Large-scale synthesis of artificial zeolite from coal fly ash with a small charge of alkaline solution

A new process for converting coal fly ash to an artificial zeolite is described. The process is comprised of a high-temperature operation and water removal during the operation. Suitable operation parameters of the process were investigated using a test unit, and the optimal conditions were found to be 2.5–3.5 mol/dm3 of NaOH and 0.88–1.10 dm3/kg of liquid/solid, sodium hydroxide charge from 2.2 to 3.9 mol/kg-CFA. The zeolites obtained from a pilot plant had a higher cation exchangeable capacity than those from the test unit and were comparable to zeolites prepared using a conventional method.