钛渣熔盐氯化用熔盐体系物相及物性研究

Study on phase and physical properties of molten salt system for chlorination of titanium slag

熔盐氯化法是针对高钙镁钛渣物料而开发的一种四氯化钛制备技术,在长期的生产实践中,发现氯化炉组分控制不当时熔盐会发生严重泡沫化,甚至出现影响生产的喷盐等现象。对此,采用XRD、SEM&EDS、DSCTGA等方法对正常盐和泡沫盐的成分、物相及物性进行深入研究。结果表明,泡沫盐中的氧含量以及水不溶固相物远高于正常盐,固相多以Na_(2)Al_(0.5)Fe_(9.5)O_(15)、Mg_(1.6)Ti_(1.1)O_(4)等复合氧化物形式存在。泡沫盐在300~1280℃的失重率为48.71%,较正常盐低13.73%,熔点呈增大趋势。泡沫盐中氧含量较正常盐高约10%,经高温挥发后残余物为富含铁、镁、铝、硅、钙、氧等元素的不规则颗粒团聚体,而正常盐的残余物则为铁、镁和氧元素均匀分布的致密体。阿基米德法无法满足含固相物的正常盐和泡沫盐密度测定,但可采用体积密度法进行测定,两者密度分别为2.02 g/cm^(3)和1.77 g/cm^(3)。

The molten salt chlorination method is a technique developed specifically for the preparation of titanium tetrachloride using high-calcium magnesium titanium slag materials.During long-term production practices,it has been observed that improper control of the composition in the chlorination furnace can lead to severe foaming of the molten salt,which in turn can result in issues such as salt spray that negatively impact production.To address this issue,a comprehensive study was conducted to investigate the composition,phase,and physical properties of both normal and foaming chlorination salts using analytical techniques including XRD,SEM&EDS,and DSC-TGA.The results reveal that the foaming salt has a significantly higher oxygen content and a greater presence of insoluble solid phase components compared to the normal salt.The insoluble solid phase components primarily consist of compound oxides such as Na_(2)Al_(0.5)Fe_(9.5)O_(15)and Mg_(1.6)Ti_(1.1)O_4.Additionally,the foaming salt exhibits a weight loss rate of 48.71%in the temperature range of 300~1280°C,which is 13.73%lower than that of the normal salt.Furthermore,the melting point of the foaming salt shows an increasing trend.The oxygen content in foam salt is about 10%higher than that of normal salt.After volatilization at high temperatures,the residue is irregular particle agglomerates rich in iron,magnesium,aluminum,silicon,calcium,oxygen,and other elements,while the residue of normal salt is a dense body of uniform iron,magnesium,and oxygen elements.Traditional Archimedean methods are unable to accurately measure the density of both normal and foaming salts due to the presence of insoluble solid phase materials.However,the volume density method can be utilized,yielding density values of 2.02 g/cm^(3)and1.77 g/cm^(3)for the normal and foaming salts,respectively.