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Belt conveyors offer numerous advantages for transporting granular materials over medium distances. They are known for their efficient performance, requiring minimal labor and energy input, and therefore belt conveyors are the most widely used system for bulk transportation. Understanding the causes of conveyor idler replacements is crucial since they represent the second highest maintenance cost in this transportation method, following the conveyor belt itself, which accounts for 30% to 70% of maintenance expenses. By analyzing data on the lifespan of 97,778 idler rollers provided by Vale, we have identified the primary factors leading to the replacement of impact, carrying, and return idler rollers. These causes include noise/vibration, wear, and idler seizure. Notably, noise/vibration plays a more significant role in carrying idler roller replacements (74.5%) compared to impact idler roller replacements (46.0%), which are subjected to more severe loading conditions that rapidly lead to seizure. Noise and vibration are consequences of bearing damages like pitting and spalling. In the case of return idlers, wear accounts for approximately three times more replacements than noise (62.0% and 20.6%, respectively). This discrepancy arises because these idlers do not directly bear the load of transported material; instead, abrasive wear occurs due to contact with the belt and the ore adhered to its surface. Understanding these causes of replacements enables us to gain insights into the specific operational conditions of idlers. With this knowledge, we can design more appropriate experimental plans tailored to the reality of belt conveyor idlers. This approach allows for better identification of key tests for determining idler lifespan based on their specific type. [ABSTRACT FROM AUTHOR]

The demand for mineral ores in modern society is prompting industry to optimise their operations to ensure sustainability of their products. One of the key components in the materials handling transportation chain are belt conveyors. The energy consumption of modern belt conveyor systems has reduced considerably over the past few decades, however, there is still significant scope for further reductions, especially when heavily loaded and long overland belt conveyors are considered. A new rail based continuous bulk material transportation system has been developed by researchers at the University of Newcastle in conjunction with FLSmidth Mining Technologies to reduce the energy consumption of heavily loaded and long overland conveyors. The Rail-Running Conveyor technology is a state-of-the-art continuous belt conveying technology which provides an innovative and novel departure from conventional continuous bulk material transportation systems with significant energy and economic benefits. This paper presents the recent developments of the Rail-Running Conveyor technology which includes both troughed and enclosed (pipe) configurations. [ABSTRACT FROM AUTHOR]

Conveyor belts are extensively used for the transportation of bulk materials due to their safe operation, economy, reliability, and high capacity. The system usually consists of a long-reinforced rubber belt supported by metallic idler rolls; however, certain applications and improper maintenance see these idlers wear. Severe wear that penetrates the idler shell forms sharp edges that might cut the conveyor belt, leading to high costs and operational downtime. Consequently, polymeric idler rolls have been presented as an alternative to improve the performance of conveyor belts, averting the sharp edges of worn idler rolls and, due to their low weight, facilitating idler replacement. However, it is still necessary to assess their technical viability. One essential parameter to be considered is the abrasion resistance of the roll. Several standard test methods, such as the DIN 4649, are used to assess the abrasion resistance of a material. These tests are classified as a twobody abrasion test, in which a (or multiple) hard particle slides over a softer surface. In practice, however, this diverges from field observations, in which three-body abrasion occurs predominantly, i.e., the particles successively indent the surface instead of scratching it. This paper presents a modification to the ASTM G65 test rig to allow three-body abrasion testing to be completed. It then compares the abrasion resistance of six commercial polymeric idler roll segments with a standard steel idler roll under operating conditions that mimic field operation. Finally, the wear mechanisms assessed by SEM are compared with material properties. Overall, the results show that the modified test rig is suitable for ranking idler roll abrasion resistance. [ABSTRACT FROM AUTHOR]

It is common practice to analyse the flow properties of a bulk material sample for a range of Moisture Contents (MC). It can also be quite common that the material supplied requires 'drying' to analyse moisture contents at lower values than what may be supplied by the client. This paper investigates the influence of thermal drying techniques on the flow properties of bulk materials. The chosen drying techniques are Air-Drying (AD), drying at ambient temperature and Oven-Drying (OD), drying using an oven at 105 °C. The flow properties of three bulk material samples are considered with each sample compared at the same MC after the drying technique has been undertaken. Each bulk material sample also has baseline testing undertaken at the As-Supplied (AS) condition. To analyse the effects of thermal drying on bulk material flow properties, a case study is also presented to consider the anticipated changes to outlet dimensions for a funnel flow bin design. [ABSTRACT FROM AUTHOR]

With recent advancements in conveying technologies, conveyors are required to achieve greater lifts, longer conveying distances and higher throughputs. As such, drive stations continue to increase in size, with gearless drive stations in excess of 10 MW in existence. A significant amount of research has been conducted into the design and optimization of these systems, however, the use of standard methodologies to quantify drive friction is a known limitation that remains. Currently, design standards use Euler's classical 'rope friction' equation to determine drive limitations, with this method failing to account for a variable friction coefficient around the drive pulley. Due to this, the calculated drive is conservative and reaches the limit of efficacy with high-capacity conveyors, due to the high belt tensions required, and the necessary overdesign in structure. This paper investigates the frictional behaviour between a belt conveyor and pulley lagging materials and presents test results demonstrating how the friction coefficient varies with changing load and slip velocity. This improved understanding of the frictional behaviour between the conveyor and drive pulley lagging will further the design capabilities of high-capacity conveyor systems. [ABSTRACT FROM AUTHOR]