Waste acid detoxification and reclamation: Final Phase II report: Summary of distillation and material degradation tests for FY 1987 and FY 1988

The objective of the Waste Acid Detoxification and Reclamation project is to develop processes for reducing the volume, quantity, and toxicity of metal-bearing waste acids. The primary incentives for implementing these types of waste minimization processes are regulatory and economic (that is, to meet requirements in the Resource Conservation and Recovery Act and reduce the cost for treatment, storage, and disposal). Two precipitation processes and a distillation process are being developed to minimize waste from fuel fabrication operations or other metal-finishing operations conducted at US Department of Energy Defense Programs (DOE-DP) facilities. Waste process acids such as (1) HF-HNO3 etch solutions containing Zr as a major metal impurity, and (2) HNO3 strip solutions containing Cu as a major metal impurity are detoxified and reclaimed by concurrently precipitating heavy metals and regenerating acid for recycle. Acid from a third waste acid stream generated from chemical milling operations is reclaimed by the use of distillation. This stream comprises HNO3 and H2SO4 containing U as the major metal impurity. Distillation allows NO3/sup /minus// to be displaced by SO4/sup /minus/2/ in metal salts; free HNO3 is then vaporized from the U-bearing sulfate stream. In a downstream precipitation step, uranium can be recovered from the sulfate stream. This report summarizes distillation tests and candidate material degradation tests conducted during FY 1987 and FY 1988