University of Wollongong Research Online University of Wollongong Thesis Collection University of Wollongong Thesis Collections 1994 Tertiary coal belt in eastern Kalimantan, Indonesia: the influence of coal quality on coal utilisation Bukin Daulay University of Wollongong Recommended Citation Daulay, Bukin, Tertiary coal belt in eastern Kalimantan, Indonesia: the influence of coal quality on coal utilisation, Doctor of Philosophy thesis, Department of Geology, University of Wollongong, 1994. http://ro.uow.edu.au/theses/1413 Research Online is the open access institutional repository for the University of Wollongong. For further information contact the UOW Library: [email protected] TERTIARY COAL BELT IN EASTERN KALIMANTAN, INDONESIA: THE INFLUENCE OF COAL QUALITY ON COAL UTILISATION A thesis submitted in (partial) fulfilment of the requirements for the award of the degree of DOCTOR OF PHILOSOPHY from THE UNIVERSITY OF WOLLONGONG by BUKIN DAULAY (B.Sc, A.G.P., Bandung; M.Sc (Hons), Wollongong) Department of Geology March 1994 This thesis contains original research work carried out by the author except where otherwise acknowledged. The work has not been previously submitted for a higher degree to any other University or similar institution Bukin Daulay ABSTRACT Eastern Kalimantan has the second largest coal resources in Indonesia after Bukit Asam and Ombilin Coalfields of Sumatera, but currently has the highest coal production. It is also the area forecast to have the highest growth rate in production to the year 2000. The Kutei, Barito, Asem Asem and Tarakan Basins developed as a result of rifting in the Makassar Strait during the mid-Tertiary. The basins have cratonic and back-arc (retro- arc) settings with similar depositional histories from the Eocene through to the Middle Miocene. Coal was deposited in both Eocene and Miocene sequences in depositional environments ranging from fluviatile to deltaic. Economic coal deposits of Miocene age occur in all basins but economic Eocene coals occur only in the Barito and Asem Asem Basins. The aim of this study was to evaluate lateral and vertical variations in coal thickness and to study the chemical and physical (including petrographic) properties to provide valuable input for short and long term planning for the utilisation of the coals of this important coal mining district. Vitrinite and liptinite are the dominant macerals in both Eocene and Miocene coals. Inertinite is a minor component but it is higher in Miocene coals. Typical ratios for vitrinite to liptinite are higher in Miocene coals (8 to 15) than for Eocene coals (5 to 10). Mineral content is low in most of the coals except in some Eocene coals where it is abundant. Five types of exsudatinite have been recognised in the present study on the basis of morphology and mode of occurrence. Veins of exsudatinite are typically associated with telovitrinite whereas lensoidal exsudatinite is associated with detrovitrinite and resinite. Both liptinite and meta-exsudatinite can be distinguished within coals that have been subjected to contact alteration. The rank of the Miocene coals ranges from soft brown coal to high volatile bituminous (Rvmax of 0.30% to 0.71%) whereas for Eocene coals it ranges from subbituminous to high volatile bituminous (Rvmax of 0.43% to 0.66%). Thus, unlike most of the Miocene coals, the Eocene coals show only a small range of coal ranks. Miocene coals in Sangatta area have been altered to semi-anthracite by igneous intrusion. Most of the eastern Kalimantan coals are suitable for feedstocks in combustion and conversion (liquefaction and gasification) processes. Combustion is the most important present day use for coals but suitability of coals for combustion is restricted by the contents of minerals, sulphur, liptinite and inertinite as well as rank. The Miocene coals from Sangatta, Mahakam and Berau are the best coals for pulverised fuel combustion processes followed by the Tanjung (both Miocene and Eocene) and Pasir (Eocene) coals. Of the coals currently mined, or likely to be mined in eastern Kalimantan, Asem Asem, Satui and Senakin coals are considered to be the least suitable coals for pulverised combustion, because they have high moisture (Asem Asem), liptinite (Satui) and mineral matter (Senakin). The exceptionally high sulphur in some coals will produce high concentrations of S02 when combusted. Nevertheless, the Satui and Senakin coals are of sufficiently high quality to be used for power generation in Indonesia and the Asem Asem coal could be used to fuel a "mine mouth" power station. The Satui and Senakin coals are only marginally suitable for export under current market conditions. All Miocene coals and the Eocene coals from Satui are suitable as feedstocks for liquefaction and