STUDI KUALITATIF DAN KUANTITATIF KARAKTERISTIK BATUBARA LEMPUNGAN FORMASI WAHAU SERTA PENGARUHNYA TERHADAP KADAR ABU BATUBARA DI KONSESI PERTAMBANGAN PT. BUMI MURAU COAL KECAMATAN MUARA WAHAU, KABUPATEN KUTAI TIMUR, PROPINSI KALIMANTAN TIMUR

Abstract

The increase of coal demand as energy resources affects in coal exploration which not based on quality, otherwise it depends on the calorific value of market requirement. For that reason, coal in lignite class will be exploited when needed by market demand. In field condition, lignite has relatively similar physical appearances with shaly coal, make it hard to determine the boundary between coal bed and shaly coal bed. Target of this research is to recognize the characteristic of shaly coal and identify a significant effect in the presence of shaly coal towards coal quality, especially ash content. This research used both qualitative and quantitative method. Qualitative method of description and analyst towards bore log and geophysical log (gamma ray log and density log in Count per Second unit/ CPS) were carried out to recognize the presence and characteristic of shaly coal. To determine any effect in the presence of shaly coal, towards ash content, a quantitative method of geostatistical “t” Student was carried out using ash content data. The result of analysis show that shaly coal in research area has gamma ray values 25 to 50 CPS and density values 780 to 2300 CPS. Shaly coal showed higher gamma ray values than coal (9-25 CPS) and lower density values than coal (1105-3500 CPS). There is effect in the presence of shaly coal towards the increase of ash content in coal beds characterized by average thickness 1.0-4.0 m and sufficient intensive to intensive presence of shaly coal. However, in coal beds characterized by average thickness 10.0-14.0 m and less intensive to sufficient intensive presence of shaly coal, its not effect in increasing of ash content.