The leaching of antimony from concrete

The use of antimony compounds as reducing agents for hexavalent chromium has proved to be the best solution regarding long term reduction, absence of negative impacts on cement quality and cost effectiveness.

Although already present in Portland cements (basically as a consequence of the use of secondary fuels [1]) antimony recently gained importance due to the fact that it had been identified as one of the most effective reducing agents for soluble chromates, the elimination of which is required for all the cements produced or imported in the European Union [2]. Antimony compounds are commonly mixed with clinker and gypsum during grinding and the amounts used (usually 5–10 ppm of antimony for each ppm of chromate to be reduced) are higher than the antimony occurring naturally in clinkers....

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