Process for the manufacture of pulp using sodium carbonate and oxygen
US4045279A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 9, 1976 |
| Grant date | Aug 30, 1977 |
| Priority date | — |
| Expiry date | Sep 9, 1996 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C11/12
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A process for preparing pulp in a closed system by pre-cooking fibrous raw material in an alkaline aqueous solution of sodium carbonate or a mixture of sodium carbonate and sodium bicarbonate as the only alkaline ingredients at 90.degree.-190.degree. C, defibrating the pre-cooked material, pulping the defibrated material in an alkaline aqueous solution of sodium carbonate or a mixture of sodium carbonate and sodium bicarbonate as the only alkaline ingredients in a pressurized vessel at 90.degree.-170.degree. C in the presence of an oxygen-containing gas, subjecting waste liquor discharged from the pre-cooking and pulping steps to wet combustion to recover an alkaline aqueous substance and recycling the alkaline aqueous substance resulting from combustion to the pre-cooking and/or pulping steps.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.