Enhancement of hardpan formation by amending sulphidic tailings with limestone or fly ash

Xenidis, A; Mylona, E; Harokopou, AD

dc.contributor.author	Xenidis, A	en
dc.contributor.author	Mylona, E	en
dc.contributor.author	Harokopou, AD	en
dc.date.accessioned	2014-03-01T01:26:17Z
dc.date.available	2014-03-01T01:26:17Z
dc.date.issued	2007	en
dc.identifier.issn	09670513	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/17988
dc.subject	Fly ash	en
dc.subject	Hardpan	en
dc.subject	Limestone	en
dc.subject	Sulphidic tailings	en
dc.subject.other	fly ash	en
dc.subject.other	hydraulic conductivity	en
dc.subject.other	lignite	en
dc.subject.other	limestone	en
dc.subject.other	soil amendment	en
dc.subject.other	tailings	en
dc.subject.other	Attica	en
dc.subject.other	Eurasia	en
dc.subject.other	Europe	en
dc.subject.other	Greece	en
dc.subject.other	Lavrion	en
dc.subject.other	Southern Europe	en
dc.title	Enhancement of hardpan formation by amending sulphidic tailings with limestone or fly ash	en
heal.type	journalArticle	en
heal.identifier.primary	10.2462/09670513.697	en
heal.identifier.secondary	http://dx.doi.org/10.2462/09670513.697	en
heal.publicationDate	2007	en
heal.abstract	The potential formation of low-permeability hardpan layers by mixing limestone or lignite fly ash with oxidized sulphidic tailings was investigated under actual field conditions. Field tests covering an area of 900 m2 were implemented in Lavrion, Greece. The field testing area was divided into four equal testpads, which were filled with: (a) Lavrion sulphidic tailings without any amendment (control test); (b) sulphidic tailings covered by a 60-cm-thick layer of tailings homogeneously mixed with 75 kg/t limestone; (c) sulphidic tailings - 75 kg/t limestone mixture having a thickness of 150 cm; and (d) sulphidic tailings covered by a 30-cm-thick layer of tailings homogeneously mixed with 180 kg/t lignite fly ash. After four years of field test operations, cemented layers or hardpan, exhibiting increased resistance to penetration, were formed in the testpads. The hardpan layer in the control test was observed at a depth of 65 cm and had a thickness of 30 cm. Limestone and fly ash addition to the oxidized tailings resulted in the formation of hardpan layers at depths of 35 cm and 15 cm respectively. The samples collected from the hardpan layers had paste pH higher than 4.5, as compared to pH 2.0 of the oxidized tailings. Limestone was proved to be more effective than fly ash in neutralizing the acidity and maintaining near-neutral pH conditions within the hardpan. On the other hand, the hardpan samples collected from limestone and fly-ash-amended testpads exhibited similar hydraulic conductivity values in the order of 10-6 m/sec. © 2007 EPP Publications Ltd.	en
heal.journalName	Land Contamination and Reclamation	en
dc.identifier.doi	10.2462/09670513.697	en
dc.identifier.volume	15	en
dc.identifier.issue	3	en
dc.identifier.spage	359	en
dc.identifier.epage	373	en