Role of arsenic oxide?

Question

What is the role of arsenic oxide in the Contact process?

Answer 1

Arsenic oxide will deactivate / poison the catalyst in contact process.

Catalyst life can be shortened significantly when subjected to severe service. Catalyst deterioration may be caused

by the following mechanisms:

1. Thermal: Operation at 650ο Celsius or higher may cause irreversible degradation of the support.

2. Mechanical: Dust or scale coming into contact with the catalyst may plug the voids between the pellets/rings and leach the active salts from the catalyst through capillary action.

3. Chemical: Contaminants react with the catalyst either to reduce activity, cause gradual loss of vanadium or decrease the pellet/ring strength.

http://209.85.175.104/search?q=cache:dan...