Extraction Of Nonferrous Metals Research Articles

ENERGY EFFICIENCY INCREASING OF ORE ENRICHMENT WASTES’ PROCESSING BY ELECTRICAL DISCHARGE METHOD

A promising and accessible raw material, comparable in terms of gold and silver content to natural ore deposits, is the lying tailings of ore flotation. Currently, billions of tons of ore tailings have been accumulated, the content of valuable components in which sometimes exceeds those in natural deposits. The processing of ore tailings from tailings for the extraction of non-ferrous metals in most cases requires complex beneficiation schemes, and in terms of technical and economic indicators and the quality of concentrates, they are uncompetitive compared to products of natural raw materials. An electric discharge method of disintegration of ore beneficiation waste to increase the number of available target components, based on the rational organization of crushing and grinding processes in relation to beneficiation tasks, was experimentally investigated. The pressure values of the compression waves generated by the electric discharge were determined to calculate the radius of effective selective influence on the studied waste samples of flotation beneficiation of copper-zinc ores. The necessary conditions for the effective operation of the technological part of the equipment are established: in the volume of the disintegrator, the pressure, created by the electric discharge, should not be less than the tensile strength of the processed material and at the same time should not exceed the strength of the disintegrator’s material. The use of the electric discharge method ensures the selectivity of disintegration of the material along the interphase boundary "dead rock - mineral inclusion", this circumstance allows to achieve a significant increase in the amount of mined valuable metals and simultaneously reduction of energy consumption by 2 - 4 times. Increasing energy efficiency is considered by the way of example with copper-zinc ore concentration’s waste. The increase in the number of target metals available in wastes of flotation concentration of copper-zinc ore after their electric discharge treatment is shown. The increase in the amount of copper extracted from copper-zinc ore enrichment waste was from 40 to 93% by mass, extracted zinc - from 39 to 94% by mass, silver extracted - from 16 to 50% by mass.

Cleaner and cost-efficient hydrometallurgical process for extraction of vanadium from Bayer vanadium sludge based on BaSO4, NaOH, ammonium, and water circulation

Bayer vanadium sludge(BVS) is a hazardous waste due to its high contents of V, P, As, and F. Full or partial utilization of this sludge could not only minimize the potential environmental risk but also promote resource recycling. In this work, a cleaner and cost-efficient process was proposed to selectively extract vanadium from BVS by employing BaSO4 as precipitant. Under the optimal conditions, a maximum vanadium precipitation efficiency of 97.86% is achieved, whereas only 1.15% arsenate and 0.12% fluoride are co-precipitated. Afterwards, the generation of 2Na3AsO4·NaF·19 H2O and NaSO4·NaF has enhanced the simultaneous removal of As and F during evaporation crystallization, and achieving the recycling of NaOH. A new strategy was adopted to in-situ convert Ba3(VO4)2 into Ba(VO3)2·H2O which can be directly leached in (NH4)2SO4 solution. Furthermore, 99.78% vanadium is precipitated as (NH4)2V6O16 from the leachate and the V2O5 product with a purity of 99.85% is prepared after calcination. The leaching residues and the spent liquor containing large amounts of NH4+ after (NH4)2V6O16 precipitation can be circulated to the next batch of vanadium precipitation and leaching, respectively. Herein, the process realizes the internal circulation of BaSO4, NaOH, ammonium, and water, saving production costs and avoiding environmental pollution.

