Abstract: Aiming to reveal the transformation of potassium during the co-pyrolysis of rice straw and coal,experiments were carried out in a high-frequency furnace to investigate the release and transformation of potassium in different forms.The results indicated that the Jincheng anthracite could restrain the release of potassium,and the total potassium release rate increased with the increase of temperature and the decrease of coal blending ratio.SiO₂ could react with potassium to form stable silicate below 1 000℃,while Kaolin could react with potassium to form stable aluminosilicate above 1 000℃.Al₂O₃ in ash could adhere potassium on the surface,whereas volatiles and fixed carbon could combine with potassium to decrease the release ratio.However,generally Jincheng anthracite promotes water soluble and ion exchangeable potassium to transform to acid soluble and residue potassium.