Dissolution of sphalerite (ZnS) in acidic ferric sulfate solution in the presence of manganese dioxide

1998 ◽  
Vol 15 (1) ◽  
pp. 29-34 ◽  
Author(s):  
K. Srinivasa Rao ◽  
R. K. Paramguru
Keyword(s):  
Manganese Dioxide ◽  
Sulfate Solution ◽  
Ferric Sulfate

scholarly journals pH-dependent leaching mechanism of carbonatitic chalcopyrite in ferric sulfate solution

2021 ◽  
Vol 31 (7) ◽  
pp. 2139-2152
Author(s):  
Kolela J NYEMBWE ◽  
Elvis FOSSO-KANKEU ◽  
Frans WAANDERS ◽  
Martin MKANDAWIRE
Keyword(s):  
Sulfate Solution ◽  
Ferric Sulfate ◽  
Ph Dependent ◽  
Leaching Mechanism

scholarly journals Comparison of the Hemostatic Activity of Quercus persica Jaub. & Spach. (Oak) With Ferric Sulfate in Bony Crypts

2015 ◽  
Vol 21 (1) ◽  
pp. 34-38 ◽  
Author(s):  
Mohammad Reza Nabavizadeh ◽  
Arman Zargaran ◽  
Fariborz Moazami ◽  
Fatemeh Askari ◽  
Safoora Sahebi ◽  
...  
Keyword(s):  
Ethanolic Extract ◽  
Sulfate Solution ◽  
Ferric Sulfate ◽  
Control Group ◽  
Hemostatic Effect ◽  
Hemostatic Activity ◽  
Cotton Pellet ◽  
The Common ◽  
Group 2 ◽  
Bleeding Score

Effective tissue hemostasis in periapical surgical site is important in the procedures. Plants with large amount of tannins may act as a local hemostatic agent. We aimed to compare the hemostatic effect of the extract of Quercus persica with one of the common hemostatic material used in periapical surgery. Six standardized bone holes were prepared in the calvaria of 5 Burgundy rabbits. Two hemostatic medicaments were tested for their hemostatic effect and were compared with control defects: Group 1, cotton pellet soaked in 15.5% ferric sulfate solution; Group 2, cotton pellet soaked in pure ethanolic extract of Q. persica. Bleeding score between the groups was compared. The ferric sulfate group exhibited significantly less bleeding than the other 2 groups. Q. persica was found to cause more hemostasis than the control group at 4 and 5 minutes but there were no significant differences between normal saline and Q. persica extract in bleeding control.

Preparation of New Nano-MnO2 and Its Molybdenum Adsorption in Manganese Sulfate Solution

2020 ◽  
Vol 12 (9) ◽  
pp. 1070-1078
Author(s):  
Wang Haifeng ◽  
Chen Xiaoliang ◽  
Zhao Pingyuan ◽  
Gao Zhaowei ◽  
You Xiaoyu ◽  
...  
Keyword(s):  
Manganese Dioxide ◽  
Adsorption Process ◽  
Removal Rate ◽  
Sulfate Solution ◽  
Crystal Form ◽  
Quality Standard ◽  
Hydroxyl Groups ◽  
Manganese Sulfate ◽  
Order Kinetic ◽  
Surface Hydroxyl

Manganese sulfate solution was in this study oxidized, using H2O2 as oxidant, to obtain new Nano-MnO2 in situ. The characterization of new MnO2 was carried out by XRD, SEM, FT-IR and BET. The effect of new manganese dioxide adsorpting molybdenum ion in manganese sulfate solution was also studied. Results showed that the main crystal form of the new MnO2 was γ type, and there was agglomeration of nanospheres with 200∼300 nm diameter from the microscopic morphology, which had abundant surface hydroxyl groups, and its specific surface area was as high as 146 m2/g. MnO2 addition was 1.0 g under optimal adsorption conditions when the pH was 2, and the reaction time was 30 min, with removal rate of 99.2% molybdenum and 0.26 ppm residual amount of molybdenum in manganese sulfate solution, which met the quality standard for high purity manganese sulfate (HG/T4823-2015) with ≤5 ppm molybdenum content. Moreover, the thermodynamics and kinetics of molybdenum adsorption by new manganese dioxide were also studied. The experiments showed that the adsorption process was in accordance with the Freundlich adsorption equation. The adsorption process of molybdenum on manganese dioxide could be described with pseudo second order kinetic model, and the internal diffusion was a controlling link of adsorption rate.

scholarly journals Synchrotron Radiation XRD Investigation of the Fine Phase Transformation during Synthetic Chalcocite Acidic Ferric Sulfate Leaching

Minerals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 461
Author(s):  
Chaojun Fang ◽  
Shichao Yu ◽  
Xingxing Wang ◽  
Hongbo Zhao ◽  
Wenqing Qin ◽  
...  
Keyword(s):  
Phase Transformation ◽  
Synchrotron Radiation ◽  
Sulfate Solution ◽  
Transformation Process ◽  
Ferric Sulfate ◽  
Dissolution Process ◽  
X Ray Diffraction ◽  
Leaching Process ◽  
Leaching Experiments ◽  
Two Stages

The fine phase transformation process of chalcocite (Cu2S) leaching in acidic ferric sulfate solution was studied by leaching experiments and synchrotron radiation X-ray diffraction (SRXRD) tests. The results showed that the dissolution process of chalcocite was divided into two stages. In the first stage, Cu2S was firstly transformed to Cu5FeS4 and Cu2−xS, then the galvanic effect between Cu5FeS4 and Cu2−xS accelerated the dissolution process of Cu1.8S → Cu1.6S → CuS, and finally Cu5FeS4 was also transformed to CuS. While in the second stage, CuS was transformed to elemental sulfur, which formed the passivation layer and inhibited the leaching of chalcocite. Specifically, Cu5FeS4 was detected during the chalcocite leaching process by SRXRD for the first time. This research is helpful for revealing the detailed leaching process of chalcocite.

Leaching of Indium from Indium-and Iron-Bearing Sphalerite Concentrate in Sulfuric Acid–Ferric Sulfate Solution

2019 ◽  
Vol 17 (10) ◽  
Author(s):  
Huang Hui ◽  
Zhang Fan ◽  
Deng Zhigan ◽  
Wei Chang ◽  
Li Xingbin ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Elemental Sulfur ◽  
Control Process ◽  
Dissolution Kinetics ◽  
Sulfate Solution ◽  
Ferric Sulfate ◽  
Ferric Ion ◽  
X Ray ◽  
Mixed Control ◽  
Iron Bearing

Abstract Leaching of indium from an indium-and iron-bearing sphalerite concentrate in sulfuric acid– ferric sulfate solution was examined. The effects of various parameters were studied. Increases in the stirring speed, temperature, ferric ion and sulfuric acid concentrations, and decreases in the particle size, enhanced the indium leaching rate. Scanning electron microscopy/energy-dispersive X-ray spectroscopy and X-ray diffraction analyses of the unreacted and reacted sphalerite concentrate particles showed that elemental sulfur was formed and precipitated at the particle surfaces. The results show that dissolution was controlled by a mixed-control process. In the initial stage, the dissolution kinetics was chemically controlled. When more elemental sulfur was present on the particle surfaces, the dissolution kinetics was controlled by mass transfer though the sulfur layer. The activation energy of the chemically controlled step was 33.9 kJ/mol. The reaction orders with respect to the initial sulfuric acid and ferric ion concentrations were approximately 0.74 and 0.60, respectively.

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