Effluent Control on a Fertiliser Manufacturing Site

Fertiliser production at ICI, Billingham is located at the Portrack complex. The current installed capacity is over 1,000,000 tonnes/yr. prilled ammonium nitrate (2 plants) and over 400,000 tonnes/yr. NPK compound fertilisers (2 plants).

Early work on effluent reduction at the NPK plants was aimed at reducing losses from the ammonium nitrate neutralisers and improving the performance of the plant scrubber systems. A later project incorporated the reduction of ammonia loss from ammonium phosphate production with further scrubber modifications to achieve a water balance on the NPK plants with no scrubber effluents going to drain. Also included in the work was a sludge/spillage recovery system for the NPK plants and a solutions recovery system for the prilled ammonium nitrate plant. All recovered solutions are transferred to the NPK plants.

The next stage of the work involved further reduction of the losses from the ammonium nitrate neutralisers on the NPK plants by the installation of a novel scrubber/filter system for recovery of both ammonia and ammonium nitrate losses. At the same time work was proceeding on the NPK plants to reduce the dust load on the scrubber system by local bag filter installations and cyclone improvements to give more capacity for using waste solutions.

The last development on the site was the introduction of the new prilled ammonium nitrate plant with the latest technology for treatment of the tower effluents and the integration of the new plant into the Portrack site effluent system.