| 摘要 |
PURPOSE:To obtain ammonium sulphate solution for the starting material of ammonium sulphate contg. no included coloring substance by washing by-produced ammonium sulphate soln. obtd. by introducing coke oven gas into an absorption tower with light oil. CONSTITUTION:Coke oven gas is introduced in an ammonia absorbing tower 2, where ammonium sulphate soln. is produced by adding sulphuric acid and water. A part of the ammonium sulphate soln. is washed with light oil at a position B in a conducting pipe 10 for sending the soln. from a mother liquid circulating tank 4 to an evaporating kettle 14. Or, the ammonium sulphate soln. in the upper layer part of the mother liquid circulation tank 4 is drawn out and washed with light oil at the poition B' in the midway of the drawn out pipe 20. Eventually, an emulsification inhibitor is mixed with the ammonium sulphate soln. taken out of the absorption tower 2, and then mixed with light oil. The mixture is stirred and then settled to separate into two layers of an ammonium sulphate soln. layer and a light oil layer. After removing the light oil, the ammonium sulphate soln. eliminated from the coloring matters is combined with the ammonium sulphate soln. in the settling part. Decoloration of by-produced ammonium suphate for the starting material of ammonium sulphate is prevented in this way.
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