The Wear on Roller Press Rollers Made of 20Cr4/1.7027 Steel under Conditions of Copper Concentrate Briquetting

Abstract

This paper defines the wear process of rollers made of 20Cr4. Rollers with a diameter of 1000 mm were installed in a roller press used for the production of drop-shaped briquettes and the copper concentrate was briquetted for 1100 h. Three-dimensional (3D) geometry analysis, metallographic analysis, macroscopy, scanning electron microscopy, as well as hardness measurements were performed. It was observed that the working surface was non-uniformly worn. The smallest wear affects the molding cavities situated on the outermost edges of the ring. The wear increases as the center of the ring is approximated, and it reaches its maximum at the middle of the ring. The molding cavities also wear asymmetrically. For the shape considered in this study, the lower part of a cavity is subject to a higher wear rate. We found that the material of the working ring was carburized, but its hardness was significantly lower than required. The roller ring microstructure changes depended on the distance from the cavity’s face. An investigation of the wear mechanisms showed different types of abrasive wear, corrosive processes, and plastic deformation. The exact type and course of wear were described, depending on the location on the working surface.

Modelling of the Fine-Grained Materials Briquetting Process in a Roller Press with the Discrete Element Method

“…A significant amount of research was conducted to study the relationships between the design parameters of the roller presses, their operation parameters, material compaction characteristics in the deformation region, etc. [ 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 ]. At the same time, the issues of studying the processes of contact interaction of the compacted material with the pressing surfaces of roller presses are relevant.…”

Analysis of the Temperature Distribution on the Surface of Saddle-Shaped Briquettes Consolidated in the Roller Press

“…The unit pressure in the fine-grained material consolidation process often reaches several hundred MPa and is a parameter which results, among other things, from the properties of the material being consolidated and the compaction system geometry [54,61,70]. Its value changes depending on the place on the molding surface [71,72]. This is one of the reasons that the briquette compaction is not uniform throughout its volume, as shown by the research presented in the works [70,73].…”

“…A similar stress distribution can be expected for an asymmetric compaction system; however, such tests were not carried out with gravity feeding. value changes depending on the place on the molding surface [71,72]. This is one of the reasons that the briquette compaction is not uniform throughout its volume, as shown by the research presented in the works [70,73].…”

The Analysis of the Morphology of the Saddle-Shaped Bronze Chips Briquettes Produced in the Roller Press

“…The continuity of the briquetting process in roller briquetting machines allows for the reduction of energy consumption necessary to carry out this process [24]. Appropriate selection of the design parameters of this type of devices allows the achievement of a longer life of the forming tools as compared to other designing solutions for briquetting machines, such as screw briquetting machines [25][26][27]. High humidity, low bulk density, the presence of hydrophobic grains or high elastic deflection after removing the pressure may negatively affect the quality of the compacts produced in a roller presses, and in some cases even prevent it [20].…”