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.

Removal of Manganese(II) from Acid Mine Wastewater: A Review of the Challenges and Opportunities with Special Emphasis on Mn-Oxidizing Bacteria and Microalgae

“…However, the removal of 16.5 mg/L Mn(II) from acidic mining wastewaters was difficult and required an initial pH value of 8.0 and a larger limestone dose (16.7 g/L), probably due to the adverse effect of calcium (Ca) sulfate coating on the limestone [43].…”

“…In addition to the limestone, dolomite, magnesite, and quartzite can be used to precipitate Mn from mine wastewater. Soluble carbonate can be added if the solution alkalinity is not high enough for precipitation [40,43].…”

Magnesium oxide impregnated polyurethane to remove high levels of manganese cations from water

“…Therefore, most Mn(II) was removed by hydrolysis as pH increased even though more complexed reactions such as sorption and coprecipitation by (Table 1). As a comparable study, Silva et al [38] conducted batch tests of Mn(II) removal by fine particles (<45 lm) of limestone or dolomite in synthetic solution. Their results revealed that Mn(II) removal capacities of limestone and dolomite were about 7.2 mg (g of limestone) À1 and 1.5 mg (g of dolomite) À1 , respectively.…”

A green approach for treatment of wastewater with manganese using wood ash

“…The current article focuses on the synthetic wastewaters emulating from real wastewaters containing high amounts of manganese and low heavy metals concentration generated by metal coating plants, electrolytic metal manganese residue leachate and mining activities …”