gasification processes. The economic of the use of eastern Kalimantan coals for both gasification and liquefaction processes is dependent upon using the solid residues produced for subsequent combustion in power generation. However, in order to use the residues for combustion specifically designed char-fired plants will have to be built. Sangatta, Senakin, Pasir and Tanjung (Eocene) coals are suitable for low-temperature (600°C to 700°C) carbonisation to produce chars. Good quality cokes, on the other hand can only be produced from coals with Rvmax in the range from 1.0% to 1.40% and the vitrinite content should be <75% and >50%. Accordingly, none of the eastern Kalimantan coals can be used as coke oven charges although selected coals such as Sangatta, Pasir, Senakin, Tanjung (Eocene) can be used as a minor component in coke blend. In the last two years most of the coal production from eastern Kalimantan was allocated for exports but in the next few years an increasing proportion of production from this area is likely to be used for additional coal-fired plants in Java. ACKNOWLEDGEMENTS The research project was carried out at the Department of Geology, University of Wollongong, through tenure of a scholarship funded by the Australian International Development Assistance Bureau (AIDAB). I wish to express my deep gratitude to both my supervisors Dr AC Hutton and Associate Professor Brian G. Jones for their suggestions of this study, encouragement, patient guidance, constructive discussion and general assistance throughout the study. I am also grateful to my earlier supervisor, Dr Alan C. Cook for visiting the field area and providing general advice. The author wishes to thank Associate Professor A.J. Wright, Head of the Department of Geology and also all academic staff for their assistance during this study. I would like to express my sincere gratitude to all technical staff for their help, especially Messrs Aivars Depers, David Carrie, John Paterson, Max Perkins, Mrs R. Varga and Mrs B.R. McGoldrick. I wish to thank the former Research and Development Director of the State Coal Mining (Perusahaan Umum Tambang Batubara) Jakarta, Dr M. Kusna, for providing an assess to coal mines along the eastern coast of Kalimantan. My special thanks go to the managements and all staff of P.T. Adaro Indonesia, P.T. Arutmin Indonesia, P.T. Berau Coal, P.T. Bukit Baiduri, P.T. Kaltim Prima Coal, P.T. Kideco Jaya Agung, P.T. Kitadin, P.T. Multi Harapan Utama, P.T. Tanito Harum and P.T. Utah Indonesia for permission to collect coal samples from mine faces and also providing shallow drill hole samples. Special appreciation is addressed to Mr. Frank S. Wojtaszak and Ms. Norma L. Buckman, the present and former Regional Directors of AIDAB, training officers and social workers who gave the author valuable assistance during the study. Also my thanks go to the postgraduate students of the Department of Geology who provided advice during many informal discussions. Finally, I am indebted to my wife Lely, son Dany Ardiansyah and daughter Tishi Tania for their companionship, patient support and encouragement throughout my study. TABLE OF CONTENTS Page ABSTRACT ACKNOWLEDGMENT LIST OF FIGURES LIST OF TABLES LIST OF PLATES CHAPTER ONE INTRODUCTION 1 1.1 GENERAL 1 1.2 ATMS OF THE STUDY 2 1.3 GEOGRAPHICAL LOCATION 3 1.4 PREVIOUS STUDIES 5 1.4.1 Regional Geology 5 1.4.2 Coal-related Investigations 6 1.5 SUMMARY 10 CHAPTER TWO GEOLOGICAL SETTING 11 2.1 REGIONAL GEOLOGICAL SETTING OF INDONESIA 11 2.2 REGIONAL GEOLOGY OF EASTERN KALIMANTAN 12 2.2.1 Stratigraphy and Sedimentation in 13 the Tarakan Basin 2.2.2 Stratigraphy and Sedimentation in 17 the Kutei Basin 2.2.3 Stratigraphy and Sedimentation in 19 the Barito and Asem Asem Basins 2.3 SUMMARY 21 CHAPTER THREE COAL POTENTIAL 23 3.1 GENERAL 23 3.2 DEPOSITION OF COAL 24 3.2.1 Barito and Asem Asem Basins 25 3.2.2 Kutei Basin 27 3.2.3 Tarakan Basin 28 3.3 COAL AND PEAT RESOURCES 29 3.3.1 Coal Resources 29 3.3.2 Peat Resources 31 3.4 CHEMICAL ANALYSES 31 3.4.1 Chemical Data for Eastern Kalimantan Coals 32 3.4.2 Comparison Between Eastern Kalimantan 36 and Other Coals 3.5 HARDGROVE GRINDABILITY INDEX (HGI) 38 3.6 SUMMARY AND CONCLUSIONS 39 CHAPTER FOUR COAL PETROLOGY 41 4.1 GENERAL jl 4.2 COAL TYPE *J 4.2.1 Miocene Coals ™ 4.2.2 Eocene Coals ^9 4.3 COAL RANK 52 4.3.1 Miocene Coals ^3 411 Pnrpnp Co3ls 4.4 SPATIAL AND TEMPORAL VARIATIONS IN COAL TYPE 56 4.5 EXSUDATINITE IN EASTERN KALIMANTAN COALS 63 4.5.1 Types of Exsudatinite 6^ 4.6 RANK VARIATIONS 68 4.7 COAL FACES AND DEPOSITIONAL ENVIRONMENTS 71 4.8 COALIFICATION AND THERMAL HISTORY 72 4.8.1 Geothermal Gradient 73 4.8.2 Palaeotemperatures 74 4.8.3 Estimation of Maximum Cover 75 4.9 SUMMARY AND CONCLUSIONS 76 CHAPTER FIVE MINERAL MATTER 79 5.1 NATURE