FIELD: textiles, paper.
SUBSTANCE: method involves a stage of refining wood, including handling of ozone to get the pulp, a stage of neutralisation of acid comprising contacting mechanical pulp with a neutralising composition containing at least one alkaline agent for more than one hour, and a stage of bleaching comprising contacting the neutralised mass with a bleaching composition. During the last 30 minutes of the stage of neutralisation the acid, pH varies by less than 0.2 units, and the pH ranges from 6 to 10 at the output from the stage of neutralisation the acid.
EFFECT: invention provides a more efficient bleaching of paper pulp with better output, or using fewer chemicals, or with formation less wastewater.
15 cl, 3 ex, 4 tbl, 1 dwg
| Title | Year | Author | Number |
|---|---|---|---|
| METHOD OF PRODUCING WOOD PULP | 2007 |
|
RU2373313C1 |
| METHOD OF PREPARING BLEACHED PULP AND A METHOD FOR DELIGNIFICATION AND BLEACHING OF LIGNOCELLULOSE MATERIAL | 1990 |
|
RU2102547C1 |
| METHOD OF BLEACHING PAPER PULP BY FINAL OZONE TREATMENT AT HIGH TEMPERATURE | 2007 |
|
RU2439232C2 |
| METHOD TO BLEACH CHEMICAL CELLULOSE | 2007 |
|
RU2413809C2 |
| SILICON OXIDE-CONTAINING COMPOSITION | 2009 |
|
RU2516846C2 |
| METHOD FOR PRODUCTION OF MAGNESIUM-BASED BLEACHED SULFITE CELLULOSE | 2000 |
|
RU2164571C1 |
| METHOD OF CELLULOSE PRODUCTION WITHOUT CHLORIDE CHEMICALS | 1993 |
|
RU2126471C1 |
| METHOD OF BLEACHING OF CELLULOSE AND OTHER CELLULOSE AND LIGNOCELLULOSE FIBROUS MATERIALS AND THREE-STAGE METHOD OF BLEACHING OF CELLULOSE AND LIGNOCELLULOSE MATERIALS | 1995 |
|
RU2141016C1 |
| PEROXIDE-ALKALINE TREATMENT OF WASTE PRODUCTS ON INTEGRATED NEUTRAL-ALKALINE PULP AND PAPER PLANT | 2010 |
|
RU2495177C2 |
| COMPOSITION AND METHOD FOR TREATING FIBROUS MATERIAL | 2008 |
|
RU2439233C2 |