Ultrasonic pretreatment-solvent extraction process for separating zinc from pickling waste liquid

Solvent extraction is the most important method for non-ferrous metals extraction and separation. In this work, solvent extraction of zinc from pickling waste liquid is investigated by using di(l-methyl heptyl) methyl phosphate (P350) diluted in sulfonated kerosene. Introduction of ultrasonic enhanced reduction of Fe3+ in the pretreatment stage of pickling waste liquid. The effect of ultrasonic time on the reduction process of Fe3+ is studied. Compared with traditional restoration, the required time for reduction is greatly shortened. The functional relationship of organic phase composition, concentration of extractant, phase contacts time and phase ratio function in single-stage extraction is studied. When concentration of extractant is 25 %, phase ratio is 4:1, the contact time is 15 min and the single-stage extraction efficiency of Zn2+ can reach 80.8 %. The extraction efficiency of Zn2+ reaches 99 % through three-stage countercurrent recovery. When O/A is 1:2, 1.6 mol/L HCl is used as the stripping agent and the stripping efficiency of P350 can reach 90.4 %. In addition, extraction stoichiometry is determined by slope analysis and extraction mechanism is analyzed by FT-IR and mass spectrometry. Overall, this work provides a new solution in the extraction of zinc from pickling waste liquid.

Improving the quality of converting products by the joint smelting of high-sulfur copper concentrate with copper-lead matte

The paper presents the results of studies on the processing of copper-lead mattes with high-sulfur copper concentrate in a converter. The effect of high-sulfur copper concentrate on the quality of converting products is shown. Based on the obtained results, a comparative analysis of the technological indicators of the 1st period of converting copper-lead mattes according to the existing technology and in the joint processing of copper-lead mattes with copper concentrate was carried out. It has been established that when the high-sulfur copper concentrate is used as a sulfidizing agent, excess sulfur released as a result of the dissociation of higher sulfides is completely absorbed by the slag melt. It is shown that elemental sulfur, interacting with oxides of non-ferrous metals and impurities, has a significant effect on the equilibrium distribution of metals between the converting products and their extraction into targeted products. The influence of sulfur on the destruction of magnetite in the process of converting was also established. New data on the distribution of non-ferrous and associated metal impurities (As, Sb, etc.) were obtained during the conversion of copper-lead mattes with high-sulfur copper concentrate. High values were established for the extraction of non-ferrous metals and impurities into targeted products: copper into matte - up to 98%, lead, zinc, arsenic, and antimony into dust - 87%, 91%, 84%, and 38%, respectively. The possibility of a significant improvement in technical and economic indicators, the quality of converting products, and environmental protection during the joint smelting of high-sulfur copper concentrate with a copper-lead matte are shown. The developed technology for converting copper-lead mattes, with high-sulfur copper concentrate, is easily integrated into the plant structure of Kazzinc LLP without any special material costs.

ЭКСТРАГЕНТСОДЕРЖАЩИЕ МИКРОЭМУЛЬСИИ КАК НАНОСТРУКТУРИРОВАННЫЕ СРЕДЫ ДЛЯ ВЫЩЕЛАЧИВАНИЯ ЦВЕТНЫХ МЕТАЛЛОВ

A method for extracting metals from solid phase particles using extractant-containing microemulsions is proposed, and its features are studied on a model system with CuO. It is shown that the microemulsion leaching method is suitable for the extraction of non-ferrous metals from various types of ore and secondary technogenic raw materials, and extractant-containing microemulsions based on sodium bis-(2-ethylhexyl)phosphate and sodium dodecyl sulfate are promising functional nanomaterials for hydrometallurgy.

Assessment of risks caused by mercury pollution in Azerbaijan

Mercury is one of the most toxic metals and is widely used in the environment. It is a heavy liquid metal, which contains extremely dangerous substances that pollute the atmosphere, water and food. Sources of mercury emissions – Mining and smelting of mercury-containing ores from sulphide ores, extraction of non-ferrous metals, gold from ore, bleaching of cellulose, chlorine, caustic, vinyl chloride, electrical equipment (lamps, various power sources), measuring and control devices (thermometer, pressure gauge), mercury-containing preparations, cement production, use of mercurycontaining pesticides, combustion of coal and fuel oil. Significant amounts of mercury are also released into the environment during waste incineration. The results of the inventory of mercury emissions in Azerbaijan are presented. There were analyzed all the main areas of national industry of Azerbaijan supposed to contain mercury, conducted quantitative assessments, and in some cases revealed their trends. One of the obligations in accordance with the requirements of the Minamata Convention is the assessment of the general effect of mercury on human health. Cadastre of mercury emissions in the environment "Mercury", prepared by the United Nations Environment Program (UNEP Chemicals). Methods of finding and calculating waste.

