Interaction of blast-furnace slag with heavy metal ions in water solutions

The interaction of Cu, Zn and Ni ions with blast-furnace slag has been investigated in 10(-3) mol l(-1) solutions at pH = 4.0. It has been established that the sorption of metal ions is accompanied by the partial solubilisation and hydrolysis of the calcium silicates and aluminosilicates of the slag. The sorption is due to various processes: ion-exchange and replacement of calcium ions from the slag by the metal ions in the solutions as chemical bonding of hydrolysis metal species with the surface. The physicochemical investigations on blast-furnace samples differing in phase composition show that the presence of well-crystallised phases increases the sorption activity. (C) 2000 Elsevier Science Ltd. All rights reserved.