WASTE ROCK SUPPLY MANAGEMENT IN UNDERGROUND MINING OPERATION PT FREEPORT INDONESIA

• Main Author: ABDULLAH 29115033, ANDRI
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/21068
• Institution: Institut Teknologi Bandung

Underground mining operation planned to be PT. Freeport Indonesia <br /> <br /> future main operation once open pit mining is depleted and reaching end of <br /> <br /> mining life. Currently underground mine is facing critical issue in both short <br /> <br /> and long term of waste rock availability to feed waste crusher for gravel and <br /> <br /> sand production that will be used for producing shotcrete and concrete to <br /> <br /> support tunnel development and underground facility construction plan. <br /> <br /> The objective of this research is to find short-interim solution that can <br /> <br /> overcome shortage supply of waste rock. Qualitative and quantitative <br /> <br /> approach is used to determine root cause and best possible solution. Current <br /> <br /> Reality Tree (CRT) is implemented to find root cause of the problem and <br /> <br /> combination of Multi Criteria Decision Making (MCDM) with Rank-Order <br /> <br /> Centroid (ROC) weights technique using six criteria is implemented to <br /> <br /> determine each alternative score. <br /> <br /> Alternative solutions to solve waste rock supply problem proposed to <br /> <br /> Underground mine management are providing material from current lime <br /> <br /> quarry at Grasberg open pit mine, providing material from new source of <br /> <br /> waste rock (new quarry development) and providing material from Kasuang <br /> <br /> waste rock stockpile using process technology (Metal separator unit). <br /> <br /> Providing material from reclaiming Kasuang stockpile using metal <br /> <br /> separator unit is the best and most preferred solution due to having the <br /> <br /> highest score out of other two alternatives. Although this option require <br /> <br /> highest amount of initial investment, this option provide lowest operational <br /> <br /> cost, lowest risk impact, acceptable quality, source reliability and <br /> <br /> implementation timing still meet short-intermediate term target. Project <br /> <br /> management using critical path method (CPM) and earn value model (EVM) <br /> <br /> implemented to monitor project implementation stage. There are three <br /> <br /> critical path of implementation stage which are mechanical engineering <br /> <br /> process, mechanical procurement process and manpower hiring process. <br /> <br /> These three critical path need more attention and effort to achieve project <br /> <br /> management deadline schedule target. <br />