Abstract:Potash feldspar was calcined at a moderate temperature with KOH as the raw material. After the clinker was dissolved in water, the digestion of silica was studied by rapid titration.The influence of calcining temperature,calcining time,alkali ratio on the digestion of SiO2 were studied.X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the mineralogical structure and microstructures of roasted clinker and residue under optimal conditions.The best conditions for the dissolution of silica by experiment are as follows:roast temperature500℃,roast time 2.5h,alkali ratio 2.5:1. Under this condition, the dissolution rate of silica can reach 99.5%.It can realize the comprehensive utilization of potash feldspar.