Copper Plant Research Articles

Industrial validation of conductivity and viscosity models for copper electrolysis processes

In copper electrorefining and electrowinning, the conductivity and viscosity of the electrolyte affect the energy consumption, and for electrorefining the purity of cathode copper. Consequently, accurate models for predicting these properties are highly important. Although the modeling of conductivity and viscosity of synthetic copper electrolytes has been previously studied, only a few models have been validated with actual industrial electrolytes. The conductivity and viscosity models outlined in this study were developed using conductivity and viscosity measurements from both synthetic and industrial solutions. The synthetic electrolytes were investigated over a temperature range between 50–70 °C and typical concentrations of Cu (40–90 g/dm3), Ni (0–30 g/dm3), Fe (0–10 g/dm3), Co (0–5 g/dm3), As (0–63.8 g/dm3), H2SO4 (50–223 g/dm3) as well as other solution impurities like Sb in some cases. Validation of the synthetic electrolyte models was performed through industrial measurements at three copper plants across Europe. Generally, the developed models predicted the conductivities and viscosities of industrial solutions with high accuracy. The viscosity models covered extended ranges of both [H2SO4] and [Cu] with percentage errors of only (2.08 ± 0.59) - (2.48 ± 0.61). For conductivity, two different models for low (<142 g/dm3) and high (>142 g/dm3) [H2SO4] electrolytes were utilized. Their error margins were (−1.96 ± 0.84) - (−1.44 ± 0.35) and (1.17 ± 0.27) - (2.52 ± 0.28), respectively. In the case of high [H2SO4] electrolytes, the validations focused on conductivity, and the highest level of accuracy was obtained when the effects of Sb and other minor impurities were considered.

ОСНОВНЫЕ НАПРАВЛЕНИЯ НАУЧНОЙ ДЕЯТЕЛЬНОСТИ СКГМИ (ГТУ) В ИССЛЕДОВАНИИ И РЕШЕНИИ ПРОБЛЕМЫ КОМПЛЕКСНОЙ И ЭКОЛОГИЧЕСКИ БЕЗОПАСНОЙ ПЕРЕРАБОТКИ ПРИРОДНОГО И ТЕХНОГЕННОГО МИНЕРАЛЬНОГО СЫРЬЯ

The result of many years research of the university scientific community in the field of topical issues of complex processing of natural and man-made mineral raw materials was the creation of a scientific school “Dynamics of working bodies of machines and equipment for fine grinding of rocks” under the leadership of Professor Dmitrak Yu. V. Research results. The dynamic parameters of the grinding bodies are determined directly in the mill grinding chamber which ensure the contactless transmission of information from the grinding ball to the receiving device. A new method of materials self-grinding and the design of a vertical centrifugal mill based on it has been developed. The mill tests during the grinding waste from the production of ceramic products (the battle of insulators, crushed mullite bricks) showed high efficiency and prospects. The tests of a laboratory vibrating mill with one grinding chamber and a rotor diameter of 250 mm for grinding dolomite were carried out. The experiments have shown the possibility of creating vibrating mills for solid materials grinding. In the development of the work of I. N. Plaksin on the flotation of ores with the jet movement of products in the scheme tested by him together with employees in the conditions of the Tekeli processing plant, the modes of joint processing of ores and gold placers were developed at the NCIMM (GTU). It was established that with the unprofitable individual development of alluvial gold mining waste, a positive economic effect can be obtained through their joint processing with ore gold reserves by fine-tuning the concentrate extracted from man-made raw materials by gravitational enrichment methods at a stationary processing plant. It is proved that the addition of the gravitational technology of alluvial gold extraction by flotation methods provides an increase in annual gold production by ~38 % due to the additional extraction of “resistant” forms of gold for gravitational methods. It has been proved in laboratory conditions that the waste slag of the Copper plant of “Ltd. MMP Norilsk Nickel” can be disposed of by joint processing with the ore of current production. It is established that the technology development using metal leaching is promising for the development of Sadonsky plant deposits.

