Bifurcation analysis of the self-oscillation model for the system potassium iodate-hydrogen peroxide-cysteine-sulfuric acid

1987 ◽  
Vol 22 (6) ◽  
pp. 637-643
Author(s):  
E. V. Protopopov ◽  
T. S. Zueva
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Bifurcation Analysis ◽  
The Self ◽  
Potassium Iodate ◽  
Oscillation Model

scholarly journals Effective Recovery Process of Copper from Waste Printed Circuit Boards Utilizing Recycling of Leachate

JOM ◽  
2020 ◽  
Author(s):  
Joona Rajahalme ◽  
Siiri Perämäki ◽  
Roshan Budhathoki ◽  
Ari Väisänen
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Printed Circuit Boards ◽  
Sulfuric Acid Concentration ◽  
Recovery Process ◽  
Copper Recovery ◽  
Circuit Boards ◽  
Printed Circuit ◽  
Waste Printed Circuit Boards ◽  
Acid Consumption

AbstractThis study presents an optimized leaching and electrowinning process for the recovery of copper from waste printed circuit boards including studies of chemical consumption and recirculation of leachate. Optimization of leaching was performed using response surface methodology in diluted sulfuric acid and hydrogen peroxide media. Optimum leaching conditions for copper were found by using 3.6 mol L−1 sulfuric acid, 6 vol.% hydrogen peroxide, pulp density of 75 g L−1 with 186 min leaching time at 20°C resulting in complete leaching of copper followed by over 92% recovery and purity of 99.9% in the electrowinning. Study of chemical consumption showed total decomposition of hydrogen peroxide during leaching, while changes in sulfuric acid concentration were minor. During recirculation of the leachate with up to 5 cycles, copper recovery and product purity remained at high levels while acid consumption was reduced by 60%.

Effect of Oxidant on the Leaching Rate of Indium from Water Quenching Slag

2013 ◽  
Vol 591 ◽  
pp. 122-125
Author(s):  
Li Jiao Yang ◽  
Si Chen ◽  
Yan Zhang ◽  
Nan Chun Chen ◽  
Jun Gao ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Potassium Permanganate ◽  
Crystal Violet ◽  
Acid Leaching ◽  
Water Quenching ◽  
Test Results ◽  
Leaching Rate ◽  
Initial Concentration ◽  
Solid Ratio

Extracting indium from water quenching slag, which contains poor indium, by two process of leaching, the effect of different oxidants and dosages on the leaching rate of indium in water quenching slag were studied. The leaching conditions: temperature 80 °C, leaching time 2 h, the liquid to solid ratio of neutral leaching 8︰1, the liquid to solid ratio of acid leaching 2︰1, initial concentration of sulfuric acid 500 g·L-1, adding different oxidants, the concentration was detected by crystal violet spectrophotometry. Test results showed that the leaching rate of indium was significantly improved by adding hydrogen peroxide and potassium permanganate. Compared with the effect of different oxidants, the effect of potassium permanganate was significantly higher than that of hydrogen peroxide on the leaching rate of indium.

scholarly journals Studies on Epoxidation of Tung oil with Hydrogen Peroxide Catalyzed by Sulfuric Acid

2020 ◽  
Vol 15 (3) ◽  
pp. 674-686
Author(s):  
Eni Budiyati ◽  
Rochmadi Rochmadi ◽  
Arief Budiman ◽  
Budhijanto Budhijanto
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Unsaturated Fatty Acids ◽  
Catalyst Concentration ◽  
Reaction Rates ◽  
Catalytic Reactions ◽  
Side Reactions ◽  
Initial Reaction ◽  
Tung Oil ◽  
Epoxidation Reaction

Tung oil with an iodine value (IV) of 99.63 g I2/100 g was epoxidized in-situ with glacial acetic acid and hydrogen peroxide (H2O2), in the presence sulfuric acid as catalyst. The objective of this research was to evaluate the effect of mole ratio of H2O2 to unsaturated fatty acids (UFA), reaction time and catalyst concentration in Tung oil epoxidation. The reaction kinetics were also studied. Epoxidation was carried out for 4 h. The reaction rates and side reactions were evaluated based on the IV and the conversion of the epoxidized Tung oil to oxirane. Catalytic reactions resulted in higher reaction rate than did non-catalytic reactions. Increasing the catalyst concentration resulted in a large decrease in the IV and an increase in the conversion to oxirane at the initial reaction stage. However, higher catalyst concentration in the epoxidation reaction caused to a decrease in reaction selectivity. The mole ratio of H2O2 to UFA had an influence identical to the catalyst concentration. The recommended optimum mole ratio and catalyst concentration in this study were 1.6 and 1.5%, respectively. The highest conversion was 48.94% for a mole ratio of 1.6. The proposed kinetic model provided good results and was suitable for all variations in reaction temperature. The activation energy (Ea) values were around 5.7663 to 76.2442 kcal/mol. Copyright © 2020 BCREC Group. All rights reserved 

Efficient leaching of scheelite in sulfuric acid and hydrogen peroxide solution

2020 ◽  
Vol 192 ◽  
pp. 105292 ◽  
Author(s):  
Changsheng Yin ◽  
Lei Ji ◽  
Xingyu Chen ◽  
Xuheng Liu ◽  
Zhongwei Zhao
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
Hydrogen Peroxide Solution
Sign in / Sign up

Export Citation Format

Share Document