Removal of Tin from Steel Scrap Using Iodine Gas

When recycling scrap iron, impurities that are difficult to remove, called trump elements, become a problem. Among them, tin (Sn) has many opportunities for contamination and affects the processability of steel, so new removal methods are needed. Sn is highly reactive with iodine(I) and becomes a metal iodide gas at high temperatures. The purpose of this was to remove Sn from iron scrap using I. We prepared Carbon-saturated iron containing 2 mass% Sn as a sample, weighed 0.1 g, and put it into the furnace. I₂ gas was then injected into the furnace. The Sn concentration and Sn removal rate were calculated by dissolving the sample after the experiment and performing analysis by ICP-OES. As a result, the Sn concentration in the sample was reduced to 0.008%, and the removal rate was up to 99.5%.