不锈钢渣矿化固定CO₂的实验研究

Experimental Study on CO₂ Sequestration by Mineralization of Stainless Steel Slag

摘要: 本实验采用Al₂O₃对不锈钢渣进行改质，并探讨浸出液温度和pH对改质不锈钢渣中Ca、Mg元素浸出行为的影响规律。结果表明：随着不锈钢渣中Al₂O₃含量的增加，铬逐渐向稳定的尖晶石相富集。当Al₂O₃含量达到12%时，铬在尖晶石相中的富集度接近100%。浸出结果认为：反应温度对改质不锈钢渣的浸出行为影响不明显，而浸出液pH对不锈钢渣的浸出行为有着显著的影响。当pH = 2.0时，Ca、Mg元素的浸出率接近70%，但铬有明显的溶出。当浸出液pH大于3.0，不锈钢渣的失重率和Ca、Mg元素的浸出率变化不大，Ca、Mg元素的浸出率稳定在30%左右。块状浸出实验表明Al2O3改质不锈钢渣中浸出液中Ca、Mg主要来源于蔷薇辉石相，而玻璃相、黄长石相及尖晶石的相结构保持稳定。

Abstract: In this experiment, Al₂O₃ was adopted to modify the stainless steel slag and the effect of reaction temperature and pH value of leaching solution on the leaching behavior of Ca, Mg element in Al₂O₃ modified stainless steel slag was deeply discussed. The results showed that Cr gradually enriched into spinel phase with the increase of Al₂O₃ content in stainless steel slag. When 12% Al₂O₃ slag was added, the enrichment degree of Cr in spinel phase could be up to nearly 100%. The leaching results indicated that the effect of temperature on the leaching behavior of stainless steel slag was not obvious, while the influence of pH on the leaching behavior could be obviously observed. When pH value was 2.0, the leaching rate of Ca, Mg could approximately reach to 70%. However, the leaching of chromium occurred. When the pH value was greater than 3.0, the weight loss rate of stainless steel slag and the leaching rate of Ca, Mg basically had no change, and the leaching rate of Ca, Mg was nearly 30%. The leaching test results of large lump sample showed that leaching source of Ca, Mg was mainly from merwinite phase in Al2O3 modified stainless steel slag, while the glass, melilite and spinel phase could exist stably in leaching solution.