Design and Evaluation of a Cutting Head Equipped with Protective-Coated Conical Picks for Underground Mine Floor Milling Machine

Underground mining operations require the preparation of access, development, and production workings to enable the extraction of mineral resources. These excavations serve several functions, among which the transportation of personnel, machinery, materials, and mined rock is essential. Since transportation is frequently carried out along the mine floor, maintaining its proper condition is crucial for ensuring operational safety and efficiency. Existing floor maintenance methods, including manual operations, roadheaders, and crawler tractors equipped with bulldozer blades, are characterized by limited effectiveness, high operating costs, and considerable labor intensity. Moreover, the confined dimensions of underground workings prevent the use of conventional surface earthmoving equipment. The paper presents an innovative solution designed for mine roadway floor maintenance, based on a tracked tractor equipped with a cylindrical milling cutting head with conical picks reinforced with special protective coatings. The proposed cutting head features a modular three-segment design with interchangeable drums of different cutting widths, enabling simultaneous floor profiling and drainage channel construction while remaining compatible with the restricted geometry of underground mine workings. The operating performance of the cutting head was evaluated through numerical simulations for different values of the rock cuttability index (1500 and 3000 N/cm), cutting depth (100 ÷ 300 mm), and machine feed speed (2 ÷ 6 m/min). The operational parameter analysis, based on calculations and simulations, demonstrated that effective floor cutting would be achieved within acceptable values of cutting forces and power consumption. The proposed solution represents a new category of machinery dedicated exclusively to underground mine floor maintenance. The developed concept has the potential to improve transportation safety, reduce roadway maintenance costs, and increase the operational efficiency of underground mining systems.