摘要
本研究探究了P-RC APMP高浓停留段MgO替代50% NaOH时,不添加螯合剂DTPA或pH缓冲剂Na2SiO3对纸浆性能和漂后残余H2O2含量的影响。结果表明,MgO替代50% NaOH后,纸浆的松厚度提高了15.4%,但不透明度和强度性能均下降;不添加DTPA的纸浆比添加DTPA的纸浆松厚度降低了6.5%,抗张指数、耐破指数和撕裂指数分别上升了6.6%、4.4%和6.6%,不透明度上升了10.3%,白度变化不大(增加了0.57%),漂后残余H2O2含量为3.55 g/L,降低了5.1%。因此,在松厚度要求不高时,MgO替代50% NaOH作为P-RC APMP高浓停留段碱源可同时替代螯合剂DTPA,即可以免加金属离子螯合剂。
在高得率制浆中,预调理盘磨化学处理碱性过氧化氢机械浆(P-RC APMP)制浆方法以其高效、清洁的特点,受到众多学者和制浆造纸企业的青睐,是我国高得率木浆的主要生产工艺之
P-RC APMP的生产流程由预汽蒸、预浸渍、螺旋挤压、高浓磨浆、高浓漂白等多道工序组
传统的P-RC APMP制浆工艺中,由于碱源NaOH的强碱性,会导致制浆过程中部分木材组分溶出,致使纸浆得率下降,制浆残液的COD浓度增
镁及其化合物(如MgO、亚硫酸氢镁、硫酸镁和醛类镁等)在纸浆漂白过程中起着重要的作
MgO部分电离产生的镁离子和氢氧根离子能够分别起到络合纸浆中的过渡金属离子和缓冲漂白体系pH的作用,将其作为P-RC APMP高浓停留段的部分碱源以减少金属离子螯合剂和pH缓冲剂添加量成为了可行的研究思路。本研究采用MgO替代50% NaOH作为P-RC APMP高浓停留段纸浆漂白的碱源,探讨了不添加DTPA或Na2SiO3对成浆性能和漂后残余H2O2含量的影响;旨在保证适当纸浆强度性能的前提下,以提高纸浆松厚度为目的,优选出P-RC APMP高浓停留段中漂白助剂的添加种类,为P-RC APMP或其他高得率纸浆的生产提供指导。
在P-RC APMP高浓停留段,添加5组不同漂白化学品的APMP样品如
在纸或纸板生产中,使用高得率浆可以提高产品的松厚度,从而提高产品的挺度,还可以减少纸浆用量,降低生产成

图1 添加不同漂白化学品P-RC APMP浆松厚度、白度及不透明度
Fig. 1 Bulk, brightness and opacity of P-RC APMP pulp with different bleaching chemicals
纸浆的强度性能是衡量纸浆质量的一个重要指标。5组纸浆样品的抗张指数、耐破指数及撕裂指数如

图2 添加不同漂白化学品P-RC APMP浆强度
Fig. 2 Strength properties of P-RC APMP pulp adding different bleaching chemicals
纸浆漂白后残液中的H2O2(简称漂后残余H2O2)含量在一定程度上可以反映纸浆在漂白过程中H2O2无效分解的程度。

图3 添加不同漂白化学品所得漂后残余H2O2含量
Fig. 3 Residual H2O2 content after bleaching by adding different bleaching chemicals
对于
在纸张生产中添加高得率纸浆,不仅可以改善纸张的松厚度和不透明度以及胶版印刷的质量,还有利于节省化学木浆的用量。而在纸板、特别是高档纸板的生产中,高得率纸浆往往被大量用于制造纸板的芯层,这是因为纸板中的芯层在纸板产品使用时,所承受的弯曲载荷(层间拉应力或压应力)相对纸板的面层、衬层和底层都较小;又因为高得率浆比化学浆的松厚度高,不仅可赋予纸板较大的厚度,大大提高了纸板产品的挺度,且在达到相同挺度值下可节省化学浆的用量。由此可见,高得率浆的性能指标,特别是纸浆的白度、松厚度和强度,在很大程度上决定了其终端的用
综合
在其他条件不变的前提下,仅在高浓停留段用MgO替代50% NaOH,所得
在高浓停留段用MgO替代50% NaOH,同时替代螯合剂DTPA或pH缓冲剂Na2SiO3,所得纸浆的性能前已述及。对比
(1)替代螯合剂DTPA后的
(2)替代pH缓冲剂Na2SiO3后的
(3)螯合剂DTPA和pH缓冲剂Na2SiO3二者都替代后的
本研究探讨了MgO替代50% NaOH作为P-RC APMP高浓停留段的碱源,并替代螯合剂DTPA或pH缓冲剂Na2SiO3时纸浆性能及漂后残余H2O2含量;分析了MgO替代50% NaOH同时取代螯合剂DTPA或pH缓冲剂Na2SiO3的可行性。
3.1 MgO替代50% NaOH后,纸浆的松厚度提高了15.4%,达到2.78 c
3.2 MgO替代50% NaOH同时取代螯合剂DTPA,所得纸浆的松厚度为2.60 c
3.3 MgO替代50% NaOH同时取代pH缓冲剂Na2SiO3,所得纸浆的松厚度为2.85 c
3.4 MgO替代50% NaOH,同时又取代螯合剂DTPA和pH缓冲剂Na2SiO3,所得纸浆松厚度只有2.53 c
综上所述,MgO替代50% NaOH作为P-RC APMP高浓停留段的碱源同时可以替代螯合剂DTPA,即在高浓停留段可以免加金属离子螯合剂。
参考文献
张红杰, 胡惠仁. 提高高得率浆光学稳定性研究的新进展[J]. 中国造纸学报, 2008, 23(2): 109-114. [百度学术]
ZHANG H J, HU H R. New Progress in Improving Optical Stability of High Yield Pulps [J]. Transactions of China Pulp and Paper, 2008, 23(2): 109-114. [百度学术]
陈安江, 王月洁, 王昱生, 等. P-RC APMP制浆工艺影响因素及生产控制的探讨[J]. 中国造纸, 2008, 27(3): 57-61. [百度学术]
CHEN A J, WANG Y J, WANG Y S, et al. Discussion on the Influence Factors and Production Control of P-RC APMP Pulping Process[J]. China Pulp & Paper, 2008, 27(3): 57-61. [百度学术]
WANG L J, LI C Y, PENG J Y, et al. A laboratory study on the use of maple CTMP and calcium carbonate fillers in fine paper production[J]. Nordic Pulp & Paper Research Journal, 2016, 31(4): 608-612. [百度学术]
