Geochemical characterisation of a pyrite containing coal washing refuse pile produced by the AnjirTangeh coal washing plant in Zirab, Mazandaran province, Northern Iran

摘要

Over the past 22 years, coal washing operation in the Anjir Tangeh plant, in Zirab, northern Iran has produced large piles of refuse materials containing pyrite. This paper presents the geochemical characterisation of these refuse materials to evaluate pyrite oxidation. Three trenches were made at about 4 m depth on a specific part of the refuse pile surface. Altogether, 25 solid samples were taken in 0.5 m intervals and geo-chemically analysed. Results show pyrite oxidation at low depths and subsequent leaching of the oxidation products. Presence of carbonate rocks raised pH of the drainages arising from refuse pile.