refractory vs intractable

refractory is a noun but intractable is not a noun.

Word	Noun	Adjective	Verb	Adverb
refractory	Yes	Yes	No	No
intractable	No	Yes	No	No

refractory (noun)	intractable (noun)
lining consisting of material with a high melting point; used to line the inside walls of a furnace

refractory (adjective)	intractable (adjective)
stubbornly resistant to authority or control	not tractable; difficult to manage or mold
temporarily unresponsive or not fully responsive to a process or stimulus
not responding to treatment