Scripture has several references to dross. For example:
You have removed all the wicked of the earth like dross; Therefore I love Your testimonies. (Psalm 119:119)
Take away the dross from the silver, And there comes out a vessel for the smith; Take away the wicked before the king, And his throne will be established in righteousness. (Proverbs 25:4-5)
Like an earthen vessel overlaid with silver dross Are burning lips and a wicked heart. (Proverbs 26:23)
There is a frightening warning found for Isra'el in Ezekiel 22:
"Son of man, the house of Israel has become dross to Me; all of them are bronze and tin and iron and lead in the furnace; they are the dross of silver. Therefore, thus says the Lord GOD, 'Because all of you have become dross, therefore, behold, I am going to gather you into the midst of Jerusalem. As they gather silver and bronze and iron and lead and tin into the furnace to blow fire on it in order to melt it, so I will gather you in My anger and in My wrath and I will lay you there and melt you. I will gather you and blow on you with the fire of My wrath, and you will be melted in the midst of it. As silver is melted in the furnace, so you will be melted in the midst of it; and you will know that I, the LORD, have poured out My wrath on you.'" (Ezekiel 22:18-22)
May we be cleansed and purified from our sinful tendencies and know that "He who began a good work in you will perfect it until the day of Messiah Yeshua." (Philippians 1:6).