Metallurgical Operations Research Articles

A comprehensive Review into Emission Sources, Formation Mechanisms, Ecological Effects, and Biotransformation Routes of Halogenated Polycyclic Aromatic Hydrocarbons (HPAHs)

Halogenated polycyclic aromatic hydrocarbons (HPAHs, H = F, Cl, Br) are a new class of PAHs derivatives that mainly originate from the incomplete combustion of halogen-laden materials and via metallurgical operations. These compounds circulate extensively in various environmental matrices. This survey provides a comprehensive review on governing synthesis routes of HPAHs, their environmental occurrence, and their health and ecological effects. The review comprehensively enlists and presents emission sources of these emerging organic pollutants into the air that serves as their main reservoir. The formation of HPAHs ensues through successive addition reactions of related precursors accompanied by ring cyclization steps; in addition to direct unimolecular fragmentation of parents halogenated. Halogenation of parent PAHs rapidly occurs in saline ecosystems, thus multiplying the availability of these notorious compounds in the environment. Certain HPAHs appear to be more carcinogenic than dioxins. Transmission routes of HPAHs from their emission sources to water bodies, soil, aquatic life, plants, terrestrial animals, and humans are well-documented. Later, the direct and indirect diffusion of HPAHs from air to the biotic (plants, animals, humans) and abiotic components (soil, water, sediments) are described in detail. The study concludes that HPAHs are permeable to the carbon matrices resulting in the alleviation of the source-to-sink interface. As a potential future perspective, understanding the transmission interfaces lays a foundation to intervene in the introduction of these toxicants into the food chain.

Stirred media mills of fine and ultrafine grinding for subsequent beneficiation operations

This paper presents a brief review of the designs, characteristics, and operating parameters of Stirred media mills supplied by foreign manufacturers. An analysis of information on Stirred media mills , which are used to improve the efficiency of beneficiation and metallurgical operations, is carried out using available publications. The obtained results indicate the inexpediency of using conventional drum ball mills for flotation separation of ores and concentrates with a fine interpenetration of minerals. The application of conventional mills in extraction of ores and concentrates resistant to cyanidation, where gold is finely disseminated in sulfides, is limited by their high power consumption and the corresponding operating costs. In this work, different types of Stirred media mills are considered, including their vertical and horizontal types. The advantages of Stirred media mills over conventional ball mills, particularly in terms of energy efficiency, are noted. The designs and main characteristics of Stirred media mills , which have received wide application, are presented. According to the data presented in the reviewed publications, the main parameters determining the grinding process in such mills are outlined, including the ratio of bead size to mill feed size, density of grinding medium, density of pulp in the mill, volume loading of beads, stirring speed, etc. The conducted analysis of literature data indicated high efficiency of mills based on agitation of grinding media for fine and ultrafine grinding of ores and concentrates in comparison with conventional ball mills. Given that the volume of ores and concentrates resistant to processing by conventional methods is increasing, the application of Stirred media mills is expected become more widespread, thereby increasing the efficiency of subsequent beneficiation and metallurgical operations.

Isothermal reduction and comparative analysis of reaction kinetics of sponge iron produced from hematite-charcoal reaction using non-contact direct reduction method

