Effect of potassium carbonate on catalytic synthesis of calcium carbide at moderate temperature

Calcium carbide was successfully synthesized by carbothermal reduction of lime with coke at 1973 K for 1.5 h.The effect of potassium carbonate as additive on the composition and morphology of the product was investi-gated using X-ray diffraction and scanning electron microscope.Addition of potassium carbonate increased the yield of calcium carbide.The sample in the presence of potassium carbonate generated acetylene gas of 168.3 L/kg,which was 10%higher than that in the absence of potassium carbonate.This result confirmed the catalytic effect of potassium carbonate on the synthesis of calcium carbide.A possible mechanism of the above effects was that the additive,which was melted at the reduction temperature,dissolved CaO and so promoted the contact between CaO and carbon,which was essential for the solid-solid reaction to form calcium carbide.