Nawee,
There have been a number of temporary shutdowns that have been announced for various smelters around the world. Some shutdowns are only for 8 weeks but could be extended if the economy does not recover.
ASARCO's smelter in El Paso, Texas was shutdown in 1999 and placed under care and maintenance. In the past few years they have been trying to restart the smelter but have faced opposition from the local community. They had an outside consultant inspect and evaluate the two acid plants to determine what would be required to restart the acid plants. The general conclusion of the report was that the two acid plants could not be salvaged and a new plant would be required. Unfortunately, the poor economy caused ASARCO to decide to abandon plans to restart the smelter. When the site was placed under care and maintenance, it was thought it would be for a short time only. The shutdown stretched into almost 10 years with the result that their assets were damaged and had to be replaced.
The lesson from this story is that it is worthwhile to properly mothball a plant so that your assets are in good condition when you want to restart the plant. It does not take long for a sulphuric acid plant to become damaged if it is not properly cared for during a shutdown. Corrosion does not stop even though the plant is not operating.
You may be aware of my book "The Handbook of Sulphuric Acid Manufacturing" 2nd edition. In the Maintenance section (Chapter 25) there is a section on "Plant Shut Down and Mothballing". The section discusses the impact of climatic conditions on plant preservation (Locations with high humidity need to be treated differently from arid climates). It discusses the different requirements for short versus long shutdowns. You need to decide what you want to do with the catalyst. Should the equipment be drained, washdown and dried? What should be done with the rotating equipment, particularly the main blower? The section in the book provides general guidelines but each plant is different. You need to adapt whatever general procedures and guidelines you have to the specifics of your plant.
Please contact me at
doug.louie@worleyparsons.com to discuss further.
Douglas
