13. The method according to any one of claims 9 to 12, wherein a pH of the first mixture in the first process is adjusted to be in a range of 10 to 11, and a pH of the second mixture in the second process is adjusted to be in a range of 11.5 to 12.0.
the first process
pH
in a range of 10 to 11
the second process
pH
in a range of 11.5 to 12.0