A review of recovery of metals from industrial waste

• Autorzy: Jadhav U U , Hocheng H.
• Języki publikacji: EN

Abstrakty

EN

Due to rapid industrialization the demand for heavy metals is ever increasing, but the reserves of high-grade ores are diminishing. Therefore there is a need to explore alternative sources of heavy metals. The rapid industrialization generates a variety of industrial wastes. These industrial wastes possess toxic elements such as heavy metals. Improper disposal of these wastes becomes a key factor in metal contamination and thus when leached into atmosphere cause serious environmental problem. These metals exert wide variety of adverse effects on human being. Some of the metals have extremely long biological half-life that essentially makes it a cumulative toxin. Also some metals are carcinogenic in nature. Among the wastes, electronic scraps, medical waste, metal finishing industry waste, spent petroleum catalysts, battery wastes, fly ash etc., are some of the major industrially produced wastes. These solid wastes mostly contain Au, Ag, Ni, Mo, Co, Cu, Zn, and Cr like heavy metals in it. Hence these waste materials which are causing serious environmental problems, can act as potential source for heavy metals. In this sense these industrial wastes can act as artifitial ores. The valuable metals can be recovered from these industrial wastes. There are varieties of methods in use for recovery of heavy metals. These include pyrometallurgical, hydrometallurgical and bio-hydrometallurgical methods. Pyrometallurgical recovery consists of the thermal treatment of ores and metal containing wastes to bring about physical and chemical transformations. This enables recovery of valuable metals. Calcining, roasting, smelting and refining are the pyrometallurgical processes used for metal recovery. The hydrometallurgical recovery uses mainly the leaching process. It involves the use of aqueous solutions containing a lixiviant which is brought into contact with a material containing a valuable metal. Further the metals are concentrated and purified by using precipitation, cementation, solvent extraction and ion exchange. The metals are finally recovered in pure form by using electrolysis and precipitation methods. Biohydrometallurgy is one of the most promising and revolutionary biotechnologies. This technique exploits microbiological processes for recovery of heavy metal ions. In last few decades the concept of microbiological leaching have played a grate role to recover valuable metals from various sulfide minerals or low grade ores. Now the microbiological leaching process has been shifted for its application to recover valuable metals from the different industrial wastes. There are many microrganisms which play important role in recovery of heavy metals from industrial wastes. Among the bacteria Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, Leptospirillum ferrooxidans, and Sulfolobus sp., are well known for the bioleaching activity while Penicillium, and Aspergillus niger are some fungi those help in metal leaching process. The process of recovery makes sense only if the cost of recovery is much less than the value of the precious metal. The restrictions imposed on waste disposal and stringent environmental regulations demand eco-friendly technologies for metal recovery. This paper reports a review of number of industrial processes that generate metal containing waste and the various methods in use for recovery of metals from these wastes. This will help in selection of a proper method for recovery of heavy metals from industrial wastes.

Słowa kluczowe

EN

environmental management; industrial waste; heavy metals; pyrometallurgical methods; hydrometallurgical methods; bio-hydrometallurgical methods

• Wydawca: International OCSCO World Press
• Czasopismo: Journal of Achievements in Materials and Manufacturing Engineering
• Rocznik: 2012
• Tom: Vol. 54, nr 2
• Strony: 159--167
• Opis fizyczny: Bibliogr. 113 poz., rys., tab.

Twórcy

autor

Jadhav U U

• Department of Power Mechanical Engineering, National Tsing Hua University, No. 101, Sec. 2, Kuang Fu Rd., 30013, Hsinchu, Taiwan ROC

autor

Hocheng H.

• Department of Power Mechanical Engineering, National Tsing Hua University, No. 101, Sec. 2, Kuang Fu Rd., 30013, Hsinchu, Taiwan ROC

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