ZHANG F D, WANG L J, AN X Y, et al. Improving sizing performance of middle layer of liquid packaging board containing high-yield pulp[J]. Cellulose, 2020, 27(8): 4707-4719. [百度学术]
刘彦成. 化机浆的应用和发展趋势[J]. 中国造纸学报, 2011, 26(1): 60-62. [百度学术]
LIU Y C. Application and Development Trend of Chemical Mechanical Pulp[J]. Transactions of China Pulp and Paper, 2011, 26(1): 60-62. [百度学术]
SUN X Q, ZHAO G T, HOU Q X, et al. Improving the efficiency of hydrogen peroxide bleaching of chemimechanical pulp by continuous replenishment of bleaching chemicals[J]. Tappi Journal, 2017, 16(6): 332-340. [百度学术]
Veisi A, Mahdavi S. Mixing bleached white poplar and wheat straw chemimechanical pulps to improve the mechanical and optical characteristics[J]. BioResources, 2016, 11(2): 2987-2997. [百度学术]
郭玉倩, 田中建, 吉兴香, 等. 化学机械浆工艺技术的研究综述[C]//中国造纸学会第十八届学术年会论文集. 南宁: 2018: 56-59. [百度学术]
GUO Y Q, TIAN Z J, JI X X, et al. Review of the research on the technology of chemical mechanical pulp[C]//Proceedings of the 18th Annual Academic Meeting of China Technical Association of the Paper Industry. Nanning: 2018: 56-59. [百度学术]
韦天辉, 李许生, 陈祖鑫. 过氧化氢漂白助剂及协同漂白技术的研究进展[J]. 西南造纸, 2004(6): 21-23. [百度学术]
WEI T H, LI X S, CHEN Z X. Research progress of hydrogen peroxide bleaching additives and synergistic bleaching technology[J]. Southwest Papermaking, 2004(6): 21-23. [百度学术]
苗庆显, 秦梦华, 陈礼辉, 等. 杨木P-RC APMP中溶解和胶体物质的特性分析[J]. 中国造纸学报, 2010, 25(3): 13-18. [百度学术]
MIAO Q X, QIN M H, CHEN L H, et al. Characteristics of Dissolved and Colloidal Substances in Poplar P-RC APMP[J]. Transactions of China Pulp and Paper, 2010, 25(3): 13-18. [百度学术]
WANG X Y, CHEN J C, CHEN H L, et al. Influence of Chemical Pretreatment on the Dissolved Organics in Poplar Alkaline Peroxide Mechanical Pulping Effluent[J]. Paper and Biomaterials, 2017, 2(1): 32-39. [百度学术]
Dietz T, Schmidt K, Siss H. Aspects of optimization of mechanical pulp bleaching-A comparison of alternative alkali sources for hydrogen peroxide bleaching[J]. International Paperworld, 2008, 12: 39. [百度学术]
LIU W, Han S, ZHANG L G, et al. Effects of Mg-based Alkaline Peroxide Bleaching on Physical Properties of Poplar Bleached Chemi-thermomechanical Pulp and Its Influence Mechanism[J]. Paper and Biomaterials, 2018, 3(3): 16-25. [百度学术]
Thakore A, Oei J, Ringrose B. The use of magnesium hydroxide as a cost-effective cellulose protector in the pressurized alkaline peroxide (Eop) bleaching stage[J]. Pulp & Paper Canada, 2005, 106(5): 46-49. [百度学术]
袁 玮, 侯庆喜, 赵江鹏, 等. 镁在制浆造纸工业中的应用[J]. 纸和造纸, 2009, 28(8): 45-49. [百度学术]
YUAN W, HOU Q X, ZHAO J P, et al. Application of Magnesium in Pulp and Paper Industry[J]. Paper and Paper Making, 2009, 28(8): 45-49. [百度学术]
Hietanen, Tomi M, Österberg, et al. Effects on Pulp Properties of Magnesium Hydroxide in Peroxide Bleaching[J]. BioResources, 2013, 8(2): 2337-2350. [百度学术]
LI Q, WANG A J, DING W H, et al. Influencing Factors for Alkaline Degradation of Cellulose[J]. BioResources, 2017,12(1): 1263-1272. [百度学术]
