Study On The Activation Of Potassium Feldspar By Mixed Alkali Fusion Method And Preparation Of Zeolites

Potassium feldspar is cheap and easy to be obtained in China.It is of high value owing to the fact that it belongs to silicon aluminate mineral including potassium and sodium.But its structure is stabe and not easy to be destroyed.Therefore,it has the important value to research the activation and processing technology of the potassium feldspar.In this thesis,the potassium feldspar was activated by Na₂CO₃-NaOH mixed alkali fusion method.4A zeolite and low silica X?LSX?zeolite were prepared.4A zeolite was successfully prepared using the active product from activating potassium feldspar by Na₂CO₃-NaOH fusion method.Referring to NaOH/Na₂CO₃ mass ratio and temperature at the lowest eutectic point of NaOH-Na₂CO₃.The activation conditions are as follows:mass ratio of NaOH-to-Na₂CO₃ is 5.91:1 and mass ratio of alkaline-to-ore is 1.85:1 at 300?for 2.5 h.The effect of crystallization time on the preparation of 4A zeolite were investigated.The results indicated that the active product can be obtained from activating potassium feldspar by Na₂CO₃-NaOH fusion method under the above condition.4A zeolites can be prepared in the system with the molar ratios of1Al₂O₃:2SiO₂:5Na₂O:185H₂O,using the active product from activating potassium feldspar.And the suitable crystallization time is 6.0 h.4A zeolite was successfully synthesized using the active product from activating potassium feldspar by Na₂CO₃-NaOH fusion method.The effects of activation temperature,activation time,mass ratio of alkaline-to-ore,mass ratio of NaOH-to-Na₂CO₃ on the activation of the potassium feldspar,and the effect of crystallization time on the preparation of 4A zeolite were investigated.The results indicated that the active product can be obtained from activating potassium feldspar by Na₂CO₃-NaOH fusion method.The suitable conditions are as follows:mass ratio of alkaline-to-ore is 2:1 and mass ratio of NaOH-to-Na₂CO₃ is 1:1 at 300?for 2.5 h.4A zeolites can be prepared in the molar ratios of 1Al₂O₃:2SiO₂:5Na₂O:185H₂O system using the active material from the activating potassium feldspar.And the suitable crystallization time is 4.0 h.The 4A zeolites present cube morphology.In order to improve resource utilization rate,mother liquor circulation route was designed.LSX zeolite was successfully prepared using the active product from activating potassium feldspar by Na2CO3-NaOH fusion method.The effects of activation temperature,activation time,mass ratios of alkali-to-ore,mass ratios of NaOH-to-Na2CO3 on activating potassium feldspar,and the effects of molar ratios of SiO2/Al2O3,Na2O/?Na2O+K2O?,H₂O/?Na₂O+K₂O?on the preparation of LSX zeolite were investigated.The results demonstrated that the suitable conditions for activating potassic rocks by Na2CO3-NaOH fusion method to obtain highly active product were as follows:the activation temperature is300?,the activation time is 3.0 h,the mass ratio of alkali-to-ore is 2.5:1 and the mass ratio of NaOH-to-Na₂CO₃ is 1.5:1.The suitable molar ratios for preparation of LSX zeolite using the highly active product from activation of potassium feldspar were SiO₂/Al₂O₃=2.2,Na2O/?Na2O+K2O?=0.78 and H2O/?Na2O+K2O?=15.32.The LSX zeolites present multi-faced spherulite morphology.These results indicate that the active product from activating potassium feldspar by mixed alkali fusion method can be used in the preparation of zeolite.Therefore,potassium feldspar from natural aluminosilicates can be take as raw materia for the preparation of zeolite.Potassium feldspar can be activated by mixed alkali fusion method at low activation temperature.