METHOD FOR ALUMINUM REDUCTION IN RECYCLED PULP AND PAPER

• Main Authors: MULCAHY, LEO THOMAS, FOSTER, JAMES JOSEPH
• Format: Patent
• Language: English; French
• Published: 12.04.1997
• Edition: 6
• Subjects: APPARATUS THEREFOR; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATERTREATMENT OR WASTE MANAGEMENT; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; PAPER-MAKING; PRODUCTION OF CELLULOSE; PRODUCTION OF CELLULOSE BY REMOVING NON-CELLULOSE SUBSTANCESFROM CELLULOSE-CONTAINING MATERIALS; REGENERATION OF PULPING LIQUORS; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TEXTILES

This invention relates to recently developed systems which produced bleached recycled fibers from high lignin content recovered paper materials such as old corrugated containers and old newspapers. Such systems of this type, generally, use chemical digestion (e.g., the kraft process) to reduce the lignin content prior to bleaching. Since recovered paper materials normally have high levels of aluminum, which are derived from the paper sizing and pH control chemical, aluminum sulfate; and since soluble aluminum causes scaling of evaporators in the kraft digestion-chemical recovery cycle, there is a need for a means to remove soluble aluminum from the recovered paper materials prior to digestion. This invention relates to recently developed systems which produced bleached recycled fibers from high lignin content recovered paper materials such as old corrugated containers and old newspapers. Such systems of this type, generally, use chemical digestion (e.g., the kraft process) to reduce the lignin content prior to bleaching. Since recovered paper materials normally have high levels of aluminum, which are derived from the paper sizing and pH control chemical, aluminum sulfate; and since soluble aluminum causes scaling of evaporators in the kraft digestion-chemical recovery cycle, there is a need for a means to remove soluble aluminum from the recovered paper materials prior to digestion.