Non-ferrous Metal Production Research Articles

The early medieval origins of copper ore extraction in the Carpathian Mountains

The case study addresses the question of the early medieval revival of copper production in Europe. The focus of the research area is the Carpathian Basin, located on the eastern periphery of the zone influenced by European early medieval processes. The research of where and when early medieval metal production started in the region in our case also provides answers to the question of how the region was linked to the European continental economic network, which is until recently an unresolved problem. Ore extraction and the production of various non-ferrous metals (copper, silver, gold) had important centres in the Carpathian Mountains throughout the Middle Ages until the Modern Era. Concerning the Avar period, our study comprises lead isotope and chemical analyses of ‘Late Avar’ (c. 8th century AD) copper rivets, used for certain purposes alongside the copper alloys predominant in the period. As rivets were selected from the entire Avar cultural area, expanding virtually to all lowland and hilly areas in the Carpathian Basin, results are representative of the entire region. It shows that Avar craftsmen producing large quantities of copper alloy objects in the 8th and the early 9th century were supplied with copper from a single mining district, from the ore deposits of the Slovak Ore Mountains in the today Central Slovakia, a region which became an important metal-processing centre in the 11th century AD.

Ecological problems of technogenic land pollution in the republic of Кazakhstan

A large territory in Kazakhstan is distinguished by the diversity of soils and the complex structure of the soil cover. Soil contamination with heavy metals, especially in the vicinity of large cities and industrial centers, is one of the environmental problems. Of great scientific and practical interest is the determination of the content of heavy metals in soil, their transformation and entry into food and feed. The accumulation of heavy metals in the soil leads to an increase in their concentration in plants, which affects public health. Therefore, the study and identification of areas with high levels of heavy metals in the soil are of increasing importance. The article summarizes the results of a study of soil and vegetation cover in areas adjacent to mining enterprises factories for the production of non-ferrous and rare metals.

The Development of Innovated Complex Process for Treatment of Old Flotation Tailings of Copper-Zinc Sulfide Ore.

The possibility of selective Cu and Zn leaching from the sample of old pyrite tailings, which is one of the most widespread types of solid waste forming during non-ferrous metal production, using sulfuric acid solutions and water was studied. It was shown that water leaching provided selective extraction of Cu and Zn and comparatively low iron ion extraction. At the same time, acid leaching provided the obtainment of pregnant solutions with high ferric ion concentration, which can be used for oxidative leaching of substandard copper concentrates. Water and acid leaching also provided increased Au recovery by cyanidation. The results suggest that acid leaching can be an effective approach for processing old flotation tailings, which allows the extraction of base metals from these wastes and treating flotation tailings for subsequent cyanidation. Effective flotation treatment methods should also provide environmental load reduction, which is caused by the long-term storage of metal-bearing wastes.

Change in mineral resource supplies in production of heavy nonferrous metals in terms of copper and nickel

Change in mineral resource supplies in production of heavy nonferrous metals in terms of copper and nickel

Экономика СССР в начальный период Великой Отечественной Войны. Часть 1

The article analyzes the economic history of the USSR, covering an important period of the history of Stalin’s economic model – the initial period of the Great Patriotic War (1941–1942). The main feature of the Soviet economy during the war was that already in the first months the USSR lost control over the most developed industrial areas. This situation required fundamental reorganization of the structure of the economy, when its main production capabilities were used to produce military equipment at the expense of reducing the output of civilian products. The losses of the USSR economy from the occupation of part of the territory are considered and it is shown that the USSR in 1941–1942 fought Germany and its allies, having halved mobilization and economic potential. The article analyzes the process of transferring the economy to the war economy, which required an increase in the length of the working day and the abolition of vacations, the introduction of the card system, and the relocation of plants to other territories. The structure of state administration bodies, changes in the organization of management and the position of its individual participants in it are studied separately. Tables are given and analyzed, giving an idea of the volume and dynamics of production of means of production in this period, the production of non-ferrous metals, the production of consumer goods, military equipment. It is shown that due to the low quality of military production in the Red Army a huge proportion of non-combat losses, which was primarily due to unrealistic plans. The situation in agriculture is examined, where the decline in productivity was due to a number of reasons, including the predominant mobilization of the population from rural areas with a minimum of reservations, the almost complete cessation of supplies of mineral fertilizers and agricultural machinery and, consequently, a sharp decline in the mechanization of work. The situation in the construction industry, in the work of railroad transport is studied. The calculation of the dynamics of national income for 1940–1942 years is given. Thus, in the initial period of the Great Patriotic War revealed the strengths of the Stalinist economic model and created in the 30-ies military-economic potential, high qualifications of the country’s leaders promoted in the last pre-war years. The greatest achievements of the Soviet economy in this period are associated with the record-breaking rapid transfer of the entire economy on military rails.

