Heats up, after slip welcomes end of Phil Salt (8)

'salt' is the definition.
(sulphate is a kind of salt)

'heats up after slip welcomes end of phil' is the wordplay.
'after' says to put letters next to each other.
'slip' is an anagram indicator.
'welcomes' indicates putting letters inside (in sense of 'invites in').
'end of' says to take the final letters.
The last letter of 'phil' is 'l'.
'heats'+'up'='heatsup'
'heatsup' anagrammed gives 'suphate'.
'suphate' going around 'l' is 'SULPHATE'.