Synthesis of potassium hexatitanate whiskers with high thermal stability from Ti-bearing electric arc furnace molten slag

Abstract Potassium hexatitanate (K 2 Ti 6 O 13 ) whiskers with excellent dispersity were synthesized from titanium-bearing electric arc furnace molten slag (Ti-bearing EAF slag) by calcination method in this paper. The effects of TiO 2 to KOH molar ratios ( R TiO 2 KOH ), calcination temperature and duration on the micromorphology and crystallinity of as-prepared K 2 Ti 6 O 13 whiskers were systematically investigated. The results indicated that well disperse and relatively pure K 2 Ti 6 O 13 whiskers were synthesized when the calcination temperature was 900 °C and calcination time was 300 min with R TiO 2 KOH value at 1.75. The diameter of prepared whiskers was larger with the increase of calcination temperature from 850 to 1100 °C and time from 10 to 300 min. At the same time, the morphology of prepared K 2 Ti 6 O 13 whiskers transformed from fibrous structure to rod-like structure. In addition, the thermal stability of K 2 Ti 6 O 13 whiskers was also discussed under optimum conditions by using TG-DSC analysis. It is shown that the product exhibited excellent thermal stability and K 2 Ti 6 O 13 whiskers would not decompose up to about 1430 °C.