Abstract

Since dissolution is typically regarded as a key rate-limiting step during CO₂-mineralization, the prospect of using non-ferrous slags for CO₂-mineralization is investigated in this study by examining their dissolving behaviours in CO₂-environments. At combinations of two temperatures (30 and 60 °C) and two CO₂-pressures (1 and 10 barg), dissolution of two copper slags and a lead slag is studied at the liquid to solid ratio (w/w) of 1000 over time (30, 60, 120, and 240 min). The lead slag exhibits Fe-dissolution of up to 10% and the copper slags up to 5–6% within four hours among the systems in which the slags are dissolved in CO₂-environments[1-15]. Nearly majority of the observations had a solution pH between 4 and 5. The slags dissolve at rates that are Following the dissolution that occurs during the first 30 to 60 minutes, systems with higher temperatures and higher CO₂ pressures also exhibit greater (or comparable and solution-pH values. Additionally, the systems with higher temperatures and CO₂ pressure continue to show faster dissolving rates throughout the trial even if they initially showed higher solution pH after 30 to 60 minutes of dissolution. They are suggested as prospective sources for CO₂-mineralization since residues like non-ferrous copper and lead slags are easily accessible in contrast to equivalent natural minerals (such olivines), which often need to be pre-processed before carbonation.