| 摘要 |
A process for making bleached pulp comprises contacting an unbleached pulp mixture with a first recycled filtrate obtained from a first location (3) of a first recycled filtrate loop, to obtain a first pulp mixture having a first consistency; bleaching the first pulp mixture, to obtain a first bleached pulp mixture; pressing or dewatering the first bleached pulp mixture, to obtain a first pressed bleached pulp mixture and a second filtrate; sending at least a portion of the second filtrate to a second location (5) of the first recycled filtrate loop, wherein the second location (5) is downstream of and in fluid communication with the first location (3); contacting the first pressed bleached pulp mixture with a second recycled filtrate obtained from a third location (6) of the first recycled filtrate loop, to obtain a second pulp mixture having a second consistency, wherein the second consistency is greater than the first consistency, and wherein the third location (6) is downstream of and in fluid communication with the second location (5); bleaching the second pulp mixture, to obtain a second bleached pulp mixture; pressing or dewatering the second bleached pulp mixture, to obtain a second pressed bleached pulp mixture and a third filtrate; sending at least a portion of the third filtrate to a fourth location (8) of the first recycled filtrate loop, wherein the fourth location (8) is downstream of and in fluid communication with the third location (6); and recycling at least a portion of the third filtrate in the first recycled filtrate loop to the first location (3); to obtain the bleached pulp. |
