Environmental Activity and Ecological Assessment of Heavy Metals in the Reductive Leaching Residue from Zinc Hydrometallurgy Industry

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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Selective Recovery of Manganese from Anode Sludge Residue by Reductive Leaching

ChemEngineering ◽

10.3390/chemengineering4020040 ◽

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.

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Preparation and adsorption characteristics for heavy metals of active silicon adsorbent from leaching residue of lead-zinc tailings

Environmental Science and Pollution Research ◽

10.1007/s11356-018-2194-9 ◽

2018 ◽

Vol 25 (21) ◽

pp. 21233-21242 ◽

Cited By ~ 4

Author(s):

Chang Lei ◽

Bo Yan ◽

Tao Chen ◽

Xian-Ming Xiao

Keyword(s):

Heavy Metals ◽

Adsorption Characteristics ◽

Lead Zinc ◽

Leaching Residue

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Ecological Assessment of the Pond Ecosystem Components, Bobrivka Village, Kharkiv District, Kharkiv Oblast

Man and Environment. Issues of Neoecology ◽

10.26565/1992-4224-2018-29-09 ◽

2018 ◽

Keyword(s):

Heavy Metals ◽

Iron Concentration ◽

Ecological Assessment ◽

Hypophthalmichthys Molitrix ◽

Complex Situation ◽

Difficult Situation ◽

Toxicological Assessment ◽

Fish Breeding ◽

Copper And Zinc ◽

Pond Ecosystem

Studies are devoted to the ecological assessment of the pond aquatic ecosystem components, Bobrivka village, Kharkiv district, Kharkiv oblast. Purpose. In order to achieve the goal, it was tasked to determine the seasonal redistribution of hydrochemical indicators, especially the distribution of heavy metals in the system "water-bottom sediments- hydrobionts". Methods. The toxicological analysis of the accumulation of heavy metals in fishery products made it possible to assess the suitability of the pond for fish breeding. It is shown that the hydrochemical parameters fully meet swater quality standards for cultural-household and recreational purposes. Results. Toxicological assessment of water suitability for fish breeding revealed a complex situation in several indicators. The content of free ammonia at all stages of sampling significantly exceeded the MAC values for fish breeding. In autumn, this figure was the highest and was 9.6 MAC. Excess the MAC values for fish breeding is fixed for nitric nitrogen. It is 1.1-4.2 MAC.The toxicological assessment for the water for fishing has shown difficult situation with respect to copper and zinc. For copper and zinc, the maximum excessive MAC was observed in December, its value was respectively 73 MAC and 19 MAC.The total iron concentration, the value of hydrogen indicator and easily soluble organic compounds are within the MAC values.Cu, Pb, Zn, Cd contents in muscle tissues of Hypophthalmichthys molitrix and Cyprinus carpio does not exceed the MAC values. Conclusions. A choice of measures is proposed to protect the pond from pollution, which must be performed for the suitability of the water pond for fish breeding.

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