Re-use of zinc smelting furnace slag in concrete Available to Purchase

Slag from the imperial smelting furnace (ISF) method of zinc production is an industry by-product that has been investigated for its potential use as an aggregate in concrete. In the UK alone, there is currently a 2·5 million t stockpile of ISF slag that could potentially be used as aggregate in the construction industry. However, the presence of the heavy metals zinc and lead in the slag raises environmental concerns about its reuse. ISF slag is physically suitable for use as an aggregate, although there are several barriers that need to be overcome before it can be used in concrete. Issues relating to the metal ions present have been addressed in other publications. However, the glassy nature of the slag initially raised concerns regarding the potential for alkali–silica reaction (ASR) to occur in concrete. A comprehensive series of accelerated ASR tests have been carried out, which indicate that the material is not susceptible to this type of deleterious reaction. In addition, site trials on a concrete roadway containing ISF slag have proved successful.