Method for recycling paper mill waste water
US4115188A · kind A · utility
20Cited by
8References
10Claims
0Family size
Inventors
Key dates
| Filing date | Nov 8, 1976 |
| Grant date | Sep 19, 1978 |
| Priority date | — |
| Expiry date | Nov 8, 1996 |
Classification
- Technology area (CPC D)Textiles; Paper
- CPC primaryD21F1/82
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is a method for coagulating the suspended solids in paper mill waste water so that the coagulated solids may be easily separated from the waste water and the clarified waste water reused in the paper making process. Coagulation is induced by first adding sulfuric acid to lower the pH to below 4, mixing thoroughly, and then adding calcium hydroxide to raise the pH to above 10. The coagulated solids separated from the waste water may be used as a landfill, used as a low grade pulp source, or dewatered and burned as a fuel.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.