Orthogonal Experimental Study on Heat Transfer Optimization of Backfill Slurry with Ice Particles

Table 3

Factors and levels in the orthogonal experiment.

Item	Factors	Levels
		1	2	3
A	Boundary heat flow (W/m^2)	111	333	555
B	Ice-water ratio	2 : 5	5 : 5	8 : 5
C	Sand-cement ratio	4 : 1	6 : 1	8 : 1
D	Slurry concentration (%)	64%	68%	72%