Implementation of industrial waste ferrochrome slag in conventional and low cement castables: Effect of calcined alumina

Peer review under responsibility of The Ceramic Society of Japan and the Korean Ceramic Society.

Figures & data

Table 1 Particle size and chemical composition of the raw materials.

	FC slag (wt.%)	Calcined bauxite (wt.%)	HAC (wt.%)	Calcined alumina (wt.%)
Al2O3	22.21	85	72	99.0
SiO2	27.14	8	–	0.007
Fe2O3	4.01	3	–	0.016
CaO	5.13	–	28	0.005
MgO	24.88	–	–	0.001
TiO2	–	4	–	0.002
Cr2O3	12.57	–	–	–

FC, ferrochrome slag; HAC, high alumina cement.

Table 2 Batch composition of ferrochrome slag-based castables.

Sample code	FC slag (wt.%)	Calcined bauxite (wt.%)	HAC (wt.%)	Calcined alumina (wt.%)
CA 0	45	40	15	00
CA 5	45	40	10	05
CA 10	45	40	5	10
CA 12	45	40	3	12

FC, ferrochrome slag; HAC, high alumina cement.

Fig. 1 Pictorial representation of the ferrochrome slag castables.

Fig. 2 X-ray diffraction pattern of ferrochrome slag-based CA 0 castables fired at different temperatures.

Fig. 3 X-ray diffraction pattern of ferrochrome slag-based CA 5 castables fired at different temperatures.

Fig. 4 X-ray diffraction pattern of ferrochrome slag-based CA 10 castables fired at different temperatures.

Fig. 5 X-ray diffraction pattern of ferrochrome slag-based CA 12 castables fired at different temperatures.

Fig. 6 SEM micrographs of castable CA 10 fired at 1300 °C for 3 h. Figures with numbers a, b, c, and d represent their magnifications, viz., 5000×, 10,000×, 20,000× and 30,000× respectively.

Fig. 7 SEM micrographs of castable CA 12 fired at 1300 °C for 3 h. Figures with numbers a, b, c, and d represent their magnifications, viz., 2500×, 5000×, 10,000× and 20,000× respectively.

Fig. 8 Bulk density and apparent porosity of ferrochrome slag-based castables as a function of temperature.

Fig. 9 CCS of different ferrochrome-based castable samples fired at different firing temperatures.

Fig. 10 CMOR of different ferrochrome slag-based castable samples fired at different firing temperatures.

Fig. 11 Residual strength of ferrochrome-based castable samples fired at 1300 °C.

Fig. 12 Permanent linear change of ferrochrome slag-based castable samples fired at 1100 °C and 1300 °C.