A Preliminary Study on Recycling Fly Ash from Municipal Waste Incineration

Abstract

In this study fly ash was taken from Chengxi Municipal Solid Waste Incineration Plant of Tainan City The materials were fly ash reaction ash and stable ash First the three materials were crushed and sieved and then they were subjected to full digestion and element analysis XRD mineral structure analysis and SEM shooting After that the water washing experiment was started The fly ash has a dissolution rate of about 27% when the liquid-solid ratio is 30 and the water is washed for 1 hour The reaction ash has a dissolution rate of about 25% when the liquid-solid ratio is 20 and the water is washed for 1 hour The stable ash has a dissolution rate of about 32% when the liquid-solid ratio is 20 and the time is 1 hour After washing the fly ash with IRC-748 resin for ion exchange to recover calcium element it can be known that the higher the pH value of the three ash water washes the more calcium IRC-748 can absorb Then IRC-748 that has adsorbed saturated calcium is used for desorption experiments with deionized water and hydrochloric acid It can be found that water can desorb calcium but the amount of desorption is less than that of hydrochloric acid The desorption amount of hydrochloric acid will increase with the concentration When it reaches the third tube the calcium concentration of 1N HCl is 18213ppm and the calcium concentration of the third tube of 3N HCl can reach 20673ppm Finally the filter cake after the water washing experiment was impregnated with hydrochloric acid for the purpose of impregnating heavy metals Pb Zn and Cu It can be found that the best parameters of fly ash are liquid-solid ratio of 15 concentration of 1N temperature of 40°C and The time was 1 hour the dissolution rate of Pb was 42% the dissolution rate of Zn was 65% and the dissolution rate of Cu was 74% The best parameters of reaction ash are liquid-solid ratio of 15 concentration of 2N temperature of 60°C and time of 2 hours the solubility rate of Pb is 44% the solubility rate of Zn is 72% the solubility rate of Cu is 49% The best parameters of stable ash are liquid-solid ratio of 20 concentration of 2N temperature of 40°C and time of 1 hour The solubility rate of Pb is 49% the solubility rate of Zn is 66% and the solubility rate of Cu is 41%

Date of Award	2020
Original language	English
Supervisor	Yun-Hwei Shen (Supervisor)