Synthesis of single phase gyrolite in the CaO-quartz-Na2O-H2O system

• Single phase gyrolite was synthesized for the first time using quartz as a silica source.
• A method of gyrolite synthesis using low-cost silica source (quartz) was developed.
• It was found that sodium hydroxide has a crucial role in gyrolite synthesis.
• It was found that there is an optimum NaOH concentration which allows to obtain pure gyrolite.

Single phase gyrolite – cation exchanger, has been successfully synthesized in the CaO–SiO2–Na2O–H2O system. It is the first successive attempt, when the single phase gyrolite was synthesized using quartz as siliceous material. It has been found that the content of NaOH is crucial for gyrolite crystallization. The results indicate that optimum amount of NaOH is in narrow range between 0.75% and 1.00%. Decreasing or increasing its amount does not allow to obtain gyrolite in pure form and in final products unreacted quartz was observed.