Chelyabinsk region is the leading metallurgical center of the country. Multiple enterprises of ferrous and non-ferrous metallurgy are located at the region’s territory. Unfortunately, a lot of industrial wastes get produced at factories of various industrial branches. This not only causes certain difficulties regarding their placement and storage, but also imposes a serious ecological threat. Scientists at South Ural State University are solving the problem of disposal of such wastes by applying them in production of building materials within a project entitled “Ecology”.
Production of building materials out of wastes simultaneously solves three problems: economizing the resources of energy raw materials, disposal of wastes, and improvement of environmental situation. Aleksandr Orlov, Head of the Department of Building Materials and Products at the SUSU Institute of Architecture and Construction (IAC), believes that technogenic products (industrial wastes) can be used for production of building materials.
“Industrial enterprises of the Chelyabinsk region produce a big amount of metallurgical slags which, as a rule, get piled in dump pits. Such dump pits take up useful territories. Our inventions allow for the use of this unwanted material and simultaneously do good for ecology,” says Aleksandr Orlov.
Researchers at the IAC Department of Building Materials and Products have been studying magnesia binders for over 15 years. Materials get produced out of industrial dump pits of the Magnezit Plant in the city of Satka. Year after year, these dump pits take up more and more space, affecting the nature and ecology of the region. The scientists managed to solve the scientific problem while making a contribution to enhancement of environmental safety as well as invent materials used, for example, for backfilling of mine workings at a minimal expense.
“Scientists at our Department are developing material, in which modified magnesia wastes of refractory and mining industries are used as a binder instead of using Portland cement, which is today’s most popular binder. Advantage of the new material is in the fact that magnesia materials acquire their grade strength under normal conditions and do not require any special steam treatment. This allows significantly reducing energy consumption and the amount of harmful emissions to the atmosphere,” emphasizes Aleksandr Orlov.
From the mixture for backfilling of mines to translucent concrete
Wastes produced in the process of exploitation of mineral deposits are a prospective raw material for manufacturing a wide range of high-quality building materials. Using them in this sphere will allow for not only reducing the ecological load on the environment and creating “green” mining companies, but will also make it possible to release competitive products of good quality.
“For example, we proposed using blast-furnace granulated slag from the Chelyabinsk Metallurgical Plant in production of dry mixtures and backfill mixtures intended for backfilling of exhausted mines. Leaving an exhausted mine to be open is unacceptable – it needs to be backfilled. For that, we propose using wastes. This is economically advisable and very beneficial from the position of ecology,” explains Aleksandr Orlov.
Products based on magnesia binders quickly acquire high strength without any thermal treatment; they are characterized by high processibility and resistance to the effect of petroleum products, fungi and bacteria. SUSU scientists are developing a number of materials for a wide application range. One of the examples is translucent concrete on the basis of magnesia binding powder, which can be produced out of dolomitic wastes of the refractory industry.
“Nowadays, translucent concrete is mainly used as a decorative finishing material, although in the future it might be quite in-demand for development of a comfortable urban environment,” says the Head of the Department of Building Materials and Products.
Fire-retardant building materials made of wastes
Another important research direction regards studying the methods of using the technogenic wastes for protection of structures against the fire. Scientists at South Ural State University managed to create materials which do not require burning. From the position of economy, this significantly reduces the expenses, as buying and maintenance of burning kilns costs a lot of money.
“We mix a special grouting agent and serpentine. According to our calculation, this variant is less costly as compared to fire-retardant materials existing in the market. We can use wastes as the grouting agent; this will allow reducing the self-cost of end product and improving the environmental situation,” assures Aleksandr Orlov.
Starting from 2018, research in the sphere of ecology have become one of the main prioritized directions in development of research and educational activity at South Ural State University together with digital industry and materials science. Implementation of the project entitled “Production of Building Materials Out of Wastes” is targeted at formation of a favorable ecological environment for Chelyabinsk and the region as a whole.