Mathematical modeling of sulfuric acid leaching of pyrite cinders after preliminary chemical activation

Pyrite cinders, waste products of pyrite concentrate processing by firing to produce sulfuric acid, can serve as raw materials for the extraction of precious, ferrous, and non-ferrous metals. The paper considers the possibilities of obtaining non-ferrous metal concentrate from pyrite cinders by sulfuric acid leaching. This operation is one of the stages in the integrated technology. To increase the extraction of non-ferrous metals during leaching, the method of preliminary chemical activation was used. Chemical activation was carried out in a solution containing 40-120 g/dm3 NaНCO3 at temperatures of 90-230 ° C and a duration of 30-300 minutes. Sulfuric acid leaching of pyrite cinder after activation was carried out in H2SO4 solutions with a concentration of 5-20 % at a temperature of 60 ° C, duration of 30 minutes, and pulp density of 33 %. To determine the optimal conditions for the sulfuric acid leaching of pyrite cinders, a mathematical planning method was used, which allows to assess with a high degree of reliability the influence of the main factors (temperature, pulp density, the concentration of the solution NaHCO3 and duration) and predict an increase in the efficiency of the process by analyzing the numerical values of the regression equations. As a result of sulfuric acid leaching of pyrite cinders after preliminary chemical activation under optimal conditions determined by a mathematical model, the extraction of iron and non-ferrous metals into a solution is 10-15% higher than without activation.

Utilization of Converter Slag from Nickel Production by Hydrometallurgical Method

The possibility of hydrometallurgical processing of converter slag from nickel production aimed at integrated use of mineral raw materials and environmental protection is shown. The scheme of hydrometallurgical processing of slag using hydrochloric acid is proposed. The method involves leaching the slag with hydrochloric acid in the presence of ferric ions. The high values of iron and nonferrous metals extraction into the leaching solution are achieved during hydrochloric acid leaching. Silicon is concentrated in an insoluble residue. Liquid extraction was used to extract iron from hydrochloric acid leaching solutions. Silica-containing residues can be successfully used in the construction industry.

Form of the Occurrence of Aluminium in Municipal Solid Waste Incineration Residue—Even Hydrogen Is Lost

In the bottom ash (BA) of municipal solid waste incineration, the content of iron and aluminum is relatively high. The efficiency of eddy current extraction of non-ferrous metals (including aluminium) routinely used in incineration plants is limited. The determination of the form of occurrence of aluminium or aluminium-rich components in BA is important in terms of its recovery or utilisation. BA from a newly built incineration plant in Poland was analysed using chemical analysis, X-ray diffraction, optical microscopy, and scanning electron microscopy with chemical microanalysis. Samples of water-quenched BA were analysed. For comparison, a non-quenched sample (collected above a water tank) was analysed. The obtained results indicate that aluminium-rich components in BA are present in both the melt phase and quench phase. In the melt phase (glassy material), the content of aluminium is low (usually below 2 wt%). Aluminium-rich components present in glass, inherited after aluminium products are usually oxidised, and occur as platy or irregular forms. Aluminium components in the quench phase are significantly transformed with the common presence of Cl− and SO42− phases formed during reaction with the quench water. Secondary phases form simple or complex rims around metallic or slightly oxidised cores, of which the size is significantly reduced during transformations. The variety in the forms of aluminium occurrence in BA makes its recovery challenging and inefficient. The reduced content of metallic aluminium indicates that the potential for hydrogen generation of BA is low.

