摘要
采用聚焦光束反射测定仪、膜分离与紫外分光光度计相结合的方法,研究了黑液体系中电解质对桦木硫酸盐木素溶解性能的影响。实验结果表明:Ca2+、Mg2+、Mn2+和Al3+对黑液中的木素溶解性能均有影响,4种离子都有明显的临界聚沉浓度,Ca2+和Al3+的临界聚沉浓度较大,分别为0.0375 mol·L-1和0.0309 mol·L-1,Mg2+和Mn2+的临界聚沉浓度较小,分别为0.00625 mol·L-1和0.00399 mol·L-1;黑液中金属离子的浓度达到临界浓度之前,颗粒数增加不大,但黑液的吸光度减少百分比会随着黑液中金属离子浓度的增加而略有增大,当黑液中的金属离子浓度超过临界浓度时,黑液的吸光度减少百分比和颗粒数量都急剧增加;NaCl对有效碱为7.94 g·L-1(以NaOH计)的黑液中木素的溶解性几乎没有影响,几种酸根离子(SO42-、NO3-、SiO32-、CO32-)对黑液中木素溶解性能影响较小。
Lignin has the characteristic of the colloid. Tne effects of electrolytes on the solubility of kraft lignin of birch in black liquor were determinated by focused-beam reflectance measurement（FBRM） instrument, filtration through track membranes and UV spectrum, q-he results showed that Ca^2＋, Mg^2＋ 、 Mn^2＋ and Al^3＋ had effects on the solubility of lignin in the black liquor. Four kinds of electrolytes all had obvious critical coagulation concentration（CCC）. Ca^2＋ and Al^3＋ had higher critical coagulation concentrations than Mg^2＋ and Mn^2＋. The CCC of Ca^2＋, Mg^2＋, Mn^2＋ and Al^3＋ were 0.0375 mol·L^-1, 0.0309 mol·L^ -1 0.00625 mol·L^-1 and 0.00399 mol·L^-1 respectively, The relative number of particles increased slowly when the concentration of electrolytes were lower than CCC, and the reduction rate of UV absorbance increased slightly with the increasing of electrolytes concentration. The reduction rate of UV absorbance and the relative number of particles increased sharply when the concentration of electrolytes added into the black liquor were higher than CCC. NaC1 had no significant effect on the solubility of lignin in the black liquor with residual effective alkaline of 7.94 g·L^- 1（ as NaOH ） ; some kinds of acid radical anions （ SO4^2-, NO3^2- , SiO3^2- , CO3^2- ） had slight effects on the solubility oflignin.
出处
《纸和造纸》
北大核心
2014年第10期25-30,共6页
Paper and Paper Making
