Abstract: Potassium extraction technology from K-feldspar assisted with microwave at low temperature was discussed.Effects of different parameters on potassium dissolution rate were analyzed when chemical reagents reacted with K-feldspar in a microwave digestion system under different conditions.Results showed that potassium dissolution rate increased with decreasing K-feldspar size.Increasing reaction temperature and the mass fraction of sulphuric acid can increase higher potassium dissolution rate.Potassium extraction efficiency remained stable when increasing reaction temperature to 160 ℃.The optimized operation conditions were obtained by using response surface methodology（RSM）.Above 83% of the potassium extraction efficiency was obtained under experimental conditions: the mass fraction of sulphuric acid was 70%，the mass ratio of K-feldspar to phosphorite was 0.8∶1，the mass ratio of calcium fluoride to calcium phosphate was 3∶1， and the temperature was 160 ℃.

Key words: microwave, K-feldspar, potassium extraction