Abstract
Mechanical rock cutting is widely employed in both the mining and construction industries. One of commonly used techniques is cutting with conical picks, which can process various rock types, including hard-workable and abrasive rocks. However, in highly demanding conditions, such as metal ore mining, the service life of conical picks is significantly limited. Therefore, researchers are constantly searching for methods to extend their operational lifespan, i.e. to improve their durability. Appropriate laboratory testing procedures are required to evaluate the durability of conical picks and compare various design or material solutions. The article presents a method for assessing wear rates of conical picks with the use of a dedicated laboratory test rig. A comprehensive procedure for quantitative quality assessment, including the unit price of picks, has been proposed. This approach enables direct comparison of products offered by different manufacturers, facilitating the selection of the most cost-effective and efficient solution. The procedure has been validated in practice during research commissioned by Polish coal companies and in numerous independent research projects. Several methods for calculating wear rate indicators have been discussed. The analysis has confirmed the robustness of the proposed methodology and its resistance to undesirable fluctuations in selected parameters. The paper outlines various formulas for determining the mass wear rate of conical picks and discusses alternative approaches to calculating performance indicators. The developed procedure allows the selection of picks to be optimised by adjusting the weighting of price-related factors according to current financial and operational requirements. The applicability of the method has been illustrated with two case studies: the first relates to tender procedures conducted by a Polish coal company, whereas the second concerns research aiming to identify materials or coatings capable of enhancing the durability of conical picks relative to widely available commercial solutions.