Effect of Na₂SO₄ on ilmenite, black sand Langkawi by carbothermal reduction and nitridation

In this paper, the effect of catalyst, Na₂SO₄ and temperature on carbothermal reduction and nitridation of Langkawi black sand was investigated. Reduction was performed under 100% nitrogen gas (N₂) with a temperature range of 1200 °C - 1400 °C for 3 hours soaking time respectively. Four different amount of catalyst, Na₂SO₄ range from 0% to 15% were investigated in the reaction. By adding of Na₂SO₄, it is slightly down the reaction temperature from 1400 °C to 1200 °C by using at least 10% of catalyst. Catalyst, Na₂SO₄ assist the formation of titanium oxycarbonitride (TiO_XC_yN_z) but the concentration of impurities not affected by catalyst. The XRD pattern indicate that titanium oxycarbonitride phase with the composition of TiO_0.19C_0.53N_0.32 at 1400 °C detected from 0%-15% of catalyst. From XRD pattern, increasing the reduction temperature, will increase the formation of titanium oxycarbonitride. With addition of catalyst, the microstructure of the iron particles coarsened whereby this coarsening is important to increase the reduction of ilmenite and titania.