To enable the effect of an aluminum compound such as aluminum sulfate to effectively be exhibited by adding a low-concentrated liquid mixture of a polyacrylamide-based polymer with a water-soluble aluminum compound to pulp slurry and by dividedly adding the water-soluble aluminum compound before and after the above addition.
This process for papermaking comprises a combination of the following two steps: adding to pulp slurry a liquid mixture where a low- concentrated liquid of 0.1-10 wt.% (preferably 0.2-3 wt.%) of at least one kind selected from amphoteric, cationic or anionic polyacrylamide-based polymers is blended with a water-soluble aluminum compound such as aluminum sulfate in an amount of 0.1-200 mol% (preferably 10-100 mol%) in terms of aluminum ion based on the above polymer; and before and after the above addition, dividedly adding the water-soluble aluminum compound in both vicinities of a machine chest and a fan pump.
MATSUNO HIDEKAZU
YOSHIKAWA KAZUHIDE
