I've noticed the Spanish hyphenation dictionaries available for LibreOffice work mostly well, but still break some words wrong from time to time. After searching for an alternative, I've found this Spanish hyphenation dictionary based on the TeX hyphenation patterns that seems to work better. I haven't yet found a single hyphenation mistake.
I've found it here:
https://github.com/vicamo/b2g_releas...es/hyphenation
It's released under the Mozilla Public License (details of the license inside the zip).