Kinetics of manganese leaching from an iron-rich manganese dioxide ore with bagasse pith as a reductant

2018 ◽  
Vol 42 (24) ◽  
pp. 20144-20151 ◽  
Author(s):  
Jiaqiao Gan ◽  
Jingxian Cui ◽  
Xueping Li ◽  
Yaseen Muhammad ◽  
Yuhong Wang ◽  
...  
Keyword(s):  
Manganese Dioxide ◽  
Bagasse Pith ◽  
Kinetics Of ◽  
Leaching Efficiency

Bagasse pith as a reductant is used for manganese leaching from an iron-rich manganese dioxide ore with leaching efficiency of 97%.

Leaching kinetics of copper and valuable metal extraction from copper-cadmium residues of zinc hydrometallurgy by oxidation acid leaching

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jihao Guo ◽  
Hongao Xu ◽  
Bo Li ◽  
Yonggang Wei ◽  
Hua Wang
Keyword(s):  
Hydrogen Peroxide ◽  
Acid Concentration ◽  
Acid Leaching ◽  
Metal Extraction ◽  
Agitation Rate ◽  
Leaching Kinetics ◽  
Solid Ratio ◽  
Zinc Hydrometallurgy ◽  
Kinetics Of ◽  
Leaching Efficiency

Abstract Multiple purification of zinc sulfate solution is an important process for zinc hydrometallurgy, and large quantities of copper-cadmium residues are generated as byproducts in this process. Copper-cadmium residues contain a large number of valuable metals that must be recovered. A comprehensive extraction process has been proposed using sulfuric acid as the leaching reagent and hydrogen peroxide as the oxidizing reagent. The effects of acid concentration, leaching temperature, leaching time, liquid-to-solid ratio, hydrogen peroxide dosage and stirring speed on the leaching efficiency were investigated. The optimum conditions were determined as an acid concentration of 150 g/L, liquid-to-solid ratio of 4:1, hydrogen peroxide amount of 20 mL, time of 60 min, temperature of 30 °C, particle size of −d75 μm, and agitation rate of 300 r/min. It was concluded that the leaching efficiency of copper and cadmium reached 97%, but because of the existence of zinc sulfide in the residues, a lower leaching efficiency of zinc was obtained. Furthermore, the leaching kinetics of copper was also studied based on the shrinking core model. The activation energy for copper leaching was 5.06 kJ/mol, and the leaching process was controlled by the diffusion through the product layer.

scholarly journals DECOMPOSITION KINETICS OF NITROUS OXIDE ON MANGANESE DIOXIDE

1974 ◽  
Vol 6 (5) ◽  
pp. 438-442 ◽  
Author(s):  
MASAYOSHI KOBAYASHI ◽  
HARUO KOBAYASHI
Keyword(s):  
Nitrous Oxide ◽  
Manganese Dioxide ◽  
Decomposition Kinetics ◽  
Kinetics Of

Stimulation Electrodes Based on MnO2 Thin Films: Electrical Properties in Carbonate Buffered Saline

1985 ◽  
Vol 55 ◽  
Author(s):  
Ellen M. Kelliher ◽  
Timothy L. Rose
Keyword(s):  
Manganese Dioxide ◽  
Active Surface ◽  
Alkaline Solutions ◽  
Manganese Acetate ◽  
Proton Diffusion ◽  
Rate Determining Step ◽  
Solid Film ◽  
Image Position ◽  
Saline Solutions ◽  
Kinetics Of

ABSTRACTHydrous manganese dioxide films are being investigated as a new redox material for the active surface of intracortical stimulation electrodes. The films are electrodeposited at room temperature on Pt substrates from a neutral solution of manganese acetate. The electrochemical properties of the films have been evaluated by cyclic voltammetry in neutral saline solutions buffered with bicarbonate. The films undergo a reversible charge injection reaction represented asThe results obtained in electrolytes of different buffer concentrations indicate the film is able to store the most charge in solutions having the lowest buffer capacity. The kinetics of the redox reaction thus favor operation in an acidic or basic environment in agreement with earlier published results. Two different mechanisms are proposed to explain the rate enhancement at the different pH's. In acidic electrolytes the reaction proceeds by dissolution of the film, while in alkaline solutions the rate determining step of proton diffusion in the solid film is increased. For neural stimulation, therefore, electrodes with manganese dioxide films should be pulsed cathodically to insure a neutral or alkaline environment around the electrode and minimize dissolution of the film.

Effects of humic acid and surfactants on the aggregation kinetics of manganese dioxide colloids

2015 ◽  
Vol 9 (1) ◽  
pp. 105-111 ◽  
Author(s):  
Xiaoliu Huangfu ◽  
Yaan Wang ◽  
Yongze Liu ◽  
Xixin Lu ◽  
Xiang Zhang ◽  
...  
Keyword(s):  
Humic Acid ◽  
Manganese Dioxide ◽  
Aggregation Kinetics ◽  
Kinetics Of

Deposition Kinetics of Colloidal Manganese Dioxide onto Representative Surfaces in Aquatic Environments: The Role of Humic Acid and Biomacromolecules

2018 ◽  
Vol 53 (1) ◽  
pp. 146-156 ◽  
Author(s):  
Xiaoliu Huangfu ◽  
Chengxue Ma ◽  
Ruixing Huang ◽  
Qiang He ◽  
Caihong Liu ◽  
...  
Keyword(s):  
Humic Acid ◽  
Manganese Dioxide ◽  
Aquatic Environments ◽  
Deposition Kinetics ◽  
Kinetics Of

Kinetics of the reaction between Manganese Dioxide and Ferrous Ion

1957 ◽  
Vol 10 (2) ◽  
pp. 150 ◽  
Author(s):  
DFA Koch
Keyword(s):  
Manganese Dioxide ◽  
Surface Area ◽  
Active Sites ◽  
Reaction Rate ◽  
Ferrous Sulphate ◽  
Zero Order ◽  
Ferrous Ion ◽  
Active Surface Area ◽  
Experimental Conditions ◽  
Kinetics Of

The kinetics of the reaction between manganese dioxide and ferrous ion in acid solution have been investigated by using the potential of the ferrous-ferric couple as a measure of the extent of reaction. The experimental conditions were such that the reaction rate was independent of ferrous, ferric, manganous ions, and acid concentrations and the agitation was sufficient to prevent bulk diffusion in the solution from being a rate-determining factor. The reaction rate of sized samples of pyrolusite and γ-MnO2 in ferrous sulphate solution was proportional to the surface area of the solid and was constant (i.e. " zero-order ") until 50 per cent. of the solid was consumed. γ-MnO2 reacted about twice as rapidly as the pyrolusite. The reaction occurred most readily at certain active sites on the particles and appeared to proceed along crystal boundaries in such a manner that the active surface area was not significantly changed during the first half of the reaction. In ferrous perchlorate the reaction rate of 10 μ diameter pyrolusite was about one-hundredth of that in sulphate and the reaction appeared to occur at a more even rate over the whole surface of the particle so that the zero-order law was no longer obeyed. Activation energies of 7.4 and 5 kcal in sulphate and perchlorate respectively, for the temperature range 18 to 40 �C, suggest that the difference in rate is a result of a change in the entropy factor of the Arrhenius equation. It is suggested that this difference in rate may result from the activation, by sulphate ions, of a less reactive lower oxide of manganese which is formed on the surface.

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