The process of fly ash magnetic separation impact on hydrothermal synthesis of zeolites

Abstract

Abstract. The aim of the experiment was modifying raw fly ash through the demagnetisation process and determining its influence on the efficiency of the synthesis of zeolite materials out of fly ash. A series of experiments have been performed on modified samples and, for the purpose of verification, on non-modified fly ash. No direct correlation has been confirmed in relation to synthesis efficiency as well as the type of obtained zeolite material. The research results indicate that the composition of fly ash determines the type of the zeolitic phases obtained. Based on the analysis of experimental data, it was found that the demagnetisation process allows to obtain additional zeolite phases, while there is no direct impact of the process used on the increase of synthesis reaction efficiency.

The influence of fly ash zeolites fusion synthesis parameters on the received products

“…In the fusion method experiment (F650 0 C) the decrease of alkali amount influence on the synthesis product was tested. In preliminary experiments [11] it was fund that the use of fly ash to alkali ratio of value 2 in most cases did not result in obtaining zeolite as a product. The only case of zeolite crystallization in this fly ash/alkali ratio was the one performed in the temperature 650 0 C, which was the criteria of selecting this temperature as a synthesis parameter for testing increase of fly ash/alkali ratio up to value 3.…”

“…Results of performed experiments indicate that it is possible to obtain zeolites of higher potential of application with the use of fly ash/alkali ratio 2. Related research [11] performed with the use of fusion method indicated that the use of higher fly ash/alkali ratio is not efficient in relation to zeolite crystallization. In the experiment performed in the temperature 550 0 C it was tested how does the change in fly ash/alkali ratio will influence the synthesis product.…”

“…Interesting application examples of its use are as: oil spills sorbents [6,7], additives for asphalt production [8], removal of benzene, toluene and xylene [9], ammonia ions [3] carbon dioxide [3,10] or sulphur dioxide [11,12].…”

Limitation of the environmental impact of ashes from combustion of sewage sludge by the synthesis of zeolites

“…Depending on the silicone to aluminum ratio of the raw material, faujasite is divided into X and Y. Zeolite X is obtained as a result of the synthesis of raw materials with the ratio between 2 and 3 [29], while zeolite Y with the ratio from 3 and more [31]. Zeolite Y, obtained under the conditions of zeolitization of sample S10, proves that the synthesis at the crystallization temperature of 90 o C is more favorable than at 60 o C [32].…”

“…CEC is a measurement of the number of cations in the channels by unit weight that may be replaced by other ions in solutions. The exchangeable cations of samples were replaced by NH4 + using 1M ammonium acetate [29]. The concentration of ammonium ions in solutions was determined with the use of ion chromatography.…”