Lufi has 23-year experiences in geotechnical, mine design, mine operation and mine management. He was graduated from Institut Teknologi Bandung majoring in Mining Engineering in 1996 and earned his master degree from Colorado School of Mines (CSM) in 1997.

Starting his career in PT Freeport Indonesia as Senior Geotechnical Engineer, Lufi had been successfully expanding his responsibilities to be Superintendent Geotechnical in 2000. In this position Lufi was responsible for all geotechnical aspects, ground control, and geotechnical section management for three active mines with total production around 50,000 tonnes per day, for studies of two future mines and for Common Infrastructures.

In 2003, Lufi was promoted to be Project Manager Strategic Planning at Freeport McMoran Copper and Gold (FCX) Head Office in New Orleans, USA. In this capacity, Lufi was responsible for Freeport’s strategic planning that managed long term studies and special projects of the FCX mines and reported to the Director. He was the Project Manager for DOZ 50k and 80k Expansion Studies, MLZ and Deep MLZ Pre-Feasibility Studies. He was also part of International Caving Study team consisting world-wide known experts in block caving with the goal of publishing the Caving HandBook.

In 2007 Lufi decided to change his professional career, returned to Indonesia and established a consultant company named GEOMINE Mining and Geotechnical Consultant. In the middle of managing his consulting company, in 2013, Lufi served as Operational Director for Baramulti Group, a public national coal mining company. He held this position until year 2015 when he decided to continue pursuing his full career in consulting. He earned KCMI Competent Person for gold dmp commodity in 2016, base metal in 2017, and JORC Competent Person in 2018. He has been actively involved in PERHAPI (Perhimpunan Ahli Pertambangan Indonesia) as well as KCMI (Komite Cadangan Mineral Indonesia). Recently, he was appointed to be the Indonesian representative for CRIRSCO (Committee for Mineral Reserves International Reporting Standards). He has published more than tens of papers that were posted in International publications.

Fourmarch Sinaga is a Mining Engineer with 21-year experiences in the mining industry both technical and operational including mining management. During his career, he has been involved in the mid-tier to large mining project and operations mostly in underground mines (copper, coal, nickel) with specialization in geotechnical, and he also spent over 7 years on surface coal mines operations.

Fourmarch started his professional career with PT Freeport Indonesia in Papua from year 2000 to year 2008 in various areas such as underground geotechnical, tunneling, project control and mine ventilation. His roles during his services with PT Freeport Indonesia as Chief Geotechnical Engineer, Chief Tunnel Engineer and Superintendent Project Ventilation. Previously, he worked with PT Dialia Setyamukti (mining contractor) from year 1999 to year 2000 as Production Engineer.

In early 2008, Fourmarch moved to Norilsk Nickel in Western Australia and later on to Cadia Mine, Newcrest Mining Limited in Orange, NSW, Australia. He worked with Newcrest from Jun 2008 to Jan 2012 as Senior Geotechnical Engineer for Cadia East Block Caving Project.

In early 2012, Fourmarch accepted a new role as a Senior Geotechnical Engineer for Xstrata Ulan Underground Coal Mine, based in NSW, Australia, a longwall mine with production of 4 Mtpa. One of his key responsibilities is to review and update Strata Failure Management Plan that must align with Australia Coal Mine Health and Safety Regulation.

In May 2013, Fourmarch returned to Indonesia and joined with PT Sumber Kurnia Buana (a subsidiary of Baramulti Group, one of national coal mining company). He looked after the feasibility study of underground coal as Project Manager Study. Starting April 2015, Fourmarch served as Operations Director for the company where his role is to direct and oversee all operational aspects of surface mining operations. In Dec 2020, he ceased the company.

Yusuf has over 30 years extensive experience in mining industry especially in various aspects of underground mining operation.

Started in 1988, Yusuf worked in PT Lusang Mining (under Billiton Group and then accused by Shell Company), an underground gold mining located in Bengkulu province. During seven years, Yusuf involved in mine operation, mine plan, and safety & quality, and was in-charge for chief of underground Mine Rescue Team and Deputy Mine Manager (Wakil Kepala Teknik).

In 1995, Yusuf started work in PT Freeport Indonesia in Papua. In almost 10 years Yusuf was responsible for surface and underground technical services, including temporary assignment for underground strategic long-term plan in New Orleans office, USA.

In 2005, Yusuf decided to work as an independent consultant for mining and geology, and during this period, he developed his owned business as an entrepreneur.

In 2012, Yusuf was appointed to be Operational Director of PT Lintas Multi Benua, an investment and mining services company until 2015.

He joined GEOMINE in 2015. He has played an important role in preparing government feasibility study document for Alexis Prima Mineral, Emas Mineral Murni, Kalimantan Surya Kencana, Kapuas Prima Coal, and Sumber Energi Jaya.

Dadang has over 8-year experiences in the mining industry. His past working experiences was with PT Jayakhisma Globe Indonesia, a coal mining in Kutai Timur, and with PT Aneka Tambang Tbk – nickel mining in Pomalaa, both are as Mining Engineer. He obtained a Bachelor degree in Mining Engineering Department at Universitas Hasanuddin and Master degree in Geotechnical Engineering Department at Institut Teknologi Bandung (Cum Laude). His thesis title is “Prediction of Geomechanical Parameter using Adaptive Neuro Fuzzy Inference Systems (ANFIS) and Multiple Regression Analysis (MRA) method”.

In his current capacity, he has involved in data collection, analysis, and report preparation for several feasibility study reports, KCMI reserve reports, and geotechnical studies reports (Arutmin, Bara Anugerah Sejahtera, Banjarsari Pribumi, Batutua Waykanan Minerals, Batutua Kharisma Permai, Bumi Suksesindo, Cikondang Kencana Prima, Citra Palu Minerals, Indo Muro Kencana, Jelai Cahaya Minerals, Kapuas Prima Coal, Kalimantan Surya Kencana, Nusa Halmahera Minerals, Sumber Energi Jaya). He is an advanced user of Mining and Geotechnical software such as Surpac, MineSched, Micromine, Slide, Phase2.