International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

This publication analyses the process of transforming the online economy into a circular one. The focus of the analysis is on the progress of the European Union member states in reducing waste. Member States’ progress towards a circular economy is slow. The circular business model should not be seen as wishful thinking, because it will be crucial for companies in the future. The circular economy is at the heart of the European Green Deal and plays a key role in decarbonisation and achieving climate neutrality by 2050 and in the fight against pollution. Circular economy means smarter use of resources. The circular economy is built using sustainable economic models based on innovation and technology to allow the repeated use of the same resources. Achieving a zero carbon footprint on the natural environment by 2050. is the top priority. This would only be possible if the world moves towards a circular economy, and this is one of the highlights of the Green Deal, while also aiming to increase the competitiveness of the economy.

The purpose of the study was to analyse and evaluate waste logistics in a large-scale agricultural enterprise in terms of a closedloop economy. A closed-loop economy was characterised and its significance for the enterprise was defined. The size and structure of the input production means, and their output were established. Based on yardsticks and indicators the degree of implementation of the closedloop economy into the enterprise was estimated and solutions improving the current situation were suggested. It was found out that in the analysed enterprise it is carried out at a high level which is proved by a high indicator of waste management in the closed loop at the level of 95%.

The combustion synthesis (CS) is an autogenous and strongly exothermic chemical reaction in a powdered mixture of a strong reducer and oxidizer. Such processes, due to short duration and fast quench, can be a source of novel nanomaterials. Here we present (i) the CS synthesis of SiC nanowires (SiCNWs) and (ii) the magnesiothermic reduction of the asbestos waste. The resulting raw and purified products were analyzed with different chemical and physicochemical techniques (XRD, SEM, TGA and Raman spectroscopy) to verify its composition and morphology.

In this paper, we consider the theoretical foundations of the synthesis of ceramic materials from natural aluminosilicates with the addition of technogenic materials (lead and copper slag) using powder metallurgy methods. The characteristics of the feedstock, properties are presented, the geographical deposits of natural components are shown. The possibility of obtaining pelletized, granular, and block ceramic materials based on natural and technogenic sorbents of Kazakhstan is shown by powder metallurgy methods.

The state of collection, storage and processing of some main waste in Bulgaria is under consideration. In accordance with the legislation in force in Bulgaria and the EU, separate collection of waste is increasingly necessary. Some examples of different types of waste show what the actual condition is and show good examples of work in this area.