Author: Alper ÖZKAN, Murat ÜNAL, Bilgehan KEKEÇ
Publishing Date: 2006
E-ISSN: 2147-9364
Volume 21 Issue 1_2
ABSTRACT:
In this study, the effect of microwave treatment on breakage rate and ultrasonic velocity of travertine and marble has been investigated. The specific rates of breakage (Si) of -850+600 µm particle size fractions of travertine and marble have been determined using a laboratory scale ceramic ball mill. The dry grinding of the samples treated and untreated with microwave followed the first-order breakage law, and the found Si values increased with parallel to increasing of microwave power. However, a significant increase in the Si values was not obtained at microwave power values higher than 600 W. On the other hand, the Si values obtained for marble increased significantly as the microwave treatment times became longer. But, the breakage rate of travertine was not improved with increasing treatment time after reaching a particular value. In addition, the values of ultrasonic velocity of these materials showed a decreasing trend with increasing microwave power and treatment time. Consequently, a partial relationship was found between the ultrasonic velocity value and breakage rate, which indicates that the ultrasonic velocity decreases, as the Si values increases.
Key Words: Microwave; Ultrasonic velocity; Specific rate of breakage