Neutralization effect of slag on the acid rock drainage

Abstract

Abstract Aims/hypothesis Pohang Tertiary mudstone presents the issue of acid rock drainage. This study analyzed the capacity of a mixed slag (70% steel slag + 30% blast furnace slag) to neutralize Pohang Tertiary mudstone’s acid rock drainage. Methods Element analysis, acid neutralization capacity (ANC) test, and net acid generation (NAG) test were conducted on Pohang Tertiary mudstone samples and the mixed slag. The XRF analysis and the XRD analysis on the mixed slag were conducted to measure the CaO content, which indicates the potential of the mixed slag as an acid-neutralizing agent. Results According to the analysis results on the Pohang Tertiary mudstone samples, the total sulfur content was high, which indicates a high risk of acid rock drainage generation. Although there were slight deviations between the samples, overall, the mudstone exhibited a high acid rock drainage generation capacity. The XRF analysis of mixed slag results showed high amounts of CaO content. From the XRD analysis graph, it was clear that a high proportion of minerals with Ca- compounds consisting of basic substances were present. The neutralization capacity of the mixed slag on Pohang Tertiary mudstone was determined by the relationship between maximum potential acidity (MPA) and acid neutralization capacity (ANC). For instance, the mixed slag of 4.5% effectively neutralizes a sulfur content of 1%.