Using mining waste for CO2 sequestration: exploring opportunities through mineral carbonation, nature-based solutions, and CCUS

Abstract

Using mining waste for CO2 sequestration presents a promising solution for managing waste and reducing greenhouse gas emissions. This article provides a comprehensive overview of established CO2 sequestration methods that can be applied to mining waste eligible for such application. Three techniques were considered: 1) passive mineral carbonation; 2) a nature-based solution (NBS); and 3) carbon capture, utilisation, and storage (CCUS). Passive mineral carbonation involves exposing mining waste rich in Ca and Mg silicates to atmospheric CO2. NBS explores the reclamation of disposal areas, estimating the carbon sequestration by topsoil, organic amendments, and revegetation. CCUS presents some storage possibilities with CO2 injection into waste piles and utilisation by incorporating waste and CO2 into cement products. Furthermore, an innovative proposal for injecting CO2 into surface and underground coal mining waste disposal areas was described as a potential action. The strategies presented in this article can be considered to offset CO2 emissions from mining projects while also contributing to waste management and more sustainable production.