Solidification and stabilization of heavy metal recovered from hydrometallurgical industry waste in the MCM-41nanomaterial framework synthesized from raw Bentonite

- The new alkaline fusion process provides a selective recovery metals.
- The mass ratio Si/Zn depends on the alkaline fusion periods.
- S/S process do not affect the structural nanomaterials properties.
- No waste or raw Bentonite impurities phases are found in MCM-41.

The purpose of this study deals with the use of a new strategy of solidification/stabilization (S/S) process of heavy metals recovered from waste sludge into low-cost nanomaterial frameworks. The new alkaline fusion process applied to waste sludge and raw Bentonite provides a selective recovery metals. The efficiency of the new adopted process in the selectivity and the yield of the metal recovery are compared with the acid leaching process. The obtained results are determined through inductively coupled plasma optical emission spectrometer (ICP-OES) analyses. As results, it is found that the acid leaching process favors the extraction of iron, zinc and copper respectively, whereas the alkaline fusion process leads to a selective extraction in favor of zinc. It is found else that the mass ratio Si/Zn depends on the alkaline fusion period. The structural and textural properties of MCM-41 synthesized depend on the mass ratio Si/Zn. Based on the XRD and N2 sorption, highly ordered hexagonal nanomaterials with uniform pore sizes around 3.8 nm and 3.9 nm, pore volumes ca. 0.7 cm3/g and 0.6 cm3/g and high specific surface areas up to 1100 m2/g and 980 m2/g have been successfully synthesized from (sup I) and (sup II) respectively without any phases such as ZnO, Zn2SiO4, and ZnAl2O4.