Development of the Use of Alternative Cements for the Treatment of Intermediate Level Waste
- Nexia Solutions, Warrington, Cheshire WA (United Kingdom)
- Nexia Solutions Limited, Havelock Road, Derwent Howe, Workington, Cumbria CA (United Kingdom)
This paper describes initial development studies undertaken to investigate the potential use of alternative, non ordinary Portland cement (OPC) based encapsulation matrices to treat historic legacy wastes within the UK's Intermediate Level Waste (ILW) inventory. Currently these wastes are encapsulated in composite OPC cement systems based on high replacement with blast furnace slag of pulverised fuel ash. However, the high alkalinity of these cements can lead to high corrosion rates with reactive metals found in some wastes releasing hydrogen and forming expansive corrosion products. This paper therefore details preliminary results from studies on two commercial products, calcium sulfo-aluminate (CSA) and magnesium phosphate (MP) cement which react with a different hydration chemistry, and which may allow wastes containing these metals to be encapsulated with lower reactivity. The results indicate that grouts can be formulated from both cements over a range of water contents and reactant ratios that have significantly improved fluidity in comparison to typical OPC cements. All designed mixes set in 24 hours with zero bleed and the pH values in the plastic state were in the range 10-11 for CSA and 5-7 for MP cements. In addition, a marked reduction in aluminium corrosion rate has been observed in both types of cements compared to a composite OPC system. These results therefore provide encouragement that both cement types can provide a possible alternative to OPC in the immobilisation of reactive wastes, however further investigation is needed. (authors)
- Research Organization:
- WM Symposia, 1628 E. Southern Avenue, Suite 9 - 332, Tempe, AZ 85282 (United States)
- OSTI ID:
- 21305419
- Report Number(s):
- INIS-US-09-WM-07328; TRN: US10V0226049611
- Resource Relation:
- Conference: WM'07: Waste Management Symposium 2007 - Global Accomplishments in Environmental and Radioactive Waste Management: Education and Opportunity for the Next Generation of Waste Management Professionals, Tucson, AZ (United States), 25 Feb - 1 Mar 2007; Other Information: Country of input: France; 8 refs
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ALUMINATES
ALUMINIUM
BLAST FURNACES
CALCIUM COMPOUNDS
CORROSION
CORROSION PRODUCTS
ENCAPSULATION
GROUTING
HYDRATION
INTERMEDIATE-LEVEL RADIOACTIVE WASTES
INVENTORIES
MAGNESIUM PHOSPHATES
MINIMIZATION
PORTLAND CEMENT
REACTIVITY