Leaching results of reactive materials

Leaching results are used in the assessment of slag for use in construction. The stability of the major phase in iron- and steelmaking slags has a direct influence on the leaching of all elements enclosed in the matrix. Steelmaking slags have varying content of glass and puzzolanic minerals, and water granulation is a means of enhancing the glass content. A crystalline and an amorphous blast furnace slag have been investigated with a long-term test to determine if diffusion or dissolution was the controlling leaching mechanisms for each slag type. Both slag types were leached by dissolution according to the results. However, leaching of slags with puzzolanic phases implies that reactions take place, resulting in both dissolution and stabilization of elements. The phase transformations probably hamper the evaluation of leaching results and should be considered.