ABRASIVE PLATES IN HIGH CONSISTENCY 2ND STAGE REFINING

Commercial and pilot plant trials were carried out to assess the appli cation of abrasive plates in high consistency mechanical pulp refining . Flat abrasive plates were evaluated in second stage refining on both single and double-disc refiners. In addition, for single-disc refinin g, plates with abrasive on the bar surfaces in or the grooves were tri ed. Because the grits on the surface tended to wear off rapidly, only the plates with abrasive in the grooves were selected for an extended mill trial. These plates approached the normal operating life of conve ntional Ni-Hard plates. Surprisingly, however, although the plates tes ted in these trials were a radical departure from conventional plates, the energy-quality relationships of the pulp for all the abrasive pat terns involved, were essentially those obtained for refining with conv entional plates.