Title: Ferro-Silicate Slag from ISF Zinc Production as a Sand Replacement: A Review

Author(s): R. Hooper, C. McGrath, C. Morrison, and K. Lardner

Publication: Symposium Paper

Volume: 209

Issue:

Appears on pages(s): 811-838

Keywords: cementitious materials; ferro-silicate slag; Imperial Smelting Furnace

DOI: 10.14359/12534

Date: 9/26/2002

Abstract:
Recent European and UK policies, for example the Landfill Duecave and the UK landfill tax, have set an agenda to promote reuse and recycling by con-trolling and minimising the landlilling of secondary materials. The UK Govern- ment and it’s agencies are actively pursuing policies of sustainable and environ- mentally responsible construction. The changing attitute towards secondary materials has encouraged investigation into the use of ferro-silicate slag from the Imperial Smelting Furnace (ISF) production of zinc in construction processes. The UK Ten Year Transport Plan, including the development of the highway infrastructure, offers opportunities to successfully demonstrate the consumption of small volume streams of secondary materials, including ISF slag, within the local area. Pavement construction offers several opportunities for consumption, the most credible of these being the replacement of the sand fractions by the slag in bound mixtures, cement and bituminous. This paper focuses upon cementitious mixtures alone. The presence of zinc and lead ions in the ISF slag are proven to have an impact on the setting characteristics of concrete mixtures, although there is little difference in the compressive strengths after 28 days. The leaching, characteristics of the slag suggest that the retardation is not linearly related to the quantities of zinc or lead leached. Additiwuilly, leaching tests in combination with pulverised fuel ash (fly ash) and ground granulated blastfurnace slag indicate that it may be possible to minimise retardation of set in by including these materials in the concrete mixture.