Study of the effect of heat treatment of copper slag particles on abrasiveness for abrasive waterjet cutting

Abstract

Abstract The known studies of heat treatment of copper slag are mainly directed to the recovery of metals from copper slag at the melting temperature. The conditions of increasing the strength of copper slag grains as a result of transition from amorphous to crystalline state during heating have not been studied. That is why the paper presents studies of microhardness and cutting properties of copper slag particles after heat treatment. Treatment regimes were assigned after calorimetric measurements of phase transition from amorphous to crystalline state of copper slag grains under isothermal conditions. It was found that for copper slag grains crystallization proceeds in two stages. The first crystallization stage started at 762.6 ℃ (1035.75 K) and the second one at 795.1 ℃ (1068.25 K). Metallographic examination of microslides of copper slag grains after heat treatment at 800 ℃ showed that the HV microhardness value increased 1.5 times. It was found that the use of heat-treated copper slag grains for water jet cutting resulted in an accurate cut and smooth surface compared to the original abrasive. It has been revealed that heat treatment of amorphous copper slag contributed to the appearance of crystallites of sillimanite, pyrope, hematite, and zinc ferrite.