Mikrodalgaya Maruz Bırakmanın Magmatik Kayaçların Dayanımı Üzerindeki Etkilerinin Araştırılması
Özet
Rock drilling and cutting technology has developed rapidly in the last century. However,
there are problems in drilling and cutting very hard rocks such as low penetration rate and
high wear rate of cutting tools. In order to increase the advance rate and reduce wear
during drilling or cutting of very hard rocks, recent studies on some innovative methods
such as microwave assisted rock breakage has been drawing attention. Studies on the
effects of microwave exposure on the mechanical properties of igneous rocks are new and
limited. Therefore, there are many gaps to be investigated in this area. In this thesis, the
effects of microwave treatment were investigated on the strength of igneous rocks.
In this study, microwave energy up to 6 kW was applied to 9 different magmatic rocks
such as; 6 granite, 2 syenite and 1 gabbro. First, thin sections of each rock used in the
experiments were prepared and the mineral contents and percentages were determined.
Then, the uniaxial compressive strength (UCS) and the Brazilian tensile strength (BTS),
density, porosity, and ultrasonic wave velocity tests were carried out. After that, more
than 600 samples were exposed to microwave energy. The microwave treatment was
applied at 1 kW, 2 kW, and 6 kW powers for the durations ranging from 60 s to 420 s.
The surface temperature of each specimen was measured with an infrared gun before the
microwave irradiation and immediately after removing the sample from the oven.
The evaluation of the results show that the rock strength decreases generally with
increasing microwave power and exposure duration. The strength losses and the heating
degrees are different for each tested rock type illuminated by microwave power because
of the different the mineral content. crackings and meltings were observed on some
samples depending on the applied microwave power, the exposure duration, and the
mineral content. The UCS and the BTS values of granites decreased usually after 200 ℃
and 100 ℃, respectively. The significant losses in the strength of syenite and gabbro
samples were generally observed below 100 ℃ due to their metallic mineral contents or
high amount of microwave absorber minerals. Concluding remark is that microwave
treatment affects strongly the strength of igneous rocks depending on the applied power,
the exposure time, and mineralogy.
