Leaching test results. Hodul [6] reported that leachability tests are one of the basic tests by which the individual
national legislation created and create criteria for further utilization of industrial waste. When exceeding certain
legislative the waste cannot be treated as secondary raw material, but as hazardous waste. During the preliminary
treatment of the solidification products (SPs) sample and following preparation of a water leachate, the procedure
according to ČSN EN 12457-4 (83 8005) is applied. The preliminary treatment of sample of waste modified by
solidification is contained in Appendix No. 7 of Regulation No. 294/2005. Technical standards were used for
chemical analyses for the analytical determination mentioned in Appendix No. 12 of Regulation No. 294/2005.
The determination was carried out by accredited testing laboratory LABTECH, located in Brno. Results of
leaching tests of the chosen solidification products are listed in Table 5. In the table are listed only major
parameters, but the determination was carried out for all elements listed in Regulation No. 294/2005. None of the
(SPs) have exceeded the parameters corresponding to the leachability class IIb. Conductivity is an approximate
degree of concentration of electrolytes (ionic dissolved solids) in aqueous solutions. Indirectly, it indicates mineral
content ("salt" dissolved solids) in the water. There is the relation between the conductivity and the volume of
dissolved substances in the leachate. Recent results from Bone et al. [7] and Li et al. [8] showed that monitoring of
pH values is also important because influence the dissolubility of metals, i.e. their extraction capacity from the
solidification product matrix. From Table 5 it is obvious that aqueous leachates of all the SPs were alkaline.