| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To recover ashes containing a filler in a good yield from a pulp slurry originated from waste newspaper. <P>SOLUTION: This method for producing deinked pulp originated from waste newspaper, including adding an additive for producing the deinked pulp to a pulp slurry originated from the waste newspaper on a deinking treatment, is characterized by adding an additive for producing the deinked pulp to the pulp slurry after a flotation process and before a process for dehydrating the pulp slurry, wherein the additive is a combination of (A) a substance for converting a water-soluble silicate into a slightly soluble silicate with (B) a water-soluble polymer; (A) the substance is selected from inorganic acids, 1 to 4C organic acids, polyvalent metal salts, polyvalent metal hydroxides, polyvalent metal salt condensation products, and the like; and (B) the water-soluble polymer is selected from amphoteric polymers, cationic polymers, and anionic polymers. Thus, atomized or dissolved silicate-based fillers much contained in the deinked pulp originated from the waste newspaper are again converted into insoluble substances with the component (A), and the insoluble substances are smoothly coagulated with the component (B). Therefore, the ashes containing the fillers can be recovered in a good yield. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