The challenge of making sponge iron, or direct reduced iron (DRI), is hard to overstate. These are a key feed for metallurgical operations while iron extraction sets these limits, which include scarcity of metallurgical coke, poor environmental impact, and high production cost. Thus, the non-contact direct reduction process of DRIs has the potential to significantly reduce carbon deposition and CO2 emission from the ironmaking process. This work produced sponge iron from commercially acquired hematite ore using an alternative reducing agent (i.e. charcoal) under specified isothermal conditions. Comparative analysis of reaction kinetics models including Ginstein−Brounshtein and Shrinking core models was also performed to ascertain the resistances that control the reaction rate for reduction degree up to 98.1%. The reduction kinetics were found to be described by reaction control time and activation energies based on a shrinking core model as the reduction time lasted for 120 min at temperatures 843–1273 K. At temperatures above 973–1073 K, the rate-limiting step was found to be solely an interfacial chemical reaction process, with an apparent activation energy of 196.1 kJ/mol. In addition, a slowing trend was observed for iron ore sample sizes 10–20 mm as a result of ash layer infiltration around the inner-core structure of the DRI metal matrix. The DRI morphological characteristics were performed using Scanning Electron Microscopy (SEM) and Electron Dispersive Spectrometry (EDS) to ascertain the mineralogical and morphological properties of the DRI samples. The XRF analysis confirms that the raw iron ore sample is hematite. Its iron content is 70.04% metallic iron (TFe) which has 83.59% Fe2O3 The SEM/EDS image also revealed the presence of micropores on the DRI morphology. This indicates that the reduction ratio and swelling extent rise with the temperature and time. This happens for all DRI sizes. However, the EDS result confirms the presence of gangue elements within the DRI metal matrix and mineralogical structure. The DRI contains very high silicon content up to 33.90%. So, a fluxing experiment is needed using limestone (CaCO3) or quicklime (CaO) quicklime to remove gangue (silicate, aluminate) from the DRI matrix. At the set reduction temperatures, the largest metallization degree of 93.05% at 1273 K for a reduction time of 120 min was achieved. This showed that the overall reduction process still follows the expected chronological order since the NDR process uses CO gas from preheated charcoal. This makes DRI be produced from raw hematite under non-contact reduction bases. Therefore, the NDR technique offers a viable option for sponge iron production in modern-day iron and steelmaking processes.

Flowsheet development for and commissioning of the Kamoa-Kakula project

The Kamoa-Kakula copper resource, located west of Kolwezi in the Democratic Republic of the Congo, was discovered and explored by Ivanhoe from 2008/9 on. As a greenfield project with prospects of high grade ore and a long life-of-mine, the need for best practice flowsheet development was recognised, so as to ensure sustainability of metallurgical performance at the at the maximum economic level from the orebody during metallurgical operations. Process Mineralogy, a hybrid discipline, has been developed in the mining industry over the last forty years, and its proper use has seen very successful outcomes in flowsheet development (Bradshaw, 2014; Lotter, 2011; Lotter et al., 2003; McKay et al., 2007; Pease et al., 2005). Drill core was sampled at site across six phases of flowsheet development that worked with the developing mine plan. The two main geomet units were hypogene and supergene, with the hypogene being unusually rich in bornite. The main variability is between supergene and hypogene, and between Kamoa and Kakula, but with less spatial variability within them. The first viable flowsheet was developed and demonstrated in nine months of test work, followed by various revisions and iterations as required by the discovery of variable mineralogy. The first flowsheet, called “Milestone”, was then challenged with an opportunity for a simpler but better-performing flowsheet, which became known as IFS4A. The simultaneous discovery of the Kakula resource refocussed the project due to its shallower depth and higher grade. Laboratory scale flotation testing using IFS4A in Phase 6 of Kamoa and two drill-holes of Kakula quickly confirmed that the Kakula ore outperformed the Kamoa supergene ore using this flowsheet. A mini-pilot plant campaign was run in 2019 with this flowsheet plus modifications, using 985 kg of metallurgical drill cores material to demonstrate the full flowsheet mass and value balance on a continuous operating campaign. This mass and value balance produced an estimated 85.6 % Cu recovery with a saleable concentrate grading 57.3 % Cu. Whereas this paper concentrates on the mineralogy and its contribution to process implications such as grinding requirements and flotation strategy, it is recognized that first-class design, engineering and construction contributed in no small measure to the successful start-up. This mass and value balance was used in the design of the grinding and flotation circuits, and contributed to the successful commissioning of the new concentrator in 2021, which averaged a recovery of 84.7 % at a grade of 50.5 % Cu, in good agreement with the testwork. A McNulty model for the commissioning data shows a better than Type 1A start-up. The flowsheet development part of the project is discussed in this paper as a case study.

