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[Display omitted] • Pyrolysis technology can be successfully applied into RDF conversion. • Heating value of pyrolytic gas was estimated at the level about 24 MJ/m3. • Residence time significantly influences the pyrolytic gas composition. • Computer simulations predicted the chemical composition of pyrolytic gas. The current COVID-19 pandemic situation and the associated restrictions have increased the amount of generated waste. It results from the necessity to wear personal protective equipment. Thus, the disposal of masks and gloves is a topical issue and requires immediate investigation. The main aims of this work are management and environmental studies of municipal solid wastes (MSW), which have been generated during the COVID-19 pandemic time. Effective waste management in relation to a circular economy is presented. A sample of refuse derived fuel (RDF) with a high content of plastics was used for the experimental and calculation studies. Pyrolysis was selected as the best thermal decomposition process for this kind of wastes. Proximate and ultimate analyses were performed for RDF and its products. Pyrolysis was carried out using a pilot-scale reactor with a continuous flow of 250 kg/h at 900 °C. Thermogravimetric analysis was applied during the pyrolysis investigation and showed that the main decomposition of RDF took place in the temperature range of 250–500 °C. The pyrolysis gas contained combustible compounds like CO (19.8%), H 2 (13.2%), CH 4 (18.9%) and C 2 H 4 (7.1%), giving a high calorific value – 24.4 MJ/m3. The experimental results were implemented for numerical calculations. Chemkin-Pro software was applied to predict the chemical composition of the pyrolysis gas. The performed computer simulations demonstrated very good agreement with the results obtained during the experiments. They also indicated that there is a strong relationship between the chemical composition of the pyrolysis gas, the process temperature and residence time in the reactor. [ABSTRACT FROM AUTHOR]

The possibility of utilizing calumite (BSF) in the glass-ceramic industry was analyzed in this study. The properties of melaphyre glasses modified with 25 % and 50 % of calumite were determined after the post-melting and directional crystallization process. The produced glasses were subjected to microstructural analysis using light LM and scanning electron microscopy SEM. Their chemical composition was determined using XRF spectroscopy. After melting and directional crystallization, the glasses' structural tests were performed using FTIR spectroscopy and XRD phase analysis. The characteristic temperatures and the thermal stability of the glasses were determined with thermal analysis (DTA/TG) and dilatometric tests, which analysis was also valuable to determine the parameters of the directional crystallization process of melaphyre glasses. The results showed that unmodified melaphyre glasses demonstrate a low crystallization ability and do not crystallize even at 900 °C, while incorporating calumite into their composition increases their crystallization ability. The study showed that calumite significantly influences the chemical and structural characteristics of melaphyre glasses, which gives it the chance to be successfully used as a raw material for producing glass crystalline materials or mineral fibres. Notably, the findings underscore the potential utility of calumite as a proficient raw material for fabricating glass crystalline fibrous or insulating materials. [ABSTRACT FROM AUTHOR]

The study assessed the possibility of using waste glass cullet from the screen part of CRTs (cathode ray tube) in the vitrification of asbestos-cement materials (ACM). The composition consisting of 50% by mass ACM and 50% by mass cullet was subjected to vitrification. The research material before and after vitrification was subjected to comparative analysis. As a result of vitrification, a transparent amorphous material was produced with a hardness about 7% higher than that of CRT glass and lower ion leachability in an aqueous environment compared to ACM. X-ray and spectroscopic examinations did not reveal the presence of chrysotile, i.e. a type of asbestos found in ACM. This fact proves that during vitrification the asbestos decomposed and formed a lattice of glass composed of the products of this decomposition. Moreover, the presence of heavy metals in the vitrified product was found, including Ba and Sr, the source of which was the CRT cullet. The obtained research results prove that ACM vitrification with CRT cullet leads to the effective utilization of both types of waste during one technological process. Therefore, the vitrification of ACM can be successfully carried out using waste CRT glass, and the harmless product obtained in the vitrification process can be used in practice. The use of CRT cullet in the vitrification of asbestos-cement materials will also have a positive impact on the environment as it will reduce the amount of electronic waste deposited in landfills. [Display omitted] • The vitrification of ACM can be successfully carried out using CRT glass cullet. • It is possible to simultaneously dispose of ACM and CRT cullet in one process. • The vitrification process transforms the hazardous wastes into a harmless product. • Vitrification is an effective method of neutralizing asbestos-cement materials. • The vitrification process leads to the complete decomposition of chrysotile. [ABSTRACT FROM AUTHOR]