining operations across different regions of Indonesia.
Get in Touch
Ready to explore new opportunities? Contact us today and let’s start your mining journey!