Prediction of energy consumption in grinding using artificial neural networks to improve the distribution of fragmentation size [Predicción del consumo de energía en la molienda utilizando redes neuronales artificiales para mejorar la distribución del tamaño de la fragmentación

The study focuses on the prediction of energy consumption in grinding processes using artificial neural networks (ANN). The purpose was to develop a predictive model based on artificial neural networks to estimate energy consumption in grinding and improve the fragmentation size distribution, which is crucial for the efficiency of mining and metallurgical operations. Energy consumption in grinding represents a significant part of operating costs and directly influences the profitability of operations. The ANN was trained from a data set of 126 records, which were divided into 80% for training and 20 % for model testing. The results of this research highlight optimal performance of the predictive model with performance metrics such as Mean Absolute Error (MAE), Mean Square Error (MSE), Root Mean Square Error (RMSE) and Correlation Coefficient (R2), with values of 0.78, 1.39, 1.18 and 0.98, respectively in the estimation of energy consumption in the grinding process. Finally, these results indicate that the ANN achieved an accurate prediction of energy consumption in the grinding process, this will allow better baking in energy optimization.

Critical Review of the Metallurgical Operation of the Greek Nickel Industry and Perspectives, based on the recent Industrial Experience on Smelting Reduction Process

The mining and industrial production of Greek ferronickel industry LARCO have ceased since 30.07.2022. The last LME nickel price crisis, exclusion from bank loaning, extremely high cost of electrical energy, management issues, resulted inter alia, in a prohibitive operational cost. Nevertheless, LARCO faces the challenge of restructuring and reoperation in the future, given that privatization is in progress, including the acquisition of the company’s assets to a joint venture enterprise.
 Within this framework, the current paper aims to contribute to the discussion for developing a new management strategy for the optimization of pyrometallurgical process, focusing on the critical step of smelting reduction. Based on industrial experience concerning open bath submerged arc electric furnaces, factors which critically affect the safety and cost-effectiveness of smelting reduction are detected and presented by means of case studies, being mainly classified as following: i) Optimal raw materials’ feed management, including laterite ores (domestic or not), solid fuels and electrode paste. Moreover, taking for granted the need for Ni-rich ‘foreign’ ores to increase the recovery and reduce the cost of the process, the extent of dependence on Fe-rich domestic ores is investigated, in order a safe and stable operation to be ensured. ii) Focus on preventive maintenance management. Substantial increase of the facilities’ operational index and cost saving is obtained, as proved by operational case studies. iii) Modern human resources management strategy. Their economical footprint is further discussed.

Emergence of Bio-hydrometallurgy to Achieve Sustainable Process Development Goals in Extractive Metallurgy

The stringent environmental regulations and growing awareness of the low-carbon economy are presenting immense challenges to metallurgical operations, one of the major sectors with high emissions. Hydrometallurgy has been identified as a lower-emission technology in comparison to the high-temperature smelting and melt-refining processes. The close monitoring of traditional hydrometallurgical operations, however, does not fulfil the criteria for a sustainable, low-emission process. Recently, biotechnology has emerged as a green alternative within the hydrometallurgical domain, albeit significantly different from the basics involved in the process. Although the application of microbial activity has been successfully established in chalcopyrite leaching and bio-oxidation of gold-bearing minerals, the acceptability of bio-hydrometallurgy for other minerals and materials is still limited due to a wide research gap to connect solution chemistry, microbial activity, and extractive metallurgy. In general, a large portion of the total chemical consumption occurs in pre-treatment and/or leaching operations; hence, the primary application of microorganisms at the forefront can significantly minimize the overall consumption. Demonstrated applications in waste printed circuit boards and spent automobile catalysts have curtailed excessive acid usage, while the energy-intensive baking/roasting of monazite is successfully altered by microbial processing. Furthermore, the remarkable reduction in carbon footprints by the green biotechnology application in hydrometallurgy has been evaluated, which indicates sustainability in process metallurgy.

Recovery of Magnetic Particles from Wastewater Formed through the Treatment of New Polycrystalline Diamond Blanks

