Piuquenes Dam Repulping and PMFC Tailings Drive

Codelco’s Andina Division began operations in the late 1960s, with the exploitation of the Rio Blanco deposit, through underground mining and, later, adding to its operations the open pit exploitation of the Sur Sur and Don Luis mines.

In November 1993, Codelco voluntarily submitted the Long-Term Tailings Disposal System Project, Ovejería Dam Project, to the Environmental Impact Assessment System (SEIA).

Codelco selected the Ovejería estate in the Til Til valley to build the dam to deposit its tailings because it had advantages such as: its isolation; its clay characteristics; the size of the basin, which has the capacity to store the tailings that the Andina Division will produce over the next 160 years; and the security represented by the 16-meter-high starting wall of compacted sand, which is impermeable.

The great engineering work involved the construction of 83 kilometres of reinforced concrete channels in 5 years, which has been in operation since December 1999 and carries the tailings to the Ovejería dam through the Tailings Transportation System (STR).

Within the framework of this Andina’s megaproject, PA Engineering carried out the Piuquenes Dam Closure Plan, the basic engineering that considered the removal of 25 MM/ton of tailings plus 8 MM/ton of dam walls; the necessary works for the execution of the Piuquenes dam repulping with the hydraulic removal method by pitoning, to then treat and pump this flow to the tailings chute of the STR.

In addition, for this project PA Engineering designed in 3D with BIM methodology in all disciplines. In this way, the administration was streamlined and there was greater control of the information, being able to visualize and optimize the design, interferences between disciplines, updating of cubic meters and drawings.