Development of Technology for Processing Pyrite Cinder to Produce Non-Ferrous Metal Concentrate

The existing technologies for processing of pyrite cinder require improvement for complex extraction of non-ferrous, precious metals and iron. The novelty of the technology used in the work for the processing of pyrite cinders is the preliminary chemical activation in a solution of sodium bicarbonate. The optimal activation modes were determined according to temperature, duration, L:S ratio and NaHCO3 concentration. It has been established that activation of pyrite cinder results in changes in phase composition and a reduction in the content of the impurity components P2O5, SO3 and As2O3. The leaching of pyrite cinder after pre-activation in 15 % H2SO4 solution resulted in an extraction into solution, wt. %: CuO 76, 8; ZnO 75, 9 and Fe2O3 26, 0. The degree of extraction of non-ferrous metals in sulphuric acid solution without chemical activation is lower by 15 - 20 %.

Continuous Bioleaching of Arsenic-Containing Copper-Zinc Concentrate and Shift of Microbial Population under Various Conditions

The goal of this work was to study the bioleaching of arsenic-containing polymetallic concentrate that contained 6.2% Cu, 7.3% Zn and 1.7% As, depending on different temperatures and in the presence of CO2 and molasses in the medium, as well as the difference in the composition of microbial population formed under various conditions. A mixed population of moderately thermophilic and thermotolerant acidophilic microorganisms formed during the continuous bioleaching of copper concentrate was used as an inoculum. The experiments were carried out in a continuous mode in laboratory scale reactors, with a temperature range of 40 °C to 60 °C. To assess the effect of CO2 and molasses on metal leaching and microbial population composition, the experiments were carried out in three reactors: CO2 (~0.01 L/min) was supplied into the first reactor; 0.02% molasses were added to the pulp of the second reactor; and no additional carbon sources were supplied into the control reactor. The highest copper recovery (27%) was achieved at 50°C in the experiment with molasses, while the highest zinc recovery (82.1%) was reached at 45°C in the control experiment. Additional carbon sources affected the extraction of non-ferrous metals only at 60 °C and increased the extraction of copper and zinc by 12.6% and 24.2%, respectively. Both the temperature and carbon source used affected the microbial population composition. The main microbial genera revealed in the populations by next generation sequencing (NGS) were bacteria of the genera Sulfobacillus and Acidithiobacillus, as well as archaea of the genera Ferroplasma, Acidiplasma, and Cuniculiplasma. At low temperatures (40 and 45 °C), Acidithiobacillus, Sulfobacillus, and Ferroplasma predominated, while at temperatures 50–55 °C, the decrease in relative abundance of these genera occurred, and the predominance of Acidiplasma archaea was observed. The usage of both CO2 and molasses led to the increase in Sulfobacillus and Acidiplasma in relative abundance.

Study on the anode stability of polyaniline with its pyrolysis products as electroactive components and the experimental study of cobalt electrowinning in chloride system

In the field of nonferrous metal extraction and wastewater treatment, novel electrode materials have been known as the “heart” of the whole electrochemical innovation process. It can be seen that they play a key innovative role in this process. In this study, the catalytic activity of the novel polyaniline composite electrode material prepared in the laboratory will be comprehensively evaluated, its stability and failure mechanism will be appraised, the mechanism of electrode failure will be described, the ways to improve electrode performance will be put forward, and the superior working performance of the Ti/SnO2-Sb2O5-PANI (9%) electrode material different from the traditional precious metal electrode material will be deeply explored. The research results mainly show that Ti/SnO 2-Sb2O5-PANI (9%) electrode has good stability and can run stably for 186 h when used as anode in electrolysis experiment, while Ti/SnO 2-Sb2O5 electrode has stable operation time of only 114 h. Its failure is mainly caused by the dissolution and falling off of surface coating. In addition, it shows high electrocatalytic activity, low cell voltage of 2.258 V and high current efficiency of 85 ∼ 96% during cobalt electrodeposition experiment.

