Remediation of Historic Waste Rock by Injection of Green Liquor Dregs : Results From a Field Scale Trial, Gladhammar, Southern Sweden

Abstract

Mining in Gladhammar, southern Sweden started in the 15th century, generating waste rock containing copper, cobalt, and arsenic. During remediation (2011) some waste rock was preserved, due to its geoscienti- c value, and placed on a geomembrane surface. Eventually, it became apparent that it had a substantial environmental impact (pH 3.8, Cu 96 mg/L, Co 21 mg/L). In 2017, green liquor dregs was injected in order to increase pH and decrease trace element mobility. Ten months a er injection pH was 8.3 and concentrations of copper and cobalt 1.3 mg/L and 1.1 mg/L, respectively. Evaluation will continue for at least five years