Functional and Operational Requirements to Be Fulfilled by Conical Picks Regarding Their Wear Rate and Investment Costs

Abstract

User’s choices of conical picks currently involve specifying their material and geometric parameters (functional requirements), incorporating the place and conditions of their work (operational requirements). The selection is usually made based on solely one criterion, which is the price. Thus, at the stage of both purchase and operation, the quality of picks, as well as their matching for a specific machine, are not assessed. The problem of defining whether the producer has fulfilled the user’s requirements arises only when the user questions the picks’ quality. Analysis of this problem has resulted in developing assumptions, concepts and research procedures based on the cutting process requirements. The procedure allows conducting tests to determine the geometric parameters of a pick, the type of material of the pick body and WC-Co insert, as well as the pick wear rate (intensity). The C2 index describes the wear rate (intensity)—the smaller its value, the slower the pick’s wear. Laboratory tests were carried out at the AGH University of Science and Technology in Kraków, Poland. Following the developed method and procedure, the quality of picks was precisely and unambiguously assessed. The C2 index, apart from testing the quality of picks, was also used to forecast their wear. Based on the C2 index, a method is proposed to estimate the wear rate of conical picks provided by different manufacturers and determine the acceptable unit price and operating costs. Thus, it is possible and reasonable to precisely define the investment requirements and appropriately select the pick. Relevant tests were carried out for eight different types of conical picks used in roadheaders, longwall shearers and shaft-boring roadheaders.

Keywords

• underground mining
• longwall shearers
• roadheaders
• conical picks
• quality
• costs