Refinement is a process of making physical metal pure by physically heating it until it melts. The impurities are then skimmed off the top of the liquid, molten metal. Refinement is an extension of purification by fire and makes things not just pure, but MORE pure. The more times a metal is refined, the more pure it gets. Refinement is also called "tried" or "try". This is how the "trials" of affliction serve to purify. And, this is how the "trial" of judgment will act as the Lake of Fire, to cleanse.

Yahweh's words (spiritual fire and water) are so pure that they are the equivalent of seven times refined (purified).

The words of Yahweh are pure words like silver refined in the crucible on the ground, refined seven times. Psalms 12:6

For thou, O Elohim, hast proved us: thou hast tried us, as silver is tried [refined]. Thou broughtest us into the net; thou laidst affliction upon our loins. Thou hast caused men to ride over our heads; we went through fire and through water: but thou broughtest us out into a wealthy place. Psalms 66:10-12

As they gather silver, and brass, and iron, and lead, and tin, into the midst of the furnace, to blow the fire upon it, to melt it; so will I gather you in mine anger [long-suffering Strongs # 00639 forebearing, forehead, + (long-)suffering, nose, nostril, snout, X worthy, wrath] and in my fury [heat, indignation], and I will leave you there, and melt you. Ezekiel 22:20

Literal physical heat melts literal physical silver for refinement. Yahweh is telling His people, through the prophet Isaiah, that He will refine His people, NOT by the literal fire used to refine silver, but in a figurative spiritual fire, a furnace of affliction.

For my name's sake [Yahweh] will I defer mine anger, and for my praise will I refrain for thee, that I cut thee not off. Behold, I have refined thee, but not with silver; I have chosen thee in the furnace of affliction. Isaiah 48:9-10

Malachi repeats the promise that He will purify His people. Here again, He uses the metaphor of a refiner's fire, saying that He, Himself, is like a refiner's fire. He is also like fuller's soap. This is lye soap used by someone working with wool (a fuller), to cleanse the wool of oil and impurities. In both cases, purification implies spiritual cleaning, NOT punishment, anger, or destruction.

And who can endure the day of his coming? And who is the one who can stand when he appears? For he is like a refiner’s fire, like launderers’ alkali. He will sit as a refiner and purifier of silver; he will purify the children of Levi, and he will refine them like gold and like silver, and they will present to Yahweh offerings in righteousness. Malachi 3:2-3

The prophet Zechariah says that Yahweh will bring a third part through fire. I don't completely understand this prophecy, but this I do know. Yahweh says that He will purify and refine (some third) by fire. Again we see refinement (not destruction or punishment) of His people by a metaphorical fire.

And I [Yahweh] will bring the remaining third into the fire, and I will refine them like one refines silver, and I will test them like one tests gold. They will call my name, and I will answer them. I will say, ‘They are my people,’ and they will say, ‘Yahweh is my Elohim.’ ” Zechariah 13:9

We are counseled to buy pure gold (refined by fire) and white raiment. These are all metaphors (figurative). The gold is figurative, the raiment is figurative and the fire is figurative (spiritual).

I counsel thee to buy of me gold tried in the fire, that thou mayest be rich; and white raiment, that thou mayest be clothed, and that the shame of thy nakedness do not appear; and anoint thine eyes with eyesalve, that thou mayest see. Revelation 3:18