HEAT-RESISTANT CONCRETE BASED ON ORTHOPHOSPHORIC ACID, WASTE OF NON-FERROUS METALLURGY AND CHEMICAL INDUSTRY

Currently, as numerous studies show, raw natural resources are running out, so it is necessary to involve in the production turnover of industrial waste for the manufacture of heat-resistant concrete. At the same time, the costs of geological exploration, construction and operation of quarries are excluded, and significant land plots are freed from the impact of negative anthropogenic factors. Multi-tonnage waste of non-ferrous metallurgy-ferrite-calcium slag containing 50-51 % Fe2O3, was used as an iron-containing filler for the production of heat-resistant concretes. Ferrite-calcium slag is a man-made raw material (production waste) of processing copper-zinc concentrates, obtained by slow cooling of the material to complete scattering, light yellow in color and resembling fine sand. The trivalent iron oxide Fe2O3 contained in the slag reacts very slowly with orthophosphoric acid H3PO4 at normal temperature; therefore, it is necessary to heat the mixture to 70 °C, since its own heat is not released by the reaction. A, the ferrous iron oxide FeO contained in the slag, as well as Fe(OH)3 hydroxide, on the contrary, reacts with the acid vigorously, releasing a significant amount of heat, so the binder dough begins to set after 2 minutes at a temperature of 20 °C due to significant heat release. Chemical industry waste - the spent IM-2201 catalyst was used as an aluminum-containing raw material and is a fine powder with a specific surface area of up to 8000 cm2/g and a fire resistance of up to 2000 oС. Studies have shown that due to the use of orthophosphoric acid as a binder, it is possible to dispose of up to 80-90 % of non-ferrous metallurgy and chemical industry waste and at the same time obtain heat-resistant concretes with high physical and mechanical properties.

Assessment of the impact of chemical pollution of ferrous metallurgy enterprises on forests using satellite photographs

The considered operating ferrous metallurgy enterprise uses three different technological modes of steel smelting, each of which is characterized by an individual composition of the ingredients of chemical pollutant emissions into the atmosphere affecting the state of the forest areas around this enterprise. Based on the decoding of satellite pixel photographs of forest areas, the technological mode with the least impact on forest areas was determined. It corresponds to the condition of the minimum area of ecological zones around the ferrous metallurgy enterprise. The authors propose an assessment of the impact of chemical pollution of ferrous metallurgy enterprises on forests in the form of areas of ecological zones of the state of forest vegetation and the volume of biomass in its various parts. The mosaic of ecological zones of forest areas is determined from their satellite pixel photographs using an original algorithm of “controlled cluster analysis”. The main recommendation for ferrous metallurgy enterprises to choose one of several alternative technological modes is as follows: the choice of technological mode should be based on a comparison of sizes of the areas of ecological zones. In this case, the technological mode with the smallest dimensions of the area is selected. Assessment of the damage caused by the chemical pollution of the plant to forest areas was determined by the area of ecological zones and the volume of biomass loss in forest areas in comparison with the background areas. The boundaries of ecological zones can be determined according to the “dose-effect” dependencies typical for the considered region.

Assessment of the risks of using hydrogen instead of carbon-containing fuels in the ferrous metallurgy

The Paris Agreement, adopted in December of 2015 at the 21st session of the UNFCCC Conference of the Parties and effected from November of 2016, coordinates the efforts of states to reduce greenhouse gas (GHG) emissions, including carbon dioxide. One of its largest emitters to the atmosphere is the metallurgical industry. Among the proposed ways to reduce carbon dioxide emissions is the widespread use of hydrogen in the ferrous metallurgy. An overview of the problems that the ferrous metallurgy will face when replacing carbon-containing fuels with hydrogen is presented. It was noted that the use of hydrogen in the ferrous metallurgy contains such technological risks as high cost in comparison with currently used fuels and reducing agents; explosion hazard and corrosion activity, the need for a radical reconstruction of thermal units when using hydrogen instead of traditional for the ferrous metallurgy natural, coke and blast furnace gases, as well as solid fuels. It is shown that minimizing these risks is not always possible or economically feasible, and the result of using hydrogen in the ferrous metallurgy instead of carbon-containing fuel from the point of view of reducing greenhouse gas emissions may be low with a significant increase of economic and social risks.

Influence of ferrous metallurgy enterprises on atmospheric air quality as an ecological component of territories sustainable development. Report 2

The adoption of the UN Sustainable Development Goals until 2030 served as an impulse for development and implementation of regulatory legal acts aimed at environmental protection in the Russian Federation, including appropriate fnancial mechanisms. The task of reducing level of air pollution is highlighted in the UN program documents as one of the priorities. The most problematic in terms of air pollution in Russia are 12 cities, seven of which have ferrous metallurgy enterprises. The problems of ecological development of large industrial centers remain (despite the implementation of the state program of the Russian Federation “Environmental Protection” since 2012, and the national project “Ecology” since 2019) introduction of a quota system for pollutant emissions substances, determination of the list of compensatory measures and creation of the federal information system for atmospheric air quality monitoring. In cities such as Krasnoyarsk and Novokuznetsk, the average actual annual concentration of some pollutants, which are highly toxic and carcinogenic substances of I and II hazard classes, exceeds the permissible maximum by 5 – 6 times. We have analyzed content of the reports of the specialized state authorities at the regional level on state and protection of environment. It is concluded that there is no unity of methodological approaches to presentation of analytical information on state and quality of atmospheric air in reports, as well as untimely publication of the reports themselves. The fact of inertia of the institutional environment was revealed in terms of including irrelevant norms in the adopted legal acts, and as a consequence – emergence of expenditure obligations of budgets, without real need for them. It was established that large enterprises of ferrous metallurgy (Chelyabinsk Metallurgical Plant PJSC (Mechel) and Krasnoyarsk Metallurgical Plant LLC), operating in cities with very high levels of air pollution, did not draw up corporate non­fnancial reporting in the GRI format.