ABSTRACT
In the Semin District and its surroundings, Kaolin is generally formed from the hydrothermal alteration in dacitic igneous rocks and tuff breccias. The potential of kaolin natural resources in these locations is very high when exploited to support various life necessities. Reserve estimation is an important work in evaluating a mining project for guidance on Kaolin procedures’ exploitation. It is an estimation of the quality and quantity of the presence of minerals that have economic value. The Reserve calculation method plays an important role in determining the efficiency in the commercial exploration of a deposit. Determining the reserve estimate requires the proposed geometry quarry mining design. Geotechnical analysis of a prospective kaolin quarry was carried out to determine the proposed slope design’s safety factor and its susceptibility to failure. The geotechnical properties, such as unit weight and uniaxial compression strength parameters, were determined. The safety factor was calculated using the Limit Equilibrium Method under static and pseudo-static loading conditions with deterministic and probabilistic sensitivity analysis. This paper presents a case study in which the effects of variations of the single and overall slope angle on the safety factor (SF) and kaolin quarry reserve estimation were analyzed. A total of 14 pits were generated by each studied final pit definition methodology, and each pit had sections with a varied single slope from 20o to 80o angles with an overall height is 85 m analyzed in the stability assessment. The recommendation of Overall slope limit in kaolin is 52o with overall height of 85 meters or single slope 70o and bench height of 10 meters will produce the excavation material taken by 584,399 BCM.