Quantification and assessment of hazardous mercury emission from industrial process and other unattended sectors in India: A step towards mitigation

Hazardous pollutants like Mercury (Hg) have emerged as a pressing challenge in recent times where the expanding industrial sector is regarded as the major source in developing country India. In this study, we are trying to identify all possible industrial sectors at district level to quantify Hg emission load across India for the year 2019 using IPCC methodology where the country-specific technological emission factors are used. We have included 5 major sectors out of which emission from coal combustion in thermal power plants accounts for 186.5 t/yr of Hg emission followed by non-ferrous metal production (88.3 t/yr), captive power plants (65.5 t/yr) and fly ash generation from various manufacturing industries (45.9 t/yr). A total of 459.4 t/yr of Hg is released into the ecosystem in 2019 with an uncertainty of ± 48%. This study also estimated that about 233 million people living in and around 10 km periphery of major industrial zones with as many as 17 million people residing near the 10 major hotspots are susceptible to hazardous Hg emissions directly or indirectly. This information would be quite useful in formulating future Hg emission control strategies in India. Environmental ImplicationsPresent study is the first-of-its-kind quantification of Hg emission load from the Industrial process and many unattended sectors over India, which will not only give an insight into potential hotspots regions across the country but also assess the population exposed to it. It will provide aid in tracking the mercury burden to match the international conventions. The findings suggest that about 233 million people are likely to be exposed to hazardous Hg emissions. It will also enlighten the government, policymakers, stakeholders and people about their mercury footprint and envision protecting the biomes and formulating future control strategies in India.

Metallographic study of non-ferrous metal products from the Maray 1 site of the Baitovo Cul-ture in the Lower Ishim River region

The article examines non-ferrous metal products from the Baitovo Culture materials of the Early Iron Age hillfort of Marai 1. This settlement is located in the forest-steppe of the Ishim River region of Western Siberia. The upper building hori-zon marks the settlement of the Baitovo Culture dating to the 4th–2nd centuries BC. Metallographic analysis of 28 items was carried out using the Axio Observer D1m microscope (Zeiss). As a result, eight technological schemes characteristic for the metalworking activities of the Baitovo population have been identified. The study shows that prevailing were smithing tech-nologies in different temperature regimes for the production of non-ferrous metal objects (16 specimens, 57.2 %). The pref-erence was given to hot forging in the red-heat regime at 600–800°C (7 specimens, 25 %), cold forging with annealing (5 specimens, 17.8 %), as well as incomplete hot forging at 300–500°C (3 specimens, 10.7 %). Casting without further refine-ment was recorded in the microstructures of arrowheads, ingots and splashes (9 specimens, 14.2 %). Casting, followed by a slight degree of deformation (20–30 %), was noted in three cases. This scheme correlates with the metalworking traditions of the Itkul and Krasnoozerskaya Cultures, and it was dominant on the territory of the Tobol-Ishim region during the Early Iron Age. Such a low percentage of items related to it could be explained by the absence in Marai 1 of large items cast in moulds needing further refinement (knives, celts, etc.). A microstructural study confirmed the use of pure oxidized copper by the craftsmen of the Baitovo Culture, with characteristic inclusions of Cu–Cu2O eutectic, associated with the Ural production centres. Arrowheads and an ingot made of pure oxidized copper were probably a direct import from the territory of the Itkul Culture. Low-alloy tin and arsenic bronzes, coming from the metal production centres of Kazakhstan and Altai, were also used to the same extent for production of some tools and jewellery. The correlation between the type of product, composition of raw materials and technology of its manufacture has been revealed, which is most clearly manifested in arrowheads and awls. The use of high temperatures and significant degrees of compression (80–90 %) has been recorded in a number of cases, resulting in the appearance of rejects. Cracks of hot brittleness, as well as of cold brittleness, occurred in the process of technological cycle, carried out with an excess of the tensile strength of the metal.

