Al 99.5%

Al 99.5% is a high-purity aluminum (≥99.50% Al), equivalent to grade 1050/1050A (EN AW-1050A). It is used as a deoxidizer in steel processes, especially in special steels, stainless steels, and tool steels where deoxidizer purity is critical. It is supplied in donuts and pieces for direct feeding into liquid steel.

It contains a minimum of 99.50% aluminum. Impurities are kept low: iron (Fe) ≤0.40%, silicon (Si) ≤0.25%, and copper (Cu), manganese (Mn), and zinc (Zn) each ≤0.05%. The low Si and Fe content minimizes the traces incorporated into the steel during deoxidation.

Al 99.5% offers higher purity than Al 95%, so it adds fewer traces of silicon, iron, and other elements to the steel. Al 95% is more economical, while Al 99.5% represents a compromise between that cheaper grade and primary aluminum (even purer). Al 99.5% is chosen when the steel process demands less contamination in the final steel.

When deoxidizing liquid steel, the aluminum dissolves into the bath and any accompanying impurity (silicon, iron, copper, etc.) can be incorporated into the steel. In special, stainless, and tool steels, those traces affect the final composition and properties, so a high-purity deoxidizer like Al 99.5% is important in secondary metallurgy and refining processes requiring minimal contamination.

It is manufactured in donuts and pieces designed for direct feeding into the furnace or liquid steel. Its density is 2.71 g/cm³ and it melts at approximately 658 °C, which aids rapid dissolution in the bath. As a high-purity aluminum, its electrical conductivity is ~60% IACS.

Because of its high purity (≥99.50% Al, with Fe ≤0.40% and Si ≤0.25%), Al 99.5% requires primary aluminum feedstock or another source of equivalent purity; recycled wheel aluminum is a casting alloy (A356.2) with too much silicon to reach this grade. TP manufactures Al 99.5% in donuts and pieces, commercializing it for steel customers producing special steels where deoxidizer purity is critical.