Jurnal Puslitbang tekMira (Teknologi Mineral dan Batubara)
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THE AVAILABILITY OF INDONESIAN OIL PRODUCT THAT IS USED IN THE UPGRADED BROWN COAL PROCESS
Indonesian coal has a potential to be a major future primary energy source due to its large resource, easy and low cost of exploitation, good quality and supported by appropriate infrastructure. However, more than 65% of the coal resources are categorized as LRC and this type of coal needs to be upgraded before it is used and transported for a long distance. One of the upgrading processes is UBC. Kerosene, LSWR and spray oils are used for UBC process as heating media, material for closing coal pores and oil for briquette machine, respectively. The specification and price of kerosene in Indonesia which is used for both household and industries are controlled by PT PERTAMINA. However in the case of LSWR, PT PERTAMINA does not control the quality and the price. Therefore in the market there are different of qualities and prices of LSWR. All oil refineries belong to PT PERTAMINA produces LSWR and kerosene. They guarantee the con- tinuity of oil supply to customer. They recommend to utilize a heavy aromatic for kerosene substitu- tion and asphalt and decant oil to substitute LSWR. The oil will be transported to the UBC plant from the nearest oil refinery using lorries or tankers transportation agency that is recommended by PT PERTAMINA
COMPARATIVE PETROGRAPHY OF OMBILIN AND BAYAH COALS RELATED TO THEIR ORIGIN
Two coalfields have been contrasted and compared on the basis of qualitative and quantitative stud- ies of macerals and minerals. Petrological comparison of the coals indicates that vitrinite and liptinite contents within Ombilin coal are higher than those of the Bayah coal. The inertinite content of both coals is somewhat similar. Mineral matter of Bayah coal is higher than that of Ombilin coal. The vitrinite reflectance and rank of the Ombilin coal is higher and thus, its coal rank (sub-bituminous to anthracite) is better than that of the Bayah coal (sub-bituminous to medium volatile bituminous). A clear distinction between the Ombilin and Bayah coals is not possible with petrographic methods alone, and other geological parameters have to be considered. The maceral compositions of the Ombilin and Bayah coals are slightly different from each other due to intrusion effect. In the thermally affected coals from both areas, liptinite generally cannot be distinguished from vitrinite and therefore it appears to contain high proportion of vitrinite (>90 %). However, thermally unaffected coals from both coalfields contain <90 % of vitrinite. Liptinite maceral is common in coals unaffected by contact alteration with some samples containing up to 10 %. In contrast, thermally affected coals have trace amounts of liptinite. Both thermally affected and affected coals contain rare inertinite with some samples containing up to 7 %. In some cases, coals with high inertinite content have a relatively high amount of mineral matter. The Ombilin and Bayah coals show variable vitrinite reflectances, due to igneous intrusion factor. Coal of lower rank has been metamorphosed to bituminous or anthracitic ranks. The extent of rank increase depends primarily on distance from the intruding igneous rock, but it may also be related to size and temperature of the intrusion. As the vitrinite reflectance (Rvmax) values of the Ombilin coal (0.62-4.69 %) are higher compared to the Bayah coal (0.53-1.23 %), this suggests that the heat source to the thermally affected coals is closer in the Ombilin coal than that of in the Bayah coal
APPLICATION OF SIMPLE DISPLACEMENT MONITORING SYSTEM FOR ROCK/SOIL MOVEMENT AT BINUNGAN MINE OPERATION OF PT. BERAU COAL
This monitoring result illustrates the real slope stability and could be used as datat for back analysis to obtain the real shear strength (c and ö).Study of monitoring system application to detect soil/rock movement at mine slope was conducted bya team from tekMIRA in 2006. The location of trial run was Binungan Mine Operation, PT. Berau Coal. The team used combinations of simple, accurate and relatively low cost monitoring equipment consists of radio modem, data logger and potential trans- ducer. Potential transducers were connected to the observation points using a wire line. When the movement occurs along the mine slope, the wire line will cause a difference potentiometer voltage. The results show a good value of linearity with value of r-square between 0.964 and 0.9
COALIFICATION TREND IN SOUTH SUMATERA BASIN
Similarities and differences in rank characteristics in the Bukit Asam coals within the South Sumatera Basin reflect their geological setting, particularly influence of the intrusion of andesite bodies and stratigraphic aspect. Rank variation was determined by vitrinite reflectance measurements of one hundred and thirty-four (134) coal samples. The higher vitrinite reflectance of the coals is a result of higher regional coalification level in the basin associated with the local and variable effects of igneous intrusions, as well as the greater cover/overburden. Philosophically, the higher the temperature, the more profound the alteration occurs; and the thicker the overburden, the more profound the rank occurs as well. The thermally affected coals have vitrinite reflectances between 0.69% (high volatile bituminous) and 2.60% (anthracite), whereas those of not affected are between 0.30% (brown coal) and 0.53% (sub-bituminous) according to the Australian classification