Effluent Treatment Facility Waste Stream Stabilization Testing.

Avila, M. ; Cooke, G. A. ; Lockrem, L. L. ; Koci, G. L. ; Guthrie, M. D. ; Lueck, K. J.

Technical Information Center Oak Ridge Tennessee

关键词: Waste forms;    Waste water;    Cements;    Concretes;    Waste management;   

RP-ID  :  DE2005859142

学科分类：工程和技术（综合）

美国|英语

来源: National Technical Reports Library

【 摘 要 】

The U.S. Department of Energy Hanford Site, the location of plutonium production for the U.S. nuclear weapons program, is the focal point of a broad range of waste remediation efforts. This presentation will describe the development of cementitious waste forms for evaporated Hanford waste waters from several sources. Basin 42 waste water and simulants of proposed Waste Treatment and Immobilization Plant secondary wastes and Demonstration Bulk Vitrification System secondary wastes were solidified in cementitious matrices termed 'dry cementitious formulation.' Solidification of these brines was difficult to deal with because of high sulfate contents. Two approaches were explored. The first was based on compositions similar to sulphoalurninate-belite cements. The main component of these cements is 4Ca0-2Al(sub 2)O(sub 3)-SO(sub 4). When hydrating in the presence of sulfate, these cements rapidly form ettringite. The goal was to consume the sulfate by rapidly forming ettringite. Forming ettringite before the mixture has filly set minimizes the potential for deleterious expansion at a later date. These formulations were developed based on mixtures of calcium-aluminate cement, a glassy blast-furnace slag, class F fly ash, and Portland cement. A second approach was based on using high alumina cement like ciment fondu. In this case the grout was a mixture of ciment fondu, a glassy blast-furnace slag, class F fly ash, and Portland cement. The literature shows that for concretes based on equal amounts of ciment fondu and blast furnace slag, cured at either 20 deg C or 38 deg C, the compressive strength increased continuously over a period of 1 year. In this second approach, enough reactive calcium aluminate was added to fully consume the sulfate at an early age. The results of this study will be presented. Included will be results for expansion and bleed water testing, adiabatic temperature rise, microstructure development, and the phase chemistry of the hydrated materials. The results of toxicity characteristic leaching procedure testing on samples of dry cementitious formulation spiked with selected metals will also be presented.