Carbonation precipitation of manganese from electrolytic manganese residue treated by CO2 with alkaline additives

Abstract

Abstract. This work reports the results of carbonate precipitation of soluble manganese by CO 2 with alkaline additives with the aim of eliminating the harm caused by electrolytic manganese residue (EMR). Results showed that CaO exhibited a better performance for the precipitation of manganese which was converted to rhodochrosite (MnCO 3 ) by infrared spectra and XRD analyses and that the precipitation rate of manganese reached 99.99% at 800 mL/min CO 2 flow rate and 5% CaO for 20 min reaction time. The leached concentration of manganese of the treated EMR was reduced to 0.2 mg/L and the leached concentrations of heavy metals of the treated EMR were less than the discharge standard of China (GB8978-1996). Another interesting finding was that the pH value and the ORP of the treated EMR slurry were about 7 and 320 mV respectively, which favoured landfill and reuse of EMR.

Migration and Transformation Behavior of Mn2+ and NH4+-N in Electrolytic Manganese Residue at Different Leaching pH Environments: Release Kinetic Model, Physical Phase Changes, and Formation of Manganese Oxide

“…Some scholars have conducted studies on pollutant management in EMR. Chen and co-workers 18,19 have shown that the content of Mn 2+ and NH 4 + -N is lower than that of fresh EMR and that there is a disappearance of FeS 2 , MnSO 4 • H 2 O, and (NH 4 ) 2 SO 4 in the stockpiled EMR. Zhou et al 20 have shown that Mn wrapped by colloids and Mn in the stable chemical state were not easily dissolved.…”

Preparation of Mesoporous Silica from Electrolytic Manganese Slags by Using Amino-Ended Hyperbranched Polyamide as Template

“…China has been the top contributor to the production of electrolytic metal manganese, accounting for over 98.5% of the total world capacity in 2014. , The recycling of EMS has become a major problem for the industry. Many scientists and engineers have studied recycling of EMS and have made progress in many approaches, including synthesis of zeolite, geopolymers, road beds, soil fertilizer, autoclaved bricks, ground granulated blast-furnace slag cement, cementing material, chemical raw materials, − and metal recovery. , These methods are very difficult to be applied industrially because of low efficiency, high cost of production, and low value of the resultant products. The recycling of EMS is still limited to laboratory scales while the increasing quantity of EMS is being stacked near factories, causing potential pollution from the heavy metals of EMS as rain soaks EMS over a long period of time.…”