Problems of the Formation of Dangerous Cr(VI) Compounds in Portland Cement and their Elimination Using New Refractories

Reusing and recycling of secondary raw materials from high-volume industrial productions (especially form construction materials and binders fabrications) is very important way of conserving environment and it is also interesting from the economical point of view. The production of common hydraulic binders, especially Portland cement, burdens the environment with considerable amount of combustion gases and consumes energy in massive scale. Alternative (low – energy) binder can be used as Portland cement substitution in applications with lower mechanical properties requirements. Mined limestone wash sediments contain large amount of clay components, but there is also indispensable share of fine calcite. This composition makes these sediments a promising material for the preparation of hydraulic binders as Roman cement or hydraulic lime.

Recycling of the product of thermal inertization of cement–asbestos for various industrial applications

For many years fuel and energy and ore-dressing industries have been the sources of industrial waste which, if treated correctly, can be reused as secondary raw material resources accumulating earlier wasted investments and power costs. The article introduces possible ways of recycling both in our country and abroad. Basing on this, ways of reusing man-produced wastes in Grozny as bottom ash waste and chippings from rock crushing into spalls have been described. Study results showed that secondary man-produced raw material can compete with and substitute non-renewable natural resources as their chemical composition and quality parameters prove their unique nature, also it is possible to take into account solution of ecological problems. Developed formulas of multi-component bindings based on finely dispersed fly-ash and concretes with the use of enriched artificial aggregates promoted recycling of secondary raw materials and improving ecological situation in the region.

Topicality. Secondary raw materials of winemaking are a rich source of biologically active compounds, which makes it possible to use it for the production of a wide range of products of high value for various industries: food, pharmaceutical, perfume and cosmetic, chemical, etc. However, currently in Ukraine and in Moldova there are no specialized enterprises for the integrated processing of secondary raw materials of winemaking. In the vast majority of cases, in particular, crests and squeezes are uncontrolledly exported to agricultural lands without special treatment, which leads to acid soil erosion and environmental pollution by metabolites of micromycetes. At the present stage of technological development there is a wide range of innovative developments in the field of recycling of secondary bio-materials, in particular grape excrements, in order to obtain biologically valuable components. The main task in this direction is to create an organizational and economic mechanism that will unite the interests of winemaking enterprises (owners of secondary raw materials), processing enterprises (producers of secondary products of winemaking), representatives of local authorities and potential consumers of innovative products. A cluster ideology may be an effective tool for consolidating the interests of stakeholders in this direction. Aim and tasks. Development of the concept, formation and functioning of the cross-border cluster on the processing of secondary raw materials of winemaking, the core of which is the innovation-investment center, which provides cooperation of science, business and administrative resources, allows to provide non-waste technologies and use innovative solutions. In the process of recycling of secondary raw materials of winemaking in Ukraine and Moldova (about 100 thousand tons) is the possibility of obtaining more than 50 secondary winemaking products, which are in high demand in various sectors of the economy. The main objectives of this study are: ensuring sustainable development and the principles of the "green economy" in the development of viticulture and winemaking in Ukraine and Moldova; creation of high value-added biologically valuable products; obtaining social and synergistic effect in the process of forming a cluster. Research results. A systematic approach to the complex processing of grapes on the basis of cluster ideology is proposed. The proposed architecture of the cluster as managerial innovation in the subregional, regional, national and transboundary context allows us to form the poles of economic growth by consolidating and converting different types of capital: human, social, productive, natural, financial and intellectual to obtain additional economic benefits. The developed concept shows that sustained efficiency is achieved, first and foremost, enterprises are able to combine efforts and capital. Conclusions. The analysis of technology of processing of grapes on wine materials in Ukraine and Moldova is carried out. The following is the list of the most promising products obtained from secondary raw materials of winemaking. The concept of creating a cross-border cluster for the processing of secondary raw materials of winemaking, which is based on the principles of the green economy.

Research in the sphere of the Arctic industrial development often leads to the identification of clear regulatory gaps of a systemic nature. A particular example is the issue of legislative regulation of the involvement of secondary raw materials, fuel and energy resources in economic use and property turnover in the context of resource conservation and resource efficiency. In this case, secondary resources are not subject to independent regulation in general, but only as one of the elements of activities related to environmental protection. Accordingly, the conditions for the development of a system of production and consumption wastes’ effective management, the creation of a recycling industry, including the reuse of such waste, have not been formed yet. The results of the analysis given in this research paper clearly indicate the lack of development of mechanisms for stimulating the use of non-target materials and substances. Industrial enterprises that use secondary resources in production do not currently receive special advantages within the framework of the implemented industrial policy. System benefits are universal and directly related to commodity production only. However, it is necessary to apply measures to encourage industrial activities to implement projects involving the reuse of secondary resources in production, including in the Russian Arctic.

