Effect of CaF2 Additions on the Yield of AZ63 Magnesium Chips during Remelting

Abstract

Magnesium is one of the metals listed in European Union’s critical raw materials list. Primary production of magnesium is a high energy demanding process which raised the necessity of recycling the magnesium alloys in an efficient way. Remelting those scraps under a salt flux consist of chlorides (NaCl, KCl, and MgCl2) and fluorides (CaF2) is a common process however, different alloys might behave differently when it comes to salt-metal-metal oxide interactions. Furthermore, the condition of the salt flux such as dry-mixed or pre-melted (fused) affects the coagulation and metal yield. This work presents results on the effect of CaF2 concentration and pre-melting the salt flux on metal yield during remelting of chips. A yield up to 75% was observed in the case of remelting of chips under a fused salt flux with 5.5% CaF2 concentration.