摘要
The phase transformation of kaolin in the presence of 1%～5% vanadium had been investigated. The results indicated that vanadium mullite emerged at 660～700℃which was at least 400℃ lower than conventional mullite formation temperature, and a chemical reaction between kaolin and vanadium took place obviously. The reaction of vanadium mullite formation could be described as a process of low melting vanadium kaolin eutectic transition.In addition, the unit cell volume of vanadium mullite was found increased with the increment of vanadium content, which could be deduced that vanadium incorporated into mullites’ framework and was therefore passivated. Furthermore, in comparison with hydro kaolin, modified kaolin—PAL and CLS reacted fast with vanadium to form more mullite and CLS could even reacted with nickel to form a rather stable compound of NiAl 10 O 16 , and therefore protected zeolite in cracking catalysts against the heavy metal poisoning effectively.
The phase transformation of kaolin in the presence of 1%～5% vanadium had been investigated. The results indicated that vanadium mullite emerged at 660～700℃which was at least 400℃ lower than conventional mullite formation temperature, and a chemical reaction between kaolin and vanadium took place obviously. The reaction of vanadium mullite formation could be described as a process of low melting vanadium kaolin eutectic transition.In addition, the unit cell volume of vanadium mullite was found increased with the increment of vanadium content, which could be deduced that vanadium incorporated into mullites' framework and was therefore passivated. Furthermore, in comparison with hydro kaolin, modified kaolin—PAL and CLS reacted fast with vanadium to form more mullite and CLS could even reacted with nickel to form a rather stable compound of NiAl 10 O 16 , and therefore protected zeolite in cracking catalysts against the heavy metal poisoning effectively.
出处
《催化学报》
SCIE
CAS
CSCD
北大核心
1999年第2期174-176,共3页
关键词
高岭土
钒
镍
催化裂化催化剂
重金属污染
kaolin, vanadium, nickel, mullite, unit cell volume, eutectic