Cobalt’s pivotal role in global development, especially in lithium-ion batteries, entails driving increased demand and strengthening global trading networks. The production of different waste solutions in metallurgical operations requires the development of an environmentally friendly research strategy. The ultrasonic spray pyrolysis and hydrogen reduction method were chosen to produce nanosized magnetic powders from waste solution based on iron and cobalt obtained during the purification process of used polycrystalline diamond blanks. With specific objectives focused on investigating the impact of reaction temperature and residence time on the morphology, chemical composition, and crystal structure of synthesized nanosized cobalt powders, our research involved 15 experimental runs using two reactors with varying residence times (7.19 s and 23 s) and distinct precursors (A, B, and C). Aerosol droplets were reduced at 600 to 900 °C with a flow rate of 3 L/min of argon and hydrogen (1:2). Characterization via scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and X-ray diffraction revealed that higher temperatures influenced the spherical particle morphology. Altering cobalt concentration in the solution impacted the particle size, with higher concentrations yielding larger particles. A short residence time (7.9 s) at 900 °C proved optimal for cobalt submicron synthesis, producing spherical particles ranging from 191.1 nm to 1222 nm. This research addresses the environmental significance of recovering magnetic particles from waste solutions, contributing to sustainable nanomaterial applications.

Impacts of Arrhenius activation energy and oblique magnetic field on the flow of freely oscillating nanofluid over a rough surface

The significance of freely oscillating unsteady stagnation flows is attributed to their use in various kinds of engineering processes like cooling systems, heat exchangers and turbomachinery. The restrictive forces produced with the help of magnetic fields are a useful technique in providing optimum flow control in the metallurgical operations and refinement of molten metals. The present study highlights the inclined magnetic field implications on an oscillatory streaming nanofluid which impinges non-orthogonally over a non-smooth surface. The surface roughness of the wall is elaborated by the slip velocity condition. The two-phase Buongiorno nanofluid model is being considered. The energy dissipation due to the active chemical reactions occurring in the flow is adopted with Arrhenius activation energy. Suitable dimension-free variables are chosen to make the mathematical model parameter dependent. The numerical outcomes of the problem are determined through the utilization of the bvp5c solver based on the finite difference method using MATLAB R2023a. The graphical representations depict significant alteration in concentration profiles with thermal ratio and Activation energy (). The findings indicate that higher activation energy and weaker temperature conditions increased the mass transfer. In conjunction, the velocity profile is enhanced for acute magnetic field angles.

Mitigation of Mining Effects on the Environment

Editor’s note: The aim of the Geology and Mining series is to introduce early career professionals and students to various aspects of mineral exploration, development, and mining in order to share the experiences and insight of each author on the myriad of topics involved with the mineral industry and the ways in which geoscientists contribute to each. Abstract All human activities produce waste and affect our environment, including the solids and water involved during mining and metallurgical operations. The nature and characteristics of these impacts vary considerably depending on many factors, including the geology of the operation, type of mining and processing implemented, sensitivity of the local environment to the operation, and proximity to human settlements or sensitive environmental settings. Environmental challenges associated with mineral extraction and processing include impacts to land, air, water, soil, flora, fauna, and socioeconomic fabric. Mines can generate large land disturbances and can also result in sterilization of land through deposition of barren, nonreactive rock piles (termed waste) during production and after operation. Other mine waste piles can be chemically reactive and interact with precipitation and runoff, leading to metal and sulfate release into surface and ground water. Impacts on soils may result directly from weathering of mine waste or through interaction with affected waters. Interaction with the atmosphere may occur, with release of aerosol or airborne metals or minerals affecting air quality. In addition, the release of gases containing CO2, SOx, and NOx and halide gases can lead to acid rain or general lowering of air quality. These challenges can be predicted, quantified, and understood during the mine design and operations processes by application of geologic knowledge, geochemical and hydrogeological data, and mining experience. Such understanding can then identify appropriate solutions, including changes to operations through sequenced mining to reduce exposure of material with high metal or sulfide content; partial or full backfill of mine excavations; use of cemented waste backfill; modifications to water discharge designs; and treatment of water prior to discharge. A critical aspect of addressing environmental challenges and reducing environmental impact involves engagement with communities, government, and society. The confidence of society is essential to the delivery of long-term sustainable plans.

