Method for brightening chemical pulp with hydrogen peroxide using a magnesium compound in silicate solution
US6699358B1 · kind B1 · utility
29Cited by
2References
2Claims
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Key dates
| Filing date | Jan 11, 2001 |
| Grant date | Mar 2, 2004 |
| Priority date | — |
| Expiry date | Jan 11, 2021 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21C9/163
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method for brightening chemical pulps with less than 18% lignin utilizing a magnesium compound in a sodium silicate solution to form a higher percentage of high molecular weight silicates. Such high molecular weight silicates preferentially adsorb transition metal impurities, which, if left in solution, would tend to decompose hydrogen peroxide and organic peroxides. Hydrogen peroxide is added to peroxide and peroxide/oxygen stages, while it is generated, along with organic peroxides during an oxygen stage.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.