Geological and geotechnical conditions of Shiraldzhin gold ore mining

Abstract

Shiraldzhin lode deposit of gold–copper–silver ore in Kyrgyzstan has been studied since the 1980s. Shiraldzhin deposit lies within the boundaries of the Upper-Riphean Kumyshtag intrusion, with the Pre-Cambrian granitoid field broken by pillars of fine-grained Uzuntash granite of the Silurian Period. The proven five lodes have the negative economic appraisal for their mining. The primary appraisal covers only the main Sterzhnevoe lode body and includes some geomechanical problems. For this reason, the estimates of the reserves are re-interpreted toward the optimized gold extraction parameters. Modeling of the ore bodies within Shiraldzhin deposit is accomplished with justification of methods and systems to implement geotechnical solutions. Preparation of commercial ore by the sensor-based grading method allows bringing diluted ore to the level of 90% of underground gold content. Naturally, the proposed technology is a master technology for Shiraldzhin deposit. The open pit mining of Sterzhnevoe ore body in combination with the underground mining method at an ore extraction ratio of 60: 40% defines the economic efficiency of the mining project. The geomechanical research of the ultimate limit open pit and the geotechnology efficiency evaluation in the underground mine, including the geotechnical behavior analysis in rock mass and the backfilling pilot testing, is a critical requirement to reach the design performance.