TY - THES

T1 - TECHNICAL – ECONOMICAL EVALUATION EXPLOITATION OF DACITA SECTOR BY SUBLEVEL CAVING MASSIVE METHOD EL TENIENTE MINE, CODELCO CHILE

AU - Bareyns, Reinaldo

N1 - embargoed until null

PY - 2009

Y1 - 2009

N2 - El Teniente Division of CODELCO needs to guarantee that its production level won’t fall below the 140.000 (tpd) in the short and medium term. This has to be archived until the production rises to the 180.000 (tpd) once the New Mine Level project gets into full and steady state operation in year 2027. Dacita project is essential to achieve this objective. This sector will allow maintaining the needed production level during its life cycle (2014 – 2026). But El Teniente faces a great challenge in the exploitation of Dacita sector, since it has the most competent rock of the Division, with low fragmentation and potential to cave. The Forced Panel Caving method seems to be feasible, but the full caving of the rock mass is not fully guaranteed. A challenging method has been proposed: Sublevel Caving for 30% of the swell rock mass removal, and conventional Panel Caving for the removal of the 70% of the rest of the broken ore. The challenging method has a net cost present value higher in KUSD140.000 than Forced Panel Caving, but it offers higher certainty regarding the full caving of the rock mass. Despite its higher certainty of caving, it also faces risks such as: •Premature entrance of dilution •Geomechanic impact, due to the subsidence in “Pipa Norte”, “Quebrada Teniente” and eventually “RENO”, if the adjacent polygons are being exploited at the time of Dacita’s exploitation •Damaging seismic events, or production level collapses followed periods of hiatus. The Engineering Department of El Teniente Division has sponsored the present project with the aim of getting a risk – cost based comparative analysis for the two methods proposed. A risk analysis was performed for both of the methods and a net present cost value was determinated. So, in order to choose among the two methods studied, the affinity to risk of the decision maker is a fundamental issue. The question is if Codelco is willing to incur in higher costs (KUSD140.000) in order to guarantee the production plan of El Teniente Division.

AB - El Teniente Division of CODELCO needs to guarantee that its production level won’t fall below the 140.000 (tpd) in the short and medium term. This has to be archived until the production rises to the 180.000 (tpd) once the New Mine Level project gets into full and steady state operation in year 2027. Dacita project is essential to achieve this objective. This sector will allow maintaining the needed production level during its life cycle (2014 – 2026). But El Teniente faces a great challenge in the exploitation of Dacita sector, since it has the most competent rock of the Division, with low fragmentation and potential to cave. The Forced Panel Caving method seems to be feasible, but the full caving of the rock mass is not fully guaranteed. A challenging method has been proposed: Sublevel Caving for 30% of the swell rock mass removal, and conventional Panel Caving for the removal of the 70% of the rest of the broken ore. The challenging method has a net cost present value higher in KUSD140.000 than Forced Panel Caving, but it offers higher certainty regarding the full caving of the rock mass. Despite its higher certainty of caving, it also faces risks such as: •Premature entrance of dilution •Geomechanic impact, due to the subsidence in “Pipa Norte”, “Quebrada Teniente” and eventually “RENO”, if the adjacent polygons are being exploited at the time of Dacita’s exploitation •Damaging seismic events, or production level collapses followed periods of hiatus. The Engineering Department of El Teniente Division has sponsored the present project with the aim of getting a risk – cost based comparative analysis for the two methods proposed. A risk analysis was performed for both of the methods and a net present cost value was determinated. So, in order to choose among the two methods studied, the affinity to risk of the decision maker is a fundamental issue. The question is if Codelco is willing to incur in higher costs (KUSD140.000) in order to guarantee the production plan of El Teniente Division.

M3 - Master's Thesis (University Course)

ER -