Mechanical Activation-Assisted Reductive Leaching of Cadmium from Zinc Neutral Leaching Residue Using Sulfur Dioxide

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.

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A surface reaction kinetic model to compare the reductive leaching of iron from goethite, magnetite, and limonitic nickel laterite ores by acidic sulfur dioxide

Metallurgical and Materials Transactions B ◽

10.1007/s11663-003-0043-8 ◽

2003 ◽

Vol 34 (5) ◽

pp. 735-738 ◽

Cited By ~ 11

Author(s):

G. Senanayake

Keyword(s):

Sulfur Dioxide ◽

Kinetic Model ◽

Surface Reaction ◽

Reaction Kinetic ◽

Nickel Laterite ◽

Reaction Kinetic Model ◽

Laterite Ores ◽

Reductive Leaching

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Influence of the Mechanical Activation on the Reactivity of Germanium-Containing Zinc Neutral Leaching Residue

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.581-582.868 ◽

2012 ◽

Vol 581-582 ◽

pp. 868-872

Author(s):

Chen Liu ◽

Hang Jun He ◽

Duo Qiang Liang ◽

Han Huang ◽

Lu Man Man ◽

...

Keyword(s):

Mechanical Activation ◽

Acid Leaching ◽

Weak Acid ◽

Leaching Kinetics ◽

Technical Standard ◽

Two Stage ◽

Compact Structure ◽

Structure Deformation ◽

Standard Operating ◽

Leaching Residue

Zinc neutral leaching residue from conventional roast-leach-electrowin often contains a considerable content of germanium. In two-stage leaching process (weak acid leaching and hot acid leaching), dissolution yield of germanium as well as zinc is low due to the compact structure of the residue. In the paper, an attempt of increasing their dissolution yield was made by pretreatment of mechanical activation. The experimental results obtained show that the activated residue has much faster leaching kinetics, and that according to current technical standard operating in Yunnan Chihong Zinc & Germanium Co., Ltd, dissolution of germanium and zinc is increased by 18.12% and 22.93%, respectively. The increase may mainly be due to the structure deformation of the residue by further investigation.

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Separation of copper and indium from zinc hydrometallurgy solution

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2020-0082 ◽

2020 ◽

Vol 18 (12) ◽

Author(s):

Zhigan Deng ◽

Yu Zheng ◽

Xingbin Li ◽

Chang Wei ◽

Minting Li ◽

...

Keyword(s):

Production Process ◽

Iron Powder ◽

Decisive Role ◽

Indium Content ◽

Reductive Leaching ◽

Powder Addition ◽

Leaching Residue ◽

Hydrolytic Precipitation ◽

Favorable Conditions ◽

Zinc Hydrometallurgy

AbstractThe separation and recovery of copper and indium from a solution arising from the reductive leaching of a zinc leaching residue was studied. Copper was enriched into a copper precipitate produced by iron powder precipitation; indium was hydrolyzed and enriched into a gypsum indium precipitate produced by limestone adjustment of pH. Separation and recovery of both copper and indium were achieved. The results showed that precipitation of copper(II) and arsenic(III) as Cu2O and Cu3As is thermodynamically feasible by adding iron powder to the reductive leach of a zinc leaching residue. Increasing the iron powder addition and reaction temperature promoted the formation of Cu2O and Cu3As. In the process of neutralizing and precipitating indium by adjusting the pH using limestone, indium was mainly concentrated in the precipitate by hydrolytic precipitation. The pH of the neutralization endpoint plays a decisive role in this hydrolytic enrichment. The extent of indium precipitation exceeded 98%, and the indium content of the precipitate reached 3.6 kg/t. Addition of limestone balances the acid across the entire production process. The main phase in the gypsum indium precipitate was CaSO4·2H2O, the stable properties of which create favorable conditions for the recovery of indium in subsequent steps.

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