Utilization of local rich banana straw bioresource to solve Cd2+ pollution problem in major non-ferrous metal production areas of Southwest China

The development of non-ferrous metal resources has caused serious cadmium pollution problem in Southwest China. Meanwhile, these areas are rich in bioresources like banana straw. With the assistance of microwave radiation, biomass may accomplish thermal breakdown and carbonization processes efficiently and quickly. In this work, banana straw was used as bioresource to synthesize biochar by microwave pyrolysis for the removal of Cd2+ from aqueous solution. The experiment result showed that the maximum Cd2+ adsorption capacity was 244.43 mg/g. The Elovich kinetic model and the Langmuir isotherm could well fit the adsorption process of Cd2+. Furthermore, the adsorption of Cd2+ by banana straw biochar is achieved through the synergistic effects of mineral precipitation, complexation with oxygen-containing functional groups (OFGs), ion exchange and Cd-π interaction, which accounted for the contribution of 86.57 %, 0.15 %, 3.73 % and 9.55 %, respectively. This study provides an innovative solution of cadmium pollution problem relying on local rich banana straw bioresource.

Development process and future trends of chemical refining agents' influence on grain refinement in aluminum alloys

Aluminum is the world's largest production of non-ferrous metals, with light weight, high specific strength, excellent electrical and thermal conductivity and other characteristics. With the continuous development of aerospace, precision electronic instruments, photovoltaic semiconductors and other emerging strategic industries, the demand for high-performance materials of aluminum alloys has become increasingly strong. This paper reviews the research progress of aluminum alloy melt refinement treatment, summarizes the development history of grain refinement, and evaluates the advantages and disadvantages of various types of refining agents, such as Al–Ti–B, Al–Ti–C, Al–Ti–B/C–Re, etc. The article points out the shortcomings of the current research on the melt refinement treatment of aluminum alloys, and looks forward to the future research direction.

Development of resource-saving technology for copper production at “Almalyk MMC” JSC

This article discusses the possibility of introducing man-made waste from the production of nonferrous metals from metallurgical processing into copper production. Industrial tests have shown that with the use of technogenic waste from the production of nonferrous metals when smelting copper in metallurgical furnaces, it was possible to reduce the copper content both in the converter slag and in the slag of the reverberatory furnace with the possibility of additional extraction of noble metals. Based on the research carried out, a technological scheme for energy- and resourcesaving copper production technology was developed.

ПЕРСПЕКТИВЫ РЕСУРСОСБЕРЕЖЕНИЯ ПРИ ДОБЫЧЕ ЦВЕТНЫХ МЕТАЛЛОВ

The reasons for the weakening of the raw material base of the industry and the relevance of the development of new technologies for the extraction of metals are determined. The results of the analysis of the development of reserves of ore deposits in comparison with world practice are presented. The substantiation of the possibility of strengthening the mineral resource base of non-ferrous metals production by involving substandard raw materials in operation is given.

Assessment of the viability of pozzolanic activity of copper slag for use as supplementary cementitious material in ordinary Portland cement

