The Effects of Temperature on the Hydrothermal Synthesis of Hydroxyapatite-Zeolite Using Blast Furnace Slag

Abstract

Blast furnace slag, an industrial by-product, is emerging as a potential raw material to synthesize hydroxyapatite and zeolite. In this study, the effects of temperature on the hydrothermal synthesis of hydroxyapatite-zeolite from blast furnace slag were investigated. Specimens were synthesized at different temperatures (room temperature, 50, 90, 120, or 150 °C). The synthesized specimens were analyzed qualitatively and quantitatively via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), BET/BJH, and scanning electron microscopy/energy dispersive using X-ray analysis (SEM/EDX). It was found that the hydroxyapatite phase was synthesized at all the reaction temperatures, while faujasite type zeolite appeared in the specimens synthesized at 90 and 120 °C. Moreover, faujasite was replaced by hydroxysodalite in the specimens synthesized at 150 °C. Additionally, the crystals of the hydroxyapatite tended to become larger and total crystallinity increased as the reaction temperature increased.

An overview of synthesis and characterization of hydroxyapatite-zeolite composites for bone implant application

“…This situation occurs because zeolite has a greater surface area and adsorption capacity than HA. Furthermore, Ryu et al [45] confirm previous studies conducted by Kuwahara and co-workers [59,60] who have reported that HA can complement the ability of zeolites that can only absorb cations.…”

“…The crystals morphological of the HA-zeolite nano-composite that have been produced by Khorasani et al [47] are mostly cylindrical and elliptical with crystallite sizes between 17-77 nm. It was reported by Ryu et al [45] that HA-zeolite composites synthesized with BFS have a pore size distribution in mesoporous (Fig. 5).…”

“…Only a few data can be found related to the crystallinity of HA-zeolite composites. However, it has been reported by Ryu and co-workers [45] related to the crystallinity of HA-zeolite composites manufactured through a hydrothermal synthesis of Blast Furnace Slag (BSF) as shown in Table 1 [45]. It is shown in Table 1 that the crystallinity of the specimen is similar when the reaction temperature rises to 50 o C from the initial temperature of 0 o C. However, the crystallinity doubled when the temperature was increased to 90 o C. In other words, it can be stated that crystallinity has a tendency to increase with increasing reaction temperatures.…”

“…Ryu et al [45] reported that they had succeeded in the hydrothermal synthesis of HA-zeolite composites from high blast furnace slags. The analysis was carried out at the varied temperature, i.e.…”

“…The HA-zeolite pore distribution synthesized using blast furnace slag at various reaction temperatures[45].…”