Analisis Kualitas Batugamping Sebagai Bahan Dasar Semen Portland di Pulau Nusakambangan, Kabupaten Cilacap, Provinsi Jawa Tengah

Abstract

Analisys of limestone quality as a raw material of portland cement conducted in Quarry XI PT. Holcim Indonesia, Nusakambangan Island, District Cilacap, Province of Central Java. Geological studies conducted to determine the order of geological research area that acts as a control that is responsible for the limestone characteristic both physically and chemically. In geological study, the data that is used is secondary data from previous research. The main goal of this research is to determine and recognize the geomorphic units, regional stratigraphic, structural geology, historical geology, deployment of limestone quality, and limestone quality as basic materials for cement. The research methodology used in this research is the study of literature and technical survey method with descriptive analysis is a researh method that is held to obtain the facts of phenomena that exist and seek factual information in the field, that is analysis of field data, geomorphological analysis, petrographic analysis, stratigraphic analysis, analysis of geological structure and chemical content analysis. Geomorphology unit in the research area consist of Karst hills unit (K2) which is characterized by hills that show significant dissolution, deposits result from weathering. In the research area the rock unit are mudstone, wackstone, and kristalin limestone which a division based of lithofacies them. That units formed during the pliocene-pleistocene, which are equal with the Paciran formation. That units was deposited in shallow marine (Inner Neritic-Middle Neritic) environment. It was interfingering upper the previous formation. Research area has been used as a limestone quarry for cement raw materials. Limestone in the research area can be divided into good quality and poor quality based on the content of CaO and MgO. Limestones with CaO (> 48%) and MgO (> 6%) can classified of limestone with high quality as a raw materials of portland cement industry.