The production of ferrous as well as non-ferrous metals generates slag as a byproduct material. Ferrous slags are extensively used in the construction sector as supplementary cementitious material (SCM) and aggregates. In this regard, the investigation of potential applications in similar areas for slags derived from the production of non-ferrous metals can help to address issues associated with their disposal, dumping, environmental concerns, etc. The primary aim of this research is to assess the pozzolanic activity of copper slag (CS), a type of non-ferrous slag. This investigation is conducted to replace a portion of ordinary Portland cement (OPC) incorporating CS as an SCM for sustainable construction. To assess the reactivity of the CS, comparisons were drawn with a known pozzolanic material fly ash (FA), and an inert material quartz powder (QP). The processing of raw CS (granular material) was carried out using a laboratory scale ball mill to achieve varying fineness to evaluate the effect of specific surface area (SSA) on reactivity. Initially, the investigations were conducted on paste samples of OPC-CS and suspensions of CS-calcium hydroxide (CH) and were later extended to mortar studies. Mechanical characteristics such as compressive strength and open porosity of mortar specimens were determined to correlate with the paste studies results. The findings suggest that CS does exhibit pozzolanic characteristics although its reactivity is comparatively lower than that of FA. An increase in the fineness of the CS resulted in enhanced pozzolanic activity. Analysis of the hydrated suspension samples showed the formation of Fe-siliceous hydrogarnet phase indicating “Fe” from CS was involved in the reaction with CH. Although OPC-CS mortar samples exhibited similar open porosity compared to OPC-QP mortar samples, the interfacial transition zone (ITZ) porosity in mortar samples of OPC-CS was observed to be reduced indicating the densification of the region due to the pozzolanic reaction of CS. The permissible replacement of OPC with CS as a substitute for FA can be adjusted according to the material's fineness and the desired compressive strength.

КОНСЕРВАЦИОННЫЕ И РАБОЧЕ-КОНСЕРВАЦИОННЫЕ СМАЗОЧНЫЕ МАТЕРИАЛЫ «РОСОЙЛ»

The paper contains an overview of Rosoil rust-preventive, protective and operating lubricants for metallurgy, mechanical engineering and other industries, including for military-industrial enterprises, as well as for the needs of the Ministry of Defense of the Russian Federation and the population. The main physicochemical and operational characteristics of rust-preventive, protective and operating lubricants are given such as rust-preventive greases for corrosion protection of ferrous and non-ferrous metal products during storage and transportation; protective grease lubricants for anticorrosive and mechanical processing of metals; protective antifriction greases for lubrication when manufacturing and operationing steel ropes made of uncoated wire and galvanized wire; universal lubricants for multi-purpose applications; corrosion-preventing oil for protection of military equipment; gun oils for cleaning, lubrication and corrosion protection of artillery and small arms during storage and operation; corrosion inhibitors to improve the protective properties of lubricating oils for various purposes and fuels. It is shown that the range of Rosoil rust-preventive, protective and operating lubricants contains 19 products, most of which are designed to replace imported materials and surpass them in protective properties and tribo-engineering characteristics.

Drivers and decoupling analysis of carbon emissions in the non-ferrous metal industry-evidence from 28 provinces in China.

Emissions from the non-ferrous metal industry are a major source of carbon emissions in China. Understanding the decoupling of carbon emissions from the non-ferrous metal industry and its influencing factors is crucial for China to achieve its "double carbon" goal. Here, we applied the Tapio decoupling model to measure the decoupling status and developmental trends of carbon output and emissions of the non-ferrous metal industry in China. The panel interaction fixed effects model is used to empirically analyze the influencing factors of carbon emissions in China's non-ferrous metal industry. The results show that carbon emissions from China's non-ferrous metal industry have experienced three main states: strong decoupling, growth connection, and negative growth decoupling. The carbon emissions of the non-ferrous metal industry in some eastern and central provinces from 2000 to 2004 were in a negative decoupling state. Most provinces in the western and central regions were either in a strong or weak decoupling state based on the developmental trend of the decoupling state of carbon emissions. However, from 2015 to 2019, the decoupling status of carbon emissions in most provinces in western and central China had a significantly negative, weakly negative, or a negative growth decoupling status. Energy structure, energy intensity, cost, and non-ferrous metal production all have a positive driving effect on carbon emissions in the non-ferrous metal industry. Production had a mitigating effect on carbon emissions in the non-ferrous metal industry between 2010-2014 in the eastern region of China. From the results of our study, we propose policy recommendations to promote a strong decoupling of carbon emissions from the non-ferrous metal industry by improving energy structure, reducing energy intensity, and optimizing production capacity.

