A novel process utilizing mechanochemical sulfidization to remove lead from cathode ray tube funnel glass

A novel process of mechanochemical sulfidization for the treatment of cathode ray tube (CRT) funnel glass has been investigated by co-grinding with the element sulfur. The ground samples were characterized by means of a set of analytical methods, including scanning electron microscopy (SEM), x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and thermogravimetric analysis (TG). The analytical results showed that during the co-grinding of the CRT funnel glass with sulfur, the Si-O-Pb bond in glass and S-S bond broke and recombined into lead sulfide (PbS). The sulfidizing reaction proceeded with an increase in grinding time and the amount of the added sulfur. The sulfidizing rate increased rapidly from 16.6% for the 10-min ground sample to 96.7% for the 120-min ground sample. Using this process, current mineral processing technology, such as flotation separation, might be used to recover PbS. The proposed technology could also be used to treat other leaded glass and even other lead-containing wastes. In this research, a mechanochemical sulfidization method was proposed to recover lead from waste cathode ray tube (CRT) funnel glass. CRT funnel glass was co-ground with sulfur in N₂ atmosphere by mechanical milling. After milling, lead in CRT funnel glass was transferred into lead sulfide (PbS). Using this process, current mineral processing technology, such as flotation separation, might be used to recover PbS from the ground sample. The process can be applied to treat other leaded glass or lead-containing wastes.