Aplication and the role of permanganate as a new bleaching agent

高锰酸盐作为一种新的化学浆漂白剂进行了试验，得到了一些有趣的结果。用高锰酸盐对阔叶木KP和OKP进行漂白，K值下降较大。高锰酸盐漂白的粘度也随着高锰酸盐用量的增加而降低。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K值相同的情况下，中性条件下高锰酸盐漂白比酸性条件下漂白的纸浆具有更高的强度性能。高锰酸盐漂白后，KP浆的质量高于OKP浆。结果表明，氧预漂白阶段是高锰酸盐漂白所必需的。无论如何，高锰酸盐漂白的纸浆性能优于臭氧漂白的纸浆。在中性条件下，高锰酸盐漂白的纸浆需要在酸性介质中用还原剂处理。这种后处理充分利用了草酸的酸性和还原剂的作用。臭氧漂白高锰酸盐漂白纸浆容易提高其白度。结果表明，漂白过程中不仅可以去除元素氯，还可以去除氯化物。

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.