Abstract
A new chemical recovery process for high sulfidity spent liquor has been developed by Mitsubishi Heavy Industries, Ltd. and Jujo Paper Manufacturing Co., Ltd.
In this new recovery process, high sulfidity smelt can be obtained by absorbing SO2 gas in the flue gas in a solution of sodium carbonate solution separated from smelt solution and buring the resulting sodium sulfite solution together with spent liquor.
The sulfidity of smelt can be easily controlled by suitably adjusting the amount of sodium carbonate recycled to the recovery system and the amount of SO2 gas absorbed in the sodium carbonate solution.
This new recovery process can also be applied to the cross recovery for alkaline and sulfite spent liquors.
