| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing composite particles using regenerated particles capable of improving whiteness of paper while restraining thickening of slurry and keeping its yield high when it is added to the paper as a filler.SOLUTION: A method for producing composite particles includes a compounding process in which silica and aluminum oxide are compounded to regenerated particles with an alkali silicate, a mineral acid and an aluminum salt. The aluminum salt is preferably sodium aluminate. This compounding process preferably has a slurry preparation process in which slurry containing the regenerated particles and the alkali silicate is obtained, a first reaction process in which a mineral acid is added to the slurry and a second reaction process in which sodium aluminate and the mineral acid are added to the slurry. |