Gibson A, Wajer M. The use of magnesium hydroxide as an alkali and cellulose protector in chemical pulp bleaching[J]. Pulp & Paper Canada, 2003, 104(11): 28-32. [百度学术]
XU F Q, CHEN J W, LIU L H. Evaluation of pretreatments for removing metal ions from industrial grade magnesium and its application during the alkaline H2O2 bleaching process of poplar chemi-thermomechanical pulp (CTMP)[C]// International Society of Computer Science and Electronic Technology. Proceedings of 2015 2nd International Workshop on Materials Engineering and Computer Sciences (IWMECS 2015). Ji’nan: Atlantis Press, 2015: 505-512. [百度学术]
NI Y H. A Review of Recent Technological Advances in the Brightening of High Yield Pulps[J]. Canadian Journal of Chemical Engineering, 2005, 83(4): 610-617. [百度学术]
WANG H, HE Z B, NI Y H. A Kinetic Model of the Magnesium Hydroxide-based Peroxide Bleaching Process of a TMP[J]. Journal of Wood Chemistry & Technology, 2008, 28(1): 55-65. [百度学术]
YE L Y, HOU Q X, LIU W, et al. Effect of partially substituting MgO for NaOH on bleaching of pine (Pinus massoniana) thermomechanical pulp[J]. Carbohydrate Polymers, 2012, 88(4): 1435-1439. [百度学术]
董翠华, 龙 柱, 庞志强. H2O2漂白助剂的研究进展[J]. 纸和造纸, 2007(S1): 38-41. [百度学术]
DONG C H, LONG Z, PANG Z Q. Research progress of H2O2 Bleaching Auxiliaries [J]. Paper and Paper Making, 2007(S1): 38-41. [百度学术]
张瑞霞, 李 静. 纸浆过氧化氢漂白稳定剂的研究进展[J]. 造纸化学品, 2012, 24(6): 1-6. [百度学术]
ZHANG R X, LI J. Research progress of stabilizers for hydrogen peroxide bleaching of pulp[J]. Paper Chemicals, 2012, 24(6): 11-13. [百度学术]
刘 杰, 韩 卿. 助剂在过氧化氢漂白中的应用[J]. 造纸科学与技术, 2011, 30(1): 56-60. [百度学术]
LIU J, HAN Q. Application of auxiliaries in hydrogen peroxide bleaching[J]. Papermaking Science and Technology, 2011, 30(1): 56-60. [百度学术]
Mannai F, Ammar M, Yanez, José Garrido , et al. Cellulose fiber from Tunisian Barbary Fig "Opuntia ficus-indica" for papermaking[J]. Cellulose, 2016, 23(3): 1-12. [百度学术]
陈 乐,龙 柱. 12种桉树化学成分分析及其硫酸盐法制浆适宜性评价[J]. 中华纸业, 2015(16): 65-70. [百度学术]
CHEN L, LONG Z. Chemical composition analysis of 12 Eucalyptus species and evaluation of their kraft pulping suitability[J]. China Pulp and Paper Industry, 2015(16): 65-70. [百度学术]
石淑兰, 何福望. 制浆造纸分析与检测[M]. 北京: 中国轻工业出版社, 2003: 125-126. [百度学术]
SHI S L, HE F W. Analysis and Detection of Pulping and Papermaking[M]. Beijing: China Light Industry Press, 2003: 125-126. [百度学术]
才 鑫. 对低定量圣经纸挺度影响因素的研究[J]. 黑龙江造纸, 2016, 44(3): 11-12. [百度学术]
CAI X. Study on the influence factors of low weight biblical paper stiffness[J]. Heilongjiang Paper Making, 2016, 44(3): 11-12. [百度学术]
邵震宇, 谢益民. 化学助剂在过氧化氢漂白中的应用[J]. 造纸化学品, 2008, 20(2): 25-28. [百度学术]
SHAO Z Y, XIE Y M. Application of chemical auxiliaries in hydrogen peroxide bleaching[J]. Paper Chemicals, 2008, 20(2): 25-28. [百度学术]
李亚琳, 邵喜泽, 赵 鹏. 高得率浆的应用及发展研究[J]. 造纸装备及材料, 2020, 185(2): 78. [百度学术]
LI Y L, SHAO X Z, ZHAO P. Application and development of high yield pulp [J]. Papermaking Equipment and Materials, 2020, 185(2):78 [百度学术]