BIOLEACHING AND BIOPRECIPITATION OF NICKEL AND IRON FROM LATERITES

ALIBHAI, KAK; DUDENEY, AWL; LEAK, DJ; AGATZINI, S; TZEFERIS, P

dc.contributor.author	ALIBHAI, KAK	en
dc.contributor.author	DUDENEY, AWL	en
dc.contributor.author	LEAK, DJ	en
dc.contributor.author	AGATZINI, S	en
dc.contributor.author	TZEFERIS, P	en
dc.date.accessioned	2014-03-01T01:42:03Z
dc.date.available	2014-03-01T01:42:03Z
dc.date.issued	1993	en
dc.identifier.issn	0168-6445	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/23690
dc.subject	HETEROTROPHIC FUNGI	en
dc.subject	BIOACIDS	en
dc.subject	IN-SITU LEACHING	en
dc.subject	NICKEL	en
dc.subject.classification	Microbiology	en
dc.title	BIOLEACHING AND BIOPRECIPITATION OF NICKEL AND IRON FROM LATERITES	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	1993	en
heal.abstract	Leaching of silicate ores, particularly nickel laterites, with the aid of heterotrophic organisms has been briefly reviewed. Samples of laterite ores from Greece were characterised mineralogically and a number of microorganisms isolated from them. One of these organisms (code F1) was successfully acclimatized to 6400 ppm nickel. Samples of the high-grade Greek Kastoria nickel laterite were leached with sulphuric acid and a number of organic acids. Sulphuric and citric acids extracted over 60 and 40% of the contained nickel, respectively, but the other acids employed were less efficient leachants. Oxalic acid precipitated nickel oxalate. Roughly the same extraction of iron was observed. The main leaching parameter was confirmed to be hydrogen ion concentration, although complexation with organic anions was a contributor. Organism F1 (a strain of Penicillium) was used in comparison with organisms from various culture collections to bioleach nickel from samples of the low-grade Greek Litharakia nickel laterite. The organisms were cultivated in a mixture of a sugar-based nutrient mineral medium and finely ground ore. Several penicillia and aspergilli leached 55-60% of the contained nickel and cobalt, and 25-35% of the iron when sucrose was the carbon source, but Fl was not efficient. However, in molasses medium, Fl extracted nearly 40% of the nickel. Biosorption and bioprecipitation reactions were observed. The mechanism of bioleaching or in situ leaching is discussed in terms of close physical and chemical association between the fungal hyphae and mineral phases in the ore. This accounted for the low overall hydrogen ion concentration observed during bioleaching.	en
heal.publisher	ELSEVIER SCIENCE BV	en
heal.journalName	FEMS MICROBIOLOGY REVIEWS	en
dc.identifier.isi	ISI:A1993LP09500013	en
dc.identifier.volume	11	en
dc.identifier.issue	1-3	en
dc.identifier.spage	87	en
dc.identifier.epage	96	en