General Introduction:
Flux refining is the old but the most common way of refining magnesium and magnesium scrap.
the flux used for cleaning the underlying metal of impurities is called Refining flux.

Function: 
the combination of magnesium and potassium chlorides provides the low melting eutectic, while the fluoride provides the surface wettability and chemical reactivity with magnesium oxide to cause sufficient removal. MgO increases the viscosity of flux.the barium compound provides the density requirement for the salt to effectively mix with the magnesium and then settle out at the bottom of the crucible. 

 

in powder or granule form 

Plays an important role in improving the quality if magnesium and magnesium alloy castings