Experimental research on wear of conical pick interacting with coal-rock

For severe wear of a conical pick on tunneling and mining equipment, the influence of pick cutting types, structure and working angle parameters on pick wear is studied using an experimental apparatus for cutting coal-rock. The influence of pick wear on cutting performance is analyzed, which provides an experimental basis for reducing pick wear. The results indicate that the pick wears on only one side under asymmetrical cutting types, which increases the pick's working life. The larger the height of carbide tip and cone angle of pick tip are, the easier it is to protect the head face of the pick-body from interference with coal-rock and avoid carbide tip loss due to wear of the pick-body. In the range of research, the suitable height of the carbide tip is found to be 20 mm ~ 24 mm, and the cone angle of the pick tip should be approximately 80°. The wear area on the pick-body increases with the head face diameter of the pick-body, and a suitable range for the head face diameter is found to be 20 mm-22 mm. Pick wear decreases with cutting angle, but the cutting angle should be maintained at 45°-50°, considering the pick cutting load and coal-rock caving effect. For picks with an inclined angle, pick wear increases with incline angle, however, wear differences on the two sides of the pick form and increase gradually, which improves the pick's self-rotatory ability. The mean peak of pick cutting torque increases with wear degree, and the largest increase percentage was found to be 30%. Furthermore, a worn pick is unfavorable for the caving of coal-rock and the coal-rock fragment size of < 2 mm increases by 14% compared to a pick without wear.