Refiner

verb (used with object), refined, refining.
1.
to bring to a fine or a pure state; free from impurities:
to refine metal, sugar, or petroleum.
2.
to purify from what is coarse, vulgar, or debasing; make elegant or cultured.
3.
to bring to a finer state or form by purifying.
4.
to make more fine, subtle, or precise:
to refine one’s writing style.
verb (used without object), refined, refining.
5.
to become pure:
The silver is refining in the furnace.
6.
to become more fine, elegant, or polished:
His parents hope that his manners will refine as he gets older.
7.
to make fine distinctions in thought or language.
Verb phrases
8.
refine on/upon, to improve by inserting finer distinctions, superior elements, etc.:
to refine on one’s previous work.
noun
1.
a person, device, or substance that removes impurities, sediment, or other unwanted matter from something
verb
1.
to make or become free from impurities, sediment, or other foreign matter; purify
2.
(transitive) to separate (a mixture) into pure constituents, as in an oil refinery
3.
to make or become free from coarse characteristics; make or become elegant or polished
4.
(transitive) often foll by out. to remove (something impure or extraneous)
5.
(intransitive; often foll by on or upon) to enlarge or improve (upon) by making subtle or fine distinctions
6.
(transitive) to make (language) more subtle or polished

refine re·fine (rĭ-fīn’)
v. re·fined, re·fin·ing, re·fines
To reduce to a pure state; purify.

The process of refining metals is referred to by way of illustrations in Isa. 1:25; Jer. 6:29; Zech. 13:9; Mal. 3:2, 3.