Comparative study of acid mine drainage neutralization by calcium hydroxide and concrete sludge–derived material. (October 2022)

• Record Type: Journal Article
• Authors: Iizuka, Atsushi; Ho, Hsing-Jung; Sasaki, Takeshi; Yoshida, Hiroyuki; Hayakawa, Yasuyuki; Yamasaki, Akihiro
• Is Part Of: Minerals engineering. Volume 188(2022)
• Publication Date: 2022-10
• Subjects: Acid mine drainage -- Neutralization -- Concrete sludge -- Calcium hydroxide -- Calcium carbonate; Mines and mineral resources -- Periodicals; Ressources minérales -- Périodiques; Mines and mineral resources; Periodicals; Electronic journals; 622
• DOI: 10.1016/j.mineng.2022.107819
• Languages: English
• ISSNs: 0892-6875

Abstract

Highlights: Acid mine drainage neutralization by concrete sludge–derived material was tested. Approximately 1.5 times more waste-derived material than Ca(OH)2 was used. Less sludge was generated from the waste-derived material than from Ca(OH)2 . Abstract: A novel neutralizing agent (PAdeCS) was produced from concrete sludge generated during the production of secondary concrete products by centrifugal molding, and the effect on actual acid mine drainage (AMD) was evaluated. The effect was compared with a conventional neutralizing agent (i.e., calcium hydroxide). Nine reaction tanks were temporarily installed and operated, imitating the treatment of actual AMD. The amount of discharged water and sediment generated was evaluated. The amount of PAdeCS required to neutralize the actual mine wastewater was 1.5 times that of Ca(OH)2, and the amount of sludge generated was less with PAdeCS than with Ca(OH)2 . The coagulation sedimentation performance of PAdeCS is greater than that of Ca(OH)2, determined by comparing the thickness of the sludge layer and the transparency of the supernatant. The reduction of CO2 emissions for the substitution of Ca(OH)2 and CaCO3 by PAdeCS was evaluated, and the neutralization performance of this novel neutralizing agent prepared from concrete sludge in AMD was determined.