Leaching behavior of cathode ray tube (CRT) glasses

Abstract

The leaching behavior of cathode ray tube (CRT) funnel and neck glasses were compared in 0.001 N HCl and 0.001 N NaOH at 70 and 90°C. We measured the weight loss and leached amount of each component and observed the surface changes by scanning electron microscopy (SEM). In acid solution funnel glass showed t 1/2 -dependent leaching, whereas neck glass only demonstrated congruent dissolution after 8 weeks. In basic solutions leaching behavior was almost equivalent for both types of glass. Dissolution halted after one or two weeks as a result of the deposition of a protective layer. This layer was formed by saturation of Pb and was subsequently dissolvable by refreshing the leachant solution.

Acid and heat treatment to reduce lead leaching from cathode ray tube funnel glass

“…The leaching of Pb ions in acid solution was reduced for the CRT cullet glass drastically after the acid and post-heat treatment in the present study, as expected from the previous study on the simple lead silicate glasses. 3) In addition, it was remarkable that the leaching of Pb ions was suppressed after the static leaching test in 0.001N HCl aq. solution for 28 days, as shown in Fig.…”

“…2) Nevertheless, the demand in Japan for the cullet as a flux is limited to approximately ten thousand tons per year and is much lower than the supply of the cullet. 3) Therefore, the cullet must be stored in controlled landfill sites, before use. While in a landfill, Pb ions leach into the groundwater, which causes environmental problems.…”