A simultaneous stabilization and solidification of the top five most toxic heavy metals (Hg, Pb, As, Cr, and Cd)

- A new CBPC-type stabilization/solidification (S/S) process was developed.
- The new process effectively and simultaneously stabilized Hg, Pb, As, Cr, and Cd.
- FeCl2, a stabilizer, was highly effective in the stabilization of As and Cr.
- The TCLP values of all the final products were below the UTS values.
- The compressive strengths of all the final products met the US NRCS requirements.

A novel chemically bonded phosphate ceramic (CBPC) binder was developed for the simultaneous treatment of the top five most toxic heavy metals (Hg, Pb, As, Cr, and Cd). Various CBPC binders were synthesized and tested, and their toxicity characteristic leaching procedure (TCLP) values were obtained. A magnesium/calcium-potassium phosphate ceramic binder with FeCl2 (M/C-KP-FeCl2) simultaneously stabilized multiple heavy metals. The TCLP value of the final product for industrial waste (IW) treatment using the M/C-KP-FeCl2 technology was well below the Universal Treatment Standard (UTS). Additionally, the compressive strength of the final product was below the US Nuclear Regulatory Commission Standard.