The Ambatovy Nickel Plant is located in eastern Madagascar close to the seaport of Tamatave (Toamasina). The metal enriched rock ore is processed into slurry and transported 220 km to this plant where it is processed into nickel briquettes, cobalt briquettes and ammonium sulphate. During production, the chrome must be reduced to prevent pollution of the drinking water. This is done in a pipe reactor by adding hydrogen sulfide (H2S ) from another process step within the plant. Since the H2S is a gas that presents a huge risk for the employees and the environment, the non reacted H2S has to be removed before it reaches the subsequent process step that takes place in large atmospheric tanks. Two 16” InLine DeGassers are installed upstream of the tanks to remove the gas from the water stream. Although the amount of H2S concentration in the gas is low, it is highly poisonous and must be removed to prevent leakage through the tank vents.
The main challenge with designing the InLine DeGassers were the extreme corrosive environment in which they have to operate. To resist this environment the InLine DeGassers are fabricated from hasteloy. Above this the operating pressure is near atmospheric, so pressure drop was very critical in the design.
Startup of the plant is expected for Q2 2011 and it will run at full capacity in 2013.