In the process of producing ferroalloys, a large amount of secondary raw materials is formed, including slag, aspiration dusts and sludge. The recycling of secondary raw materials can create resources and bring environmental and economic benefits. Wet secondary raw materials (WSRMs) are characterized by a high chromium oxide content (averaging 24%), but due to their high moisture levels, they cannot be directly used in arc furnaces. As a strategic approach, mixing WSRMs with drier, more chromium-rich dusts (up to 45% Cr2O3) has been proposed. This not only reduces the overall moisture content of the mixture but also enhances the metallurgical value of the charge material. This paper presents the results of laboratory studies on the agglomeration of secondary wet raw materials using briquetting, extrusion and pelletizing methods. The main factors influencing the quality of the resulting product were analyzed, including the method of agglomeration, the composition of the mixture, as well as the type and dosage of the binder component. The strength characteristics of the finished agglomerated samples were evaluated in terms of resistance to splitting, impact loads and falling. Notably, the selected binders are organic and polymer substances capable of complete combustion under metallurgical smelting conditions.

The increasing demand for raw materials in our society and the requirements for supply security in particular regarding the critical raw materials require the implementation of sustainable resource management in the sense of the best possible conservation of natural resources as well as the promotion of recycling and recovery of valuable materials from waste. In the mining sector, classification systems like CRIRSCO were introduced to communicate the viability of projects. In the realm of resource classification, the United Nations Framework Classification of Resources (UNFC) stands as a crucial tool, offering a principles-based approach to classifying the viability of any kind of resource development projects including renewable energy or groundwater. By systematically classifying projects based on their environmental, socio-economic, and technical aspects, the UNFC provides decision-makers with valuable insights for making choices regarding their viability and offers the opportunity to take sustainability aspects into account. A consistent evaluation and classification of projects according to the same premises as for primary raw materials can significantly contribute to the efficiency of initiatives for the recovery and recycling of secondary raw materials including mining waste. There is a Guidance[1] for the Application of the United Nations Framework Classification for Resources (UNFC) for Mineral and Anthropogenic Resources in Europe. However, it doesn’t include end-of-life products as anthropogenic resources. There are also no instructions on how to evaluate and classify SRM projects. To bridge the gap, our focus has centered on the development of a web-based tool explicitly designed for the assessment of SRM recovery projects in line with the principles of the UNFC. A seven-stage approach was developed to streamline the evaluation process and by that, improve the accessibility and applicability of the classification system. Its design, features, and functionalities are tailored to ensure a user-friendly interface. Users are guided from the outset by defining the project and its systems boundaries, formulating the project’s objective and the context of evaluation, including the choice of the controlling factors, to carry out a thorough analysis of SRMs and thus align their initiatives with the principles of the UNFC. At the end, a template is available for reporting. This poster presentation aims to emphasize the versatility and effectiveness of our web-based tool through a practical example, using a publication developed to classify a tailings storage facility in Germany. Through an interactive demonstration, the user-friendly interface, the power of customizable inputs, and the seven coordinated steps that guide users in assessing the feasibility and viability of secondary raw material projects will be discussed. Attendees will gain a deeper understanding of how the tool facilitates informed decision-making by providing a systematic approach to evaluating projects involving secondary raw materials, aligning with the principles of the UNFC. [1] https://unece.org/sites/default/files/2022-11/UNFC%20GUIDANCE%20EUROPE-FINAL.pdf

With the popularity of new-energy vehicles, the recovery and reuse of lithium-ion battery (LIB) resources have become topics of great concern. This study explores the risks of the lithium resource chain in terms of supply–demand balance and lithium resource criticality. We propose a prediction algorithm for lithium production based on reverse-order MT-EGM-SD (metabolism–even grey model–system dynamics), upon which a system dynamics model for lithium resource recycling and reuse is constructed. We use dynamic simulation to evaluate the benefits of lithium resource recovery and the effects of different LIB recovery strategies. The results show that LIB recycling strategies, such as enhancing subsidy levels and strengthening public awareness initiatives, can significantly increase lithium resource recovery rates. From a medium- and long-term perspective, however, the technological progress strategy can greatly reduce lithium consumption intensity in the battery. Cascade use policy has significant economic benefits, but it delays the recycling of secondary raw materials. Under the joint strategy with the best resource efficiency (stringent government recycling regulations and significant advancements in battery production technology), the lithium supply–demand balance and the lithium resource recovery rate increase by 301.89% and 795.65%, respectively. Meanwhile, lithium resource chain risk, lithium criticality, and actual lithium demand decrease by 18.77%, 18.86%, and 75.11%, respectively.

