Removing tars from ammonium sulphate solns. - by adding a selective adsorbent for the tar then filtering

摘要

Sepn. of tars present in (NH4)2SO4 soln. obtd. by treating waste H2SO4 with NH3 comprises first mixing the soln. with a specific adsorbant for the tars. The mixt. is then filtered conventionally to give a clear soln. while leaving a filter cake composed of the adsorbant and tar. Pref. the adsorbant is a by-product of wood processing such as shavings, sawdust etc. The clear filtrate can be evapd. to recover crystalline (NH4)2SO4 for use as fertilizer. The solid cake can be incinerated and its absorbs very little of the clear soln. with NH3 losses being well below 2%.