Salvage kits are used to attain crafting materials ( basic items like diamond or gold bar/platinum bar by salvaging a diamond ring) from salvageable items (ex: diamond ring) . The item is always destroyed in the process.
You can find salvage kits in chests or buy them from the coming ships or find them in the fishing net.
1 salvage kit should have multiple charges .
If you like my suggestion fell free to ask for more details
