Research on brightening modification of molecular sieves coated fly ash based on alkaline melting hydrothermal method

Abstract

Improving the utilization rate of fly ash (FA) and realizing its resource utilization has always been a popular research topic in the application field of solid waste recycling. This paper aims to improve the basic brightness of fly ash (FA) before calcium carbonate coating, and realize the filling application of fly ash in medium and high-end paper. Taking advantage of the high brightness of molecular sieves (MS) (brightness ≥ 90 %ISO), the alkali melting hydrothermal synthesis (AM-HS) method was used to generate high brightness MS on the surface of fly ash. The results showed that the optimum conditions of alkali melting hydrothermal synthesis (AM-HS) modification were as follows: the mass ratio of sodium hydroxide to fly ash was 1:1, the time of hydrothermal modification was 6 h, the temperature of hydrothermal modification was 80 °C, and the brightness reached to 64.54 %ISO; The results of SEM, particle size analysis and ultrasonic vibration showed that the surface of fly ash is covered by MS and has strong binding effect.

Removal of COD in wastewater by magnetic coagulant prepared from modified fly ash

“…The primitive y ash has limited ability to remove pollutants. Therefore, the current research has focused on modi cation of y ash, so as to improve its ability to remove pollutants from wastewater (Gao et al 2021;Hussain et al 2021). used HCl and NaOH for acid-base modi cation of y ash to remove nor oxacin from water.…”