Process for the stabilization of soluble chromium contaminated solid by down draft sintering
AssigneeCouncil of Scientific and Industrial Research
InventorsBansidhar Nayak, Birendra Kumar Mohapatra, Binod Behari Nayak, Hemshankar Ray
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Abstract
The invention relates to a process for the stabilisation of soluble chromium in contaminated solids by down draft sintering by mixing chromium contaminated solids with different proportions of CaO, MgO, Al2O3, SiO2, SO4 and solid carbon bearing waste materials to maintain the desired ratio of CaO/SiO2, SiO2/Al2O3+Fe2O3 and SO3/Cr in the mixture. The Cr(VI) and chromates are converted into non-leachable compounds.
Claims14
A process for the stabilisation of soluble chromium in contaminated solids by down draft sintering, which comprises mixing chromium contaminated solids with different proportions of CaO, MgO, Al2O3, SiO2, SO4 and solid carbon bearing waste materials to maintain a ratio of CaO/SiO2 of <2.5, SiO2/Al2O3+Fe2O3 of 0.5 to <4 and SO3/Cr of 0.2 to 1 in the mixture, homogenisation of the mixture, pelletisation of the mixture in the presence of moisture to form a pelletised charge material, sintering of the pelletised charge material at a temperature in the range of 800 to 1500° C. by down draft sintering to convert and stabilise the Cr(VI) and chromates into stable non-leachable compounds to obtain soluble chromium stabilized sintered material.
Dependencies are inferred from the claim text.