Por: Karim Batallanos, Compañía Minera Antapaccay, y Fernando Altamirano Escobar, experto HSE.

Abstract

This technical paper is the result of a comprehensive view of the business, where people's safety is a priority.

The Compañía Minera Antapaccay Concentrator Plant has a comminution circuit consisting of a 60''x113'' primary crusher, which transports the crushed ore via a 7 km conveyor belt (Overland) to a 450 kton stockpile.

The grinding circuit begins with four feeders located in the stockpile, which feed the conveyor belt to a 40'x22' @ 24 MW Sag mill and two 26'x40' @ 16.4 MW ball mills (see Figure 1).

The stockpile starts with a capacity of 120 kton; this volume has subsequently been increased due to the need to increase the processing capacity (throughput) of the concentrator. Over the years, there have been problems with grinding due to variability in particle size and hardness, as well as tonnage losses when the primary crushing circuit entered maintenance.

The problems indicated were related to stock management, requiring the use of auxiliary equipment (tractors) to move the ore and deposit it strategically to avoid imbalances in the grinding circuit.

Before the system was implemented, the bulldozers operated in the coarse ore stockpile without having a clear idea of the exact location of the feeders that fed both concentrator plants. This resulted in unsafe working conditions for workers. The tractors had no system to alert operators when they were approaching the area where an inverted cone could eventually form as a result of the operation of the conveyor belt feeders.

To address these issues, the “Stockpile Safety” risk warning system was developed and implemented. This preventive engineering control system minimizes the likelihood of serious accidents caused by tractors sinking while moving material on the coarse ore stockpile. The system can indicate the risk zone within the auxiliary equipment cabins in real time and also generates an alert in the main control room (double assurance).

Creating this system involved several phases, including collecting data in the field, evaluating the coarse ore stockpile and auxiliary equipment, and defining risk warnings. In addition, the necessary hardware was installed, testing and parameter adjustments were carried out, operators and supervisors were trained, and continuous system monitoring was performed.

The results of the implementation of the Stockpile Safety system have been remarkable. Safety in the handling of the coarse ore stockpile has improved significantly, operational losses have been reduced, and a safer working environment has been created for the workers performing material handling tasks on the coarse ore stockpile in the Antapaccay comminution circuit. In summary, the implementation of the Stockpile Safety system has proven to be an innovative and effective solution for improving safety and efficiency in the handling of the coarse ore stockpile.