Mississippi Phosphates Corp. said Feb. 20 that a converter in one of its two 1,500 st/d sulfuric acid plants at its DAP facility in Pascagoula, Miss., suffered a failure when a weld near the top of the vessel suddenly ruptured. There was an associated release of process gases.
Two contractor employees received burns as a result of the accident. They were treated at local facilities and released.
Miss Phos said it continues to conduct air monitoring, which reveals no detectable concentration of gas or odor offsite. Onsite gas levels fall below threshold levels of concern. Miss Phos said all appropriate governmental authorities and agencies have been notified, and the group continues to closely monitor what appears to be an improving situation. Representatives of the Mississippi Department of Environmental Quality have been onsite and are assisting the company’s efforts. Miss Phos and regulatory officials will continue to closely monitor the situation.
The cause of the weld failure and the extent of damage to the sulfuric acid plant are unknown and are under investigation.
The release occurred Wednesday, Feb. 20 around 8:00 a.m., according to the local media, which said an all clear was given to the local community around noon. At that point, local schools were allowed to let their children go outdoors.
The sulfuric acid plant involved went down for repairs in late January. Its outage took approximately half the company’s DAP production offline. The plant had been slated to come back up by the end of February. However, Miss Phos on Feb. 20 had no immediate assessment of when the plant would be back up. Until the sulfuric acid plant comes back up, DAP production will be limited to approximately 900 st/d. The DAP and acid plants that were running at the time of the rupture remained in operation and continue to produce.
Miss Phos has had trouble with the sulfuric acid plant in the past. The company filed suit in October 2007 against the contractor, seeking to recover damages caused by the contractor’s failure to complete its work in a proper and timely manner.