REDOX TRENDS IN SIMULATED MELTER FEEDS FORMULATED WITH OXALIC ACID AND MELTED IN A RESEARCH-SCALE MELTER

摘要

The Research-Scale Melter at the Pacific Northwest National Laboratory was run with a simulated West Valley Demonstration Project melter feed containing nitrate, nitric acid, and oxalic acid in different ratios and total amounts. Oxalic acid was added to react with the nitric acid and nitrate in the melter feed to control the iron oxidation state. The melter feed containing oxalate as the reducing species appears to be as good a melter feed as the sugar-containing version and may provide even better and easier reduction-oxidation (redox) control. The ratio of Fe(II)/total Fe (only metal considered) indicated that the glass redox state increased proportionately with the amount of excess oxalate in the melter feed. Based on the amount of iron per kilogram of melter feed, the Fe(II)/total Fe ratio, and the amount of oxalate present, the oxalate is approximately 20 percent efficient in reducing Fe(III) to Fe(II).