钛渣酸解过程中物相变化特征探讨

明确物相变化是剖析钛渣酸解机理和改进酸解工艺的关键点之一。综合应用化学分析、X射线衍射(XRD)分析、矿物解离分析以及扫描电镜形貌分析对某74钛渣酸解过程中主要物相的含量、形貌变化以及Ti、Si两种元素的含量及赋存变化进行了研究。结果表明:钛渣主要由黑钛石和辉石组成,酸解过程中黑钛石含量逐渐减小,辉石含量逐渐增加;反应过程中,酸主要以扩散的形式渗透到黑钛石颗粒表面及内部孔缝,从而分解黑钛石;酸解前后,辉石形貌无明显变化,但随反应深入,其解离度逐步提高;钛渣中Ti元素主要赋存于黑钛石中,Si元素主要赋存于辉石中,部分赋存于黑钛石和黑钛石-辉石混合物中,反应过程中Ti元素主要由黑钛石向TiOSO₄迁移,部分迁移至黑钛石-辉石混合物中;Si元素迁移并主要富集于辉石以及黑钛石-辉石混合物中。

Discussion on phase transformation characteristics of titanium slag during acidolysis

The confirmation of phase transformation is one of key points to analyze the acidolysis mechanism of titanium slag and improve the acidolysis process.The content and morphology changes of the main phases,and the content and occurrence changes of Ti and Si in the acidolysis of 74 titanium slag were comprehensively studied by chemical analysis,X-ray diffraction (XRD) analysis,mineral liberation analysis and scanning electron microscope (SEM) morphology analysis.The results showed that the titanium slag was mainly composed of anosovite and augite.The content of anosovite decreased gradually and the content of augite increased gradually during acidolysis.In the reaction process,the acid permeated into the surface and internal pores and cracks of anosovite particles in the form of diffusion to decompose the anosovite.There was no significant change in the morphology of augite before and after acidolysis,but its liberation degree gradually increased along with the reaction.In titanium slag,the Ti element mainly existed in anosovite,while the Si element mainly existed in augite,and partly existed in anosovite and the mixture of anosovite and augite.In the reaction,the Ti element mainly was migrated from anosovite to the TiOSO₄,and partially migrated to the mixture of anosovite and augite;the Si element was migrated and mainly enriched in the augite and the mixture of anosovite and augite.