Natural Pyrite-assisted Mechanochemical Recovery of Insoluble Manganese from Electrolytic Manganese Residue: Kinetics and Mechanisms

Abstract

Numerous traditional methods have been applied to extracting manganese from electrolytic manganese residue (EMR). However, most of them focused on the recovery of water-soluble manganese from EMR, while insoluble manganese, whose content is usually high in EMR, was generally ignored. Herein, the recovery of insoluble manganese in EMR was systematically investigated by a natural pyrite-assisted mechanochemical method. The recovery efficiency of insoluble manganese exceeded 86%, and the leaching efficiency of iron was lower than 1% under optimal conditions (the pyrite/EMR mass ratio of 4% and mechanochemical treatment at 300–500 rpm for 120 min). Toxicity characteristic leaching procedure experiments showed that after treatment the leaching concentration of manganese decreased by more than 12 times, and ammonia nitrogen decreased by 27 times, which met the regulatory discharge limit (GB/T 8978-1996). Tescan integrated mineral analyzer analysis directly confirmed that the insoluble Mn­(IV) in treated EMR was completely reduced to soluble Mn­(II), and iron was solidified in the forms of Fe–S-(Si–Al–O) and pyrrhotite. A potential mechanism could be that the insoluble manganese encapsulated in EMR matrix was exposed to the particle surface by the mechanochemical reaction; whereafter, the redox reaction between pyrite and insoluble Mn­(IV) was facilitated by the generated crystal defects and surfaces with dangling bonds under mechanochemical action. This study provides a direction for the resource utilization of insoluble Mn­(IV) in EMR and also expands the theoretical basis for exploring the reduction mechanism of pyrite-assisted mechanochemical method.

Fabrication of Iron-Containing Biochar by One-Step Ball Milling for Cr(VI) and Tetracycline Removal from Wastewater

“…A new characteristic peak was observed at 35.22°, which may be attributed to β-FeCr 2 O 4 . , These results indicated that Fe 3+ attaches to the surface and pore structure of biochar, providing more adsorption sites, which was beneficial for the adsorption of a large number of pollutants. Moreover, the results indicated that a series of chemical reactions may have occurred between Fe and Cr­(VI) on Fe@MBC during the progress of the removal reaction. , …”

Recovery and Utilization of Lead in Lead–Containing Waste Residue from Electrolytic Manganese Production

“…However, there is still ammonia nitrogen in the electrolyte that has not been removed, and so, it is necessary to further study how to treat it synchronously. In addition, the recovery of insoluble manganese from electrolytic manganese slag is also worth exploring [18], so as to realize harmless treatment and resource utilization in the real sense.…”

Aminopoly(carboxylic acid)-Functionalized PolyHIPE Beads toward Eliminating Trace Heavy Metal Ions from Water

“…In past decades, tremendous progress has been made to eliminate heavy metals from water. − Some low-cost advantage-oriented approaches (i.e., chemical precipitation, ion flotation, ion exchange, adsorption, and coagulation/flocculation) have been used to remove heavy metals from wastewater. − Among these approaches, adsorption is considered suitable for dealing with wastewater containing low concentrations of metal ions . Adsorbents such as activated carbon, mesoporous resins, and membranes have been reported for removal of heavy metals.…”