Peroxide Bleaching of NSAQ Aspen Pulp Without Silicate, 1990 Pulping Conference Proceedings
A neutral sulphite-anthraquinone (NSAQ) aspen pulp was bleached with an OPP sequence using commercial DTMPA and DTPA peroxide stabilizers,instead of conventional sodium silicate. This approach would allow better management of peroxide bleaching effluents,in terms of scale control,effluent recycling and chemical recovery.
The results obtained with a mill-produced, oxygen-delignified NSAQ aspen pulp show that the silicate can be replaced by the organic stabilizers at comparable cost. The best bleaching results were achieved with DTMPA, producing a 85+ brightness pulp. The optimal stabilizer dosage, bleaching conditions, effluent pollution loads, and pulp properties were determined. Fully bleached NSAQ pulps can thus be manufactured with an environmentally-acceptable process at equivalent quality and higher yield than kraft pulps.
Peroxide Bleaching of NSAQ Aspen Pulp Without Silicate, 1990 Pulping Conference Proceedings