Chromium leaching from stainless steel tailings is an urgent problem risking of the environments, calcite integument of tailings by accelerated direct gas-solid carbonation process can be formed and the inhibition factor of carbonation degree on chromium leaching rate is discussed in detail. Stainless steel tailings accelerated direct gas-solid carbonation process is investigated at 300 degrees C-700 degrees C and 0.2-0.4 MPa, and the effect of temperature, reaction time, particle size and CO2 pressure on carbonation degree are analyzed by TGA-DSC, FTIR, SEM-EDS analysis. The results show that the maximum CO2 uptake obtained (8.2%), corresponding to 16% carbonation degree can be obtained when 48-75 mu m stainless steel tailings are carbonated for 90 min at 300 degrees C and 0.4 MPa. Tailings particle size, carbonation time, and carbon dioxide pressure display a positive relationship with carbonation degree, but carbonation temperature has a negative relationship. 48-75 mu m carbonated tailings with varied carbonation degree and original tailings are investigated for the inhibitory factor between carbonation degree and Cr leaching rate, when leaching process is at 60 degrees C for 90min on the condition that L/S ratio equals 20 ml/g. The results show the inhibitory factor is fitted by random function better, and the value decreases from 31.5% to 9.7%, when carbonation degree is from 2% to 8%, and then keeps stable, when carbonation degree is still increases from 8% to 14%, which illustrates that carbonation process as a better strategy of tailings innocuous treatment at high temperature is valid for restricting Cr leaching behavior. (C) 2018 Elsevier Ltd. All rights reserved.