Sample of catalyst, extrusions of desulphuriser, ICI 41-6, stored in glass flask (displayed inverted) for animated process flow display, part of model of 'Ammonia Four', an ammonia synthesis plant at ICI Agricultural Division, Billingham works, by Cleveland Process Designs and ICI Ltd, Stockton on Tees, England, 1976. Sample of catalyst, extrusions of desulphuriser, ICI 41-6, for ICI Billingham 'Ammonia Four' model 1976