Utilizing granulated blast furnace slag as an alternative cement binder

This study addresses the challenges associated with the accumulation of technogenic waste in the production of ferrous and non-ferrous metals. We present the findings of global research on the utilization of blast furnace slag as a sustainable alternative to traditional cement binders. Our scientific investigation focuses on the laboratory exploration of replacing cement binders with a highly efficient clinkerless alternative based on blast furnace slag. The fundamentals of formulating clinkerless binders from slag were thoroughly examined for binder design. Through an extensive review, we conducted tests to identify an optimal composition, constrained within the ranges of 70-90% blast-furnace granulated slag, 14% lime, 1.5-2% gypsum, 1.5-2% C-3, and 2-25% microsilica. The outcome of these tests resulted in the development of a novel binder that combines the characteristics and properties of a lime-slag binder with the advantages of a low water consumption binder. This clinker-free binder presents a sustainable solution for construction, serving as a viable substitute for traditional cement. Our findings contribute to the ongoing efforts in adopting environmentally friendly practices in the construction industry.

Оценка нейрофизиологических параметров состояния нервной системы у работающих в производстве цветных металлов

A comprehensive assessment of the health status includes the functional exploration of the central and peripheral nervous systems. Results of the neurophysiological examination allow elaboration of effective personified therapeutic and preventive programs for the core personnel of non-ferrous metal industry. Our objective was to study functional disorders of the central and peripheral nervous systems in smelter operators for further development of risk-based rehabilitation programs for workers engaged in production of non-ferrous metals. Two cohorts of male workers were examined. The case cohort included 60 smelter operators of a large metallurgical plant situated in the Sverdlovsk Region and the control cohort consisted of 50 unexposed employees. The cohorts were matched by age and years of work experience. The mean age of smelter operators was 37.8 ± 7.9 years and their mean length of current employment was 4.1 ± 4.6 years, while the total length of work under hazardous occupational conditions was 7.1 ± 6.0 years. The case cohort included 39 operators of refinery boilers (mean age: 35.6 ± 7.2 years, mean length of employment: 4.2 ± 4.7 years) and 21 operators of the ore thermal furnace (mean age: 41.9 ± 7.6 years, mean length of current employment: 3.9 ± 4.4 years). All subjects underwent a neurocognitive examination (higher brain function testing), electroneuromyography, the somatosensory evoked response test, and electroencephalography. The results of examining the higher brain function enabled us to form the neurocognitive profile of the workers. We revealed signs of mild cognitive impairment in 30 % and a decrease in the cognitive reserve in 35 % of the cases. The diagnosed peripheral nervous system disorders included distal sensory polyneuropathy of the upper and lower extremities, carpal and cubital tunnel syndromes, cervical and lumbar radiculopathy. The comprehensive neurophysiological examination helps detect early changes in the central and peripheral nervous systems. The findings should be taken into account when developing personal medical rehabilitation programs.

Assessment of neurophysiological parameters of the nervous system in non-ferrous foundry workers

A comprehensive assessment of the health status includes the functional exploration of the central and peripheral nervous systems. Results of the neurophysiological examination allow elaboration of effective personified therapeutic and preventive programs for the core personnel of non-ferrous metal industry. Our objective was to study functional disorders of the central and peripheral nervous systems in smelter operators for further development of risk-based rehabilitation programs for workers engaged in production of non-ferrous metals. Two cohorts of male workers were examined. The case cohort included 60 smelter operators of a large metallurgical plant situated in the Sverdlovsk Region and the control cohort consisted of 50 unexposed employees. The cohorts were matched by age and years of work experience. The mean age of smelter operators was 37.8 ± 7.9 years and their mean length of current employment was 4.1 ± 4.6 years, while the total length of work under hazardous occupational conditions was 7.1 ± 6.0 years. The case cohort included 39 operators of refinery boilers (mean age: 35.6 ± 7.2 years, mean length of employment: 4.2 ± 4.7 years) and 21 operators of the ore thermal furnace (mean age: 41.9 ± 7.6 years, mean length of current employment: 3.9 ± 4.4 years). All subjects underwent a neurocognitive examination (higher brain function testing), electroneuromyography, the somatosensory evoked response test, and electroencephalography. The results of examining the higher brain function enabled us to form the neurocognitive profile of the workers. We revealed signs of mild cognitive impairment in 30 % and a decrease in the cognitive reserve in 35 % of the cases. The diagnosed peripheral nervous system disorders included distal sensory polyneuropathy of the upper and lower extremities, carpal and cubital tunnel syndromes, cervical and lumbar radiculopathy. The comprehensive neurophysiological examination helps detect early changes in the central and peripheral nervous systems. The findings should be taken into account when developing personal medical rehabilitation programs.

