Zheng Zhuang, You Yang, Guo Jiabao, Li Gang, You Zhixiong, Lv Xuewei
College of Materials Science and Engineering, Chongqing University, Chongqing 400044, China.
ACS Omega. 2022 Aug 8;7(33):29116-29124. doi: 10.1021/acsomega.2c02991. eCollection 2022 Aug 23.
The transformation behavior of pyrite (FeS) in the blast furnace process is critical to control the formation and emission of gaseous sulfides in the top gas of ironmaking but has seldom been explored. In present work, the pyrolysis of pyrite from 200 to 900 °C under a CO-H atmosphere was investigated by thermal-gravimetric and mass spectrometry. The thermodynamic theoretical calculations were carried out to further understand the transformation process. The results show that FeS is almost completely reduced to FeS under various CO-H atmospheres. HS and carbonyl sulfide (COS) are the main gaseous sulfides formed through the pyrolysis reactions of FeS under a CO-H atmosphere. A higher H concentration can reduce the pyrolysis reaction temperature of FeS, which is favorable for the conversion of sulfides to HS, while a higher CO concentration promotes the conversion of sulfides to COS. Besides, the pyrolysis products of FeS by order from the former to latter under a strong reductive atmosphere (CO-H) with increasing temperature are as follows: COS → S → HS → S → CS.
在高炉炼铁过程中，黄铁矿（FeS）的转化行为对于控制炼铁炉顶煤气中气态硫化物的形成与排放至关重要，但这方面的研究却很少。在本研究中，通过热重分析法和质谱分析法，对黄铁矿在200至900°C的CO-H气氛下的热解过程进行了研究。进行了热力学理论计算，以进一步了解转化过程。结果表明，在各种CO-H气氛下，FeS几乎完全还原为FeS。HS和羰基硫（COS）是在CO-H气氛下通过FeS的热解反应形成的主要气态硫化物。较高的H浓度可以降低FeS的热解反应温度，这有利于硫化物转化为HS，而较高的CO浓度则促进硫化物转化为COS。此外，在强还原气氛（CO-H）下，随着温度升高，FeS的热解产物依次为：COS→S→HS→S→CS。