Investigating energy performance of large-scale seasonal storage in the district heating system of chifeng city: Measurements and model-based analysis of operation strategies

This paper presents a modeling and simulation method that supports energy performance assessment and operation strategy investigation of borehole thermal energy storage in the Chifeng district heating (DH) system. A living laboratory in Chifeng, China that integrates a 0.5 million m3 borehole thermal energy storage system, an on-site solar thermal plant and excess heat from a copper plant is presented. The research adopts Modelica models from open source libraries to evaluate the system. The validity of the borehole thermal energy storage model is evaluated through an inter-model comparison study and an empirical validation test. We used the validated model to investigate three operation strategies. We conclude that the time-scheduled combined operation strategy is more beneficial for the studied system regarding CO2 emission reduction.

Calcium, copper, manganese and zinc and plant diseases: a review

All crops are usually affected by phytosanitary and nutritional problems. It is known that fertilizers can elevate productivity and control of diseases, characteristics that make nutrients indispensable in combating hunger, and can help to reduce the use of fungicides and their negative impact on the environment. There are more than 15 elements considered essential for plants, including calcium, manganese, copper, and zinc, which will be detailed in this study in order to understand how they can affect the control of plant diseases.

Green dyeing of modified cotton fabric with Acalypha wilkesiana leave extracts

Over the last few decades, a number of natural dyes have become non-toxic, eco-friendly and biocompatible substitutes of highly carcinogenic synthetic dyes. Herein, we selected the Acalypha wilkesiana (copper plant) as the source of a natural colorant for auxiliary-free dyeing of cotton, a way forward to eco-friendly dyeing. The bioactive phytochemical constituents of this plant include tannins, flavonoids, phlobatanins, cardiac glycosides, saponins, alkaloids, terpenes and steroids. Both the aqueous and methanol extracts of copper leaf were extracted and applied to unmodified and modified cotton fabrics with the percentage shade depths of 0.5%, 1%, 2%, 4%, 5% and 6% both at pH 4 and 7. The cationized samples rendered substantial improvement in color strength (K/S) values as compared to un-cationized ones. Aqueous and methanolic extracts offered very similar K/S values on cationized samples. Without using any metallic salts as mordants, the color fastness properties like rubbing fastness, washing fastness were also slightly improved due to greater dye fixation on cationized samples compared to uncationized ones. In conclusion, the aqueous extract exhibited dye fixation and color fastness properties comparable to methanolic extract at pH 4 and 7. Thus, it suggested the avoidance of toxic organic solvent for extraction and auxiliary chemicals in subsequent dyeing, a step towards eco-friendly sustainable dyeing.

Designs of new operating copper processing plants: process types, equipment selection, industry trends

The article describes the largest operating processing plants for lowgrade copper sulphide ores of our time: 10 plants using the semi-autogenous grinding (SAG) technology and 10 plants using high-pressure grinding rolls (HPGR), with the output of 18 to 100 Mtpa. The unfavorable natural and economic factors are balanced by improved ore preparation and concentration technologies and high-capacity equipment units, combined with cost-saving layout solutions. The ore preparation sector is currently divided between the competing technologies of semi-autogenous grinding and HPGR. The article contains an overview of their advantages and disadvantages. The world’s largest monosection with the capacity of 55.5 Mtpa, that uses the SAG technology, is described. The role of the Drop Weght Test JKSimMet (A×b) parameter in the selection of the ore preparation method and the trend for using HPGR in the processing of strong ores are shown. Examples are provided for the consequences of an inadequate assessment of the feed strength in SAG-based plant designs. Examples of ore preparation process intensification through the use of HPGR in semi-autogenous grinding circuits are also given. The volume of impeller flotation cells installed has reached 600 m3. An overview of the two largest processing plants of our time with the output of 88 and 100 Mtpa of ore is presented. The innovative technical solutions of a newest low-capacity copper plant are highlighted. Based on the results of the overview, a future processing plant is predicted to use ∅12.8–13 m SAG mills, HPGRs with the roll diameter of 3 m, vertical VTM-7000 mills in ore grinding cycles, large fine screens, large-scale impeller flotation cells, and staged SFR and DFR flotation reactors.

