Belt conveyor (BC) transportation systems are considered to be the most effective for handling large volumes of bulk material. With regards to the rules of sustainable development, the improvement of belt conveyor technology is, in many cases, focused on environmental issues, which include the idea of energy usage optimization. The key issue in an energy-efficient transportation system is reducing the value of specific energy consumption (SEC) by increasing conveyor capacity whilst decreasing belt conveyor motion resistance. The main idea of this paper is to conduct an analysis of the modernization of existing belt conveyor transportation systems operated in open-pit lignite mines, in order to achieve relatively small electric energy consumption for a considered transportation task. The first part of the paper investigates the relationship between a conveyor’s SEC and material flow rate for various conveyor design parameters. Then, based on multi-parameter simulations, an analysis of electric energy consumption for a belt conveyor transportation system is carried out. Finally, an energy-saving, environmentally friendly solution is presented.

Milling is among the most energy-consuming technological stages of copper ore processing. It is performed in mills, which are machines of high rotational masses. The start of a mill filled to capacity requires appropriate solutions that mitigate the overloading. One method for increasing the energy efficiency of ball mills is to optimize their drive systems. This article looks at two variants of drive systems with efficiencies higher than the already existing solutions. The first variant is a low-speed synchronous motor with permanent magnets without a gearbox, and the second variant is an asynchronous high-efficiency motor with a gearbox and a fluid coupling. The energy performance analysis of the three solutions was based on the average energy consumption indicator per mass unit of the milled material and on the energy consumption per hour. The investigations required models of the drive systems and analyses with the use of the Monte Carlo methods. The highest energy efficiency is observed in the case of the solution based on the permanent magnet motor. However, the drive system with the high-speed motor offers a gentle start-up possibility owing to the fluid coupling.

This paper presents a method of measuring the resistances to motion of a single three-roller idler set with the use of a specially designed measuring stand. The design and calibration of the stand are described. The stand allows to conduct measurements in real operating conditions and with variable stream of bulk material. The frame with the data acquisition equipment is mobile and thus allows the measuring system to be installed in any point along the route of any belt conveyor. A base (reference) belt conveyor representative for the group of belt conveyors used in copper ore mines was selected for the tests. The results of research into the resistance to motion of a single carrying idler set are presented. The measuring system enabled determination of the loading of the tested idler set in the whole range of belt conveyor capacity. Owing to this fact, the dependence between the motion resistance of a single carrying idler set and the mass capacity was determined. The degree of belt conveyor loading was found to have a significant impact on the values of motion resistances generated by a single three-idler set.