The effects of sampling temperature on the variation of phosphorus content in molten copper before and after casting

Abstract

This study explores the challenges faced in producing pure copper (99.9999% IACS) from secondary scrap, emphasizing the significance of preventing oxidation during the melting and casting process. Due to more clout for sustainability of metals that are finite, it is imperative to make use of metals such as copper to their full potential, this can be done by implementing systems, improving parameters and processes that allow for the metal to be recyclable without losing its properties Specifically, the research investigates the effects of sampling temperature and consistent diffusion time on phosphorus variations of 15% Phosphorus-85% Copper blocks melted in a channel induction furnace. The study showed that sampling at higher temperatures (1200<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">o</sup>C), with consistent diffusion time of 900 seconds, resulted in a slight increase in phosphorus consistency, however, it caused a higher chance for the furnace to overheat resulting in mechanical failure, and its statistical process control (SPC) proved to be out-of-control, showing casts with phosphorus out of specification. While sampling at 1150°C at the same diffusion time improved casting processes and resulted in slabs with electrical conductivity exceeding 99.5% AICS. The SPC demonstrated that sampling temperature and diffusion time significantly influenced phosphorus variations without compromising the microstructure of the as-cast slab. Additionally, the study reveals a decrease in the crystallinity of copper slabs with an increase in phosphorus content.