Properties of liquid CaO–SiO2 and CaO–SiO2-‘Fe2O3’tot slags measured by a combination of maximum bubble pressure and rotating bob methods

Liquid slag properties are essential for understanding complex mass and momentum phenomena in metallurgical operations. The density, surface tension and viscosity were measured in six silicate-rich slags of the CaO–SiO2 and CaO–SiO2-‘Fe2O3’tot systems by combining the maximum bubble pressure and rotating bob methods. The properties investigated were sensitive to the temperature, SiO2 and Fe2O3 contents. Different experimental trends were derived due to the amphoteric properties of Fe2O3. The slags with ferric oxide were denser than the silicate melts. Surface tension gradually decreased with temperature and indicated firstly a rise and then decline with further Fe2O3 addition. Raman spectra were analyzed to provide structural information of the polymer melt and indicated an enhancement in the polymerization degree with Fe3+. The derived experimental trends and role of Fe3+ in the silicates were attributed to the interplay of complex factors: different bonding in the melt, cation interactions and the oxidation state of iron. The influence of Fe3+/Fe2+ on the melt properties was discussed.

Novel applications of Cold Atmospheric Plasma for the treatment of Plaque Psoriasis

Plasma is the fourth state of matter other than solid, liquid and gases. About 99 percent of mixture of free positive negative charges, neutral particles and photons. The plasma exists in two forms: hot plasma and cold plasma. Hot plasma is used in metallurgical operations while cold plasma is used in medical, skin psoriasis treatment, food agricultural, preservation and waste water treatment. Many clinical studies prove the effectiveness of cold plasma in dermatological disease management. Recent researches have established that combined use of cold plasma and nano-formulations is helpful in delivery of poorly water-soluble drugs. Plaque psoriasis is an autoimmune disorder in which silvery, thick, dead layer of skin shades off and cause inflammation, sometimes bleeding. It occurs in 3-4 percent of total world population. Scientific studies have proved that nano-scale particles permeate easily and interact with immune cells like lnterleukin-16, cytokines and TNF-alfa during inflammation and autoimmune disorders. As a result of which, thick layer of keratinocytes is produced and formation of TNF-alfa and interleukin is inhibited which are the causes of Plaque psoriasis. Since conventional medication has only been helpful in managing it, researches have been carried out using various techniques like phototherapy, use of UVA, UVB, IPL (Intense Pulsed Light), PDL (Pulsed Dye Light), LASER and low-level LASER light etc. but their excess exposure causes risk of skin cancer. Other therapies like use of nanometric Liposomes, Niosomes and their combination therapy are some novel clinical techniques for combating symptoms but are still in clinical trial. Since, Plasma therapy is non irritating and stops the triggering mechanism of inflammation, hence the use of nanotechnological topical formulation in combination with plasma therapy has the potential to become possible treatment of Plaque Psoriasis in future.

Statistical Optimization of Bioleaching for Simultaneous Recovery of Cu, Sn, Pb, and Zn from Computer-Printed Circuit Boards

Electronic garbage is one of the fastest-growing waste streams. Its disposal and appropriate management are a worldwide concern. Printed circuit boards (PCBs) are critical components in contemporary electronic gadgets that contain toxic elements. Bioprocessing of PCBs for metal recovery employing microbial methods has evolved as a green solution in metallurgical operations. Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were used in this study to leach metals from powdered waste PCBs. The RSM is used for optimizing the leaching conditions. The optimal conditions obtained were a bacterial activation period of 28 days, a pulp density of 23 g/L, and a temperature of 31°C. A confirmatory experiment under these optimal circumstances yielded recovery rates of Cu2+, Sn2+, Pb2+, and Zn2+ of 95.62%, 96.27%, 95.6%, and 98.25%, respectively.

Copper technology at the Early Iron Age fortified settlements near Lakes Itkul and Irtyash, middle Trans-Urals

