Effects of sintering parameters on the preparation and properties of foamed ceramics from cyanide tailings

Figures & data

Figure 1. X-ray diffraction pattern of the CTs.

Table 1. The chemical composition of the raw materials (wt.%).

Raw materials	Al2O3	SiO2	CaO	MgO	Na2O	K2O	Fe2O3	SO3	LOI.
CTs	14.46	45.56	2.94	0.82	2.71	3.3	18.44	10.61	13.98
FA	32.41	52.43	3.93	0.81	0.53	2.51	4.73	0.572	4.44
Fsp	21.10	63.40	2.09	0.18	11.1	1.23	0.62	0.02	2.03

Table 2. The designed sintering parameters of samples.

Number	Sintering temperature (°C)	Firing rate (°C/min)			Holding time (min)
		<400	400–600	>600
W1–W5	1110–1170	4	4	4	60
B1–B4	1155	4	4	4	20–80
S1–S4	1155	4	1–8	4	60

Figure 2. The height and morphology variation of the sample projection during the heating process.

Figure 3. The physical properties of samples with different sintering temperatures: (a) apparent porosity and total porosity, (b) bulk density and water absorption.

Figure 4. Pore morphology and pore size distribution of samples with different sintering temperatures: (a) 1110°C, (b) 1125°C, (c) 1140°C, (d) 1155°C, (e) 1170°C, (f) pore size distribution.

Figure 5. XRD patterns of samples with different sintering temperatures.

Figure 6. The physical properties of samples with different holding times: (a) total porosity and apparent porosity, (b) bulk density and water absorption.

Figure 7. Pore morphology and SEM images of samples with different holding times: (a) 20 min, (b) and (e) 40 min, (c) 60 min, (d) and (f) 80 min.

Figure 8. XRD patterns of samples with different holding times.

Figure 9. The TG-DTG-MS curves of the green body.

Figure 10. Pore morphology and average pore size of samples with different heating rates: (a)1°C/min, (b) 2°C/min, (c) 4°C/min, (d) 8°C/min, (e) average pore.

Figure 11. The Fe2P XPS spectra of samples at 8°C/min: (a) bottom of the sample, (b) top of the sample.

Figure 12. SEM images of the samples at 8°C/min: (a-c) top of the samples, (d-f) bottom of the samples.

Figure 13. The physical properties of samples with different firing rates: (a) total porosity and apparent porosity, (b) bulk density and water absorption, (c) compressive strength.