Plasma diagnostics by optical emission spectroscopy on manganese ore in conjunction with XRD, XRF and SEM-EDS

Manganese(Mn) is an important industrial mineral.Information about the chemical and phase constitution along with the concentration of impurities presented in Mn ore is compulsory in assessing its suitability for different applications.We performed the qualitative and quantitative analysis of low-grade Mn ore(LGMO) using laser-induced breakdown spectroscopy(LIBS) in conjunction with x-ray diffraction(XRD), x-ray fluorescence(XRF) and scanning electron microscopy(SEM) coupled with energy dispersive x-ray electron spectroscopy(EDS).The optical emission spectra of the LGMO sample displayed the presence of Mn, Si, Ca, Fe, Al, Mg,V, Ti, Sr, Ni, Na, Ba and Li.The plasma parameters, electron temperature and number density were estimated using the Boltzmann plot and Stark broadening line profile methods and were found to be 7500 K±750 K and 8.18±0.8×1017 cm-3, respectively.Quantitative analysis was performed using the calibration-free LIBS(CF-LIBS) method and its outcome along with XRD, XRF and SEM-EDS data showed almost analogous elemental composition, while the LIBS method gave acceptably precise elemental analysis by detecting the low atomic number element Li besides V and Sr.The results obtained using LIBS for the LGMO exhibited its ability as a powerful analytical tool and XRF, XRD and SEM-EDS as complementary methods for the compositional analysis of complex low-grade mineral ore.

Hydrometallurgical leaching and kinetic modeling of low-grade manganese ore with banana peel in sulfuric acid

Manganese was leached from a low-grade manganese ore(LGMO)using banana peel as the reductant in a dilute sulfuric acid medium.The effects of banana peel amount,H2SO4 concentration,reaction temperature,and time on Mn leaching from the complex LGMO were studied.A leaching efficiency of~98%was achieved at a leaching time of 2 h,banana peel amount of 4 g,leaching temperature of 120°C,manganese ore amount of 5 g,and sulfuric acid concentration of 15vol%.The phase,microstructural,and chemical analyses of LGMO samples before and after the leaching process confirmed the successful leaching of manganese.Furthermore,the leaching process followed the shrinking core model and the leaching rate was controlled by a surface chemical reaction(1−(1−x)^1/3=kt)mechanism with an apparent activation energy of 40.19 kJ·mol^−1.

Phase, Microstructure and Beneficiation of Manganese Ore by Acid Leaching

In this research work, sawdust was used as a reducing agent for sulphuric acid leaching of manganese ore from Prang Ghar, Lower Mohmand Agency, Pakistan. X-ray diffraction of the powdered sample indicated the presence of Hausmannite (Mn3O4), Calcium Aluminum Silicate Hydrate, Silica (SiO2) and Hematite (Fe2O3). X-ray diffraction and the energy dispersive spectroscopic analysis show that the manganese ore sample was siliceous in nature. In the present study, six process parameters were investigated i.e. the particle size of the ore, leaching temperature, time duration, Mn ore amount, sulphuric acid concentration and amount of sawdust. Manganese extraction of 88.93 (wt%) was achieved for a leaching time of 60 minutes at 120°C using 5% (v/v) H2SO4 concentration for 10 g Mn ore and 5 g sawdust. The results demonstrate that sawdust is a low cost, renewable and non-hazardous reducing agent in comparison to other available reagents.

Metamorphic Temperature Investigation of Coexisting Calcite and Dolomite Marble Examples from Nikani Ghar Marble and Nowshera Formation,Peshawar Basin,Pakistan

Using marble samples from the Nikani Ghar marble and Nowshera Formation from Northern Pakistan the determination of the temperature of metamorphism was undertaken with the help of calcite-dolomite solvus geothermometer. Two types of marbles, that is, calcite-dolomite marble and quartz-bearing calcite-dolomite marble were selected. Petrographic and scanning electron microscope analysis of dolomite samples indicated different grain sizes. X-ray diffraction technique indicated the calcites MgCO3 content up to 7.93 mol.%. Nikani Ghar marble samples have shown lower contents of MgCO3 as compared to samples from Nowshera Formation. The calcite-dolomite-quartz marble has also showed relatively lower MgCO3 content and hence rather low temperature （-500 ℃）. The temperature reached during peak metamorphism of the investigated marble occurrence, based on calcitedolomite solvus was 628 ℃. Metamorphic temperatures derived from the present study were shown as a linear graph and values were in good agreement with the published literature.

High energy storage density with ultra-high efficiency and fast charging-discharging capability of sodium bismuth niobate lead-free ceramics

Ceramics-based capacitors with excellent energy storage characteristics,fast charging/discharge rate,and high efficiency have received significant attention.In this work,Na0.73Bi0.09NbO3(NBN)ceramics were processed through solid-state sintering route.The investigated ceramics were crystallized in a single perovskite phase.Dense microstructure,with small average grain size(~0.92 mm)is obtained for the investigated ceramics.A high dielectric constant>1000 accompanied by a low dielectric loss was achieved for these ceramics at ambient temperature.A recoverable energy density~0.92 J/cm3 and ultra-high efficiency of 96.33%at 138 kV/cm were obtained at room temperature.Furthermore,a lower discharging time of 0.14 ms was also achieved.This material is a suitable candidate for power pulsed applications.