During the EIA (7th-3rd c. BCE), the middle Trans-Urals were populated by the Itkul culture of metalworkers. Most of the Itkul sites were excavated in 1960-1980′s, and ever since then the copper smelting technology, and exploited ore sources remained limitedly understood. To provide insight into these questions, we consider the archaeological context of copper production and apply methods of OM, SEM-EDS and LA ICP-MS to analyse copper slag, technical ceramics and ores from the Itkul culture settlement of Dautovo-1 (Itkul-1). This data is considered against the analyses of ores from the EIA sites and the Gumeshevsky mine in the Polevskoy area located 35 km from Dautovo, and the formerly investigated copper slags (Stepanov et al., 2021) from the site of Irtyash-1 located 50 km apart. The obtained results confirm that secondary copper ores of the Gumeshevsky mine, long regarded as the main ore source of the Itkul culture, were smelted at the site of Dautovo-1. We also identify the plate slag as the residue attesting to the most frequently used smelting technique, which consisted of the smelting of secondary copper ores in shallow open furnaces or crucibles and under moderately reducing conditions. The smelt ended with the removal and fast-cooling of slag outside the furnace. In contrast to Dautovo-1, only slags from secondary metallurgical operations were found at the site of Irtyash-1, which aligns with the dominance of secondary copper-working remains at the latter site. The production probably was likely performed on a seasonal basis, the metalworking society was divided into smelters and copper-workers, and the copper supply was likely oriented at both domestic and external (nomadic) markets.

The Dawn of Metallurgy at Chalcolithic Arslantepe: Metal Finds and Other Metallurgical Remains from Level VII

This paper deals with archaeometallurgical remains from period VII (Late Chalcolithic 3-4, 3900-3400 BC) of the settlement of Arslantepe (Malatya, Turkey). It aims at compiling early metallurgy (metallurgical artefacts, slags) by means of interdisciplinary scientific analysis. In contrast to later periods, the metallurgy of the Late Chalcolithic has as yet only been investigated to a limited degree. Trace elements and lead isotope analysis of metal artefacts and slags allowed for a reconstruction of provenances of raw materials in order to deal with trade networks. Lead and copper slags were analysed for texture and phase content to reconstruct metallurgical operations. Late Chalcolithic activities from Arslantepe level VII are compared with the metallurgy of the previous level, VIII, as well as of later periods (levels VI A, VI B). Various metal groups could be identified at Arslantepe VII, most notably copper, arsenic copper and arsenic-nickel copper. The slag samples show the smelting and processing of copper and lead within the settlement, while the lead slags may also indicate the extraction of silver. The differing compositions indicate the use of differentraw material sources, which is also supported by the lead isotope analysis data.

An Overview of High-Entropy Alloys Prepared by Mechanical Alloying Followed by the Characterization of Their Microstructure and Various Properties

Some modern alloys, such as high-entropy alloys (HEAs), are emerging with greater acceleration due to their wide range of properties and applications. HEAs can be prepared from many metallurgical operations, but mechanical alloying is considered to be one of the most simple, economical, popular, and suitable methods due to its increased solid solubility, nano-crystalline structure, greater homogeneity, and room-temperature processing. Mechanical alloying followed by the consolidation of HEAs is crucial in determining the various surface and mechanical properties. Generally, spark plasma sintering (SPS) methods are employed to consolidate HEAs due to their significant advantages over other conventional sintering methods. This is one of the best sintering methods to achieve greater improvements in their properties. This review discusses the mechanical alloying of various HEAs followed by consolidation using SPS, and also discusses their various mechanical properties. Additionally, we present a brief idea about research publications in HEA, and the top 10 countries that have published research articles on HEAs. From 2010 to 18 April 2022, more than 7700 Scopus-indexed research articles on all the fields of HEA and 130 research articles on HEA prepared by mechanical alloying alone have been published.

Assessment of the phytoremediation effectiveness in the restoration of uranium mine tailings

Uranium (U) contamination due to mining and metallurgical operations is a serious problem and poses a high potential threat to humans and other organisms. The application of amendments and/or plants, known as assisted phytoremediation, can accelerate the adsorption, complexation and precipitation processes in soil, and therefore can facilitate the restoration of U mining areas. This study located in the central-west of peninsular Spain was focussed on two different U mine waste dumps (MWD), where the assisted phytoremediation process was implemented. At each MWD, an area of 10 ha (approx.) was selected for sugar lime (SL) application, at a rate of 75 T ha −1. In addition, after SL addition, common grasses Cynodon dactylon, Secale cereale, and the leguminosae Vicia sativa were seeded. Evolution of soil physico-chemical properties and plant development was monitored for 69 months in Top, Medium and Low areas of both MWDs. The main results indicated a positive effect of the amendment, improving the development of the spontaneous and induced vegetation and the accumulation of soil organic matter. Values of pH were maintained in the range of the neutrality during all the experimentation period. In general, total concentrations of trace elements (including U) presented a high variability. Values were similar in the different studied areas of each MWD (Top, Medium and Low) and did not change in time. Trace elements contents were, in general, higher than those found in non-contaminated soils. However, U and Mn availability decreased with time, as well as the accumulation of trace elements (especially U and Mn) in the studied plants. Moreover, these contents were lower than the permitted limit for animal consumption. In conclusion, application of phytoremediation contributed to the stabilization of U within the soil-plant system, mainly by its positive effects on vegetation cover and the consequent increase in soil organic matter.

