Sulfur resource recovery based on electrolytic manganese residue calcination and manganese oxide ore desulfurization for the clean production of electrolytic manganese

An environmentally friendly and resource-conserving route to the clean production of electrolytic manganese was developed,in which the electrolytic manganese residue(EMR)was initially calcined for cement buffering;then the generated SO2-containing flue gas was managed using manganese oxide ore and anolyte(MOOA)desulfurization;at last,the desulfurized slurry was introduced to the electrolytic manganese production(EMP).Results showed that 4.0 wt%coke addition reduced the sulfur of calcined EMR to 0.9%,thereby satisfying the cement-buffer requirement.Pilot-scale desulfurization showed that about 7.5 vol%of high SO2 containing flue gas can be cleaned to less than 0.1 vol%through a five-stage countercurrent MOOA desulfurization.The desulfurized slurry had 42.44 g·L-Mn2+and 1.92 g·L-1 S2 O62-,which was suitable for electrowinning after purification,and the purity of manganese product was 99.93%,satisfy the National Standard of China YB/T051-2015.This new integrated technology fulfilled 99.7%of sulfur reutilization from the EMR and 94.1%was effectively used to the EMP.The MOOA desulfurization linked the EMP a closed cycle without any pollutant discharge,which promoted the cleaner production of EMP industry.

Reduction of low-grade manganese oxide ore by biomass roasting

The reduction process of manganese dioxide in low-grade manganese ore by biomass roasting was investigated.The calcine of manganese oxide ore was further leached by sulphuric acid, the manganese in ore can be converted into manganese sulfate.Effects of the mass ratio of manganese ore to sawdust, roasting temperature and time, leaching temperature and time, leaching agent concentration and liquid-solid ratio were studied.97.71% of manganese recovery can be achieved under the optimal conditions：the mass ratio of manganese ore to sawdust of 5：1, roasting temperature at 500℃ for 40 min, leaching temperature at 60℃ for 40 min, sulphuric acid concentration of 1 mol/L and liquid-solid ratio of 10：1.Other types of low-grade manganese ore like Guilin ore, Nanning ore and Gongcheng ore were tested and the same results were obtained.

Microstructure of Solid Phase Reduction on Manganese Oxide Ore Fines Containing Coal by Microwave Heating

Microstructure of solid phase reduction on manganese oxide ore fines containing coal （MOOFCC） is one of important kinetics conditions of influencing microwave heating. On condition thai an atomic molar ratio of ro ： rc in MOOFCC is 1 ： 1.06 as well as a molecular molar ratio of rSiO2： rCaO is 1 ： 1.28, 1 kg of MOOFCC is heated by microwave to reach 1 000-1 300℃ and hold different time respectively. Experiments show that the metal phase takes the iron-based metal compounds containing manganese as the main content. The manganese content of metal phase increases with the xise of temperature. The particle size of the metal phase is within the range from 0. 01 to 0.05 mm. MO2 phase in the stuff is entirely changed into MnO phase and the slag phase is mainly composed of wollastonite and manganese olivine. The stuff reduced is loose and massive as a whole and its porosity is from 30% to 45%. The low softening-melting property and the low density of the stuff impact, to some degree, the solid phase reduction of powder by microwave heating.

Rare earth elements(REE)and isotope composition(δ^(13)C andδ^(18)O)of manganese ores of Chiatura deposit(Georgia):features of ore formation and genesis

The rare earth elements(REE)geochemistry and the isotope(δ^(13)C,δ^(18)O)composition of manganese ores of the Chiatura(Georgia)deposit were studied.One of the major features of all types of manganese ores is negative cerium(Ce/Ce*_(PAAS))anomaly and the absence of europium(Eu/Eu*_(PAAS))anomaly.Oxide oolitic manganese ores were formed in oxic shallow marine environments.The content and distribution of REEs(in particular Ce and Eu)in these ores are connected mainly with ferrous oxides.The performed C-and O-isotope research in Mn-carbonates(oolitic and massive)has indicated that carbonate ores were formed by the participation of isotopic ally light CO_(2)which is a result of the oxidation of organic matter in the sediment strata by reducing environments of early diagenesis(and,partially,catagenesis)zone.Obtained negative cerium anomalies in the studied carbonate ores reflect the specific REE patterns in pore waters of sediments of earlier isdiagenesis zone of the Oligocene Chiatura's basin.The deficiency of cerium in this zone remains debatable and requires further study.Formation of manganese carbonates took place multistage by the input of incisional solutions of different chemistry into sea bottom waters and sediments.The absence of europium anomaly indicates about lack of hydrothermal solution input.

Reduction of Low-grade Manganese Dioxide Ore Pellets by Biomass Wheat Stalk

An investigation on reducing low-grade manganese dioxide ore pellets was carried out by using wheat stalk as reductant. The main impact factors of reduction percent such as particle size, biomass/ore ratio, heating rate, nitrogen flow rate, temperature and time in reduction process were discussed. The morphology and component of manganese dioxide ore particle at different stages were also analyzed by scanning electron microscopy （SEM） and energy dispersive X-ray spectroscopy （EDS）. The results show the increase of the reduction temperature and time, biomass/ore ratio, and the decrease of particle size, heating rate and nitrogen flow rate can significantly enhance reduction efficiency. The reduction kinetic of the manganese ore is controlled by three-dimensional mass diffusion of gaseous reductive volatiles passing from the surface to the core of the ore particles. The activation energy E and frequency factor A were calculated to be 24.15 kJ.mol^-1 and 166 min^-1, respectively. Biomass pyrolysis volatiles adsorbed onto the surface of the ore particle leads to serious variation of the microstructures and chemical composition of the manganese ore particles.

An investigation on stability of biomass reduced manganese dioxide ore

In this study, how to improve the stability of reduced manganese oxide ore was dis- cussed by investigating reoxidation conditions and kinetics mechanism in the cooling process of manganese dioxide ore reduced by biomass. The effects of the temperature and time, chip size of biomass, raw materials thickness and different additives on stability of the products were determined. The valence variation of manganese in ore and the reoxidation kinetics of reduced products were studied. The results show that decrease of reduction temperature and time, and increase of raw materials thickness and little H2SO4 additive are favorable for the stability of the reduced products. The kinetics mechanism of the reoxidation is controlled by diffusion with dynamic appar- ent activation energy of E1--25.10 kJ.mol-1, and conformation of manganese in the process is changed from MnO to Mn3O4.