高温熔融法固化催化裂化废催化剂重金属研究

SOLIDIFICATION OF HEAVY METAL IN WASTE CATALYTIC CRACKING CATALYST BY HIGH TEMPERATURE MELTING TECHNOLOGY

采用高温熔融处理技术对催化裂化(FCC)废催化剂进行固化处理,选取CaO,SiO_(2),CaF_(2)作为助熔剂,考察助熔剂类型、助熔剂添加比例、反应温度和反应时间等条件对FCC废催化剂固化处理的影响。结果表明,3种助熔剂对FCC废催化剂上的重金属Ni、V都具有一定的固化作用,其中酸性助熔剂SiO_(2)固化效果最好,表面微观结构显示添加SiO_(2)后的废催化剂表面更加光滑均匀、结构致密、表面无孔隙,其结构类似于玻璃体结构。当助熔剂SiO_(2)添加量(w)为20%、反应温度为1000℃、反应时间为2 h时,重金属Ni和V的浸出质量浓度分别为1.0 mg/L和0.5 mg/L。提高反应温度和延长反应时间可以提高对重金属Ni、V固化程度。

The high temperature melting technology was used to solidify the waste catalytic cracking(FCC)catalyst.Three different fluxes,CaO,SiO_(2) and CaF_(2),were selected to investigate the effects of the fluxing agent type,addition ratio,reaction temperature and reaction time on the solidification of the waste catalyst.The results showed that three kinds of fluxing agents could cure the heavy metals Ni and V on the waste FCC catalysts,and the acid fluxing agent SiO_(2) had the best effect.The surface microstructure showed that the catalyst with SiO_(2) was smoother,more compact,and had no surface porosity,which was similar to the structure of vitreous body.The leached concentration of the heavy metal Ni and V in the cooling slag were 1.0 mg/L and 0.5 mg/L,respectively when the addition of SiO_(2) was 20%,the reaction temperature was 1000℃ and the reaction time was 2 h.Increasing the reaction temperature and prolonging the reaction time could strengthen the immobilization of heavy metals Ni and V.