Patent ID: 6416251
Filing Date: 2002-07-09
Classification: A62D,B09B,B09C,C04B,C22B,Y02P

Abstract:
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 1500Â° 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.