title: Manganese and limestone interactions during mine water treatment.
abstract: Manganese removal from mining-affected waters is an important challenge for the mining industry. Addressed herein is this issue in both batch and continuous conditions. Batch experiments were carried out with synthetic solutions, at 23+/-2 degrees C, initial pH 5.5 and 8.3 g limestone/L. Similarly, continuous tests were performed with a 16.5 mg/L Mn(2+) mine water, at 23 degrees C, initial pH 8.0 and 20.8 g limestone/L. Calcite limestone gave the best results and its fine grinding proved to the most effective parameter for manganese removal. In either synthetic solutions or industrial effluents, the final manganese concentration was below 1 mg/L. A change in limestone surface zeta potential is observed after manganese removal and manganese carbonate formation was suggested by IR spectroscopy. The conclusion is that limestone can remove manganese from industrial effluents for values that comply with environmental regulations.
authors.affiliation: Bio&Hydrometallurgy Laboratory - Universidade Federal de Ouro Preto., Campus Morro do Cruzeiro, Ouro Preto, MG, 35400-000, Brazil.
authors.forename: A M
authors.initials: AM
authors.lastname: Silva
authors.forename: F L S
authors.initials: FL
authors.lastname: Cruz
authors.forename: R M F
authors.initials: RM
authors.lastname: Lima
authors.forename: M C
authors.initials: MC
authors.lastname: Teixeira
authors.forename: V A
authors.initials: VA
authors.lastname: Leão
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry*; D002254:Carbonates; D007220:Industrial Waste / Q000517:prevention & control; D008345:Manganese / Q000737:chemistry / Q000302:isolation & purification*; D008906:Mining; D014874:Water Pollutants, Chemical / Q000737:chemistry*; D018508:Water Purification / Q000379:methods
chemical_list: D002254:Carbonates; D007220:Industrial Waste; D014874:Water Pollutants, Chemical; D008345:Manganese; C045327:manganese carbonate; D002119:Calcium Carbonate