Cost-Effective Treatment of Hemihydrate Phosphogypsum and Phosphorous Slag as Cemented Paste Backfill Material for Underground Mine

Figure 9

SEM images of specimens of backfill body. (a) S22 cured for 7 days; (b) S22 cured for 28 days; (c) S23 cured for 7 days; (d) S23 cured for 28 days.

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(b)

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(d)