Experimental research on laser thermal rock breaking and optimization of the process parameters

The high-energy beam laser breaking of rock is an emerging noncontact physical rock-breaking method. The technology of laser thermal rock breaking has the advantages of energy concentration, high rock breaking ef-ficiency, and no mechanical wear. An experimental study of laser thermal rock breaking was conducted to study the best combination of laser irradiated granite processing parameters. Parameters such as the total broken rock mass, mass specific energy, and cross-sectional groove area were used to quantify and analyze the efficiency of laser thermal rock breaking. The regression models of the total broken rock mass, mass specific energy, and cross-sectional groove area were established by the response surface method. Experiments verified the reliability of the regression models and the optimal parameters. The research shows that with the increase in laser power or the decrease in scanning speed, the total broken rock mass and the size of the burning groove become more sig-nificant, and the efficiency of rock breaking is improved. As the radiation distance increases, the depth of the burning groove decreases, but the width increases. With increasing radiation distance, the total broken rock mass and the cross-sectional groove area of the burning groove are approximately constant. When the laser power and radiation distance are increased, it will cause an increased energy consumption of the breaking of rock either. When the laser power is 1300 W, the scanning speed is 6.7 mm/s, and the radiation distance is 51.6 mm, the laser thermal breaking efficiency is the highest, the energy consumption is the lowest, and the best effect on rock breaking.