摘要
Spinel is an appropriate phase for sequestrating chromium in stainless steel slag to prevent chromium from polluting,and the crystal size of spinel has a significant effect on the stability of chromium and the extraction efficiency of spinel.The enrichment behavior of chromium in spinel during cooling process was investigated,and the growth process of spinel was studied based on the crystal size distribution theory.The results showed that the enrichment degree of chromium in spinel increased from 88.5% to nearly 100% during the cooling process from 1773 to 1573 K at a rate of 5 K/min.The mean diameter of spinel in stainless steel slag had an obvious growth in the cooling process,and a rapid growth of spinel occurred during the cooling process from 1623 to 1523 K.Leaching results indicated that the leaching amount of chro- mium could reduce to less than 0.01 mg/L by controlling the cooling condition.The growth mechanism of spinel was investigated and proposed to consist of two stages:in the first stage,the spinel was in the surface-controlled growth with a decaying nucleation rate from 1773 to 1573 K,and in the second stage,the growth mechanism was transformed to supply- controlled Ostwald ripening-below 1573 K.
基金
National Key R&D Program of China (No. 2017YFC0805100)
National Natural Science Foundation of China (Project No.51704068 and 51374059)
China Postdoctoral Science Foundation (No.2017M610184)
Fundamental Research Funds for the Central Universities (No.N172504020)
Postdoctoral Foundation of Northeastern University (No.20170305).
