关键词: 钾长石, 硝酸脲, 钾溶出率

Abstract: New technology of refining potassium from the potassium feldspar-phosphate rock-urea nitrate system was studied in detail，the feasibility of this system to resolve potassium feldspar extracting effective potassium was validated.The orthogonal experiment results showed that the sequence of factors which affected potassium extraction ratio was: reaction temperature>dosage of nitric acid>reaction time>the amount-of-substance ratio of urea to nitric acid.The suitable technology conditions were obtained as follows：the amount-of-substance ratio of urea to nitric acid was 1∶1，nitric acid（5.5 mol/L） dosage was 4 mL，reaction temperature was 120 ℃，and reaction time was 2 h.Under those conditions，the effective potassium extraction rate could be up to 96.23%，and water-soluble potassium extraction rate reached 29.65%.The suitable technology conditions through the optimization of single factor experiments were as follows: reaction temperature was at 105～115 ℃， dosage of nitric acid was about 4.7 mL，and reaction time was about 2 h.

Key words: potassium feldspar, urea nitrate, potassium extraction rate