REFRACTORY

adj. stubborn, obstinate; resistant to usual treatments; difficult to fuse or process

The term refractory refers to the quality of a material to retain its strength at high temperatures. Refractory materials are used to make crucibles and linings for furnaces, kilns and incinerators. There is no clearly established boundary between refractory and non-refractory materials, though a practical requirement often cited is the ability of the material to withstand temperatures above 1100 °C without softening.
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Noun
1. lining consisting of material with a high melting point; used to line the inside walls of a furnace
(synonym) furnace lining
(hypernym) lining
(substance-meronym) fireclay
Adjective
1. resistant to authority or control; "as refractory as a mule"
(similar) uncooperative
2. not responding to treatment; "a stubborn infection"; "a refractory case of acne"
(synonym) stubborn
(similar) intractable
(classification) medicine, medical specialty
3. marked by stubborn resistance to and defiant of authority or guidance; "a recalcitrant teenager"; "everything revolves around a refractory individual genius"
(synonym) recalcitrant
(similar) intractable
4. stubbornly resistant to authority or control; "a fractious animal that would not submit to the harness"; "a refractory child"
(synonym) fractious
(similar) disobedient

(n.)
Refractoriness.
  

(n.)
OPottery) A piece of ware covered with a vaporable flux and placed in a kiln, to communicate a glaze to the other articles.
  

(n.)
A refractory person.
  

(a.)
Resisting ordinary treatment; difficult of fusion, reduction, or the like; -- said especially of metals and the like, which do not readily yield to heat, or to the hammer; as, a refractory ore.
  

(a.)
Obstinate in disobedience; contumacious; stubborn; unmanageable; as, a refractory child; a refractory beast.
  

Not yielding (at least not yielding readily) to treatment.

Anemia (a shortage of red blood cells) unresponsive to treatment.