| 摘要 |
<p>Waste sulphite liquors contg. alkali or alkaline earth metals which result as a by-product of cellulose production are re-constituted by neutralising with a volatile base, pref. ammonia soln., to a pH >5 and pref. >6.5, followed by a multi-stage evaporation. The pH adjustments can be carried out either in the initial and final stages only or at the final stage only or before stage of the process. The process can be operated with fermentation plant, where the pH of the liquor is adjusted initially to 4.1-4.5 and, after alcohol extraction, readjusted to >5 before the evaporation process.</p> |
