The starting point of this research was the ‘Soliroc’ process
for stabilization of hazardous wastes containing metals (5),
which neutralises harmful elements by using silicate reagent
and additives to create inert metal silicates incorporated in
a concrete resembling matrix. The process involves the
formation of a mixture of an amorphous and a crystalline
silicate structure, and it is claimed that, for arsenic-containing
wastes, As is bound as a silica-alumina-arsenate