| 摘要 |
<p>A method for bleaching pulp includes introducing a bleaching liquor in at least one refiner to contact lignocellulosic particulates processed therein in the formation of pulp, wherein the bleaching liquor includes at least one peroxide, magnesium sulfate, caustic hydroxide, at least one chelating agent, and less than 0.1%, or less than 0.01%, or less than 0.001% by weight silicate based on dry weight of the lignocellulosic particulates. Magnesium perhydroxide is generated in situ in the refining system with bleaching of the particulates during refining and reduced scale occurs by use of the silicate or essentially silicate free conditions. A free or essentially silicate-free bleaching liquor which can provide highly brightened pulps also is described.</p> |
