Biomass is commonly considered as a renewable fuel, which taking into account emission of CO2 does not contribute to the emission of the greenhouse gases. In the research, combustion tests of two types of fuel formed on the basis of straw with addition of polyethylene were performed in the laboratory. The article presents results of measurements of gas pollution coming from the combustion of the formed fuel. Obtained results were compared with similar literature data for the combustion of coal. The research covers also testing of chemical content, content of heavy metals and selected physical properties of ashes generated during the process of burning fuel based on straw.

Mining wastes are by-products generated during search, excavation and processing, both physical and chemical, of ores and other minerals. In 2017, wastes from group 01 constituted 60% of total wastes produced in Poland. According to the statistical data, approximately 92% of the waste generated during the excavation and processing of hard coal is economically reused. 30% of this waste used in industry and nearly 70% is used for the reclamation of the degraded industrial areas. At present, there is a tendency in the E uropean Union to shift from a linear economy to the Circular E conomy. The goal is to maintain economical value of the resources, among others, by their reuse in a productive way, which at the same time eliminates waste. One of the industrial branch where the ideals of a Circular E conomy can be implemented is the mining industry. Mining wastes may form one of the sources of anthropogenic minerals, as they belong to alternative aggregates. Deposits of anthropogenic minerals are considered sources of valuable raw materials which guarantee that the products made on their basis will be of high quality. The article presents the results of physico-chemical tests, the leachability of contaminations and phytotoxicity tests carried out on the basis of the selected mining waste in light of a Circular E conomy.