The waste material studied is a fly ash, resulting as a waste
product from a Cu refining process. The major elements in
the waste are As, Sb, and Pb. All waste material studied
originates from the same metallurgical process, but samples
were obtained at different times. In these samples, the
concentrations range from 23% to 47% (wt %) for As, from 16% to 35% for Sb, and from 8% to 23% for Pb. In Belgium,
this waste material is produced in quantities of several
thousand tons per year,andsince it is classified as a hazardous
waste, it has to be treated as such.