scholarly journals Selective Recovery of Manganese from Anode Sludge Residue by Reductive Leaching

2020 ◽  
Vol 4 (2) ◽  
pp. 40
Author(s):  
Toni Kauppinen ◽  
Tuomas Vielma ◽  
Justin Salminen ◽  
Ulla Lassi
Keyword(s):  
Hydrogen Peroxide ◽  
Sulfuric Acid ◽  
High Selectivity ◽  
Sulfate Solution ◽  
Correct Choice ◽  
Manganese Sulfate ◽  
Solid Residue ◽  
Reductive Leaching ◽  
Novel Method ◽  
Leaching Residue

Manganese-containing anode sludge is a common side-product in the electrowinning of zinc. The anode sludge consists mainly of oxidized manganese, but also lesser amounts of lead, calcium, and other minor metals. The impurities present in the anode sludge mandate new recycling strategies for its efficient use. This work demonstrates a novel method for selective manganese recovery from lead- and calcium-bearing manganese oxide solid residue. Leaching with sulfuric acid in the presence of a selected reducing agent, such as hydrogen peroxide or citric acid, yields a concentrated MnSO4 solution with high selectivity over calcium and lead. Manganese yields up to 98% can be obtained. Minimization of calcium and lead in final manganese product can be accomplished with the correct choice of leaching conditions. Alongside manganese sulfate solution, leaching residue with high content of lead and silver was also formed.

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%.

Microwave-Assisted Leaching Vanadium from Stone Coal

2011 ◽  
Vol 189-193 ◽  
pp. 3916-3919 ◽  
Author(s):  
Hong Zhou Ma ◽  
Xin Zhe Lan ◽  
Yao Ning Wang ◽  
Yu Hong Tian
Keyword(s):  
Sulfuric Acid ◽  
Microwave Power ◽  
Orthogonal Design ◽  
Chemical Constituents ◽  
Influence Factors ◽  
Sulfate Solution ◽  
Leaching Rate ◽  
Stone Coal ◽  
Microwave Assisted ◽  
Design Experiments

Technological process of microwave-assisted leaching of vanadium with sulfate solution has been defined on the base of phase and chemical constituents of stone coal. The influence factors such as content of sulfuric acid, microwave power, and leaching time were studied on leaching rate of vanadium from the stone coal. One element experiments and orthogonal design experiments are carried out to achieve optimized parameters. The experimental results showed that the leaching rate of vanadium was improved by the change of influence factors at some range. The single leaching rate of vanadium reached 80.9% under the optimal conditions of sulfuric acid content of 12%, microwave power 539w,leaching time of 2h.

Separation of Heavy Metal Ions from the Solution Obtained by Leaching Low-Grade Pyrolusite with Pyrite and H2SO4

2013 ◽  
Vol 773 ◽  
pp. 283-288
Author(s):  
Xing Zou ◽  
Xiang Quan Chen ◽  
Hai Chao Xie ◽  
Xiao Dan Qiu
Keyword(s):  
Heavy Metal ◽  
Metal Ions ◽  
Heavy Metal Ions ◽  
Separation Efficiency ◽  
Ph Value ◽  
Sulfate Solution ◽  
Ion Concentration ◽  
Manganese Sulfate ◽  
Low Grade ◽  
High Concentration

The manganese sulfate solution leached from low-grade pyrolusite with pyrite and H2SO4 contains heavy metal ions of high concentration, influencing the quality of the final products of manganese compounds and causing manganese ions not to be electrolyzed. The present study was focused on the separation of Co, Ni and Zn ions from the leached solution with BaS. By controlling the pH value at 5.0-6.5, temperature at 50-60°C, reaction time at 15 min and mixing velocity at 78 rpm, the heavy metal ions could be separated effectively. Under the above optimized conditions, the ion concentration of Co, Ni, and Zn in the solution was reduced to 0.06 mg.L-1, 0.27mg.L-1 and 0.01mg.L-1, and the separation efficiency was 99.72%, 99.18% and 99.9% respectively. The obtained pure solution meets the demands of manganese electrowinning.

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