Серебряные и медные рудники на реке Цильме: миф или реальность?

The results of the search for evidence of cop¬per and silver ore mining in the XV – XVII centu¬ries on the Tsil’ma river (Ust’-Tsil’ma region of the Komi Republic, Russia) and the substantiation for inclusion of the «Silver and Copper Mines» (5 pits) archaeological site (Mines) in the Unified State Register of Cultural Heritage Objects (historical and cultural monuments) of the peoples of the Rus-sian Federation (Register), are published. The authors analyzed normative documenta¬tion, narrative records; studied the results of re¬gional historical, archaeological and geological re¬search; conducted an archaeological exploration in the valley of the Tsil’ma River. It was determined that all ideas of the Mines correspond to four models: ideological, folklore, scientific and protective. The paper fo-cuses on the development of scientific and «protective» models. It is established that the state pro-tection of the mines was not the result of archaeological field¬work, but was based on the data of written sourc¬es and their free interpretation by historian N.M. Karamzin, who created an ideological model, on which basis distorted scientific ideas were later formed. All available information about Mines includes reliable information about search attempts and finding of copper and silver ore oc-currences on the Tsil’ma river and unconfirmed yet unproven data on systematic and long-term ex-traction of non-fer¬rous metals in this region. However, copper mining is probable locally and in small amounts for the needs of the Old Believers. Thus, information about the extraction of non-ferrous metals at a scale essential for the state is a myth that people need to demonstrate the exclusivity and significance of their birthplace and motherland.The lack of evidence of the func¬tioning of mines and the signs of cultural heritage objects documenting this type of site allows us to assert that the inclusion of the «Silver and Copper Mines» (5 pits) archaeological site in the Register is unrea-sonable.

The possibility of using DES based on polypropylene glycol 425 and tetrabuthylammonium bromide in the extraction processes of transition metals

Traditionally, the method of liquid extraction is used to extract metals from aqueous. This work is devoted to the combination of perspective alternative for hazardous solvents (aqueous two-phase systems based on water-soluble polymers) and the novel deep eutectic solvents in the non-ferrous metals extraction processes. In this work, the synthesis of deep eutectic solvent based on a water-soluble polymer (PPG-425) and tetrabutylammonium bromide (TBAB) by stirring for 10 minutes at 80° C has been shown. The obtained results showed not only the possibility of using DES in the metal extraction process, but the selectivity to the Fe(III) and Zn(III), the distribution coefficients were 71.64 and 25.17 respectively. The metal concentrations were determined spectrophotometrically using 4-(2-pyridylazo)resorcinol. This work shows the perspectives of using DESs in the metal extraction processes.

Extraction of Nonferrous Metals and Arsenic from Thin Dusts of Copper Fuel Production by Combined Technology

Extraction of Nonferrous Metals and Arsenic from Thin Dusts of Copper Fuel Production by Combined Technology

Extraction of non-ferrous metals and arsenic from fine dusts of copper smelter production by combined technology

Fine dusts of copper smelting production are a valuable raw material for the extraction of heavy non-ferrous, noble and rare metals. A feature of dusts is the high content of arsenic in them, which must be removed from the production cycle in the form of a product suitable for safe storage. The most rational way is the combined technology for processing copper smelting production dusts including low-temperature dust roasting (calcination) in order to distill arsenic into a separate product and to break up poorly soluble sulfide and ferrite zinc and copper compounds. The chemical and phase composition of Ausmelt technology dusts is presented. Thermodynamic calculations of reactions occurring during the dust roasting were carried out in order to study the behavior of copper, zinc, arsenic and iron compounds when roasted in the temperature range of 20–1000 °C, features of solid phase formation and composition, optimization of arsenic roasting and distillation conditions. It was established that dust calcination allows the conversion of poorly soluble sulfides and ferrites of zinc and copper into acidsoluble oxides and sulfates. Thermodynamic parameters were determined for the sulfuric acid leaching of individual cinder compounds. The results of laboratory studies showed that the calcination temperature of 550 °C provides the most satisfactory results of arsenic conversion to sublimates (more than 95 %) as well as copper and zinc recovery into the solution during sulfuric acid leaching (more than 90 %). The initial acidity of solutions of 50 g/dm3 and solution temperature of 60°C are sufficient to achieve high values of copper and zinc recovery into the solution.

