Acuña, EI & Soto, G 2014, 'Theoretical determination of the number of adits and cross-sectional area for the airflow requirements of the New Level Mine Project', in M Hudyma & Y Potvin (eds), Deep Mining 2014: Proceedings of the Seventh International Conference on Deep and High Stress Mining, Australian Centre for Geomechanics, Perth, pp. 801-811, https://doi.org/10.36487/ACG_rep/1410_58_Acuna
(https://papers.acg.uwa.edu.au/p/1410_58_Acuna/)
Abstract: The New Level Mine Project (NLMP) underground expansion represents the future of the El Teniente mines in Rancagua, Chile. With the expansion, the daily production rate is expected to be between 137 ktpd and a maximum of 180 ktpd, with production planned to start in the end of 2017 or early 2018. The airflow requirements of the project have been estimated in the range of 4,000 m³/s when reaching the end of the ramp up, shortly after the year 2025 for 137 ktpd. In order to deliver such volume of fresh airflow the NLMP is considering the construction of several parallel adits for intake and exhaust that will allow the circulation of the required volume. The adits are considered to be built over the upcoming years, with the first pair of adits being under construction, at a cross-sectional area of 7 × 7 m. Currently, the NLMP is considering the possibility of using larger cross-sections which have not been built before at El Teniente. This paper presents a theoretical exercise developed to determine the optimum number of adits and cross-sectional area to circulate the required airflow, assuming a symmetrical condition and concentrating only in the optimisation of the intake adits. The theoretical exercise consists of expanding the initial development of a single airway economic cross-sectional area into multiple airways economic cross-sectional area based on developing a trade-off between the capital and operational (energy) costs. As the initial development, the approach found in the literature consists of finding the economical balance point between the capital or development cost and the operational or energy cost. The results are presented and discussed with the recommendation made to the NLMP, which is being considered for the detailed engineering phase.