Comparison of static and mineralogical ARD prediction methods in the Nordic environment

Abstract

Acid rock drainage (ARD) is a major problem related to the management of mining wastes, especially concerning deposits containing sulphide minerals. Commonly used tests for ARD prediction include acid–base accounting (ABA) tests and the net acid generation (NAG) test. Since drainage quality largely depends on the ratio and quality of acid-producing and neutralising minerals, mineralogical calculations could also be used for ARD prediction. In this study, several Finnish waste rock sites were investigated and the performance of different static ARD test methods was evaluated and compared. At the target mine sites, pyrrhotite was the main mineral contributing to acid production (AP). Silicate minerals were the main contributors to the neutralisation potential (NP) at 60% of the investigated mine sites. Since silicate minerals appear to have a significant role in ARD generation at Finnish mine waste sites, the behaviour of these minerals should be more thoroughly investigated, especially in relation to the acid produced by pyrrhotite oxidation. In general, the NP of silicate minerals appears to be underestimated by laboratory measurements. For example, in the NAG test, the slower-reacting NP-contributing minerals might require a longer time to react than is specified in the currently used method. The results suggest that ARD prediction based on SEM mineralogical calculations is at least as accurate as the commonly used static laboratory methods.

Natural oxidation of coal tailings from Middelburg area (South Africa), and impact on acid-generation potential

“…The total acid-neutralizing capacities of S1, S2, S3, and S4 based on mineralogy (ANC min ) were calculated using Equation [19], where ANC min,c is the ANC based on carbonate minerals and ANC min,nc is the ANC based on non-carbonate minerals (Karlsson et al, 2018).…”

“…ANC min = ANC min,c + ANC min,nc [19] The acid-neutralizing capacities of S1, S2, S3, and S4 based on the carbonate minerals (ANC min,c ) were calculated using Equation [20] (Karlsson et al, 2018).…”

“…The acid generated during the oxidation of sulphide minerals reacts with acid-neutralizing minerals within the tailings deposits. Carbonate and silicate minerals contribute the most to acid neutralization (Blowes et al, 2013;Karlsson et al, 2018).…”

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“…Исследование потенциальной экологической опасности и пригодности к переработке некондиционных медно-никелевых руд и техногенных образований Мурманской области позволяет предприятиям и потенциальным переработчикам отходов снизить затраты на выбор технологий и обосновать экономическую эффективность новых производств. Для определения опасности природных и техногенных объектов был изучен вещественный состав и рассчитан баланс между способностью минеральных ассоциаций производить и нейтрализовать кислоту [Abrosimova et al, 2015;Karlsson et al, 2018]. Объекты были ранжированы по их потенциальной экологической опасности и с позиций пригодности к переработке кучным биовыщелачиванием [Светлов, 2019].…”

Static Test-Based Acid Rock Drainage Formation Potential of Metalliferous Tailings from O’Kiep, South Africa

“…Silicate minerals were found to be the most important contributors to the neutralization potential. Of the silicate minerals, Anorthite was observed to be the most important contributor to the total NP, followed by the other silicate minerals of the fast weathering groups [30]. Currently, there is a community that lives within the surroundings of the TSF in O'Kiep wind-borne, certainly being inhaled by the populace.…”