Selective enrichment of Ti element and phase transformation of MgAl₂O₄ in titanium-containing electric furnace molten slag during the alkali fusion process

Using potassium hydroxide as a modifier, Ti element was selectively enriched in potassium metatitanate from titanium-containing electric furnace molten slag, and magnesium aluminium spinel and forsterite were successfully converted to aluminates and silicates after the alkali fusion reaction between potassium hydroxide and the slag. The effects of calcining time, alkali/slag mass ratio and calcining temperature on the enrichment of Ti element and the phase transformation of magnesium aluminate spinel were investiga-ted by X-ray diffraction analysis. When the alkali/slag mass ratio is controlled at 1:2.1, the calcining temperature is 700℃ and the calcining time is 1 h, the highest diffraction peak of potassium metatitanate and the lowest diffraction peak of magnesium aluminium spinel appear, suggesting that the selective enrichment of Ti element and the phase transformation of magnesium aluminium spinel are efficiently realized. It is verified that a higher molar ratio of K₂O to TiO₂ plays an important role in the formation of potassium metati-tanate. Using this alkali fusion slag obtained under the optimum conditions as raw materials, potassium hexatitanate nanowhiskers can be successfully synthesized by subsequent processing at 850℃.