Issue34

Q. Like et alii, Frattura ed Integrità Strutturale, 34 (2015) 543-553; DOI: 10.3221/IGF-ESIS.34.60 550 mineral boundary failure rates are all 94.5%. This outcome is principally attributed to the fact that the microwave heating is categorized as internal heating; under the same mineral crystal size, a similar mineral liberation effect is generated. (a) 3% (b) 7% (c) 11% (d) 15% Figure 9 : Distribution diagram of mechanical state of rock (Pd=10 9 W / m 3 , t=20 ms). Fig. 10 illustrates the relationship between mineral boundary failure rate and irradiation time with different mineral contents. Although mineral content curves are slightly different at the failure rate growth phase, the beginning and completion times are similar, that is, the same optimal microwave irradiation period, which indicates that the mineral content has a slight effect on the failure rate of the mineral boundary failure element. Figure 10 : Relationship between failure around mineral boundary and irradiation time with different mineral content Effect of mineral crystal size on rock failure state Figs. 11 to 14 depict the relationship between mineral boundary failure rate curve and irradiation time, with a mineral content of 5%, microwave power density of 1×10 9 W/m 3 , and galena crystal sizes of 0.2 mm, 0.4 mm, 0.8 mm, and 1.0 mm, respectively. As the mineral grains become larger, the slope of the growth curve is greater in the optimal microwave irradiation time; the smaller the mineral crystal is, the later the mineral boundary failure begins, and the later the failure completes. Moreover, as the mineral crystal is smaller, the irradiation time required by mineral boundary failure completion is longer.