Stabilization of copper sludge by high-temperature CuFe2O4 synthesis process.

ABSTRACT

Copper sludge was stabilized by high-temperature CuFe(2)O(4) ferritization technique with different sintering temperature, isothermal time and Fe(3+)/M(2+) molar ratio. Copper is stabilized by inserting the copper ion into the stable CuFe(2)O(4) structure by ferritization. The result indicates that sintering temperature above 800 degrees C would be proper temperature range for CuFe(2)O(4) synthesis. When the Fe(3+)/M(2+) molar ratio of sludges are above the stoichiometric ratio of 2, copper ion in sludge would be stabilized and hence be kept from leaching out. From the result of relative XRD intensity ratio, the equilibrium of the ferritization reaction could be reached by prolonging the isothermal time to 10h. Judging by the TCLP results, the optimum ferritization parameters are Fe(3+)/M(2+) molar ratio equal to 3.5, sintering temperature at 800 degrees C and isothermal time above 10h.