Using shell-type tuyeres at Pierce–Smith horizontal converters of the Nadezhda Metallurgical Plant

Since 2015 the processing capacity reconfiguration at the Polar Branch of MMC Norilsk Nickel (hereinafter PB) sets new goals for conventional pyrometallurgical processes of smelting and converting. The design flowsheet of Kolesnikov Nadezhda Metallurgical Abstract: Plant (hereinafter NMP) provided for «cross-converting» when copper matte was first processed in one converter to produce blister copper followed by nickel matte processing to yield copper-nickel converter matte bypassing the discharge of dry coagulated slag. This flowsheet allowed for converter heat balance optimization, decreasing the formation of refractory reverts and significant extension of the converter campaign. PB Nickel Plant shutdown resulted in copper processing elimination at NMP and switching the converters to the conventional nickel converting flowsheet. In turn, it gave rise to the need for solutions to extend converter campaign while maintaining the possibility to process large amounts of nickel slag from the second converting stage at the PB Copper Plant. For this purpose the series of lab experiments were carried out to develop the technology and design documentation for the system to supply oxygen-enriched air (up to 45 %) to horizontal converters using shell-type tuyeres. In addition, literature data were analyzed on this topic along with the experience of smelters in this area. Process design calculations were done. The efforts were taken in cooperation with the PB engineering personnel and Laboratory of Pyrometallurgy of LLC «Gipronickel Institute». The use of reduced diameter shell-type tuyeres to inject the oxygen-air mixture was found to decrease the converter blowing and off-gas volumes. The decline in off-gas quantity leads to reduced heat load on the converter mouth and flue duct system, as well as to lowered converter dust entrainment. The use of oxygen-enriched blowing implies the higher smelt heating rate. Excess heat compensation requires timely charging of cold reverts and flux. In emergencies (if cold reverts are not available) the oxygen content of the blowing has to be reduced until switching over to air blowing. The series of the above efforts will offer a possibility to use the shell-type tuyeres keeping the converter off-gas temperature at the current level. Thus continuous monitoring and efficient control will ensure the off-gas temperature and volume at the inlets of gas cooling and cleaning systems not exceeding the limiting values. The introduction of the reduced diameter shell-type tuyeres for air-oxygen mixture injection does not require any upgrade of the existing gas cooling and cleaning systems. Moreover, switching to these tuyeres will reduce gas load on the flue duct system and heat load on the water-cooled dust cap, lower dust entrainment and non-recoverable dust losses after the gas cleaning system.

Identification and Metabolism of Naturally Prevailing Microorganisms in Zinc and Copper Mineral Processing

It has only recently been discovered that naturally prevailing microorganisms have a notable role in flotation in addition to chemical process parameters and overall water quality. This study’s aim was to assess the prevailing microbial communities in relation to process chemistry in a zinc and copper mineral flotation plant. Due to the limitations of cultivation-based microbial methods that detect only a fraction of the total microbial diversity, DNA-based methods were utilised. However, it was discovered that the DNA extraction methods need to be improved for these environments with high mineral particle content. Microbial communities and metabolism were studied with quantitative PCR and amplicon sequencing of bacterial, archaeal and fungal marker genes and shotgun sequencing. Bacteria dominated the microbial communities, but in addition, both archaea and fungi were present. The predominant bacterial metabolism included versatile sulfur compound oxidation. Putative Thiovirga sp. dominated in the zinc plant and the water circuit samples, whereas Thiobacillus spp. dominated the copper plant. Halothiobacillus spp. were also an apparent part of the community in all samples. Nitrogen metabolism was more related to assimilatory than dissimilatory nitrate and nitrite oxidation/reduction reactions. Abundance of heavy metal resistance genes emphasized the adaptation and competitive edge of the core microbiome in these extreme conditions compared to microorganisms freshly entering the process.

