###### Abstract  
Ore retention bunkers and receiving bins are important for continuous operation of transport system in a mine. Although the designs of the bins used in the KGHM PM S.A. mines have undergone modifications, their operating principle has remained unchanged since their initial commissioning. Their operation entails many problems, which are caused by the durability and functionality of the entire structure. Preventive actions and research into directions for possible modernizations require the type of damage and its reasons to be identified in the first place. This article presents an evaluation of the documented types of damage and an analysis of the repair works performed for the entire population of the receiving bins operated in one mine. The comparative evaluation of the bin failure rate is here proposed to be performed with the use of a number-based failure indicator and of a mass indicator. The key problem identified in the research was the wear and tear on steel elements due to abrasive processes. The linings of the bin elements were observed to undergo intensive abrasive wear. This abrasive wear of the analyzed bin elements is influenced by a combination of factors, the most important of which include variable physical and mechanical properties of the copper ore.  
retention bunker; receiving bin; underground copper mine; wear damage; failure analysis +
Footnote †: journal: Medicalthe material bounces and slides. This issue is of great significance for the durability of the structural elements, as it leads to the loss of their physical properties and also increases the chances for ore congestion which may result in a limited transportation capacity of the entire ore haulage system. The problem of blockages may cause damage to the steel lining of reciprocating plate feeder. It happens when discharged opening is blocked and the trough reciprocates. Publications [4; 5] provide a complex description of the issues related to the design and operation of retention bunkers with respect to their operating parameters and types of observed failures. The design of a retention bunker should allow its effective, failure-free, and safe operation. Each prolonged downtime of a retention bunker which results in the downtime of the mining unit may cause the mine to incur financial losses due to the lost production [6]. The research discussed in the literature focuses mostly on the designs and strength-related analyses of the bunkers with respect to the loads from the surrounding rock mass [7; 8], and to a lesser extent on the analysis of damage to the structure of or the wear and tear on the steel surfaces of the bunker elements due to the contact with the ore. Problem Definition  
Polish copper ore mines experience a number of maintenance problems related to the excessive wear of steel elements and friction linings, or to the loss of strength observed in structural elements. The solutions to these problems are temporary, and typically involve solidifying the structure or frequently replacing the worn elements. Copper ore receiving bins installed in retention bunkers are typical examples of elements subject to frequent failures. Therefore, bunkers for individual mining plants need to be designed on the basis of a set of guidelines which would allow for specific conditions in each mine, as suggested in [9]. Figure 2 shows the design of a typical receiving bin with a reciprocating plate feeder. Figure 1: A representative design of a retention bunker with a receiving bin in its lower part, which enables the transfer of copper ore to the belt conveyor. In the device, copper ore passes by the force of gravity from the bunker to the hopper, which narrows in the direction of the material movement and which is limited on the four sides by inclined walls. The walls include two side walls C, a front wall D, and a back wall H. The surfaces of the walls in the hopper are lined with wear-resistant steel. A feeder trough G is installed in the bottom of the hopper.