Study on neutral sodium sulfite anthraquinone pulping of corn bast

The neutral sodium sulfite-anthraquinone pulping of corn bast and its chemical composition were studied in this paper. The results indicated that the optimum cooking conditions were total chemical dosage 13% (as Na2O), alkali ratio 0.4, maximum temperature 160 degrees C, time at maximum temperature 1.75h, dosage of anthraquinone 0.1% and liquor to corn bast ratio 5:1. Under optimum cooking conditions, the characteristics of corn bast pulp could be obtained with screened yield 51.59%, Kappa number 8.1, intrinsic viscosity 1268mL/g, brightness of unbleached pulp 42.7%ISO and bleach requirement 1.7%. The strength properties of NS-AQ unbleached pulp without refining were tensile index 50.5 N m/g, tear index 6.1 mN m(2)/g and burst index 3.8 kPa m(2)/g. These datas are higher than National Standard of the People's Republic of China -1-Bk pulp (1st grade bleached sulphite hard wood pulp)strength standard in GB13506-1992.