Potential copper plant Vanyukov furnace gas desulphurization capacity

To enable maximum disposal of Vanyukov furnace flue gas, the authors of this paper examined the spare capacity of the Elemental Sulphur Site at the Copper Plant of Nornickel’s Polar Division. Thus, the paper considers an optimized three-stage flue gas treatment process (which also includes a thermal reduction stage) and the possibility to skip the stage of preliminary condensation of sulphur from reduced gas. To estimate how it will affect the overall recovery of sulphur (desulphurization factor), a series of calculations was carried out to compare the Elemental Sulphur Site’s performance during two different treatment processes: a complete process that includes preliminary condensation of sulphur from thermally reduced gas; and a short process, i.e. without preliminary condensation of sulphur. In both cases, the concentration of sulphur dioxide in the Vanyukov furnace gas was [SO2] = 28 vol %. The results of the calculations were verified through experiments conducted on a pilot unit owned by Gipronikel Institute with the gas flow reaching ~1.2 nm3/h, and they confirm the possibility of implementing the three-stage treatment process using the available plant space and reaching the capacity of 40,000 nm3/h and the sulphur recovery of ~89 %. The obtained data on the specific consumption rates of natural gas, oxygen and boiler water can be used for a feasibility study to justify the adoption of the short treatment process at the Elemental Sulphur Site of the Copper Plant of Nornickel’s Polar Division.

Pilot tests of low-temperature catalytic reduction of sulfur dioxide in realistic conditions of sulfur recovery unit at copper plant of Polar Division of PSC “Norilsk Nickel”

Pilot tests of low-temperature catalytic reduction of sulfur dioxide in realistic conditions (technological gases of Vanyukov furnace) of sulfur recovery unit at Copper Plant of Polar Division of JSC “Norilsk Nickel” have been carried out. It has been demonstrated that the developed CuCr catalyst provides sulfur recovery not less than 90% at GHSV-2000 h−1 in a temperature range 200-260°C.

Projects and Reality: Industrial Construction in the First Five-Year Plans in the Central Urals

This article considers the peculiarities of designing industrial enterprises and their settlements in the USSR during the first five-year plans. Referring to the Pyshminsky Electrolytic Copper Plant (Rus. PMEZ) and Medny Rudnik, the settlement around it, the author carries out a comparative analysis of its designs and their implementation. The author refers to the collections of the State Archive of Sverdlovsk Region, periodicals, and materials related to plans for the economic development of the Urals and the USSR. Analysis of the main decisions demonstrates a gradual departure from the project in each of the points, often caused by subjective reasons. The plan of the settlement combined ideas of new Soviet everyday life and real conditions, reflecting national trends in the life of an individual enterprise and locality. The construction of the PMEZ and its settlement is compared with other projects from the first five-year plans (Uralmash, Magnitostroy, etc.), singling out typical and specific features. The author pays special attention to the reasons for a significant discrepancy between what was initially planned and what was implemented, such as insufficient funding, constant short-ages of materials and equipment, lack of personnel, changing administrative trends, the specialisation of regions and industrial complexes, and architectural policy. Many elements of the projects were unrealistic, and some solutions that were implemented but proved unsustainable reveal serious problems in the field of industrial design in the USSR between the 1920s and 1930s.

Behaviour of selenium and tellurium in copper electrowinning process

The revamping project to be implemented at Norilsk Nickel’s refining facilities includes commissioning of a nickel plant and increasing the output of copper obtained by electrowinning from liquors produced in matte leach processes. At the revamped facility, a major portion of selenium and a considerable share of tellurium will be transferred with calciner gases to a sulphuric acid facility. The microimpurities that remain after calcination get distributed between the leachates. Considering that semiproducts keep circulating between the nickel and copper plants, selenium and tellurium can accumulate in the product solutions and thus affect the quality of finished metals. This paper examines the behaviour of selenium and tellurium in copper electrowinning process and formulates certain requirements for copper electrolyte that will ensure production of high-purity copper cathodes for commercial application. It is shown that, at low concentrations of selenium (IV) and tellurium (IV) in the copper electrolyte, their discharge follows the laws of diffusion kinetics, i.e. occurs at maximum current, together with cathode reduction of copper, and the concentrations of selenium and tellurium in copper change in correlation with the concentration of chalcogenides in the solution. Simultaneously with cathode reduction on a lead anode, selenium (IV) and tellurium (IV) get oxidized to selenium (VI) and tellurium (VI) that are not precipitable with copper and get accumulated in circulating solutions. It is shown that the concentration of chalcogenides has a negative first order from the removal of copper per unit volume of electrolyte. That’s why the contamination of cathode copper with selenium and tellurium rapidly decreases with an increase in copper removal. The paper provides data that can be used to estimate the allowable concentration of toxic microimpurities in the feed electrolyte that would not affect the desired copper purity level.

