Patent ID: 6200455
Filing Date: 2001-03-13
Classification: C01D

Abstract:
A method to control the in situ cladding of metal onto surfaces of production equipment, vessels and piping for the production of alkali metal hydroxides, the method which comprises,continuously providing a cell liquor containing metal to a first magnet;magnetically removing up to about one third of said metal present in the cell liquor forming a first fluid;evaporating a significant amount of water out of said first fluid using at least one evaporator and raising the temperature of the first fluid to above 330 F forming a highly concentrated solution, and then further evaporating using flash pans forming a second fluid;cooling said second fluid using at least one cooler forming a cooled solution;continuously providing the cooled solution to a second magnet;magnetically removing an additional amount of said metal from said cell liquor forming a second cooled stream;filtering said second cooled stream using at least one filter and forming a filtered solution;continuously providing the filtered solution to a third magnet; andmagnetically removing any additional metal from said filtered solution forming a alkali metal hydroxide containing 40-55 wt % caustic.