<p>The decomposition behavior and kinetics of Ti-containing melting slag in the alkali fusion process has been investigated. The results indicated that the alkali fusion temperature, slag–alkali mass ratio (<i>R</i>_slag/NaOH), and alkali fusion time had significant effects on the element conversion of Ti-containing melting slag. Specifically, at an alkali fusion temperature of 650°C, with an <i>R</i>_slag/NaOH of 1:1.1 and an alkali fusion time of 50&#xa0;min, the element conversion rates for titanium, magnesium, silicon, and calcium exceeded 98%. Furthermore, the decomposition kinetics of Ti-containing, Al-containing, and Cr-containing phases during the alkali fusion process has been examined, and the findings revealed that the decomposition of Ti-containing melting slag followed the unreacted shrinking core model. The conversion process for Ti, Al, and Cr was controlled by mixed control, mixed control, and solid product layer diffusion control, with the apparent activation energies of 34.899, 19.459, and 9.577&#xa0;kJ/mol, respectively. Additionally, the decomposition kinetics equations for the Ti-containing phase, Al-containing phase, and Cr-containing phase were established.</p>