2026 年 112 巻 11 号 p. 551-558
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%.