Por: Gianncarlo Zamora, geólogo de Modelamiento y Jean Paul Bueno, gerente de Geología, Nexa Resources, Cerro Lindo.

Abstract

The Ore Sorting project seeks to implement advanced ore sorting technologies to improve operational efficiency and reduce environmental impacts at mining operations. Higher ore recoveries, reduced waste and more sustainable processing are expected.

For Cerro Lindo, this project is focused on reducing the environmental impact by reducing the disposal of waste by recovering part of this material and increasing the operating life of the waste rock dump, in addition to calculating the economic benefit that this initiative would bring.

The Ore Sorting technology has not been widely developed in polymetallic deposits, so it was necessary to perform different mineral compatibility tests. The result of these tests determined that the combination of XRF and color sensors adequately identify the minerals present especially in the SPB and VM domains in the Cerro Lindo deposit. 

Also, in a next stage of tests, the percentage of mass recovery and the increase in grades that would be obtained by processing this material through the sorter were determined. In addition, it was estimated that the percentage of mass recovered would range from 20% to 40%, and the increase in grade would vary between 2.50 to 5.38 times its original value in the Zn, Pb and Ag elements (SPB and VM domains).

The estimated economic benefit that this initiative would generate from its implementation would be US$ 2.34 million per year, considering the costs incurred in its implementation. With a sustainable production plan until 2030, the Ore Sorting project would reuse 1,128 Kton of material, extending the life of the waste rock dump by 0.58 years (210 days).

The report explains the possibility of increasing reserves through this technology by converting submarginal stopes into economically viable ones, with the possibility of converting 1.04 million tons into reserves.