2 O 3 and Cm 2 O 3 on weight percent basis. The batch vitrification processing includes the three distinct steps of drying, calcination and vitrification prior to draining the glass to a storage canister. Descriptions of the three steps are presented below. The drying step removes the free aqueous fraction required to transfer the precipitated feed slurry to the melter and chemically bound waters of hydration. The amount of time required to dry a single batch varies between 1 - 4 hours depending upon the total batch size and flush water used.
Water is the main constituent in the off-gas during the drying step.
Oxalic acid, nitrous oxides and a small quantity of carbon monoxide and carbon dioxide are also evolved. The amount of time required to calcine a single batch is a function of the heating rate and the total batch size. Vitrification occurs as the oxides and the 25SrABS glass composition begins to soften and melt to form a low viscosity glass. The liberation of oxygen during the transition of high to low viscosity glass results in a small frothy bubble accumulation at the glass surface. The time to complete the vitrification step may include a hold period to fine the bubbles before the vitrified glass is drained from the melter into a stainless steel canister.