METHOD OF PAPERMAKING HAVING ZERO LIQUID DISCHARGE

摘要

A method of papermaking having zero liquid discharge. A cellulosic pulp composed of either virgin or recycled materials is initially cleaned, the cleaned pulp is then washed and the washed pulp is then utilized in the papermaking process. The contaminants are separated from the liquid residue resulting from the pulp cleaning operation (3), preferably by floatation clarification (4), and the effluent from the clarification is evaporated to produce steam along with an evaporated residue. The evaporated residue is combined with the suspended solids and the combined residue is then subjected to a mechanical dewatering operation (5) so that the dewatered material can then be either landfilled or incinerated. The condensate from the evaporation is combined with fresh water and used in the papermaking process (9) and water recovered from the papermaking process (9) is recycled to the washing operation (8). Water recovered from the washing operation (8) can be recycled to the pulp cleaning (3) and pulping operations (1).