Stabilization of Arsenic- and Barium-Rich Glass Manufacturing Waste

Effective solidification stabilization (S S) of arsenic- and barium-containing D004 D005 waste was accomplished by using a binder of cement with 40% class C fly ash and either ferrous sulfate or ferric sulfate as an additive. Addition of iron salts improves arsenic solidification stabilization (S S). Barium may be encapsulated within the stabilized matrix as barium sulfate. Recommended mole ratios for iron arsenic and barium sulfate are at least 6 and 1.2, respectively. A binder waste ratio of 0.15 is volume efficient, but the mix design must be carefully controlled to achieve adequate S S. In practice, the heterogeneity of waste and large-scale mix operations may preclude close control of reagent dosages, so a binder waste ratio of 0.40 is preferable. Ferrous sulfate additive is preferable for arsenic S S because it is effective over a wider range of mix designs and over a long-term curing period. Toxicity characteristic leaching procedure results degraded with long curing time for some mix designs with ferric sulfate additive.