Application of Multivariable Data Analysis in Mineral Processing

Data analysis and application of machine learning (ML) have demonstrated successful performance in various data rich industrial applications. Mineral processing and metallurgical operations are considered suitable for implementation of novel ML-based algorithms. The key operating performance and product outputs are usually obtained from the lab measurements and analyses that can be expensive, complex, and time consuming. Therefore, the development and application of a soft sensor and/or a state observer is a useful option to be considered due to their ability to provide the distribution of desired outputs in a continuous manner. In addition, the motivation to apply a soft sensor (a data-based model) is to provide guidance and/or information feedback to the operator in charge of making operational decisions. The soft sensor was developed at Sherritt's Metal Plant in Fort Saskatchewan as a nonlinear neural network model and it was based on two years of plant historical data. The model was also validated based on historical data, live testing, and additional sampling of process streams during simultaneous sampling campaign.

A Review of Groundwater Status and Problems due to Industrial Pollution: Case Study of Ghaziabad City

In India, the availability of groundwater is decreasing at an alarming rate. Both natural and anthropogenic factors are equally responsible for its declining. Groundwater usage for irrigation, manufacturing, construction activities, metallurgical operations and domestic consumption has resulted in over pumping leading to its exhaustion. Also the available groundwater is contaminated with heavy metal discharge from industrial waste. This is in addition to climate change phenomenon, which aggravate food and water security in India. Ground water managers are concerned about the diminishing water tables, mixing of salt water, exhaustion of aquifers, groundwater contamination and water logging. The water levels are declining each year by 1–2 m as reported from different areas of India. Pollution is also one of the serious issues. If this situation continues, in future, India might face major water crisis as it has groundwater as a source next to surface water. To overcome this problem Government of India has initiated several acts and regulations. But because of unawareness and insufficient infrastructure these measures have yet not fulfilled the need. In this paper, the status of groundwater is presented through a case study of Ghaziabad city. The groundwater scenario of the city, industrial discharge leading to groundwater pollution, its severe consequences, and measures to tackle these problems are shown in this paper.

РЕСУРСНО-СЫРЬЕВАЯ БАЗА ИТКУЛЬСКОЙ МЕТАЛЛУРГИИ РАННЕГО ЖЕЛЕЗНОГО ВЕКА СРЕДНЕГО ЗАУРАЛЬЯ

The paper addresses the question of ore resources (occurrences and deposits) exploited by the Early Iron Age metallurgists of the Itkul culture in the middle Urals. The main method of the study was the analysis of geological maps and reports, and the analysis of the correlation between the identified ore occurrences and the Itkul culture metal production centers. The results of the study reveal a relationship between the location of the Itkul culture settlement clusters and various types of copper ore (VMS, skarn and stratiform) and iron ore (infiltration and sedimentary ironstone) deposits, which could have been exploited for copper, and iron metallurgy in antiquity. We suggest that the primary smelting of copper ore was performed only in clusters: Polevskoy, Itkulsky, Isetsky and Irtyashsky. The use of ironstone ores is attested in copper metallurgy, where they were added into the charge as fluxes to reduce the viscosity of the slag melt and more efficiently extract copper from the ore. The Itkul metallurgical settlements seem also to have direct evidence of iron smelting. The ironstone deposits of infiltration-sedimentary type, common in the middle Trans-Urals, were apparently one of the main ore sources used. The provided geological maps showing the location of the possible iron and copper metallic resources make it possible to localize areas having the potential for finding new archaeological evidence of ancient mining and primary metallurgical operations. Based on these data, the first early Iron Age iron ore mine was discovered in the Urals.