Journal
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
Volume 36, Issue 6, Pages 1479-1485Publisher
ELSEVIER SCI LTD
DOI: 10.1016/j.jeurceramsoc.2015.12.036
Keywords
Cr(VI); Refractory castables; Calcium alumina cement; Ca4Al6CrO16; Leachability
Categories
Funding
- Kerneos
Ask authors/readers for more resources
Refractory castables can contain Cr2O3, either as a specific addition or as a impurity element in the raw materials. When calcium aluminate cement is used as a binder in such castables, Cr(III) can transform to Cr(VI) during use, which can cause subsequent problems with the disposal of the used refractory lining. The formation of Cr(VI) in Al2O3-CaO-Fe2O3-4wt% Cr2O3 mixtures, representing a simplified refractory castable system, was investigated as well as its leachability. Samples were prepared from reagent grade chemicals, equilibrated at 1300 degrees C in air and quenched in liquid nitrogen. A Cr(VI)-containing phase Ca4Al6CrO16 (hauyne) formed in all the examined samples. During the ASTM D3987-85 leach test the co-existing C(3)A, C(12)A(7), Ca-2(Al,Fe)(2)O-5 and CA phases encapsulated the Cr(VI) by forming Cr(VI) analogue phases 3CaO center dot Al2O3 center dot CaCO4 center dot nH(2)O. These phases decreased the leachability of Cr(VI) to below the EPA limit of 5 mg/l. Decreasing the pH and increasing the temperature can however remobilise the Cr(VI). (C) 2015 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available