Radioactively contaminated electric arc furnace dust as an addition to the immobilization mortar in low- and medium-activity repositories.
Electric arc furnace dust (EAFD), generated by the steel-making industry, is in itself an intrinsic hazardous waste; however, the case may also be that scrap used in the process is accidentally contaminated by radioactive elements such as cesium. In this case the resulting EAFD is to be handled as radioactive waste, being duly confined in low- and medium-activity repositories (LMAR). What this paper studies is the reliability of using this radioactive EAFD as an addition in the immobilization mortar of the containers of the LMAR, that is, from the point of view of the durability. Different mixes of mortar containing different percentages of EAFD have been subjected to flexural and compressive strength, initial and final setting time, XRD study, total porosity and pore size distribution, determination of the chloride diffusion coefficient, dimensional stability tests, hydration heat, workability of the fresh mix, and leaching behavior. What is deduced from the results is that for the conditions used in this research, (cement + sand) can be replaced by EAFD upto a ratio [EAFD/(cement + EAFD)] of 46% in the immobilization mortar of LMAR, apparently without any loss in the long-term durability properties of the mortar.
Castellote
Marta
M
Institute of Construction Science Eduardo Torroja (IETcc), CSIC, Serrano Galvache s/n, 28033 Madrid, Spain. martaca@ietcc.csic.es
Menéndez
Esperanza
E
Andrade
Carmen
C
Zuloaga
Pablo
P
Navarro
Mariano
M
Ordóñez
Manuel
M
D002484:Cementation; D019245:Compressive Strength; D004391:Dust / Q000032:analysis; D008669:Metallurgy; D016062:Porosity; D011848:Radioactive Pollutants / Q000032:analysis; D011850:Radioactive Waste / Q000032:analysis; D013232:Steel; D013997:Time Factors; D018505:Waste Management / Q000379:methods*; D014961:X-Ray Diffraction
D004391:Dust; D011848:Radioactive Pollutants; D011850:Radioactive Waste; D013232:Steel