New refining flux launched to remove ultra-fine oxides
Aluminium Casthouse Technologies (ACT) has launched a pioneering new granular refining flux for removing highly-damaging, ultra-fine particles that lead to blocked filters and aborted casts from the melt.
While existing fluxes designed for removing inclusions and reducing dross on the market can cope with removing particles above 15 microns in size, new Refinal HAL F7 can remove particles below 12 microns.
These include very fine oxides that are commonly found in light scrap used in remelts.
A key component of the new flux is the addition of a high activity fluoride, which enhances performance and increases efficiency.
John Courtenay, co–director of ACT and former technical director of Foseco Aluminium, said the new product was the next big thing in flux innovation.
“Before magnesium chloride refining fluxes such as ACT’s Refinal range came along, traditional practice was to inject chlorine gas into melting or holding furnaces to reduce hydrogen and alkali metals, as well as metallic and non-metallic inclusions,” he said.
“But in shallow furnaces, this created large bubbles and low residence time, resulting in acid gas and toxic particulates and presenting major health and safety concerns. Our Refinal flux range gives casthouses an environmentally-friendly alternative, with other advantages including cost savings.
“However, while highly effective at removing alkalis, these fluxes do not produce a dry dross and are not effective at removing fine oxide inclusions. We hope our new product will help casthouses reduce their aborted casts massively.”
Refinal HAL F7 was instigated by industry legend Bob Wagstaff, former head of research at aluminium giant Novellis, who introduced ACT to the product at TMS in 2024. This resulted in a collaboration and successful trials with a remelt customer in the UK, where the recipe was further enhanced by ACT and developed for market.
“Bob created something quite extraordinary and we are excited at the prospect of getting it out there to casthouses, helping those using increasing amounts of light scraps in their charge make ups,” said John.
“We started this company as we wanted to revolutionise our part of the industry, reduce waste and poor quality material and ensure better quality finished products across the board and Refinal HAL 7 is the next step in this.”
As well as Refinal HAL F7, the flux range includes Refinal 350 – based on a minimum 35% magnesium chloride, Refinal 352XF – based on a minimum 35% magnesium chloride with the addition of fluoride, further enhancing performance and increased efficiency by up to 25%, and Refinal 565XF – based on partial substitution of the potassium chloride content with up to 30% sodium chloride to increase cost effectiveness.