Development strategy of Russian metallurgical companies in the new world economic order

Subject. The article investigates features of modern strategic development of iron and steel plants in the Russian Federation Objectives. The purpose is to determine the main directions of development strategy of the metallurgical complex in the production of ferrous and non-ferrous metals in Russia to identify further prospects for industry enterprises. Methods. The study employs methods of scientific cognition, like comparative analysis, synthesis, induction, and deduction. These methods helped to build dynamic and structural models. Results. We performed the analysis of technological innovation effectiveness in the production process of metallurgical enterprises, identified the main problems of the industry resulting from the crisis situation in the country and the world, and considered issues related to interaction of innovation activity and the use of R&D in the development of the industry. The study unveiled the specifics of the Russian metallurgical industry in the field of export, allocation of funds for the introduction of innovation. Conclusions. The development strategy of Russian metallurgical industry for the period up to 2030 set benchmarks for the growth of ferrous and non-ferrous metallurgy, however, Russian enterprises need investments in R&D, which, in the future, will entail an increase in the profitability of their products and a more stable position among international competitors in the market.

Cobalt vacancy-originated TiMnCoCN compounds with a self-adjusting ability for the high-efficiency acidic oxygen evolution reaction

Oxygen evolution reaction (OER) electrocatalysts in acidic media, except for precious IrO2, have difficulty realizing good electrocatalytic activity and high electrochemical stability simultaneously. However, the scarcity of IrO2 as an acidic OER electrocatalyst impedes its large-scale application in hydrogen generation, organic synthesis, nonferrous metal production and sewage disposal. Herein, we report the design and fabrication of a nanoporous TiMnCoCN compound based on the nanoscale Kirkendall effect, possessing an intriguing self-adjusting capability for the oxygen evolution reaction (OER) in a 0.5 M H2SO4 solution. The nanoporous TiMnCoCN compound electrode for the acidic OER displays a low overpotential of 143 mV for 10 mA cm−2 and exhibits no increase in potential over 50,000 s, which is ascribed to the self-adjusting ability, Carbon/nitrogen (C/N) incorporation and nanoporous architecture. The concentration of inert TiO2 on the reconstructed surface of the compound can self-adjust with the change in OER potential via a cobalt-dissolved vacancy approach according to the stabilization requirement. In this work, the self-reconstruction law of surface structure was discovered, providing a novel strategy for designing and fabricating nonnoble OER electrocatalysts with superior catalytic performance and robust stability in acidic media.

Synthesis of new dithiocarbamate and xanthate complexes and their application in enrichment processes

Ore flotation is the main and defining technological process in ore benefication and non-ferrous metals production. The flotation process requires the use of a variety of chemical reagents, including collectors, frothers, surface modifiers, and pH regulators. The development and selection of suitable reagents for the processed material play a vital role in efficient flotation. The flotation activity of collectors depends fundamentally on the composition and structure of the hydrophobic and hydrophilic fragments forming the flotation agent molecule, as well as on the nature of the ore that undergoes flotation processing. In this regard, the identification and study of the “substance structure–flotation activity” relation, as well as the search for new effective flotation reagents gain importance within applied organic and organoelement chemistry and related branches of science and technology. In this article, we review syntheses of effective collector reagents, namely xanthates and dithiocarbamates, based on the literature data for the past five years. Where necessary, earlier sources are provided. The reaction conditions and yields of the target compounds are presented using schemes. In addition, we present the results of flotation tests on the surfaces of various ores and the data on the mechanism of concentrate extraction. According to the reviewed publications, the fixation of collector reagents on the surface of minerals can be regarded as a complexation process of the collector functional groups and metal ions located on the surface of the mineral.