Obtaining selenium concentrate from the slime of the sulfuric acid workshop of the Balkhash copper plant and extracting selenium from it into solution

The article presents the results of large-scale laboratory tests of obtaining selenium concentrate from the slime of the sulfuric acid workshop (hereinafter: slime) of the Balkhash copper smelting plant and the extraction of selenium from it into solution. This slime, in contrast to similar slime from non-ferrous metallurgy plants, significantly differs in chemical and material compositions, especially in the selenium content (4.6 - 12.5 wt.%). Involving it in the production sphere will increase the production of selenium by more than 20% from that obtained by the plant from copper electrolyte slime. The slime is washed with water to remove sulfuric acid, dried at 105 ° C. Selenium concentrate was obtained by sequential leaching of slime with solutions of sodium carbonate and nitric acid, selenium from the concentrate was leached with solutions of sodium sulfite (atmospheric pressure) and sodium hydroxide (high pressure, autoclave leaching). Slime, concentrate, cakes, precipitates isolated from solutions, and solutions were analyzed using modern devices of a new generation: An Optima-8300 inductively coupled plasma spectrometer, an Axios X-ray fluorescence spectrometer, an Optima 2000 atomic emission spectroscope, a D8 Advance diffractometer, a D8 Advance infrared spectrometer Avatar 370. From the slime containing, wt. %: 51.2 Pb, 12.5 Se, 3.21 Hg and other elements, a selenium concentrate was obtained with the composition, wt. %: 0.41 Pb, 59.16 Se, 15.4 Hg. The technological indicators for obtaining a concentrate are given, %: concentrate yield - 20.74, Pb recovery - 0.81, Se - 98.23, Hg - 99.50. According to XRD and IR spectroscopy, the concentrate contains elemental selenium and mercury selenide from 10 selenium substances contained in the slime (given in the article). The extraction of selenium from the concentrate into the solution was, %: sodium sulfite - 76.84, sodium hydroxide - 89.65. The pulp from opening the concentrate with sodium hydroxide solution was filtered very poorly. The filtrates contained a colloidal suspension, which could not be filtered off either under vacuum or centrifugation. Therefore, to determine the qualitative and material composition of the filtrates, salts were obtained by evaporating a certain and then neutralized volume to dryness. It was found that only elemental selenium is leached from the concentrate by solutions of both reagents, while mercury selenide remains in the cakes. Moreover, over time, elemental selenium partially precipitated again from selenium-containing sodium sulfite solutions; the salts contain only elemental selenium. An explanation is given for the transition of soluble selenium salts to its elemental state. Despite the higher recovery of selenium from the concentrate by leaching in autoclaves, taking into account the equipment, the complexity of its maintenance, filtration of the pulp and the chemical composition of the filtrate, it is preferable to use the method of leaching with sodium sulfite.

A robust data reconciliation method for fast metal balance in copper industry

Data reconciliation along with gross error detection is the key technology for providing accurate and reliable data relating to metal balance in copper industry. However, it can be computationally expensive, especially when the number of variables becomes large, i.e., more than 200, and the constraints are notably complex as in bilinear form. In order to address this problem, a robust estimator-based data reconciliation model for solving the metal balance problem is developed in this study, in which the inconsequent deviation between the measured and reconciled value is fully taken into account, and the gross errors are detected according to the reconciliation results. Specifically, considering the computational efficiency and the early convergence of the evolutionary algorithm, a novel joint optimization strategy is designed to substitute the high-dimensional variables by low-dimensional Lagrange multipliers and restrict the population density in a reasonable range during optimization process to obtain more accurate reconciled results. The practical data collected from a copper plant in China are used to validate the proposed approach. The results demonstrate a significant improvement in performance and computational efficiency with respect to both large-scale data reconciliation and gross error detection thanks to the proposed robust model and joint optimization strategy. Besides, a software system based on the proposed method has been developed and applied in field studies, providing a systematic guidance for practical metal balance.

