Final Disposal in a Glass of a Solid Residue from the Purification of an Effluent Loaded With Sr, K and HF

This Vitrification is a process used for the final disposal of toxic waste for various unit operations for the decontamination of both toxic and radioactive effluents. The aim of this study is the vitrification of natural clay issued from a column extraction of the elements Sr, K and Hf. These last are from a water effluent containing: 10^-3 mmol/L Sr, 3 10^-2 mmol/L K and 2 10^-5 mmol/L Hf. The effluent was purified by column extraction filled with a KT3 type kaolin mived with 10% of silica. After 06 cycles, the elemental extraction yields are 27.28% of Sr and 5.28% of K. the Hf can’t be quantified due to the low values. The loaded kaolin is dried and vitrification tests are performed by double melting at 1400°C in a borosilicate glass of chemical formula: 44%SiO₂-7%Al₂O₃-20%Na₂O-18%B₂O₃-1%Cs₂O-8.5MoO₃-.5%Nd₂O₃, with a clay content varying between 0 to 15%. The final compact glasses are characterized by both XRD and FTIR spectroscopic analyses. The results show that for 5% of clay, the glass is homogeneous and does not contain any mineral residues. For both 10 and 15% clay contents, minor ceramic phases are identified inside the glass. The FTIR analysis of the materials allows identifying the glass main groups’ vibrations of: O-Si-O from SiO₄ around 1016 cm^-1 and B-O bond of BO₃ around 1200 cm^-1. Such an innovative process (extraction/vitrification) made it possible to purify the effluent by using an abundant natural material in Algeria and thus definitively isolate toxic and radioactive elements from both man and environment, using a glass ready to be disposal.