Preparation of chemical manganese dioxide from manganese sulfate

2010 ◽  
Vol 20 (6) ◽  
pp. 877-881 ◽  
Author(s):  
Jiangang FU ◽  
Zhangxing HE ◽  
Hui WANG ◽  
Wei LIANG ◽  
Chao GUO
2021 ◽  
Vol 5 (1) ◽  
pp. 20-28
Author(s):  
Jorge Luis Mendoza Bobadilla ◽  
Adolfo Enrique Guerrero Escobedo ◽  
Walter Moreno Eustaquio ◽  
Marina Ponce Zavaleta ◽  
Luisa Carbajo Arteaga

The residual effluents from the fur stage of the bovine leather tannery industry are characterized by having a high concentration of sulfides. The objective of this study was to evaluate the effects of aeration time and pH in the residual effluents of the leather stage of the tannery, with the catalysts MnO2 and MnSO4 separately; as well as, determine adjustment models through the response surface methodology and the optimal intervals of the best conditions that lead to a higher percentage of sulfide removal. For this reason, the sulphide removal percentage was evaluated from samples extracted from the pellet stage, by means of catalytic oxidation treatments; varying the catalyst, pH and aeration time. The catalysts used were manganese dioxide (MnO2) and manganese sulfate (MnSO4) and for each catalyst the pH was varied in the values ​​of 8.5; 9.5; 10.2 and 13.4; likewise, the aeration time was varied in the values ​​of 30, 60, 90, 120, 150, 180, 210 and 240 minutes. 64 treatments were carried out, with 3 repetitions each, reporting the average values ​​of the sulfide removal percentage. The response surface methodology was used to adjust the correlation of the variables to a quadratic model; Likewise, through contour graphs the regions with the highest percentage of sulfide removal were easily identified and by superimposing contour graphs the optimal ranges of the variables pH and aeration time were determined for removal percentages greater than 98%. Based on this evaluation, it is proposed for treatments with manganese dioxide, aeration times between 160 to 240 min and pH between 8.5 to 9 and for treatments with manganese sulfate, aeration times between 110 to 240 min and pH between 8.5 to 9.8. The coefficients of multiple determination R2 for the models with catalyst MnO2 and MnSO4 were 97.51% and 95.12% respectively. With the MnSO4 catalyst, higher removal percentages were achieved at a shorter aeration time, compared to the treatments carried out with the MnO2 catalyst.


ChemInform ◽  
2010 ◽  
Vol 30 (20) ◽  
pp. no-no
Author(s):  
Masao Hirano ◽  
Sigetaka Yakabe ◽  
Hideki Chikamori ◽  
James H. Clark ◽  
Takashi Morimoto

Synlett ◽  
1998 ◽  
Vol 1998 (01) ◽  
pp. 35-36 ◽  
Author(s):  
Toyohiko Aoyama ◽  
Naoko Sonoda ◽  
Mariko Yamauchi ◽  
Kyoko Toriyama ◽  
Masahiro Anzai ◽  
...  

1998 ◽  
pp. 770-771 ◽  
Author(s):  
Masao Hirano ◽  
Sigetaka Yakabe ◽  
Hideki Chikamori ◽  
James H. Clark ◽  
Takashi Morimoto

2020 ◽  
Vol 12 (9) ◽  
pp. 1070-1078
Author(s):  
Wang Haifeng ◽  
Chen Xiaoliang ◽  
Zhao Pingyuan ◽  
Gao Zhaowei ◽  
You Xiaoyu ◽  
...  

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.


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