Aurubis iron-silicate fines: universal sustainable construction material: a state-of-the-art review

This article brings together a lot of research information that deals with iron-silicate fines (ISF), as a basic by-product produced by the copper plant of Aurubis, located in Bulgaria. As a rare material, produced only in couple of plants in the world, ISF has a wide variety of applications due to its specific physical, chemical and mechanical characteristics. Well known for decades by the clinker cements industry, nowadays Aurubis presents a wide variety of new perspectives for creating green and sustainable building materials out of ISF. Sustainability in the construction sector is mostly referred to as zero waste scenarios related to the use of recycled and secondary materials (RSM). Such RSM materials differ significantly and their performance remains to be established separately as well as the properties of the construction products produced by them. Besides this each production unit has its own experience with raw materials for its production and introducing a new one is always causing some initial doubts. ISF not only covers preliminary expectations but even exceeds them.One of the main purposes of this article is to present opportunities to academics, researchers, design engineers, research and development & production managers in companies, specialists and contractors, for sustainable building products development of this not so well-known material with great potential. Most of the presented applications are prepared on industrial scale with different percentages of ISF for testing the effect of its quantity on the properties of the final products.

Извлечение никеля из имитаторов пульп никелевого производства в процессе газофазной конверсии

A new approach to Ni removal from simulators of dump waste product of the industrial waste purification of the wet gas-cleaning plant and the copper electrolysis workshop at the Copper Plant (Polar branch PJSC MMC «Norilsk Nickel») is proposed. The method is based on gas-phase treatment of waste product with NOХ, HNO3, or NH3 vapors, followed by dissolution of Ni salt in water. It has been found out that using nitrating media, containing HNO3 (vapor), NOX and H2O (vapor), allowed us to perform the effective leaching of nickel from the pulp simulator volume. A possible disadvantage of the method is a simultaneous leaching of considerable amounts of calcium and sulfur.

LEAD AND CADMIUM SUBCHRONIC INTOXICATION IN RATS AS A FACTOR OF DAMAGE TO THE CARDIOVASCULAR SYSTEM

Lead-cadmium intoxication is an occupational risk factor for copper-smelting industry workers. People inhabiting the areas near the copper plants are also at risk. Subchronic intoxication was modeled by repeated intraperitoneal injections of lead acetate and cadmium chloride both in isolation and in combination, 3 times a week for 6 weeks. A heart rate decrease in animals with Cd intoxication and a blood flow velocity decrease in those with Pb intoxication have been found. The impact of Pb and Cd on blood pressure proved to be contra-directional. ECG analysis revealed a prolonged duration of QRS in Cd intoxication, a prolonged QT interval and a baseline lowering in Pb+Cd intoxication. A variety of changes has been found with respect to the diameter of cardiomyocytes and the thickness of aortic wall layers in Pb and/or Cd intoxication. Any toxic exposure resulted in the decrease in number of nuclei per unit area of myocardium histological preparation.

Flotation separation of nickel slag of the Polar Division Copper Plant at Nadezhdinsky Metallurgical Plant with the production of nickel and copper concentrates

Flotation separation of nickel slag of the Polar Division Copper Plant at Nadezhdinsky Metallurgical Plant with the production of nickel and copper concentrates

Practical Experience in Large-Scale Development of Zijinshan Low-Grade Gold-Copper Mine

The Zijinshan gold-copper mine, in spite of the low-grade nature of the ore, has become one of the largest production-scale and most profitable non-ferrous metal mines in China. The successful application of hydrometallurgy as well as proper engineering design are the key factors for large-scale development of the Zijinshan gold-copper mine. In this contribution, the practical experience acquired in the development of the Zijinshan gold and copper mines is summarized. This covers most aspects of the production process including mining, beneficiation, ore stacking, heap (bio)leaching, carbon-in-leach, solvent extraction, electrowinning, wastewater and tailing treatments. The authors believe that this practical experience will not only help to promote the development of hydrometallurgy, but can also serve as a model for other gold and/or copper plants around the world.

Waelz process adopted by Chelyabinsk Zinc Plant to process copper plant dusts

Waelz process adopted by Chelyabinsk Zinc Plant to process copper plant dusts