Lead recoverable slag is of economic and environmental importance. The aim of this study was to assess the possibilities of its recovery by flotation with sodium lauryl sulfate (SLS). The similar nature of the lead and iron particles formed by solidification of the melted slag impairs selectivity during the flotation process. In order to verify the most favorable conditions for selectivity, SLS adsorption mechanisms for lead and iron particles were studied. The adsorption was monitored by means of zeta potential and surface tension determinations. Flotation tests were conducted under the most promising conditions identified for selectivity. The results suggest that SLS adsorption in lead particles is of a chemical nature. It was observed that the formation of lead lauryl sulfate is easier in alkaline medium. A 79% lead recovery was obtained at pH 10 using only 10-3 M collector concentration. Nevertheless, the best selectivity conditions were obtained in an acid medium.
Flotation; metallurgical slag flotation; sodium lauryl sulfate; secondary lead; recycling of industrial waste
