Sequential Leaching Characteristics of Chromium in AOD Slag-Based Cementitious Materials

Abstract

AOD slag was employed as main raw material, and cement clinker was added into AOD slag to prepare composite cementitious material. The obtained material was subjected to sequential leaching experiment to illustrate the influence of particle size, liquid–solid ratio, initial pH of leaching solution on leaching characteristics of chromium from cementitious material. The results indicated that the fine particle size of the cementitious material has a positive effect on the dissolution of the chromium-bearing mineral, thereby increasing the chromium concentration in the leaching solution. When the liquid–solid ratio was increased from 10:1 to 20:1 and 100:1, the chromium concentration in the leaching solution did not decrease proportionally with the increase of the liquid–solid ratio. The strong acidic and weak alkaline leaching solution possessed a great influence on the dissolution concentration of Cr6+ in the cementitious material, and the leaching risk of chromium cannot be ignored.