Better safety and operational continuity using Tangram’s automated detection feature

Better safety and operational continuity using Tangram’s automated detection feature

Overview 

Escondida is the highest producing copper mine in the world. In its two open pits, the falling blocks are a constant risk that could affect the mine’s safety and operational continuity. When unstable blocks fall, the mine is forced to shut down its operations in order to remove the fallen blocks, which, on occasion, can lead to operational losses and pose a risk to human safety and equipment. These unplanned events affect the company’s ability to comply with its mining plan, which undermines the reliability of that plan and the mine’s productivity.

To decrease the probability of blocks falling, Escondida’s geotechnical team used TIMining’s Tangram software to analyze and detect instabilities on planned and built slopes in order to increase the predictability of these events and make mining plan development and execution more reliable. TIMining’s Tangram software identifies and recommends removal of unstable blocks. Using Tangram, the geotechnical team increased the operation’s safety and the short-term plan designs’ compliance. This resulted in:

1. Early identification of nearly 40% of all the blocks based on the density mapping in current work zones.
2. Identification of 4 unstable blocks per month on average.

“Since adding this tool to our processes, we have been able to reduce the risk of not complying with our short-term mining plan. By decreasing the number of geotechnical events, we have increased our operational continuity and plan reliability.”

– Cristian Roa, Senior Geotechnical Engineer, Escondida.

Methodology

Escondida’s geotechnical team established exhaustive processes to analyze and detect instabilities on planned and built slopes in order to increase the predictability of these events and make mining plan development and execution more reliable.

The team relied on the TIMining Tangram software to support these processes. TIMining Tangram is a tool that allows companies to automatically geolocate instabilities by mapping structures at the mine site and on planned and built slopes. The Escondida team can now identify and predict when instabilities are forming on its short-term plan designs. The problem is solved by employing the methodology described below:

1. All intermediate and major faults historically mapped on-site are uploaded.
2. The mapped faults are then projected onto the lower benches of the slopes included in the short-term plan design.
3. The software automatically detects instabilities present on design slopes and identifies which areas have a high potential for forming removable blocks in the short term.
4. A Safety Factor and Failure Probability are calculated for each block detected by Tangram.

TIMining recommends removing all blocks with a Safety Factor equal to or less than 1.5 and/or a Failure Probability greater than 20% once the bench in question has been mined with a shovel. This will reduce the possibility of having blocks fall out of schedule and improve operational safety and compliance with the short-term plan.

Results

The following is a sample of some of the results obtained from Tangram.

Topographic Surface of Design N°1

1. Plane Fault (0.2 Kton), Safety Factor (0.98) and Failure Probability (24%)
2. Plane Fault (1.7 Kton), Safety Factor (0.75) and Failure Probability (83%)

Topographic Surface of Design N°2

1. Plane Fault (1.1 Kton), Safety Factor (0.45) and Failure Probability (99%)
2. Plane Fault (1.7 Kton), Safety Factor (0.83) and Failure Probability (74%)

Impact

By identifying and predicting the formation of instabilities in short-term plan designs, the geotechnical team was able to:

1. Identify early on close to 40% of all the blocks that were formed based on the density mapping in the current work zones.
2. Identify 6 unstable blocks in the November 2019 plan and 4 unstable blocks on average each month.
3. Include in the monthly planning the operational tasks required to control and manage on-site geotechnical risks faced by mine personnel.
4. Recommend that operational personnel use shovels or other mechanized equipment to unload the blocks immediately after mining the benches. This makes for a more dynamic expansion of the mining process because you can prevent operational shutdowns, make strategic decisions that do not impact production, and ensure the operational continuity of the mining plan.
5. Geotechnically, the process has provided the team with greater visibility for its risk management activities and to benefit in the short-term from the analysis efforts.