salt mine vs occupation

salt mine and occupation both are nouns.

Word	Noun	Adjective	Verb	Adverb
salt mine	Yes	No	No	No
occupation	Yes	No	No	No

As nouns, occupation is a hypernym of salt mine; that is, occupation is a word with a broader meaning than salt mine:

Other hypernyms of salt mine include business, job, line, line of work.

salt mine (noun)	occupation (noun)
a job involving drudgery and confinement	the principal activity in your life that you do to earn money
a mine where salt is dug	the act of occupying or taking possession of a building
	the control of a country by military forces of a foreign power
	any activity that occupies a person's attention
	the period of time during which a place or position or nation is occupied