Aplication and the role of permanganate as a new bleaching agent

本文研究了过氧化氢作为化学浆的一种新的漂白剂，得到了一些有趣的结果：用过氧化氢漂白阔叶木KP和OKP，使K值有较大的降低。随着高锰酸盐用量的增加，高锰酸盐漂白的粘度也降低。高锰酸盐漂白采用中性条件时，粘度下降幅度较大，K值较高。在相同K值下，高锰酸盐漂白中性条件比酸性条件具有更高的强度。KP浆经高锰酸盐漂白后，纸浆质量优于OKP浆。由此可见，氧预漂是高锰酸盐漂白的必要步骤。在中性条件下，高锰酸盐漂白的纸浆需在酸性介质中用还原剂处理。用草酸作为酸和还原剂充分进行后处理，臭氧漂白易提高高锰酸盐漂白浆的白度。结果表明，漂白工序不仅可以去除单质氯，而且可以去除氯化合物。

Permanganate was examined as a new bleaching reagent for chemical pulp and some interesting results were obtained.Bleaching of hardwood KP and OKP with perman-ganate resulted in a greater reduction in K value. Viscosity were also decreased by permanganate bleaching with increasing the charge of permanganate. As employing neutral condition in permanganate bleaching, the drop in viscosity was improved, resulted in higher K value. Comparing at the same K value, neutral condition in permanganate bleaching gave the pulps with higher strength properties than acidic condition. KP gave higher quality pulps after permanganate bleaching than Okp. From this result, oxygen prebleaching stage found to be necessary for permanganate bleaching. In any case, permanganate bleaching gave the pulp with superiorproperties to pulp bleached with ozone.In neutral condition, bleached pulp with per-manganate required to treat with reductant in acidic medium. This post treatment was carried out sufficiently with oxalic acid which playd the role as a acid and a reductant.Brightness of permanganate bleached pulp wereeasily increased with ozone bleaching. The result indicates that not only elementary chlorine but chlorine compounds could be eliminated from bleaching sequence.