Use of Selected Minerals as Secondary Raw Materials in Cement Industry. Part I: Effect on the Burnability of Raw Mix

The reuse and recycling of secondary raw materials is essential to ensure sustainable development and the rational use of natural resources. One of the most important types of secondary raw materials is plant-based food waste, which is generated in large quantities at food processing plants, including sugar beet pulp, which is a valuable resource for further use. One of the main problems with using beet pulp is its high moisture content, which is ≈ 80 % wt. It is proposed to dry beet pulp by filtration drying, which is highly efficient. The calculation of industrial equipment for filtration drying should take into account the costs of overcoming the hydraulic resistance of a stationary layer of material. The aim of the article was to study the hydrodynamics of the flow of a thermal agent through a stationary layer of beet pulp of different heights and to perform computer modelling of this process. The obtained results will allow predicting the hydraulic resistance of a material layer of different heights and the required pressure drop to ensure the course of the drying process under various possible technological modes. For computer modelling of the flow of a thermal agent through a stationary layer of beet pulp, the porous media method was used in the ANSYS Fluent 2022 R2 software package. The process was simulated on the basis of the Navier-Stokes system of differential equations and the flow continuity equation with the additional use of the Darcy equation to determine the value of the hydraulic resistance of the layer ΔP. Computer simulations of the hydrodynamics of the thermal agent flow through a stationary layer of beet pulp were performed for the range of stationary layer heights H = 90÷110 mm with an interval of 5 mm. The obtained data showed a relative average deviation of 2.19 % from the experimental data, which indicates a high accuracy of calculations in this range. The study for the extended range of layer heights H = 80÷120 mm with an interval of 10 mm showed an increase in the relative average deviation to 4.09 % from the experimental data, but the results are still sufficiently accurate for practical use in the calculation of drying equipment. The obtained dependencies may be used to determine the value of the hydraulic resistance of a stationary layer of material using the filtration drying method and for practical calculations of drying equipment. Together with the results of the kinetic regularities of filtration drying, the obtained experimental data and computer modelling data on the hydrodynamics of the flow of a heat transfer agent through a material layer will allow us to calculate the optimal parameters of filtration drying for beet pulp and to assess the efficiency of filtration drying for drying beet pulp in comparison with other methods of dehydration.

The paper presents an analysis of experience of using the products of dismantling of buildings and structures, the technology of recycling of secondary raw materials to produce secondary raw materials for concrete. We presented results of tests of heavy concrete based on filled binders using the products of processing of concrete and brick scrap.

Recycling of the product of thermal inertization of cement–asbestos for the production of concrete

На сегодняшний день положение отечественных сельхозпроизводителей обусловлено отсутствием стабильности производства продукции АПК и существующей нехваткой знаний и компетентной составляющей в глубокой переработке и реализации данной сельхозпродукции. Чтобы отечественные сельхозпроизводители вышли на уровень конкурентоспособных участников рыночной экономики, необходимо внедрять и запускать шестеренки решающих факторов, как одних из основополагающих развития. В данной статье выработана стратегия и рекомендации по применению в сельскохозяйственной промышленности безотходных и малоотходных технологий, которые обеспечивают комплексную переработку сырья, что позволяет увеличить производительность производства и одновременно снизить антропогенное воздействие на экологию. Переработка вторичного сырья будет способствовать созданию конкурентного преимущества. Для такой высокорентабельной переработки и реализации вторичного животноводческого сырья требуются определенные научные, практические знания и специальное оборудование. Today, the position of domestic agricultural producers is due to the lack of stability in the production of agricultural products and the existing lack of knowledge and a competent component in the deep processing and sale of these agricultural products. In order for domestic agricultural producers to reach the level of competitive participants in the market economy, it is necessary to introduce and launch gears of decisive factors, as one of the fundamental development. This article has developed a strategy and recommendations for the useof non-waste and low-waste technologies in the agricultural industry, which provide a comprehensive processingof raw materials, which allows increasing production productivity and at the same time reducing the anthropogenicimpact on the environment. Recycling of secondary raw materials will help create a competitive advantage. For such a highly profitable processing and sale of secondary livestock raw materials, certain scientific, practical knowledge and special equipment are required.

A review of the use of industrial wastes in our country and abroad was conducted, and prospects for using man-made raw materials at the Grozny CHP and wastes of subsurface rocks crushing were considered. The analysis of the results of the conducted research is carried out, which showed that secondary technogenic raw materials can successfully compete and replace exhaustible natural resources, since the chemical composition and qualitative parameters of the materials under study confirm its uniqueness and, moreover, there is can see a solution of environmental problems. The formulation of multicomponent binders and concretes based on fine-dispersed ash microspheres and enriched artificial aggregates promoted recycling of secondary raw materials and improvement of the ecological situation in the region.

The experience of operating a DC arc furnace in JSC "Krastsvetmet" for recycling of secondary raw materials using periclase-carbon products as a working layer of lining is presented. A comparative analysis of the operation of a DC arc furnace with periclase and periclase-carbon lining is described.Ill.2.