Tailing Storage Within a Heap Leach Facility - An Update on the Success at Yanacocha

Tailing Storage Within a Heap Leach Facility - An Update on the Success at Yanacocha

Author: Felix E. Garcia Prado, AnaMaria Rios Pando, Thomas F. Kerr, Antonio Belmar, Miguel E. Gutierrez, Thomas Byers, John Lupo
Conference: Heap Leaching Mining Solutions
Date: October 18-20, 2016

ABSTRACT
The Yanacocha Operation is an open pit gold mine located in mountainous terrain in Northern Peru. The Operation includes one tailing storage facility (TSF) and four heap leach facilities (HLFs). Given constraints imposed by topography and permitted boundaries, the efficient use of space is a priority. As an example of a design driven by the need to use space efficiently, the existing La Quinua (LQ) TSF was constructed entirely within one of the HLFs (the LQHLF) and uses the heap leach ore to form the containing embankments for the tailings (termed mill sands at the site). The LQHLF has been in operation since the mid-1990’s and the LQTSF was commissioned in 2008. The combined facility has consistently performed within its design expectations. However, both have now been developed to their maximum heights (with the maximum height of ore above the liner at 130 meters) and due to additional mining and the existing LQTSF nearing its design capacity, there is a requirement for the mine to develop additional tailings storage capacity. To meet this demand a new TSF was designed beside the existing LQTSF in the same LQHLF. The new TSF, designated the LQTSF North Expansion, is currently under construction.

In contrast to the existing LQTSF, which was progressively developed in a basin in the LQHLF as the facility was being loaded, the LQTSF North Expansion is being built as a new excavation within the LQHLF after the ore had been placed and leached. Key design considerations included (1) stability and deformation potential of the excavation slopes under static and seismic conditions, and (2) water removal from the excavation. Both considerations were for the short term (during the construction), and the long term, thereafter.

The majority of storage will be developed in the basin excavation, but some storage in the upper LQTSF North Expansion will be developed behind a low height embankment across the north perimeter, termed the North Embankment. The embankment is being constructed as an engineered fill structure using the mine haulage fleet to place and compact it. The original intent was to use leach ore from the excavation as fill but high moisture contents in the material led to a requirement to use other borrow sources. The suitability and compaction requirements for these borrow sources were evaluated with test fills, laboratory testing, and fields density testing. Slope displacement monitoring during construction was carried out using inclinometers, conventional prism surveying, and slope monitoring radar.

The construction is on schedule with regard to timeline and cost, and operation of the facility is planned to start in late 2017.

 

Download the full technical paper.

Download

Recent Insights

June 2024
Estimating Shear Stress within a Clay Foundation Using the Burgers-Creep Model
May 2024
Knight Piésold: Ensuring African Excellence in the DRC
May 2024
Wild Coast N2 Highway Project Taking Shape
April 2024
Risk Mitigation through Design Optimization Utilizing Seasonal Effects under Arctic Conditions at the Amaruq Mine
April 2024
Synthetic Rock Mass Modeling of Progressive Unravelling and Overall Slope Stability Using the Discrete Element Method
April 2024
Operational Slope Stability Risk Management for Large Open Pits at the Mount Milligan Mine – A Case Study
April 2024
Risk and Informed Approach to TSF Design and Operation
February 2024
Empowerment and Resilience
January 2024
Balancing Act: Water Usage Management Vital for a Sustainable Future
January 2024
A Difficult Balance Between Engineering, Environmental, Social and Economic Aspects
November 2023
Knight Piésold Commences with the ESIA for Haib Copper
November 2023
Insights from the Compilation and Critical Assessment of Breach and Runout Characteristics from Historical Tailings Dam Failures: Implications for Numerical Modelling
November 2023
Earthquake-induced Deformation Analysis of a TSF Undergoing Tailings Reprocessing
November 2023
Case Study: Approach to Determining the Risk Mitigation Priority of a Historic TSF in North America
October 2023
Data Management and Insights for Effective Tailings Storage Facility Management
October 2023
The Role of Sensitivity Analysis in Selecting Dam Breach Parameters
October 2023
Influence of Increased Confining Stress on Undrained Behavior of Tailings: A Case History at the Candelaria Mine
October 2023
The Re-use of Existing Bituminous Stabilised Materials for the Rehabilitation of National Route 7 - Case Study
September 2023
Transición energética para gerentes de mina
August 2023
Interview: Guillermo Barreda, Gerente General, Knight Piésold Perú