The refinement amalgamator is a combiner of refinements of the exact same description, and works in a similar fashion as a scroll binder with power scrolls. It has a blue interior when it is empty, and turns orange when double clicked and you target the refinement. For example you might have 2 refinements "Scour Of Defense, Armor Type: Chainmail" pieces. In classic client with the amalgamator and 2 identical refinements in your main backpack, double clicking the amalgamator and targeting both pieces will turn them into a single Scour Of Protection, Armor Type: Chainmail, emptying the amalgamator and turning it blue again.
Combine 3 Scour of Protection pieces of identical armor type to make a Scour Of Hardening. Four of the same armor Scour Of Hardening pieces will yield a Scour Of Fortification refinement. Finally using the amalgamator on five Scour Of Fortification pieces will give you the Scour of Invulnerability. One cannot combine two Scour Of Defense with different armor types like chainmail with ringmail. Nor can you make a refinement from targeting the Scour Of Defense with a Polish Of Defense even if it is the same armor type. Takes a lot of patience to get the Invulnerability pieces. Good luck!