Ключевые слова: secondary raw materials

Research on air purification from pulverized large-tonnage tailings of non-ferrous metal ores and the possibility of their use as secondary raw materials

https://doi.org/10.58224/2618-7183-2025-8-6-1
Аннотация
Pulverized waste (large-tonnage tailings) from the enrichment of non-ferrous metal ores pose a significant environmental threat and a health hazard to the personnel of enterprises and the population of nearby territories. In this regard, this study is devoted to solving the problem of dust suppression with the prospect of subsequent complex tailings processing. The effectiveness of a combined method combining fine-dispersed hydraulic spraying and pulsating ventilation for dust deposition from the tailings of the former Kentau Enrichment Plant (Kentau, Kazakhstan) has been experimentally studied. Laboratory tests were carried out on a specialized stand with monitoring of microclimatic parameters. The results showed that the combined method reduces the dust deposition time by approximately 30% compared to traditional irrigation and by more than two times compared to natural precipitation. Optimal process parameters have been established: nozzle diameter of 10 microns, liquid pressure of 5.4 MPa, air flow velocity of 4 m/s, pulsation frequency of 13 Hz. Based on the X-ray phase analysis of the tailings composition (the total content of zinc compounds is ~3.77%, lead ~4.47%), the economic feasibility of their complex processing is substantiated. A two-stage technology is proposed: preliminary, associated extraction of valuable metals (Zn and Pb) followed by the use of a non-metallized residue rich in oxides of silicon, aluminum and calcium in the production of building materials (cement clinker, ceramics). Thus, effective dust suppression is the first step towards the transition from passive waste storage to active recycling within the framework of the principles of circular economy, which will significantly improve the environmental situation in the region.
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Hydraulic activity of crushing screenings of waste open-hearth slag

https://doi.org/10.58224//2618-7183-2024-7-3-3
Аннотация
Theoretically and experimentally studied the hydraulic activity of crushing screenings of waste open-hearth slag and methods for intensifying the hydration hardening of slag stone during operation. During the hardening of slag stone, three periods of pronounced syneresis with gel new formations strengthening the material were established at the ages of 28 – 60, 90 – 180 days and 1 – 2 years. The first period of syneresis, in contrast to the subsequent ones without changing the strength of the samples, is recorded by the linear shrinkage of the samples, the squeezing out of bound water and the increase in pH. The introduction of two percent of cement dust or lime into the crushing screenings of waste open-hearth slag leads to the strengthening of the slag stone at 28 and 90 days of age by 3 – 4 times. However, by the age of two years, the strength of the samples stabilizes. This fact indicates that the additions of cement dust or lime are not additional binders, but hardening accelerators.
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Study of the characteristics of pavement elements made of rein-forced soil with the use of secondary resources

https://doi.org/10.58224/2618-7183-2023-6-6-2
Аннотация
The importance of using secondary resources on the basis of industrial waste is understood by both governments of developed countries and business (production of Portland cement using ground metallurgical slag as a mineral additive at Novotroitsk, Magnitogorsk, Sterlitamak, Katav-Ivanovsk and other plants in the South Urals). The use of secondary raw materials requires the creation of technological infrastructure for processing of secondary raw materials, the costs of which can be quickly recouped due to the cheapness and availability of industrial secondary raw materials and freeing the territory from environmental pollution. In order to recoup the costs of the infrastructure, it is necessary to guarantee full compliance of the quality of pavement elements with the requirements of GOST R 59120-2021. Secondary raw materials have a great variety and laboratory analysis of the quality of pavement elements is required in order to design compositions with the best quality, satisfy-ing all regulatory requirements. In our work the authors present the results of laboratory research and evaluation of the possibility of using clinker-free lime-slag binder based on the mineral product of so-da production and metallurgical slags to strengthen and stabilize soils for their use in pavement struc-tures in the construction of roads for various purposes and climatic zones.
It is experimentally shown that the addition of lime-slag binder in the amount of 8-10% of the dry weight of both cohesive (loamy soil, loamy sand) and non-cohesive (fine sand) soil allows to obtain reinforced soil with improved strength and elastic-deformative characteristics, which can be used in-stead of scarce natural crushed stone and gravel in the construction of underlying layers of pavements in the construction and reconstruction of highways. This technology can be used not only in the Rus-sian Federation, but also in a number of other countries, including those with hot dry climates (e.g., the Republic of Egypt).
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Recycling of Municipal Solid Waste in Construction

https://doi.org/10.58224/2618-7183-2023-6-5-7
Аннотация
This article discusses a promising direction focused on the use of recycled municipal solid waste in construction. In Russia, there are problems related to municipal solid waste management, which necessitates the modernization of this process and confirms the relevance of the issues raised. Analysis and use of the experience of foreign countries in the processing of municipal solid waste and its secondary use in Russia contributes to the search for a more environmentally responsible approach that entails both economic and social benefits. The use of solid municipal waste recycling products in construction is aimed at minimizing the negative impact on the environment and is a step towards the transition to a circular economy, where waste is turned into valuable resources.
The article reflects on the various methods of recycling municipal waste and analyzes the priority areas for the processing of municipal solid waste. In addition, examples of successful building projects using recycled products are given, and the challenges and prospects of this approach, as well as its significance for sustainable development and environmental responsibility in the construction industry, are revealed.
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