热红联用研究高硫铝土矿的氧化焙烧

脱硫是高硫铝土矿资源综合利用的前提，开展高硫铝土矿焙烧反应特征研究是焙烧脱硫技术开发的基础。对含硫量为4.32%的贵州高硫铝土矿开展热分析和傅里叶变换红外(FTIR)光谱分析联用试验，采用TG，DTG，DSC和FTIR联用方法，综合分析、研究了高硫铝土矿在氧化焙烧过程中发生反应的种类、反应历程和主要特征，并讨论了悬浮态脱硫新工艺的开发。采用一种改进的红外光谱分析方法，从混合气体产物的红外吸收光谱中分离出气体组分的流量特征，从而将高硫铝土矿的脱水和脱硫过程分离并进行分析。结果表明，主要反应是一水硬铝石脱水、黄铁矿氧化脱硫和方解石分解，释放的气体产物分别是H₂O(g)，SO₂和CO₂。一水硬铝石脱水为单步反应，温度范围为380~580 ℃，黄铁矿脱硫为两步反应，温度范围为388.0~574 ℃，方解石的分解的温度范围是700~860 ℃。高硫铝土矿脱硫的放热能够直接补偿脱水的吸热，悬浮态脱硫适宜的操作温度为580~650 ℃。研究结果为高硫铝土矿悬浮态脱硫技术开发提供基础数据参考。

Study on the Oxidation Roasting of High-Sulfur Bauxite by DSC-TG-FTIR Coupling

Desulfurization is the prerequisite of high-sulfur bauxite comprehensive utilization. Researches of roasting characteristics of high-sulfur bauxite provide foundations for developing a new desulfurization technology. Coupling test of thermal analysis and Flourier transform infrared (FTIR) spectrum analysis was carried out for high-sulfur bauxite with sulfur content of 4.32% from Guizhou. The types, process and main characteristics of reaction occurring during oxidation roasting process of high-sulfur bauxite were comprehensively analyzed and studied by TG, DTG, DSC and FTIR coupling method, and the development of new desulfurization process with suspension state was discussed. A new approach for infrared spectroscopy analysiswas developed to separate the release features of various components from the infrared spectroscopy of gaseous product mixture, and it was used to separate the desulfurization process and dehydration process of high-sulfur bauxite. Results showed that: The main reactions of high-sulfur bauxite in the roasting process were dewatering of diaspora, oxidation desulfurization of pyrite and decomposition of calcite. The gaseous products of the reaction were H₂O(g), SO₂ and CO₂. Dewatering of diaspora was a single step reaction, which appeared in the range of 380.0~580.0 ℃. The reaction of oxidation of pyrite is two step reaction, and which appeared in the range of 388.0~574.0 ℃. The decomposition temperature range of calcite was at 700.0 to 860.0 ℃. The quantity of desulfurization of high sulfur bauxite can directly compensate the endothermic quantity of the dehydration. The suitable operation temperature for suspension state desulfurization process was 580.0~650.0 ℃. The conclusions of this paper can serve as References developing a new suspension desulfurization technology for high-sulfur bauxite.