The Concept of Dumping Nickel Slag Processing with Preliminary Extraction of Metals

The present study considers various technological approaches to the processes of complex utilization of nickel slags with preliminary additional extraction of non-ferrous metals, iron, and ways of utilization of the obtained gangue. The valuable components are often produced from waste using the mineral acids or mixtures; the metals are extracted from acid solutions in a free form or in the form of compounds using electrochemical or chemical methods. Slag dumps have a heterogeneous structure and mineralization; the zone distribution of slag is clearly defined due to different cooling and solidification rates. The slag composition is mostly represented by dense low-porous varieties consisting of dark brown glass. The porous slag fragments are secondary. The third texture diversity in the composition of slag is represented by nodular and kidney-shaped particles. The diversity and size of the ore minerals is directly connected with the distribution of pores in slag. The major ways for utilization of nickel industrial waste are pyro-metallurgical and hydrometallurgical methods. In addition, each of the methods is usually preceded by the stage of mechanical preparation of the raw materials, where the techno-genic waste is crushed.

Research of the Technology of Joint Processing of Stale Copper-Smelting Slags and Pyrite Cinders with the Extraction of Non-Ferrous Metals into a Commercial Product

The article deals with the problems of slags processing from copper-smelting production, both current production and those which had been accumulating over many years of enterprises’ activity in heaps (stale). There are data about possible methods of slag processing. It is proposed a technology for the joint processing of stale copper-smelting slags of the Urals and pyrite cinders (waste from the production of sulfuric acid) - smelting with obtain a poor matte, into which copper and precious metals will be transferred. The results of scientific research on matte melting are presented. It is shown that when the ratio in the furnace charge "stale slag: pyrite cinder" at the level of 2.5, the extraction of non-ferrous metals into the matte is at the level of 90%.

РЕСУРСОСБЕРЕЖЕНИЕ ПРИ ДОБЫЧЕ ЦВЕТНЫХ МЕТАЛЛОВ

The main directions of resource saving in the extraction of non-ferrous metals in Rus-sia are considered, the basis of which is the extraction of the useful component by leaching in underground blocks, piles and high-speed disintegrator mills. The current ideas about the problem are systematized and investigated, and a forecast of the use of resource-saving tech-nologies in the future is given.

Ways of the lead-bearing slag waste utilization

The article presents the results of research on the influence of lead production slag on the environment and ecology of the city. Due to the open storage of slags, an excess of maximum permissible levels (MPL) of lead was established: near the plant, the concentration of lead in the soil exceeds 3000 mg/kg, while the MPL is 3.2 mg/kg. The data of analyzes obtained by methods of scanning electron microscopy and X-ray microanalysis, performed on a scanning electron microscope (SEM), as well as the results of X-ray fluorescence semi-quantitative analysis, performed on an X-ray fluorescence wave-dispersive spectrometer, have been presented. The results of thermal analysis of samples in air in the 20-1000 °C temperature range are presented.It was revealed that lead slag contains a fairly high amount of toxic metal compounds. It has been established that the average content of toxic metals in slags formed as a result of the activity of a lead plant is: lead - 2, 38%; zinc - 9.81%; copper - 0.97%; iron - 25.31%; silicon oxide - 24.62%; calcium oxide - 16.21%; potassium oxide - 1.42%; sulfur - 1.35% of the total sample weight.The offered technology of a selective method for the extraction of non-ferrous metals allows to enhance the ecological state of the environment and reduce their negative impact on human health by means of the disposal of the lead production slags.