Cordierite-based ceramics from stevensite clay and coal fly ash

Figures & data

Table 1. Chemical composition of Ghassoul and fly ash (wt. %).

Materials	Chemical composition (wt.%)
	SiO2	Al2O3	MgO	Fe2O3	CaO	Na2O	K2O	P2O5	L.O.I (%)
Ghassoul	54.12	2.73	21.0	1.25	4.0	0.61	0.57	0.54	15
Coal fly ash	48.84	32.79	1.46	6.12	4.37	0.06	1.12	0.51	5

Table 2. Batch composition of the prepared samples.

	Wt.%
	Ghassoul	Fly ash	Silica gel	Aluminum hydroxide
Formulation A	47.22	27.86	–	24.92
Formulation B	49.25	–	12.31	38.43

Figure 1. Granulometric analysis of the prepared formulations.

Figure 2. XRD patterns of raw formulations (s: stevensite, d: dolomite, a: aluminum hydroxide, M: mullite, q: quartz).

Figure 3. DTA-TGA curves of the prepared formulations.

Figure 4. XRD patterns of the heated formulations at the range 800–1250°C (d: Diopside, M: Mullite, q: Quartz, L: Clinoenstatite, c: cristobalite, p: protoenstatite, S: Spinel, I: cordierite, r: corindon, e: Enstatite).

Figure 5. Infrared spectra of the heated formulations in the range 800–1250°C.

Figure 6. Dilatometric analysis of the prepared formulations.

Figure 7. SEM observation of both formulations heated at 1250°C.

Figure 8. Flexural strength of the heated samples in the range 1000–1200°C A (■) and B (●).